{
  "manifest": {
    "name": "rambda",
    "version": "9.4.2",
    "scripts": {
      "out": "yarn populatedocs && yarn populatereadme && yarn immutable && yarn build && yarn create-docsify",
      "x": "yarn populatedocs:x && yarn populatereadme:x && yarn immutable:x && yarn create-docsify:x",
      "build": "yarn build:main && yarn build:web",
      "build:main": "cross-env NODE_ENV=build rollup -c files/rollup.config.mjs",
      "build:web": "cross-env NODE_ENV=build rollup -c files/rollup.web.config.mjs",
      "immutable": "cd ../rambda-scripts && yarn immutable:rambda",
      "immutable:x": "cd ../rambda-scripts && yarn immutable:rambdax",
      "populatedocs": "cd ../rambda-scripts && yarn populate:docs",
      "populatedocs:x": "cd ../rambda-scripts && yarn populate:docs:rambdax",
      "populatereadme": "cd ../rambda-scripts && yarn populate:readme",
      "populatereadme:x": "cd ../rambda-scripts && yarn populate:readme:rambdax",
      "test": "jest -o -u --watch",
      "test:all": "jest source/*.spec.js -u --bail=false",
      "test:ci": "jest source/*.spec.js --coverage --no-cache -w 1",
      "test:typings": "dtslint --localTs ./node_modules/typescript/lib --expectOnly ./source",
      "create-docsify": "cd ../rambda-scripts && yarn create-docsify",
      "create-docsify:x": "cd ../rambda-scripts && yarn create-docsify:rambdax",
      "ts": "yarn test:typings"
    },
    "depFn": [
      "@definitelytyped/dtslint"
    ],
    "dependencies": {},
    "devDependencies": {
      "@babel/core": "7.26.0",
      "@babel/plugin-proposal-object-rest-spread": "7.20.7",
      "@babel/preset-env": "7.26.0",
      "@definitelytyped/dtslint": "0.0.182",
      "@rollup/plugin-babel": "6.0.4",
      "@rollup/plugin-commonjs": "28.0.1",
      "@rollup/plugin-node-resolve": "15.3.0",
      "@rollup/plugin-replace": "6.0.1",
      "@types/jest": "29.5.14",
      "combinate": "1.1.11",
      "cross-env": "7.0.3",
      "fast-check": "3.23.1",
      "helpers-fn": "2.0.0",
      "is-ci": "3.0.1",
      "jest": "29.7.0",
      "jest-extended": "4.0.2",
      "lodash": "4.17.21",
      "rambdax": "11.2.0",
      "ramda": "0.30.1",
      "rollup": "4.28.1",
      "rollup-plugin-cleanup": "3.2.1",
      "rollup-plugin-sourcemaps": "0.6.3",
      "rollup-plugin-uglify": "6.0.4",
      "types-ramda": "0.30.1",
      "typescript": "5.7.2"
    },
    "jest": {
      "testEnvironment": "node",
      "testRegex": ".*\\.(spec|test)\\.js$",
      "setupFilesAfterEnv": [
        "./files/testSetup.js"
      ],
      "collectCoverageFrom": [
        "source/*.js",
        "!_internals",
        "!benchmarks"
      ]
    },
    "repository": {
      "type": "git",
      "url": "git+https://github.com/selfrefactor/rambda.git"
    },
    "license": "MIT",
    "author": {
      "name": "self_refactor"
    },
    "description": "Lightweight and faster alternative to Ramda with included TS definitions",
    "keywords": [
      "ramda",
      "fp",
      "functional",
      "utility",
      "lodash"
    ],
    "homepage": "https://github.com/selfrefactor/rambda#readme",
    "files": [
      "dist",
      "src",
      "CHANGELOG.md",
      "index.d.ts",
      "immutable.d.ts",
      "rambda.js",
      "immutable.js"
    ],
    "sideEffects": false,
    "main": "./dist/rambda.js",
    "umd": "./dist/rambda.umd.js",
    "module": "./rambda.js",
    "types": "./index.d.ts",
    "_registry": "npm",
    "_loc": "/home/josie/.cache/yarn/v6/npm-rambda-9.4.2-integrity/node_modules/rambda/package.json",
    "readmeFilename": "README.md",
    "readme": "# Rambda\n\n`Rambda` is smaller and faster alternative to the popular functional programming library **Ramda**. - [Documentation](https://selfrefactor.github.io/rambda/#/)\n\n[![codecov](https://codecov.io/gh/selfrefactor/rambda/branch/master/graph/badge.svg)](https://codecov.io/gh/selfrefactor/rambda)\n![Commit activity](https://img.shields.io/github/commit-activity/y/selfrefactor/rambda)\n![Library size](https://img.shields.io/bundlephobia/minzip/rambda)\n[![install size](https://packagephobia.com/badge?p=rambda)](https://packagephobia.com/result?p=rambda)\n[![PR's Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat)](https://github.com/selfrefactor/rambda/pulls)\n[![GitHub contributors](https://img.shields.io/github/contributors/selfrefactor/rambda.svg)](https://github.com/selfrefactor/rambda/graphs/contributors)\n\n## ❯ Example use\n\n```javascript\nimport { compose, map, filter } from 'rambda'\n\nconst result = compose(\n  map(x => x * 2),\n  filter(x => x > 2)\n)([1, 2, 3, 4])\n// => [6, 8]\n```\n\nYou can test this example in <a href=\"https://rambda.now.sh?const%20result%20%3D%20R.compose(%0A%20%20R.map(x%20%3D%3E%20x%20*%202)%2C%0A%20%20R.filter(x%20%3D%3E%20x%20%3E%202)%0A)(%5B1%2C%202%2C%203%2C%204%5D)%0A%0A%2F%2F%20%3D%3E%20%5B6%2C%208%5D\">Rambda's REPL</a>\n\n* [Differences between Rambda and Ramda](#differences-between-rambda-and-ramda)\n* [API](#api)\n* [Changelog](#-changelog)\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-example-use)\n\n## ❯ Rambda's advantages\n\n### TypeScript included\n\nTypeScript definitions are included in the library, in comparison to **Ramda**, where you need to additionally install `@types/ramda`.\n\nStill, you need to be aware that functional programming features in `TypeScript` are in development, which means that using **R.compose/R.pipe** can be problematic.\n\nImportant - Rambda version `7.1.0`(or higher) requires TypeScript version `4.3.3`(or higher).\n\n### Understandable source code due to little usage of internals\n\n`Ramda` uses a lot of internals, which hides a lot of logic. Reading the full source code of a method can be challenging.\n\n### Better VSCode experience\n\nIf the project is written in Javascript, then `go to source definition` action will lead you to actual implementation of the method.\n\n### Immutable TS definitions\n\nYou can use immutable version of Rambda definitions, which is linted with ESLint `functional/prefer-readonly-type` plugin.\n\n```\nimport {add} from 'rambda/immutable'\n```\n\n### Deno support\n\nLatest version of **Ramba** available for `Deno` users is 3 years old. This is not the case with **Rambda** as most of recent releases are available for `Deno` users.\n\nAlso, `Rambda` provides you with included TS definitions:\n\n```\n// Deno extension(https://marketplace.visualstudio.com/items?itemName=denoland.vscode-deno)\n// is installed and initialized\nimport * as R from \"https://deno.land/x/rambda/mod.ts\";\nimport * as Ramda from \"https://deno.land/x/ramda/mod.ts\";\n\nR.add(1)('foo') // => will trigger warning in VSCode as it should\nRamda.add(1)('foo') // => will not trigger warning in VSCode\n```\n\n### Dot notation for `R.path`, `R.paths`, `R.assocPath` and `R.lensPath`\n\nStandard usage of `R.path` is `R.path(['a', 'b'], {a: {b: 1} })`.\n\nIn **Rambda** you have the choice to use dot notation(which is arguably more readable):\n\n```\nR.path('a.b', {a: {b: 1} })\n```\n\nPlease note that since path input is turned into array, i.e. if you want `R.path(['a','1', 'b'], {a: {'1': {b: 2}}})` to return `2`, you will have to pass array path, not string path. If you pass `a.1.b`, it will turn path input to `['a', 1, 'b']`.\nThe other side effect is in `R.assocPath` and `R.dissocPath`, where inputs such as `['a', '1', 'b']` will be turned into `['a', 1, 'b']`.\n\n### Comma notation for `R.pick` and `R.omit`\n\nSimilar to dot notation, but the separator is comma(`,`) instead of dot(`.`).\n\n```\nR.pick('a,b', {a: 1 , b: 2, c: 3} })\n// No space allowed between properties\n```\n\n### Speed\n\n**Rambda** is generally more performant than `Ramda` as the [benchmarks](#-benchmarks) can prove that.\n\n### Support\n\nOne of the main issues with `Ramda` is the slow process of releasing new versions. This is not the case with **Rambda** as releases are made on regular basis.\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-rambdas-advantages)\n\n## ❯ Missing Ramda methods\n\n<details>\n<summary>\n  Click to see the full list of 46 Ramda methods not implemented in Rambda and their status.\n</summary>\n\n- construct - Using classes is not very functional programming oriented.\n- constructN - same as above\n- into - no support for transducer as it is overly complex to implement, understand and read.\n- invert - overly complicated and limited use case\n- invertObj\n- invoker\n- keysIn - we shouldn't encourage extending object with `.prototype` \n- lift\n- liftN\n- mapAccum - `Ramda` example doesn't looks convincing\n- mapAccumRight\n- memoizeWith - hard to imagine its usage in context of `R.pipe`/`R.compose`\n- mergeDeepWith - limited use case\n- mergeDeepWithKey\n- mergeWithKey\n- nAry - hard to argument about and hard to create meaningful TypeScript definitions\n- nthArg - limited use case\n- o - enough TypeScript issues with `R.pipe`/`R.compose` to add more composition methods\n- otherwise - naming is confusing\n- pair - `left-pad` types of debacles happens partially because of such methods that should not be hidden, bur rather part of your code base even if they need to exist.\n- partialRight - I dislike `R.partial`, so I don't want to add more methods that are based on it\n- pipeWith\n- project - naming is confusing, but also limited use case\n- promap\n- reduceRight - I find `right/left` methods confusing so I added them only where it makes sense.\n- reduceWhile - functions with 4 inputs - I think that even 3 is too much\n- reduced\n- remove - nice name but it is too generic. Also, `Rambdax` has such method and there it works very differently\n- scan - hard to explain\n- sequence\n- splitWhenever\n- symmetricDifferenceWith\n- andThen\n- toPairsIn\n- transduce - currently is out of focus\n- traverse - same as above\n- unary\n- uncurryN\n- unfold - similar to `R.scan` and I find that it doesn't help with readability\n- unionWith - why it has its usage, I want to limit number of methods that accept more than 2 arguments\n- until\n- useWith - hard to explain\n- valuesIn\n- xprod - limited use case\n- thunkify\n- __ - placeholder method allows user to further customize the method call. While, it seems useful initially, the price is too high in terms of complexity for TypeScript definitions. If it is not easy exressable in TypeScript, it is not worth it as **Rambda** is a TypeScript first library.\n\nThe following methods are not going to be added(reason for exclusion is provided as a comment):\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-missing-ramda-methods)\n  \n## ❯ Install\n\n- **yarn add rambda**\n\n- For UMD usage either use `./dist/rambda.umd.js` or the following CDN link:\n\n```\nhttps://unpkg.com/rambda@CURRENT_VERSION/dist/rambda.umd.js\n```\n\n- with deno\n\n```\nimport {add} from \"https://deno.land/x/rambda/mod.ts\";\n```\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-install)\n\n## Differences between Rambda and Ramda\n\n- Rambda's **type** detects async functions and unresolved `Promises`. The returned values are `'Async'` and `'Promise'`.\n\n- Rambda's **type** handles *NaN* input, in which case it returns `NaN`.\n\n- Rambda's **forEach** can iterate over objects not only arrays.\n\n- Rambda's **map**, **filter**, **partition** when they iterate over objects, they pass property and input object as predicate's argument.\n\n- Rambda's **filter** returns empty array with bad input(`null` or `undefined`), while Ramda throws.\n\n- Ramda's **clamp** work with strings, while Rambda's method work only with numbers.\n\n- Ramda's **indexOf/lastIndexOf** work with strings and lists, while Rambda's method work only with lists as iterable input.\n\n- Error handling, when wrong inputs are provided, may not be the same. This difference will be better documented once all brute force tests are completed.\n\n- TypeScript definitions between `rambda` and `@types/ramda` may vary.\n\n> If you need more **Ramda** methods in **Rambda**, you may either submit a `PR` or check the extended version of **Rambda** - [Rambdax](https://github.com/selfrefactor/rambdax). In case of the former, you may want to consult with [Rambda contribution guidelines.](CONTRIBUTING.md)\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-differences-between-rambda-and-ramda)\n\n## ❯ Benchmarks\n\n<details>\n\n<summary>\nClick to expand all benchmark results\n\nThere are methods which are benchmarked only with `Ramda` and `Rambda`(i.e. no `Lodash`).\n\nNote that some of these methods, are called with and without curring. This is done in order to give more detailed performance feedback.\n\nThe benchmarks results are produced from latest versions of *Rambda*, *Lodash*(4.17.21) and *Ramda*(0.30.1).\n\n</summary>\n\nmethod | Rambda | Ramda | Lodash\n--- |--- | --- | ---\n *add* | 🚀 Fastest | 21.52% slower | 82.15% slower\n *adjust* | 8.48% slower | 🚀 Fastest | 🔳\n *all* | 🚀 Fastest | 7.18% slower | 🔳\n *allPass* | 🚀 Fastest | 88.25% slower | 🔳\n *allPass* | 🚀 Fastest | 98.56% slower | 🔳\n *and* | 🚀 Fastest | 89.09% slower | 🔳\n *any* | 🚀 Fastest | 92.87% slower | 45.82% slower\n *anyPass* | 🚀 Fastest | 98.25% slower | 🔳\n *append* | 🚀 Fastest | 2.07% slower | 🔳\n *applySpec* | 🚀 Fastest | 80.43% slower | 🔳\n *assoc* | 72.32% slower | 60.08% slower | 🚀 Fastest\n *clone* | 🚀 Fastest | 91.86% slower | 86.48% slower\n *compose* | 6.07% slower | 16.89% slower | 🚀 Fastest\n *converge* | 78.63% slower | 🚀 Fastest | 🔳\n *curry* | 🚀 Fastest | 28.86% slower | 🔳\n *curryN* | 🚀 Fastest | 41.05% slower | 🔳\n *defaultTo* | 🚀 Fastest | 48.91% slower | 🔳\n *drop* | 🚀 Fastest | 82.35% slower | 🔳\n *dropLast* | 🚀 Fastest | 86.74% slower | 🔳\n *equals* | 58.37% slower | 96.73% slower | 🚀 Fastest\n *filter* | 6.7% slower | 72.03% slower | 🚀 Fastest\n *find* | 🚀 Fastest | 85.14% slower | 42.65% slower\n *findIndex* | 🚀 Fastest | 86.48% slower | 72.27% slower\n *flatten* | 🚀 Fastest | 85.68% slower | 3.57% slower\n *ifElse* | 🚀 Fastest | 58.56% slower | 🔳\n *includes* | 🚀 Fastest | 81.64% slower | 🔳\n *indexOf* | 🚀 Fastest | 80.17% slower | 🔳\n *indexOf* | 🚀 Fastest | 82.2% slower | 🔳\n *init* | 🚀 Fastest | 92.24% slower | 13.3% slower\n *is* | 🚀 Fastest | 57.69% slower | 🔳\n *isEmpty* | 🚀 Fastest | 97.14% slower | 54.99% slower\n *last* | 🚀 Fastest | 93.43% slower | 5.28% slower\n *lastIndexOf* | 🚀 Fastest | 85.19% slower | 🔳\n *map* | 🚀 Fastest | 86.6% slower | 11.73% slower\n *match* | 🚀 Fastest | 44.83% slower | 🔳\n *merge* | 🚀 Fastest | 12.21% slower | 55.76% slower\n *none* | 🚀 Fastest | 96.48% slower | 🔳\n *objOf* | 🚀 Fastest | 38.05% slower | 🔳\n *omit* | 🚀 Fastest | 69.95% slower | 97.34% slower\n *over* | 🚀 Fastest | 56.23% slower | 🔳\n *path* | 37.81% slower | 77.81% slower | 🚀 Fastest\n *pick* | 🚀 Fastest | 19.07% slower | 80.2% slower\n *pipe* | 🚀 Fastest | 0.11% slower | 🔳\n *prop* | 🚀 Fastest | 87.95% slower | 🔳\n *propEq* | 🚀 Fastest | 91.92% slower | 🔳\n *range* | 🚀 Fastest | 61.8% slower | 57.44% slower\n *reduce* | 60.48% slower | 77.1% slower | 🚀 Fastest\n *repeat* | 48.57% slower | 68.98% slower | 🚀 Fastest\n *replace* | 33.45% slower | 33.99% slower | 🚀 Fastest\n *set* | 🚀 Fastest | 50.35% slower | 🔳\n *sort* | 🚀 Fastest | 40.23% slower | 🔳\n *sortBy* | 🚀 Fastest | 25.29% slower | 56.88% slower\n *split* | 🚀 Fastest | 55.37% slower | 17.64% slower\n *splitEvery* | 🚀 Fastest | 71.98% slower | 🔳\n *take* | 🚀 Fastest | 91.96% slower | 4.72% slower\n *takeLast* | 🚀 Fastest | 93.39% slower | 19.22% slower\n *test* | 🚀 Fastest | 82.34% slower | 🔳\n *type* | 🚀 Fastest | 48.6% slower | 🔳\n *uniq* | 🚀 Fastest | 84.9% slower | 🔳\n *uniqBy* | 51.93% slower | 🚀 Fastest | 🔳\n *uniqWith* | 8.29% slower | 🚀 Fastest | 🔳\n *uniqWith* | 14.23% slower | 🚀 Fastest | 🔳\n *update* | 🚀 Fastest | 52.35% slower | 🔳\n *view* | 🚀 Fastest | 76.15% slower | 🔳\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-benchmarks)\n\n## ❯ Used by\n\n- [ESLint plugin Mocha](https://www.npmjs.com/package/eslint-plugin-mocha)\n\n- [WatermelonDB](https://github.com/Nozbe/WatermelonDB)\n\n- [Walmart Canada](https://www.walmart.ca) reported by [w-b-dev](https://github.com/w-b-dev) \n\n- [VSCode Slack integration](https://github.com/verydanny/vcslack)\n\n- [Webpack PostCSS](https://github.com/sectsect/webpack-postcss)\n\n- [MobX-State-Tree decorators](https://github.com/farwayer/mst-decorators)\n\n- [Rewrite of the Betaflight configurator](https://github.com/freshollie/fresh-configurator)\n\n- [MineFlayer plugin](https://github.com/G07cha/MineflayerArmorManager)\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-used-by)\n\n## API\n\n### add\n\nIt adds `a` and `b`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.add(2%2C%203)%20%2F%2F%20%3D%3E%20%205\">Try this <strong>R.add</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#add)\n\n### addIndex\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.addIndex(R.map)((val%2C%20idx)%20%3D%3E%20val%20%2B%20idx%20%2B%201%2C%20%5B1%2C%202%2C%203%5D)%0A%2F%2F%20%3D%3E%20%5B2%2C%204%2C%206%5D\">Try this <strong>R.addIndex</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#addIndex)\n\n### addIndexRight\n\nSame as `R.addIndex`, but it will passed indexes are decreasing, instead of increasing.\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#addIndexRight)\n\n### adjust\n\n```typescript\n\nadjust<T>(index: number, replaceFn: (x: T) => T, list: T[]): T[]\n```\n\nIt replaces `index` in array `list` with the result of `replaceFn(list[i])`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.adjust(%0A%20%200%2C%0A%20%20a%20%3D%3E%20a%20%2B%201%2C%0A%20%20%5B0%2C%20100%5D%0A)%20%2F%2F%20%3D%3E%20%5B1%2C%20100%5D\">Try this <strong>R.adjust</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nadjust<T>(index: number, replaceFn: (x: T) => T, list: T[]): T[];\nadjust<T>(index: number, replaceFn: (x: T) => T): (list: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.adjust</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\nimport { curry } from './curry.js'\n\nfunction adjustFn(\n  index, replaceFn, list\n){\n  const actualIndex = index < 0 ? list.length + index : index\n  if (index >= list.length || actualIndex < 0) return list\n\n  const clone = cloneList(list)\n  clone[ actualIndex ] = replaceFn(clone[ actualIndex ])\n\n  return clone\n}\n\nexport const adjust = curry(adjustFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { add } from './add.js'\nimport { adjust } from './adjust.js'\nimport { pipe } from './pipe.js'\n\nconst list = [ 0, 1, 2 ]\nconst expected = [ 0, 11, 2 ]\n\ntest('happy', () => {})\n\ntest('happy', () => {\n  expect(adjust(\n    1, add(10), list\n  )).toEqual(expected)\n})\n\ntest('with curring type 1 1 1', () => {\n  expect(adjust(1)(add(10))(list)).toEqual(expected)\n})\n\ntest('with curring type 1 2', () => {\n  expect(adjust(1)(add(10), list)).toEqual(expected)\n})\n\ntest('with curring type 2 1', () => {\n  expect(adjust(1, add(10))(list)).toEqual(expected)\n})\n\ntest('with negative index', () => {\n  expect(adjust(\n    -2, add(10), list\n  )).toEqual(expected)\n})\n\ntest('when index is out of bounds', () => {\n  const list = [ 0, 1, 2, 3 ]\n  expect(adjust(\n    4, add(1), list\n  )).toEqual(list)\n  expect(adjust(\n    -5, add(1), list\n  )).toEqual(list)\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#adjust)\n\n### all\n\n```typescript\n\nall<T>(predicate: (x: T) => boolean, list: T[]): boolean\n```\n\nIt returns `true`, if all members of array `list` returns `true`, when applied as argument to `predicate` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%200%2C%201%2C%202%2C%203%2C%204%20%5D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3E%20-1%0A%0Aconst%20result%20%3D%20R.all(predicate%2C%20list)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.all</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nall<T>(predicate: (x: T) => boolean, list: T[]): boolean;\nall<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.all</strong> source</summary>\n\n```javascript\nexport function all(predicate, list){\n  if (arguments.length === 1) return _list => all(predicate, _list)\n\n  for (let i = 0; i < list.length; i++){\n    if (!predicate(list[ i ])) return false\n  }\n\n  return true\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { all } from './all.js'\n\nconst list = [ 0, 1, 2, 3, 4 ]\n\ntest('when true', () => {\n  const fn = x => x > -1\n\n  expect(all(fn)(list)).toBeTrue()\n})\n\ntest('when false', () => {\n  const fn = x => x > 2\n\n  expect(all(fn, list)).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {all} from 'rambda'\n\ndescribe('all', () => {\n  it('happy', () => {\n    const result = all(\n      x => {\n        x // $ExpectType number\n        return x > 0\n      },\n      [1, 2, 3]\n    )\n    result // $ExpectType boolean\n  })\n  it('curried needs a type', () => {\n    const result = all<number>(x => {\n      x // $ExpectType number\n      return x > 0\n    })([1, 2, 3])\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#all)\n\n### allPass\n\n```typescript\n\nallPass<T>(predicates: ((x: T) => boolean)[]): (input: T) => boolean\n```\n\nIt returns `true`, if all functions of `predicates` return `true`, when `input` is their argument.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20input%20%3D%20%7B%0A%20%20a%20%3A%201%2C%0A%20%20b%20%3A%202%2C%0A%7D%0Aconst%20predicates%20%3D%20%5B%0A%20%20x%20%3D%3E%20x.a%20%3D%3D%3D%201%2C%0A%20%20x%20%3D%3E%20x.b%20%3D%3D%3D%202%2C%0A%5D%0Aconst%20result%20%3D%20R.allPass(predicates)(input)%20%2F%2F%20%3D%3E%20true\">Try this <strong>R.allPass</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nallPass<T>(predicates: ((x: T) => boolean)[]): (input: T) => boolean;\nallPass<T>(predicates: ((...inputs: T[]) => boolean)[]): (...inputs: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.allPass</strong> source</summary>\n\n```javascript\nexport function allPass(predicates){\n  return (...input) => {\n    let counter = 0\n    while (counter < predicates.length){\n      if (!predicates[ counter ](...input)){\n        return false\n      }\n      counter++\n    }\n\n    return true\n  }\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { allPass } from './allPass.js'\n\ntest('happy', () => {\n  const rules = [ x => typeof x === 'number', x => x > 10, x => x * 7 < 100 ]\n\n  expect(allPass(rules)(11)).toBeTrue()\n\n  expect(allPass(rules)(undefined)).toBeFalse()\n})\n\ntest('when returns true', () => {\n  const conditionArr = [ val => val.a === 1, val => val.b === 2 ]\n\n  expect(allPass(conditionArr)({\n    a : 1,\n    b : 2,\n  })).toBeTrue()\n})\n\ntest('when returns false', () => {\n  const conditionArr = [ val => val.a === 1, val => val.b === 3 ]\n\n  expect(allPass(conditionArr)({\n    a : 1,\n    b : 2,\n  })).toBeFalse()\n})\n\ntest('works with multiple inputs', () => {\n  const fn = function (\n    w, x, y, z\n  ){\n    return w + x === y + z\n  }\n  expect(allPass([ fn ])(\n    3, 3, 3, 3\n  )).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {allPass, filter} from 'rambda'\n\ndescribe('allPass', () => {\n  it('happy', () => {\n    const x = allPass<number>([\n      y => {\n        y // $ExpectType number\n        return typeof y === 'number'\n      },\n      y => {\n        return y > 0\n      },\n    ])(11)\n\n    x // $ExpectType boolean\n  })\n  it('issue #642', () => {\n    const isGreater = (num: number) => num > 5\n    const pred = allPass([isGreater])\n    const xs = [0, 1, 2, 3]\n\n    const filtered1 = filter(pred)(xs)\n    filtered1 // $ExpectType number[]\n    const filtered2 = xs.filter(pred)\n    filtered2 // $ExpectType number[]\n  })\n  it('issue #604', () => {\n    const plusEq = function(w: number, x: number, y: number, z: number) {\n      return w + x === y + z\n    }\n    const result = allPass([plusEq])(3, 3, 3, 3)\n\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#allPass)\n\n### always\n\nIt returns function that always returns `x`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20R.always(7)%0A%0Aconst%20result%20%3D%20fn()%0A%2F%2F%20%3D%3E%207\">Try this <strong>R.always</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#always)\n\n### and\n\nLogical AND\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.and(true%2C%20true)%3B%20%2F%2F%20%3D%3E%20true%0AR.and(false%2C%20true)%3B%20%2F%2F%20%3D%3E%20false%0Aconst%20result%20%3D%20R.and(true%2C%20'foo')%3B%20%2F%2F%20%3D%3E%20'foo'\">Try this <strong>R.and</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#and)\n\n### any\n\n```typescript\n\nany<T>(predicate: (x: T) => boolean, list: T[]): boolean\n```\n\nIt returns `true`, if at least one member of `list` returns true, when passed to a `predicate` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%5D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20*%20x%20%3E%208%0Aconst%20result%20%3D%20R.any(fn%2C%20list)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.any</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nany<T>(predicate: (x: T) => boolean, list: T[]): boolean;\nany<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.any</strong> source</summary>\n\n```javascript\nexport function any(predicate, list){\n  if (arguments.length === 1) return _list => any(predicate, _list)\n\n  let counter = 0\n  while (counter < list.length){\n    if (predicate(list[ counter ], counter)){\n      return true\n    }\n    counter++\n  }\n\n  return false\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { any } from './any.js'\n\nconst list = [ 1, 2, 3 ]\n\ntest('happy', () => {\n  expect(any(x => x < 0, list)).toBeFalse()\n})\n\ntest('with curry', () => {\n  expect(any(x => x > 2)(list)).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {any} from 'rambda'\n\ndescribe('R.any', () => {\n  it('happy', () => {\n    const result = any(\n      x => {\n        x // $ExpectType number\n        return x > 2\n      },\n      [1, 2, 3]\n    )\n    result // $ExpectType boolean\n  })\n\n  it('when curried needs a type', () => {\n    const result = any<number>(x => {\n      x // $ExpectType number\n      return x > 2\n    })([1, 2, 3])\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#any)\n\n### anyPass\n\n```typescript\n\nanyPass<T>(predicates: ((x: T) => boolean)[]): (input: T) => boolean\n```\n\nIt accepts list of `predicates` and returns a function. This function with its `input` will return `true`, if any of `predicates` returns `true` for this `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20isBig%20%3D%20x%20%3D%3E%20x%20%3E%2020%0Aconst%20isOdd%20%3D%20x%20%3D%3E%20x%20%25%202%20%3D%3D%3D%201%0Aconst%20input%20%3D%2011%0A%0Aconst%20fn%20%3D%20R.anyPass(%0A%20%20%5BisBig%2C%20isOdd%5D%0A)%0A%0Aconst%20result%20%3D%20fn(input)%20%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.anyPass</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nanyPass<T>(predicates: ((x: T) => boolean)[]): (input: T) => boolean;\nanyPass<T>(predicates: ((...inputs: T[]) => boolean)[]): (...inputs: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.anyPass</strong> source</summary>\n\n```javascript\nexport function anyPass(predicates){\n  return (...input) => {\n    let counter = 0\n    while (counter < predicates.length){\n      if (predicates[ counter ](...input)){\n        return true\n      }\n      counter++\n    }\n\n    return false\n  }\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { anyPass } from './anyPass.js'\n\ntest('happy', () => {\n  const rules = [ x => typeof x === 'string', x => x > 10 ]\n  const predicate = anyPass(rules)\n  expect(predicate('foo')).toBeTrue()\n  expect(predicate(6)).toBeFalse()\n})\n\ntest('happy', () => {\n  const rules = [ x => typeof x === 'string', x => x > 10 ]\n\n  expect(anyPass(rules)(11)).toBeTrue()\n  expect(anyPass(rules)(undefined)).toBeFalse()\n})\n\nconst obj = {\n  a : 1,\n  b : 2,\n}\n\ntest('when returns true', () => {\n  const conditionArr = [ val => val.a === 1, val => val.a === 2 ]\n\n  expect(anyPass(conditionArr)(obj)).toBeTrue()\n})\n\ntest('when returns false + curry', () => {\n  const conditionArr = [ val => val.a === 2, val => val.b === 3 ]\n\n  expect(anyPass(conditionArr)(obj)).toBeFalse()\n})\n\ntest('with empty predicates list', () => {\n  expect(anyPass([])(3)).toBeFalse()\n})\n\ntest('works with multiple inputs', () => {\n  const fn = function (\n    w, x, y, z\n  ){\n    console.log(\n      w, x, y, z\n    )\n\n    return w + x === y + z\n  }\n  expect(anyPass([ fn ])(\n    3, 3, 3, 3\n  )).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {anyPass, filter} from 'rambda'\n\ndescribe('anyPass', () => {\n  it('happy', () => {\n    const x = anyPass<number>([\n      y => {\n        y // $ExpectType number\n        return typeof y === 'number'\n      },\n      y => {\n        return y > 0\n      },\n    ])(11)\n\n    x // $ExpectType boolean\n  })\n  it('issue #604', () => {\n    const plusEq = function(w: number, x: number, y: number, z: number) {\n      return w + x === y + z\n    }\n    const result = anyPass([plusEq])(3, 3, 3, 3)\n\n    result // $ExpectType boolean\n  })\n  it('issue #642', () => {\n    const isGreater = (num: number) => num > 5\n    const pred = anyPass([isGreater])\n    const xs = [0, 1, 2, 3]\n\n    const filtered1 = filter(pred)(xs)\n    filtered1 // $ExpectType number[]\n    const filtered2 = xs.filter(pred)\n    filtered2 // $ExpectType number[]\n  })\n  it('functions as a type guard', () => {\n    const isString = (x: unknown): x is string => typeof x === 'string'\n    const isNumber = (x: unknown): x is number => typeof x === 'number'\n    const isBoolean = (x: unknown): x is boolean => typeof x === 'boolean'\n\n    const isStringNumberOrBoolean = anyPass([isString, isNumber, isBoolean])\n\n    isStringNumberOrBoolean // $ExpectType (input: unknown) => boolean\n\n    const aValue: unknown = 1\n\n    if (isStringNumberOrBoolean(aValue)) {\n      aValue // $ExpectType unknown\n    }\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#anyPass)\n\n### ap\n\n```typescript\n\nap<T, U>(fns: Array<(a: T) => U>[], vs: T[]): U[]\n```\n\nIt takes a list of functions and a list of values. Then it returns a list of values obtained by applying each function to each value.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.ap(%0A%20%20%5B%0A%20%20%20%20x%20%3D%3E%20x%20%2B%201%2C%0A%20%20%20%20x%20%3D%3E%20x%20%2B%202%2C%0A%20%20%5D%2C%0A%20%20%5B1%2C%202%2C%203%5D%0A)%0A%2F%2F%20%3D%3E%20%5B2%2C%203%2C%204%2C%203%2C%204%2C%205%5D\">Try this <strong>R.ap</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nap<T, U>(fns: Array<(a: T) => U>[], vs: T[]): U[];\nap<T, U>(fns: Array<(a: T) => U>): (vs: T[]) => U[];\nap<R, A, B>(fn: (r: R, a: A) => B, fn1: (r: R) => A): (r: R) => B;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.ap</strong> source</summary>\n\n```javascript\nexport function ap(functions, input){\n  if (arguments.length === 1){\n    return _inputs => ap(functions, _inputs)\n  }\n\n  return functions.reduce((acc, fn) => [ ...acc, ...input.map(fn) ], [])\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { ap } from './ap.js'\n\nfunction mult2(x){\n  return x * 2\n}\nfunction plus3(x){\n  return x + 3\n}\n\ntest('happy', () => {\n  expect(ap([ mult2, plus3 ], [ 1, 2, 3 ])).toEqual([ 2, 4, 6, 4, 5, 6 ])\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#ap)\n\n### aperture\n\n```typescript\n\naperture<N extends number, T>(n: N, list: T[]): Array<Tuple<T, N>> | []\n```\n\nIt returns a new list, composed of consecutive `n`-tuples from a `list`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.aperture(2%2C%20%5B1%2C%202%2C%203%2C%204%5D)%0A%2F%2F%20%3D%3E%20%5B%5B1%2C%202%5D%2C%20%5B2%2C%203%5D%2C%20%5B3%2C%204%5D%5D\">Try this <strong>R.aperture</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\naperture<N extends number, T>(n: N, list: T[]): Array<Tuple<T, N>> | [];\naperture<N extends number>(n: N): <T>(list: T[]) => Array<Tuple<T, N>> | [];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.aperture</strong> source</summary>\n\n```javascript\nexport function aperture(step, list){\n  if (arguments.length === 1){\n    return _list => aperture(step, _list)\n  }\n  if (step > list.length) return []\n  let idx = 0\n  const limit = list.length - (step - 1)\n  const acc = new Array(limit)\n  while (idx < limit){\n    acc[ idx ] = list.slice(idx, idx + step)\n    idx += 1\n  }\n\n  return acc\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { aperture } from './aperture.js'\n\nconst list = [ 1, 2, 3, 4, 5, 6, 7 ]\n\ntest('happy', () => {\n  expect(aperture(1, list)).toEqual([ [ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ] ])\n  expect(aperture(2, list)).toEqual([\n    [ 1, 2 ],\n    [ 2, 3 ],\n    [ 3, 4 ],\n    [ 4, 5 ],\n    [ 5, 6 ],\n    [ 6, 7 ],\n  ])\n  expect(aperture(3, list)).toEqual([\n    [ 1, 2, 3 ],\n    [ 2, 3, 4 ],\n    [ 3, 4, 5 ],\n    [ 4, 5, 6 ],\n    [ 5, 6, 7 ],\n  ])\n  expect(aperture(8, list)).toEqual([])\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#aperture)\n\n### append\n\n```typescript\n\nappend<T>(xToAppend: T, iterable: T[]): T[]\n```\n\nIt adds element `x` at the end of `iterable`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20x%20%3D%20'foo'%0A%0Aconst%20result%20%3D%20R.append(x%2C%20%5B'bar'%2C%20'baz'%5D)%0A%2F%2F%20%3D%3E%20%5B'bar'%2C%20'baz'%2C%20'foo'%5D\">Try this <strong>R.append</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nappend<T>(xToAppend: T, iterable: T[]): T[];\nappend<T, U>(xToAppend: T, iterable: IsFirstSubtypeOfSecond<T, U>[]) : U[];\nappend<T>(xToAppend: T): <U>(iterable: IsFirstSubtypeOfSecond<T, U>[]) => U[];\nappend<T>(xToAppend: T): (iterable: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.append</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\n\nexport function append(x, input){\n  if (arguments.length === 1) return _input => append(x, _input)\n\n  if (typeof input === 'string') return input.split('').concat(x)\n\n  const clone = cloneList(input)\n  clone.push(x)\n\n  return clone\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { append } from './append.js'\n\ntest('happy', () => {\n  expect(append('tests', [ 'write', 'more' ])).toEqual([\n    'write',\n    'more',\n    'tests',\n  ])\n})\n\ntest('append to empty array', () => {\n  expect(append('tests')([])).toEqual([ 'tests' ])\n})\n\ntest('with strings', () => {\n  expect(append('o', 'fo')).toEqual([ 'f', 'o', 'o' ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {append, prepend} from 'rambda'\n\nconst listOfNumbers = [1, 2, 3]\nconst listOfNumbersAndStrings = [1, 'b', 3]\n\ndescribe('R.append/R.prepend', () => {\n  describe(\"with the same primitive type as the array's elements\", () => {\n    it('uncurried', () => {\n      // @ts-expect-error\n      append('d', listOfNumbers)\n      // @ts-expect-error\n      prepend('d', listOfNumbers)\n      append(4, listOfNumbers) // $ExpectType number[]\n      prepend(4, listOfNumbers) // $ExpectType number[]\n    })\n\n    it('curried', () => {\n      // @ts-expect-error\n      append('d')(listOfNumbers)\n      append(4)(listOfNumbers) // $ExpectType number[]\n      prepend(4)(listOfNumbers) // $ExpectType number[]\n    })\n  })\n\n  describe(\"with a subtype of the array's elements\", () => {\n    it('uncurried', () => {\n      // @ts-expect-error\n      append(true, listOfNumbersAndStrings)\n      append(4, listOfNumbersAndStrings) // $ExpectType (string | number)[]\n      prepend(4, listOfNumbersAndStrings) // $ExpectType (string | number)[]\n    })\n\n    it('curried', () => {\n      // @ts-expect-error\n      append(true)(listOfNumbersAndStrings)\n      append(4)(listOfNumbersAndStrings) // $ExpectType (string | number)[]\n      prepend(4)(listOfNumbersAndStrings) // $ExpectType (string | number)[]\n    })\n  })\n\n  describe(\"expanding the type of the array's elements\", () => {\n    it('uncurried', () => {\n      // @ts-expect-error\n      append('d', listOfNumbers)\n      append<string | number>('d', listOfNumbers) // $ExpectType (string | number)[]\n      prepend<string | number>('d', listOfNumbers) // $ExpectType (string | number)[]\n    })\n\n    it('curried', () => {\n      // @ts-expect-error\n      append('d')(listOfNumbers)\n      const appendD = append('d')\n      appendD<string | number>(listOfNumbers) // $ExpectType (string | number)[]\n      const prependD = prepend('d')\n      prependD<string | number>(listOfNumbers) // $ExpectType (string | number)[]\n    })\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#append)\n\n### apply\n\n```typescript\n\napply<T = any>(fn: (...args: any[]) => T, args: any[]): T\n```\n\nIt applies function `fn` to the list of arguments. \n\nThis is useful for creating a fixed-arity function from a variadic function. `fn` should be a bound function if context is significant.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.apply(Math.max%2C%20%5B42%2C%20-Infinity%2C%201337%5D)%0A%2F%2F%20%3D%3E%201337\">Try this <strong>R.apply</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\napply<T = any>(fn: (...args: any[]) => T, args: any[]): T;\napply<T = any>(fn: (...args: any[]) => T): (args: any[]) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.apply</strong> source</summary>\n\n```javascript\nexport function apply(fn, args){\n  if (arguments.length === 1){\n    return _args => apply(fn, _args)\n  }\n\n  return fn.apply(this, args)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { apply } from './apply.js'\nimport { bind } from './bind.js'\nimport { identity } from './identity.js'\n\ntest('happy', () => {\n  expect(apply(identity, [ 1, 2, 3 ])).toBe(1)\n})\n\ntest('applies function to argument list', () => {\n  expect(apply(Math.max, [ 1, 2, 3, -99, 42, 6, 7 ])).toBe(42)\n})\n\ntest('provides no way to specify context', () => {\n  const obj = {\n    method (){\n      return this === obj\n    },\n  }\n  expect(apply(obj.method, [])).toBeFalse()\n  expect(apply(bind(obj.method, obj), [])).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {apply, identity} from 'rambda'\n\ndescribe('R.apply', () => {\n  it('happy', () => {\n    const result = apply<number>(identity, [1, 2, 3])\n\n    result // $ExpectType number\n  })\n  it('curried', () => {\n    const fn = apply<number>(identity)\n    const result = fn([1, 2, 3])\n\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#apply)\n\n### applySpec\n\n```typescript\n\napplySpec<Spec extends Record<string, AnyFunction>>(\n  spec: Spec\n): (\n  ...args: Parameters<ValueOfRecord<Spec>>\n) => { [Key in keyof Spec]: ReturnType<Spec[Key]> }\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20R.applySpec(%7B%0A%20%20sum%3A%20R.add%2C%0A%20%20nested%3A%20%7B%20mul%3A%20R.multiply%20%7D%0A%7D)%0Aconst%20result%20%3D%20fn(2%2C%204)%20%0A%2F%2F%20%3D%3E%20%7B%20sum%3A%206%2C%20nested%3A%20%7B%20mul%3A%208%20%7D%20%7D\">Try this <strong>R.applySpec</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\napplySpec<Spec extends Record<string, AnyFunction>>(\n  spec: Spec\n): (\n  ...args: Parameters<ValueOfRecord<Spec>>\n) => { [Key in keyof Spec]: ReturnType<Spec[Key]> };\napplySpec<T>(spec: any): (...args: unknown[]) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.applySpec</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\n// recursively traverse the given spec object to find the highest arity function\nexport function __findHighestArity(spec, max = 0){\n  for (const key in spec){\n    if (spec.hasOwnProperty(key) === false || key === 'constructor') continue\n\n    if (typeof spec[ key ] === 'object'){\n      max = Math.max(max, __findHighestArity(spec[ key ]))\n    }\n\n    if (typeof spec[ key ] === 'function'){\n      max = Math.max(max, spec[ key ].length)\n    }\n  }\n\n  return max\n}\n\nfunction __filterUndefined(){\n  const defined = []\n  let i = 0\n  const l = arguments.length\n  while (i < l){\n    if (typeof arguments[ i ] === 'undefined') break\n    defined[ i ] = arguments[ i ]\n    i++\n  }\n\n  return defined\n}\n\nfunction __applySpecWithArity(\n  spec, arity, cache\n){\n  const remaining = arity - cache.length\n\n  if (remaining === 1)\n    return x =>\n      __applySpecWithArity(\n        spec, arity, __filterUndefined(...cache, x)\n      )\n  if (remaining === 2)\n    return (x, y) =>\n      __applySpecWithArity(\n        spec, arity, __filterUndefined(\n          ...cache, x, y\n        )\n      )\n  if (remaining === 3)\n    return (\n      x, y, z\n    ) =>\n      __applySpecWithArity(\n        spec, arity, __filterUndefined(\n          ...cache, x, y, z\n        )\n      )\n  if (remaining === 4)\n    return (\n      x, y, z, a\n    ) =>\n      __applySpecWithArity(\n        spec,\n        arity,\n        __filterUndefined(\n          ...cache, x, y, z, a\n        )\n      )\n  if (remaining > 4)\n    return (...args) =>\n      __applySpecWithArity(\n        spec, arity, __filterUndefined(...cache, ...args)\n      )\n\n  // handle spec as Array\n  if (isArray(spec)){\n    const ret = []\n    let i = 0\n    const l = spec.length\n    for (; i < l; i++){\n      // handle recursive spec inside array\n      if (typeof spec[ i ] === 'object' || isArray(spec[ i ])){\n        ret[ i ] = __applySpecWithArity(\n          spec[ i ], arity, cache\n        )\n      }\n      // apply spec to the key\n      if (typeof spec[ i ] === 'function'){\n        ret[ i ] = spec[ i ](...cache)\n      }\n    }\n\n    return ret\n  }\n\n  // handle spec as Object\n  const ret = {}\n  // apply callbacks to each property in the spec object\n  for (const key in spec){\n    if (spec.hasOwnProperty(key) === false || key === 'constructor') continue\n\n    // apply the spec recursively\n    if (typeof spec[ key ] === 'object'){\n      ret[ key ] = __applySpecWithArity(\n        spec[ key ], arity, cache\n      )\n      continue\n    }\n\n    // apply spec to the key\n    if (typeof spec[ key ] === 'function'){\n      ret[ key ] = spec[ key ](...cache)\n    }\n  }\n\n  return ret\n}\n\nexport function applySpec(spec, ...args){\n  // get the highest arity spec function, cache the result and pass to __applySpecWithArity\n  const arity = __findHighestArity(spec)\n\n  if (arity === 0){\n    return () => ({})\n  }\n  const toReturn = __applySpecWithArity(\n    spec, arity, args\n  )\n\n  return toReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { applySpec as applySpecRamda, nAry } from 'ramda'\n\nimport {\n  add,\n  always,\n  compose,\n  dec,\n  inc,\n  map,\n  path,\n  prop,\n  T,\n} from '../rambda.js'\nimport { applySpec } from './applySpec.js'\n\ntest('different than Ramda when bad spec', () => {\n  const result = applySpec({ sum : { a : 1 } })(1, 2)\n  const ramdaResult = applySpecRamda({ sum : { a : 1 } })(1, 2)\n  expect(result).toEqual({})\n  expect(ramdaResult).toEqual({ sum : { a : {} } })\n})\n\ntest('works with empty spec', () => {\n  expect(applySpec({})()).toEqual({})\n  expect(applySpec([])(1, 2)).toEqual({})\n  expect(applySpec(null)(1, 2)).toEqual({})\n})\n\ntest('works with unary functions', () => {\n  const result = applySpec({\n    v : inc,\n    u : dec,\n  })(1)\n  const expected = {\n    v : 2,\n    u : 0,\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('works with binary functions', () => {\n  const result = applySpec({ sum : add })(1, 2)\n  expect(result).toEqual({ sum : 3 })\n})\n\ntest('works with nested specs', () => {\n  const result = applySpec({\n    unnested : always(0),\n    nested   : { sum : add },\n  })(1, 2)\n  const expected = {\n    unnested : 0,\n    nested   : { sum : 3 },\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('works with arrays of nested specs', () => {\n  const result = applySpec({\n    unnested : always(0),\n    nested   : [ { sum : add } ],\n  })(1, 2)\n\n  expect(result).toEqual({\n    unnested : 0,\n    nested   : [ { sum : 3 } ],\n  })\n})\n\ntest('works with arrays of spec objects', () => {\n  const result = applySpec([ { sum : add } ])(1, 2)\n\n  expect(result).toEqual([ { sum : 3 } ])\n})\n\ntest('works with arrays of functions', () => {\n  const result = applySpec([ map(prop('a')), map(prop('b')) ])([\n    {\n      a : 'a1',\n      b : 'b1',\n    },\n    {\n      a : 'a2',\n      b : 'b2',\n    },\n  ])\n  const expected = [\n    [ 'a1', 'a2' ],\n    [ 'b1', 'b2' ],\n  ]\n  expect(result).toEqual(expected)\n})\n\ntest('works with a spec defining a map key', () => {\n  expect(applySpec({ map : prop('a') })({ a : 1 })).toEqual({ map : 1 })\n})\n\ntest('cannot retains the highest arity', () => {\n  const f = applySpec({\n    f1 : nAry(2, T),\n    f2 : nAry(5, T),\n  })\n  const fRamda = applySpecRamda({\n    f1 : nAry(2, T),\n    f2 : nAry(5, T),\n  })\n  expect(f).toHaveLength(0)\n  expect(fRamda).toHaveLength(5)\n})\n\ntest('returns a curried function', () => {\n  expect(applySpec({ sum : add })(1)(2)).toEqual({ sum : 3 })\n})\n\n// Additional tests\n// ============================================\ntest('arity', () => {\n  const spec = {\n    one   : x1 => x1,\n    two   : (x1, x2) => x1 + x2,\n    three : (\n      x1, x2, x3\n    ) => x1 + x2 + x3,\n  }\n  expect(applySpec(\n    spec, 1, 2, 3\n  )).toEqual({\n    one   : 1,\n    two   : 3,\n    three : 6,\n  })\n})\n\ntest('arity over 5 arguments', () => {\n  const spec = {\n    one   : x1 => x1,\n    two   : (x1, x2) => x1 + x2,\n    three : (\n      x1, x2, x3\n    ) => x1 + x2 + x3,\n    four : (\n      x1, x2, x3, x4\n    ) => x1 + x2 + x3 + x4,\n    five : (\n      x1, x2, x3, x4, x5\n    ) => x1 + x2 + x3 + x4 + x5,\n  }\n  expect(applySpec(\n    spec, 1, 2, 3, 4, 5\n  )).toEqual({\n    one   : 1,\n    two   : 3,\n    three : 6,\n    four  : 10,\n    five  : 15,\n  })\n})\n\ntest('curried', () => {\n  const spec = {\n    one   : x1 => x1,\n    two   : (x1, x2) => x1 + x2,\n    three : (\n      x1, x2, x3\n    ) => x1 + x2 + x3,\n  }\n  expect(applySpec(spec)(1)(2)(3)).toEqual({\n    one   : 1,\n    two   : 3,\n    three : 6,\n  })\n})\n\ntest('curried over 5 arguments', () => {\n  const spec = {\n    one   : x1 => x1,\n    two   : (x1, x2) => x1 + x2,\n    three : (\n      x1, x2, x3\n    ) => x1 + x2 + x3,\n    four : (\n      x1, x2, x3, x4\n    ) => x1 + x2 + x3 + x4,\n    five : (\n      x1, x2, x3, x4, x5\n    ) => x1 + x2 + x3 + x4 + x5,\n  }\n  expect(applySpec(spec)(1)(2)(3)(4)(5)).toEqual({\n    one   : 1,\n    two   : 3,\n    three : 6,\n    four  : 10,\n    five  : 15,\n  })\n})\n\ntest('undefined property', () => {\n  const spec = { prop : path([ 'property', 'doesnt', 'exist' ]) }\n  expect(applySpec(spec, {})).toEqual({ prop : undefined })\n})\n\ntest('restructure json object', () => {\n  const spec = {\n    id          : path('user.id'),\n    name        : path('user.firstname'),\n    profile     : path('user.profile'),\n    doesntExist : path('user.profile.doesntExist'),\n    info        : { views : compose(inc, prop('views')) },\n    type        : always('playa'),\n  }\n\n  const data = {\n    user : {\n      id        : 1337,\n      firstname : 'john',\n      lastname  : 'shaft',\n      profile   : 'shaft69',\n    },\n    views : 42,\n  }\n\n  expect(applySpec(spec, data)).toEqual({\n    id          : 1337,\n    name        : 'john',\n    profile     : 'shaft69',\n    doesntExist : undefined,\n    info        : { views : 43 },\n    type        : 'playa',\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {multiply, applySpec, inc, dec, add} from 'rambda'\n\ndescribe('applySpec', () => {\n  it('ramda 1', () => {\n    const result = applySpec({\n      v: inc,\n      u: dec,\n    })(1)\n    result // $ExpectType { v: number; u: number; }\n  })\n  it('ramda 1', () => {\n    interface Output {\n      sum: number,\n      multiplied: number,\n    }\n    const result = applySpec<Output>({\n      sum: add,\n      multiplied: multiply,\n    })(1, 2)\n\n    result // $ExpectType Output\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#applySpec)\n\n### applyTo\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.applyTo(%0A%20%201%2C%0A%20%20x%20%3D%3E%20x%20%2B%201%0A)%0A%2F%2F%20%3D%3E%202\">Try this <strong>R.applyTo</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#applyTo)\n\n### ascend\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.sort(R.descend(x%20%3D%3E%20x)%2C%20%5B2%2C%201%5D)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%5D\">Try this <strong>R.ascend</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#ascend)\n\n### assoc\n\nIt makes a shallow clone of `obj` with setting or overriding the property `prop` with `newValue`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.assoc('c'%2C%203%2C%20%7Ba%3A%201%2C%20b%3A%202%7D)%0A%2F%2F%20%3D%3E%20%7Ba%3A%201%2C%20b%3A%202%2C%20c%3A%203%7D\">Try this <strong>R.assoc</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#assoc)\n\n### assocPath\n\n```typescript\n\nassocPath<Output>(path: Path, newValue: any, obj: object): Output\n```\n\nIt makes a shallow clone of `obj` with setting or overriding with `newValue` the property found with `path`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20path%20%3D%20'b.c'%0Aconst%20newValue%20%3D%202%0Aconst%20obj%20%3D%20%7B%20a%3A%201%20%7D%0A%0Aconst%20result%20%3D%20R.assocPath(path%2C%20newValue%2C%20obj)%0A%2F%2F%20%3D%3E%20%7B%20a%20%3A%201%2C%20b%20%3A%20%7B%20c%20%3A%202%20%7D%7D\">Try this <strong>R.assocPath</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nassocPath<Output>(path: Path, newValue: any, obj: object): Output;\nassocPath<Output>(path: Path, newValue: any): (obj: object) => Output;\nassocPath<Output>(path: Path): (newValue: any) => (obj: object) => Output;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.assocPath</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\nimport { createPath } from './_internals/createPath.js'\nimport { isArray } from './_internals/isArray.js'\nimport { isIndexInteger } from './_internals/isInteger.js'\nimport { assocFn } from './assoc.js'\nimport { curry } from './curry.js'\n\nexport function assocPathFn(\n  path, newValue, input\n){\n  const pathArrValue = createPath(path)\n  if (pathArrValue.length === 0) return newValue\n\n  const index = pathArrValue[ 0 ]\n  if (pathArrValue.length > 1){\n    const condition =\n      typeof input !== 'object' ||\n      input === null ||\n      !input.hasOwnProperty(index)\n\n    const nextInput = condition ?\n      isIndexInteger(pathArrValue[ 1 ]) ?\n        [] :\n        {} :\n      input[ index ]\n\n    newValue = assocPathFn(\n      Array.prototype.slice.call(pathArrValue, 1),\n      newValue,\n      nextInput\n    )\n  }\n\n  if (isIndexInteger(index) && isArray(input)){\n    const arr = cloneList(input)\n    arr[ index ] = newValue\n\n    return arr\n  }\n\n  return assocFn(\n    index, newValue, input\n  )\n}\n\nexport const assocPath = curry(assocPathFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { assocPathFn } from './assocPath.js'\n\ntest('happy', () => {\n  const path = 'a.c.1'\n  const input = {\n    a : {\n      b : 1,\n      c : [ 1, 2 ],\n    },\n  }\n  assocPathFn(\n    path, 3, input\n  )\n  expect(input).toEqual({\n    a : {\n      b : 1,\n      c : [ 1, 2 ],\n    },\n  })\n})\n\ntest('string can be used as path input', () => {\n  const testObj = {\n    a : [ { b : 1 }, { b : 2 } ],\n    d : 3,\n  }\n  const result1 = assocPathFn(\n    [ 'a', 0, 'b' ], 10, testObj\n  )\n  const result2 = assocPathFn(\n    'a.0.b', 10, testObj\n  )\n\n  const expected = {\n    a : [ { b : 10 }, { b : 2 } ],\n    d : 3,\n  }\n  expect(result1).toEqual(expected)\n  expect(result2).toEqual(expected)\n})\n\ntest('difference with ramda - doesn\\'t overwrite primitive values with keys in the path', () => {\n  const obj = { a : 'str' }\n  const result = assocPathFn(\n    [ 'a', 'b' ], 42, obj\n  )\n\n  expect(result).toEqual({\n    a : {\n      0 : 's',\n      1 : 't',\n      2 : 'r',\n      b : 42,\n    },\n  })\n})\n\ntest('adds a key to an empty object', () => {\n  expect(assocPathFn(\n    [ 'a' ], 1, {}\n  )).toEqual({ a : 1 })\n})\n\ntest('adds a key to a non-empty object', () => {\n  expect(assocPathFn(\n    'b', 2, { a : 1 }\n  )).toEqual({\n    a : 1,\n    b : 2,\n  })\n})\n\ntest('adds a nested key to a non-empty object', () => {\n  expect(assocPathFn(\n    'b.c', 2, { a : 1 }\n  )).toEqual({\n    a : 1,\n    b : { c : 2 },\n  })\n})\n\ntest('adds a nested key to a nested non-empty object', () => {\n  expect(assocPathFn('b.d',\n    3,{\n    a : 1,\n    b : { c : 2 },\n  })).toEqual({\n    a : 1,\n    b : {\n      c : 2,\n      d : 3,\n    },\n  })\n})\n\ntest('adds a key to a non-empty object', () => {\n  expect(assocPathFn('b', 2, { a : 1 })).toEqual({\n    a : 1,\n    b : 2,\n  })\n})\n\ntest('adds a nested key to a non-empty object', () => {\n  expect(assocPathFn('b.c', 2, { a : 1 })).toEqual({\n    a : 1,\n    b : { c : 2 },\n  })\n})\n\ntest('changes an existing key', () => {\n  expect(assocPathFn(\n    'a', 2, { a : 1 }\n  )).toEqual({ a : 2 })\n})\n\ntest('undefined is considered an empty object', () => {\n  expect(assocPathFn(\n    'a', 1, undefined\n  )).toEqual({ a : 1 })\n})\n\ntest('null is considered an empty object', () => {\n  expect(assocPathFn(\n    'a', 1, null\n  )).toEqual({ a : 1 })\n})\n\ntest('value can be null', () => {\n  expect(assocPathFn(\n    'a', null, null\n  )).toEqual({ a : null })\n})\n\ntest('value can be undefined', () => {\n  expect(assocPathFn(\n    'a', undefined, null\n  )).toEqual({ a : undefined })\n})\n\ntest('assignment is shallow', () => {\n  expect(assocPathFn(\n    'a', { b : 2 }, { a : { c : 3 } }\n  )).toEqual({ a : { b : 2 } })\n})\n\ntest('empty array as path', () => {\n  const result = assocPathFn(\n    [], 3, {\n      a : 1,\n      b : 2,\n    }\n  )\n  expect(result).toBe(3)\n})\n\ntest('happy', () => {\n  const expected = { foo : { bar : { baz : 42 } } }\n  const result = assocPathFn(\n    [ 'foo', 'bar', 'baz' ], 42, { foo : null }\n  )\n  expect(result).toEqual(expected)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {assocPath} from 'rambda'\n\ninterface Output {\n  a: number,\n  foo: {bar: number},\n}\n\ndescribe('R.assocPath - user must explicitly set type of output', () => {\n  it('with array as path input', () => {\n    const result = assocPath<Output>(['foo', 'bar'], 2, {a: 1})\n\n    result // $ExpectType Output\n  })\n  it('with string as path input', () => {\n    const result = assocPath<Output>('foo.bar', 2, {a: 1})\n\n    result // $ExpectType Output\n  })\n})\n\ndescribe('R.assocPath - curried', () => {\n  it('with array as path input', () => {\n    const result = assocPath<Output>(['foo', 'bar'], 2)({a: 1})\n\n    result // $ExpectType Output\n  })\n  it('with string as path input', () => {\n    const result = assocPath<Output>('foo.bar', 2)({a: 1})\n\n    result // $ExpectType Output\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#assocPath)\n\n### binary\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.binary(%0A%20%20(a%2C%20b%2C%20c)%20%3D%3E%20a%20%2B%20b%20%2B%20c%2C%0A)(1%2C%202%2C%203%2C%204)%0A%2F%2F%20%3D%3E%203\">Try this <strong>R.binary</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#binary)\n\n### bind\n\n```typescript\n\nbind<F extends AnyFunction, T>(fn: F, thisObj: T): (...args: Parameters<F>) => ReturnType<F>\n```\n\nCreates a function that is bound to a context.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20log%20%3D%20R.bind(console.log%2C%20console)%0Aconst%20result%20%3D%20R.pipe(%0A%20%20R.assoc('a'%2C%202)%2C%20%0A%20%20R.tap(log)%2C%20%0A%20%20R.assoc('a'%2C%203)%0A)(%7Ba%3A%201%7D)%3B%20%0A%2F%2F%20%3D%3E%20result%20-%20%60%7Ba%3A%203%7D%60%0A%2F%2F%20%3D%3E%20console%20log%20-%20%60%7Ba%3A%202%7D%60\">Try this <strong>R.bind</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nbind<F extends AnyFunction, T>(fn: F, thisObj: T): (...args: Parameters<F>) => ReturnType<F>;\nbind<F extends AnyFunction, T>(fn: F): (thisObj: T) => (...args: Parameters<F>) => ReturnType<F>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.bind</strong> source</summary>\n\n```javascript\nimport { curryN } from './curryN.js'\n\nexport function bind(fn, thisObj){\n  if (arguments.length === 1){\n    return _thisObj => bind(fn, _thisObj)\n  }\n\n  return curryN(fn.length, (...args) => fn.apply(thisObj, args))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { bind } from './bind.js'\n\nfunction Foo(x){\n  this.x = x\n}\nfunction add(x){\n  return this.x + x\n}\nfunction Bar(x, y){\n  this.x = x\n  this.y = y\n}\nBar.prototype = new Foo()\nBar.prototype.getX = function (){\n  return 'prototype getX'\n}\n\ntest('returns a function', () => {\n  expect(typeof bind(add)(Foo)).toBe('function')\n})\n\ntest('returns a function bound to the specified context object', () => {\n  const f = new Foo(12)\n  function isFoo(){\n    return this instanceof Foo\n  }\n  const isFooBound = bind(isFoo, f)\n  expect(isFoo()).toBeFalse()\n  expect(isFooBound()).toBeTrue()\n})\n\ntest('works with built-in types', () => {\n  const abc = bind(String.prototype.toLowerCase, 'ABCDEFG')\n  expect(typeof abc).toBe('function')\n  expect(abc()).toBe('abcdefg')\n})\n\ntest('works with user-defined types', () => {\n  const f = new Foo(12)\n  function getX(){\n    return this.x\n  }\n  const getXFooBound = bind(getX, f)\n  expect(getXFooBound()).toBe(12)\n})\n\ntest('works with plain objects', () => {\n  const pojso = { x : 100 }\n  function incThis(){\n    return this.x + 1\n  }\n  const incPojso = bind(incThis, pojso)\n  expect(typeof incPojso).toBe('function')\n  expect(incPojso()).toBe(101)\n})\n\ntest('does not interfere with existing object methods', () => {\n  const b = new Bar('a', 'b')\n  function getX(){\n    return this.x\n  }\n  const getXBarBound = bind(getX, b)\n  expect(b.getX()).toBe('prototype getX')\n  expect(getXBarBound()).toBe('a')\n})\n\ntest('preserves arity', () => {\n  const f0 = function (){\n    return 0\n  }\n  const f1 = function (a){\n    return a\n  }\n  const f2 = function (a, b){\n    return a + b\n  }\n  const f3 = function (\n    a, b, c\n  ){\n    return a + b + c\n  }\n\n  expect(bind(f0, {})).toHaveLength(0)\n  expect(bind(f1, {})).toHaveLength(1)\n  expect(bind(f2, {})).toHaveLength(2)\n  expect(bind(f3, {})).toHaveLength(3)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {bind} from 'rambda'\n\nclass Foo {}\nfunction isFoo<T = any>(this: T): boolean {\n  return this instanceof Foo\n}\n\ndescribe('R.bind', () => {\n  it('happy', () => {\n    const foo = new Foo()\n    const result = bind(isFoo, foo)()\n\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#bind)\n\n### both\n\n```typescript\n\nboth(pred1: Pred, pred2: Pred): Pred\n```\n\nIt returns a function with `input` argument. \n\nThis function will return `true`, if both `firstCondition` and `secondCondition` return `true` when `input` is passed as their argument.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20firstCondition%20%3D%20x%20%3D%3E%20x%20%3E%2010%0Aconst%20secondCondition%20%3D%20x%20%3D%3E%20x%20%3C%2020%0Aconst%20fn%20%3D%20R.both(firstCondition%2C%20secondCondition)%0A%0Aconst%20result%20%3D%20%5Bfn(15)%2C%20fn(30)%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.both</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nboth(pred1: Pred, pred2: Pred): Pred;\nboth<T>(pred1: Predicate<T>, pred2: Predicate<T>): Predicate<T>;\nboth<T>(pred1: Predicate<T>): (pred2: Predicate<T>) => Predicate<T>;\nboth(pred1: Pred): (pred2: Pred) => Pred;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.both</strong> source</summary>\n\n```javascript\nexport function both(f, g){\n  if (arguments.length === 1) return _g => both(f, _g)\n\n  return (...input) => f(...input) && g(...input)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { both } from './both.js'\n\nconst firstFn = val => val > 0\nconst secondFn = val => val < 10\n\ntest('with curry', () => {\n  expect(both(firstFn)(secondFn)(17)).toBeFalse()\n})\n\ntest('without curry', () => {\n  expect(both(firstFn, secondFn)(7)).toBeTrue()\n})\n\ntest('with multiple inputs', () => {\n  const between = function (\n    a, b, c\n  ){\n    return a < b && b < c\n  }\n  const total20 = function (\n    a, b, c\n  ){\n    return a + b + c === 20\n  }\n  const fn = both(between, total20)\n  expect(fn(\n    5, 7, 8\n  )).toBeTrue()\n})\n\ntest('skip evaluation of the second expression', () => {\n  let effect = 'not evaluated'\n  const F = function (){\n    return false\n  }\n  const Z = function (){\n    effect = 'Z got evaluated'\n  }\n  both(F, Z)()\n\n  expect(effect).toBe('not evaluated')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {both} from 'rambda'\n\ndescribe('R.both', () => {\n  it('with passed type', () => {\n    const fn = both<number>(\n      x => x > 1,\n      x => x % 2 === 0\n    )\n    fn // $ExpectType Predicate<number>\n    const result = fn(2) // $ExpectType boolean\n    result // $ExpectType boolean\n  })\n  it('with passed type - curried', () => {\n    const fn = both<number>(x => x > 1)(x => x % 2 === 0)\n    fn // $ExpectType Predicate<number>\n    const result = fn(2)\n    result // $ExpectType boolean\n  })\n  it('no type passed', () => {\n    const fn = both(\n      x => {\n        x // $ExpectType any\n        return x > 1\n      },\n      x => {\n        x // $ExpectType any\n        return x % 2 === 0\n      }\n    )\n    const result = fn(2)\n    result // $ExpectType boolean\n  })\n  it('no type passed - curried', () => {\n    const fn = both((x: number) => {\n      x // $ExpectType number\n      return x > 1\n    })((x: number) => {\n      x // $ExpectType number\n      return x % 2 === 0\n    })\n    const result = fn(2)\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#both)\n\n### call\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.call(%0A%20%20(a%2C%20b)%20%3D%3E%20a%20%2B%20b%2C%0A%20%201%2C%0A%20%202%0A)%0A%2F%2F%20%3D%3E%203\">Try this <strong>R.call</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#call)\n\n### chain\n\n```typescript\n\nchain<T, U>(fn: (n: T) => U[], list: T[]): U[]\n```\n\nThe method is also known as `flatMap`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20duplicate%20%3D%20n%20%3D%3E%20%5B%20n%2C%20n%20%5D%0Aconst%20list%20%3D%20%5B%201%2C%202%2C%203%20%5D%0A%0Aconst%20result%20%3D%20chain(duplicate%2C%20list)%0A%2F%2F%20%3D%3E%20%5B%201%2C%201%2C%202%2C%202%2C%203%2C%203%20%5D\">Try this <strong>R.chain</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nchain<T, U>(fn: (n: T) => U[], list: T[]): U[];\nchain<T, U>(fn: (n: T) => U[]): (list: T[]) => U[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.chain</strong> source</summary>\n\n```javascript\nexport function chain(fn, list){\n  if (arguments.length === 1){\n    return _list => chain(fn, _list)\n  }\n\n  return [].concat(...list.map(fn))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { chain as chainRamda } from 'ramda'\n\nimport { chain } from './chain.js'\n\nconst duplicate = n => [ n, n ]\n\ntest('happy', () => {\n  const fn = x => [ x * 2 ]\n  const list = [ 1, 2, 3 ]\n\n  const result = chain(fn, list)\n\n  expect(result).toEqual([ 2, 4, 6 ])\n})\n\ntest('maps then flattens one level', () => {\n  expect(chain(duplicate, [ 1, 2, 3 ])).toEqual([ 1, 1, 2, 2, 3, 3 ])\n})\n\ntest('maps then flattens one level - curry', () => {\n  expect(chain(duplicate)([ 1, 2, 3 ])).toEqual([ 1, 1, 2, 2, 3, 3 ])\n})\n\ntest('flattens only one level', () => {\n  const nest = n => [ [ n ] ]\n  expect(chain(nest, [ 1, 2, 3 ])).toEqual([ [ 1 ], [ 2 ], [ 3 ] ])\n})\n\ntest('can compose', () => {\n  function dec(x){\n    return [ x - 1 ]\n  }\n  function times2(x){\n    return [ x * 2 ]\n  }\n\n  const mdouble = chain(times2)\n  const mdec = chain(dec)\n  expect(mdec(mdouble([ 10, 20, 30 ]))).toEqual([ 19, 39, 59 ])\n})\n\ntest('@types/ramda broken test', () => {\n  const score = {\n    maths   : 90,\n    physics : 80,\n  }\n\n  const calculateTotal = score => {\n    const { maths, physics } = score\n\n    return maths + physics\n  }\n\n  const assocTotalToScore = (total, score) => ({\n    ...score,\n    total,\n  })\n\n  const calculateAndAssocTotalToScore = chainRamda(assocTotalToScore,\n    calculateTotal)\n  expect(() =>\n    calculateAndAssocTotalToScore(score)).toThrowErrorMatchingInlineSnapshot('\"fn(...) is not a function\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {chain} from 'rambda'\n\nconst list = [1, 2, 3]\nconst fn = (x: number) => [`${x}`, `${x}`]\n\ndescribe('R.chain', () => {\n  it('without passing type', () => {\n    const result = chain(fn, list)\n    result // $ExpectType string[]\n\n    const curriedResult = chain(fn)(list)\n    curriedResult // $ExpectType string[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#chain)\n\n### clamp\n\nRestrict a number `input` to be within `min` and `max` limits.\n\nIf `input` is bigger than `max`, then the result is `max`.\n\nIf `input` is smaller than `min`, then the result is `min`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.clamp(0%2C%2010%2C%205)%2C%20%0A%20%20R.clamp(0%2C%2010%2C%20-1)%2C%0A%20%20R.clamp(0%2C%2010%2C%2011)%0A%5D%0A%2F%2F%20%3D%3E%20%5B5%2C%200%2C%2010%5D\">Try this <strong>R.clamp</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#clamp)\n\n### clone\n\nIt creates a deep copy of the `input`, which may contain (nested) Arrays and Objects, Numbers, Strings, Booleans and Dates.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20objects%20%3D%20%5B%7Ba%3A%201%7D%2C%20%7Bb%3A%202%7D%5D%3B%0Aconst%20objectsClone%20%3D%20R.clone(objects)%3B%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.equals(objects%2C%20objectsClone)%2C%0A%20%20R.equals(objects%5B0%5D%2C%20objectsClone%5B0%5D)%2C%0A%5D%20%2F%2F%20%3D%3E%20%5B%20true%2C%20true%20%5D\">Try this <strong>R.clone</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#clone)\n\n### collectBy\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.collectBy(%0A%20%20x%20%3D%3E%20x%20%25%202%2C%0A%20%20%5B1%2C%202%2C%203%2C%204%5D%0A)%0A%2F%2F%20%3D%3E%20%5B%5B2%2C%204%5D%2C%20%5B1%2C%203%5D%5D\">Try this <strong>R.collectBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#collectBy)\n\n### comparator\n\nIt returns a comparator function that can be used in `sort` method.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.sort(%0A%20%20R.comparator((a%2C%20b)%20%3D%3E%20a.x%20%3C%20b.x)%2C%0A%20%20%5B%7Bx%3A%202%7D%2C%20%7Bx%3A%201%7D%5D%0A)%0A%2F%2F%20%3D%3E%20%5B%7Bx%3A%201%7D%2C%20%7Bx%3A%202%7D%5D\">Try this <strong>R.comparator</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#comparator)\n\n### complement\n\nIt returns `inverted` version of `origin` function that accept `input` as argument.\n\nThe return value of `inverted` is the negative boolean value of `origin(input)`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20origin%20%3D%20x%20%3D%3E%20x%20%3E%205%0Aconst%20inverted%20%3D%20complement(origin)%0A%0Aconst%20result%20%3D%20%5B%0A%20%20origin(7)%2C%0A%20%20inverted(7)%0A%5D%20%3D%3E%20%5B%20true%2C%20false%20%5D\">Try this <strong>R.complement</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#complement)\n\n### compose\n\nIt performs right-to-left function composition.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.compose(%0A%20%20R.map(x%20%3D%3E%20x%20*%202)%2C%0A%20%20R.filter(x%20%3D%3E%20x%20%3E%202)%0A)(%5B1%2C%202%2C%203%2C%204%5D)%0A%0A%2F%2F%20%3D%3E%20%5B6%2C%208%5D\">Try this <strong>R.compose</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#compose)\n\n### composeWith\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.composeWith(%0A%20%20(fn%2C%20intermediateResult)%20%3D%3E%20fn(intermediateResult)%2C%0A%20%20%5B%0A%20%20%20%20R.map(x%20%3D%3E%20x%20%2B%201)%2C%0A%20%20%20%20R.map(x%20%3D%3E%20x%20*%202)%2C%0A%20%20%5D%0A)(%5B1%2C%202%2C%203%5D)%0A%2F%2F%20%3D%3E%20%5B3%2C%205%2C%207%5D\">Try this <strong>R.composeWith</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#composeWith)\n\n### concat\n\nIt returns a new string or array, which is the result of merging `x` and `y`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.concat(%5B1%2C%202%5D)(%5B3%2C%204%5D)%20%2F%2F%20%3D%3E%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20result%20%3D%20R.concat('foo'%2C%20'bar')%20%2F%2F%20%3D%3E%20'foobar'\">Try this <strong>R.concat</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#concat)\n\n### cond\n\nIt takes list with `conditions` and returns a new function `fn` that expects `input` as argument. \n\nThis function will start evaluating the `conditions` in order to find the first winner(order of conditions matter). \n\nThe winner is this condition, which left side returns `true` when `input` is its argument. Then the evaluation of the right side of the winner will be the final result.\n\nIf no winner is found, then `fn` returns `undefined`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20R.cond(%5B%0A%20%20%5B%20x%20%3D%3E%20x%20%3E%2025%2C%20R.always('more%20than%2025')%20%5D%2C%0A%20%20%5B%20x%20%3D%3E%20x%20%3E%2015%2C%20R.always('more%20than%2015')%20%5D%2C%0A%20%20%5B%20R.T%2C%20x%20%3D%3E%20%60%24%7Bx%7D%20is%20nothing%20special%60%20%5D%2C%0A%5D)%0A%0Aconst%20result%20%3D%20%5B%0A%20%20fn(30)%2C%0A%20%20fn(20)%2C%0A%20%20fn(10)%2C%0A%5D%20%0A%2F%2F%20%3D%3E%20%5B'more%20than%2025'%2C%20'more%20than%2015'%2C%20'10%20is%20nothing%20special'%5D\">Try this <strong>R.cond</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#cond)\n\n### converge\n\nAccepts a converging function and a list of branching functions and returns a new function. When invoked, this new function is applied to some arguments, each branching function is applied to those same arguments. The results of each branching function are passed as arguments to the converging function to produce the return value.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.converge(R.multiply)(%5B%20R.add(1)%2C%20R.add(3)%20%5D)(2)%0A%2F%2F%20%3D%3E%2015\">Try this <strong>R.converge</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#converge)\n\n### count\n\nIt counts how many times `predicate` function returns `true`, when supplied with iteration of `list`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%7Ba%3A%201%7D%2C%201%2C%20%7Ba%3A2%7D%5D%0Aconst%20result%20%3D%20R.count(x%20%3D%3E%20x.a%20!%3D%3D%20undefined%2C%20list)%0A%2F%2F%20%3D%3E%202\">Try this <strong>R.count</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#count)\n\n### countBy\n\n```typescript\n\ncountBy<T extends unknown>(transformFn: (x: T) => any, list: T[]): Record<string, number>\n```\n\nIt counts elements in a list after each instance of the input list is passed through `transformFn` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%20'a'%2C%20'A'%2C%20'b'%2C%20'B'%2C%20'c'%2C%20'C'%20%5D%0A%0Aconst%20result%20%3D%20countBy(R.toLower%2C%20list)%0Aconst%20expected%20%3D%20%7B%20a%3A%202%2C%20b%3A%202%2C%20c%3A%202%20%7D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.countBy</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ncountBy<T extends unknown>(transformFn: (x: T) => any, list: T[]): Record<string, number>;\ncountBy<T extends unknown>(transformFn: (x: T) => any): (list: T[]) => Record<string, number>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.countBy</strong> source</summary>\n\n```javascript\nexport function countBy(fn, list){\n  if (arguments.length === 1){\n    return _list => countBy(fn, _list)\n  }\n  const willReturn = {}\n\n  list.forEach(item => {\n    const key = fn(item)\n    if (!willReturn[ key ]){\n      willReturn[ key ] = 1\n    } else {\n      willReturn[ key ]++\n    }\n  })\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { countBy } from './countBy.js'\n\nconst list = [ 'a', 'A', 'b', 'B', 'c', 'C' ]\n\ntest('happy', () => {\n  const result = countBy(x => x.toLowerCase(), list)\n  expect(result).toEqual({\n    a : 2,\n    b : 2,\n    c : 2,\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {countBy} from 'rambda'\n\nconst transformFn = (x: string) => x.toLowerCase()\nconst list = ['a', 'A', 'b', 'B', 'c', 'C']\n\ndescribe('R.countBy', () => {\n  it('happy', () => {\n    const result = countBy(transformFn, list)\n\n    result // $ExpectType Record<string, number>\n  })\n  it('curried', () => {\n    const result = countBy(transformFn)(list)\n\n    result // $ExpectType Record<string, number>\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#countBy)\n\n### curry\n\nIt expects a function as input and returns its curried version.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20(a%2C%20b%2C%20c)%20%3D%3E%20a%20%2B%20b%20%2B%20c%0Aconst%20curried%20%3D%20R.curry(fn)%0Aconst%20sum%20%3D%20curried(1%2C2)%0A%0Aconst%20result%20%3D%20sum(3)%20%2F%2F%20%3D%3E%206\">Try this <strong>R.curry</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#curry)\n\n### curryN\n\nIt returns a curried equivalent of the provided function, with the specified arity.\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#curryN)\n\n### dec\n\nIt decrements a number.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.dec(2)%20%2F%2F%20%3D%3E%201\">Try this <strong>R.dec</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dec)\n\n### defaultTo\n\n```typescript\n\ndefaultTo<T>(defaultValue: T, input: T | null | undefined): T\n```\n\nIt returns `defaultValue`, if all of `inputArguments` are `undefined`, `null` or `NaN`.\n\nElse, it returns the first truthy `inputArguments` instance(from left to right).\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.defaultTo('foo'%2C%20'bar')%20%2F%2F%20%3D%3E%20'bar'%0AR.defaultTo('foo'%2C%20undefined)%20%2F%2F%20%3D%3E%20'foo'%0A%0A%2F%2F%20Important%20-%20emtpy%20string%20is%20not%20falsy%20value(same%20as%20Ramda)%0Aconst%20result%20%3D%20R.defaultTo('foo'%2C%20'')%20%2F%2F%20%3D%3E%20'foo'\">Try this <strong>R.defaultTo</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ndefaultTo<T>(defaultValue: T, input: T | null | undefined): T;\ndefaultTo<T>(defaultValue: T): (input: T | null | undefined) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.defaultTo</strong> source</summary>\n\n```javascript\nfunction isFalsy(input){\n  return (\n    input === undefined || input === null || Number.isNaN(input) === true\n  )\n}\n\nexport function defaultTo(defaultArgument, input){\n  if (arguments.length === 1){\n    return _input => defaultTo(defaultArgument, _input)\n  }\n\n  return isFalsy(input) ? defaultArgument : input\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { defaultTo } from './defaultTo.js'\n\ntest('with undefined', () => {\n  expect(defaultTo('foo')(undefined)).toBe('foo')\n})\n\ntest('with null', () => {\n  expect(defaultTo('foo')(null)).toBe('foo')\n})\n\ntest('with NaN', () => {\n  expect(defaultTo('foo')(NaN)).toBe('foo')\n})\n\ntest('with empty string', () => {\n  expect(defaultTo('foo', '')).toBe('')\n})\n\ntest('with false', () => {\n  expect(defaultTo('foo', false)).toBeFalse()\n})\n\ntest('when inputArgument passes initial check', () => {\n  expect(defaultTo('foo', 'bar')).toBe('bar')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {defaultTo} from 'rambda'\n\ndescribe('R.defaultTo with Ramda spec', () => {\n  it('happy', () => {\n    const result = defaultTo('foo', '')\n    result // $ExpectType \"\" | \"foo\"\n  })\n  it('with explicit type', () => {\n    const result = defaultTo<string>('foo', null)\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#defaultTo)\n\n### descend\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.sort(R.descend(x%20%3D%3E%20x)%2C%20%5B1%2C%202%5D)%0A%2F%2F%20%3D%3E%20%5B2%2C%201%5D\">Try this <strong>R.descend</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#descend)\n\n### difference\n\n```typescript\n\ndifference<T>(a: T[], b: T[]): T[]\n```\n\nIt returns the uniq set of all elements in the first list `a` not contained in the second list `b`.\n\n`R.equals` is used to determine equality.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20a%20%3D%20%5B%201%2C%202%2C%203%2C%204%20%5D%0Aconst%20b%20%3D%20%5B%203%2C%204%2C%205%2C%206%20%5D%0A%0Aconst%20result%20%3D%20R.difference(a%2C%20b)%0A%2F%2F%20%3D%3E%20%5B%201%2C%202%20%5D\">Try this <strong>R.difference</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ndifference<T>(a: T[], b: T[]): T[];\ndifference<T>(a: T[]): (b: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.difference</strong> source</summary>\n\n```javascript\nimport { includes } from './includes.js'\nimport { uniq } from './uniq.js'\n\nexport function difference(a, b){\n  if (arguments.length === 1) return _b => difference(a, _b)\n\n  return uniq(a).filter(aInstance => !includes(aInstance, b))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { difference as differenceRamda } from 'ramda'\n\nimport { difference } from './difference.js'\n\ntest('difference', () => {\n  const a = [ 1, 2, 3, 4 ]\n  const b = [ 3, 4, 5, 6 ]\n  expect(difference(a)(b)).toEqual([ 1, 2 ])\n\n  expect(difference([], [])).toEqual([])\n})\n\ntest('difference with objects', () => {\n  const a = [ { id : 1 }, { id : 2 }, { id : 3 }, { id : 4 } ]\n  const b = [ { id : 3 }, { id : 4 }, { id : 5 }, { id : 6 } ]\n  expect(difference(a, b)).toEqual([ { id : 1 }, { id : 2 } ])\n})\n\ntest('no duplicates in first list', () => {\n  const M2 = [ 1, 2, 3, 4, 1, 2, 3, 4 ]\n  const N2 = [ 3, 3, 4, 4, 5, 5, 6, 6 ]\n  expect(difference(M2, N2)).toEqual([ 1, 2 ])\n})\n\ntest('should use R.equals', () => {\n  expect(difference([ 1 ], [ 1 ])).toHaveLength(0)\n  expect(differenceRamda([ NaN ], [ NaN ])).toHaveLength(0)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {difference} from 'rambda'\n\nconst list1 = [1, 2, 3]\nconst list2 = [1, 2, 4]\n\ndescribe('R.difference', () => {\n  it('happy', () => {\n    const result = difference(list1, list2)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = difference(list1)(list2)\n\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#difference)\n\n### differenceWith\n\n```typescript\n\ndifferenceWith<T1, T2>(\n  pred: (a: T1, b: T2) => boolean,\n  list1: T1[],\n  list2: T2[],\n): T1[]\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.differenceWith(%0A%20%20(a%2C%20b)%20%3D%3E%20a.x%20%3D%3D%3D%20b.x%2C%0A%20%20%5B%7Bx%3A%201%7D%2C%20%7Bx%3A%202%7D%5D%2C%0A%20%20%5B%7Bx%3A%201%7D%2C%20%7Bx%3A%203%7D%5D%0A)%0A%2F%2F%20%3D%3E%20%5B%7Bx%3A%202%7D%5D\">Try this <strong>R.differenceWith</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ndifferenceWith<T1, T2>(\n  pred: (a: T1, b: T2) => boolean,\n  list1: T1[],\n  list2: T2[],\n): T1[];\ndifferenceWith<T1, T2>(\n  pred: (a: T1, b: T2) => boolean,\n): (list1: T1[], list2: T2[]) => T1[];\ndifferenceWith<T1, T2>(\n  pred: (a: T1, b: T2) => boolean,\n  list1: T1[],\n): (list2: T2[]) => T1[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.differenceWith</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { _indexOf } from './equals.js'\n\nexport function differenceWithFn(\n  fn, a, b\n){\n  const willReturn = []\n  const [ first, second ] = a.length >= b.length ? [ a, b ] : [ b, a ]\n\n  first.forEach(item => {\n    const hasItem = second.some(secondItem => fn(item, secondItem))\n    if (!hasItem && _indexOf(item, willReturn) === -1){\n      willReturn.push(item)\n    }\n  })\n\n  return willReturn\n}\n\nexport const differenceWith = curry(differenceWithFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { differenceWith } from './differenceWith.js';\n\nconst fn = (a, b) => a.x === b.x;\n\ntest('same length of list', () => {\n\tconst result = differenceWith(fn, [{ x: 1 }, { x: 2 }], [{ x: 1 }, { x: 3 }]);\n\texpect(result).toEqual([{ x: 2 }]);\n});\n\ntest('different length of list', () => {\n\tconst foo = [{ x: 1 }, { x: 2 }, { x: 3 }];\n\tconst bar = [{ x: 3 }, { x: 4 }];\n\tconst result = differenceWith(fn, foo, bar);\n\texpect(result).toEqual([{ x: 1 }, { x: 2 }]);\n});\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#differenceWith)\n\n### dissoc\n\nIt returns a new object that does not contain property `prop`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.dissoc('b'%2C%20%7Ba%3A%201%2C%20b%3A%202%2C%20c%3A%203%7D)%0A%2F%2F%20%3D%3E%20%7Ba%3A%201%2C%20c%3A%203%7D\">Try this <strong>R.dissoc</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dissoc)\n\n### dissocPath\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.dissocPath(%5B'a'%2C%20'b'%5D%2C%20%7Ba%3A%20%7Bb%3A%201%2C%20c%3A%202%7D%7D)%0A%2F%2F%20%3D%3E%20%7Ba%3A%20%7Bc%3A%202%7D%7D\">Try this <strong>R.dissocPath</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dissocPath)\n\n### divide\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.divide(71%2C%20100)%20%2F%2F%20%3D%3E%200.71\">Try this <strong>R.divide</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#divide)\n\n### drop\n\n```typescript\n\ndrop<T>(howMany: number, input: T[]): T[]\n```\n\nIt returns `howMany` items dropped from beginning of list or string `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.drop(2%2C%20%5B'foo'%2C%20'bar'%2C%20'baz'%5D)%20%2F%2F%20%3D%3E%20%5B'baz'%5D%0Aconst%20result%20%3D%20R.drop(2%2C%20'foobar')%20%20%2F%2F%20%3D%3E%20'obar'\">Try this <strong>R.drop</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ndrop<T>(howMany: number, input: T[]): T[];\ndrop(howMany: number, input: string): string;\ndrop<T>(howMany: number): {\n  <T>(input: T[]): T[];\n  (input: string): string;\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.drop</strong> source</summary>\n\n```javascript\nexport function drop(howManyToDrop, listOrString){\n  if (arguments.length === 1) return _list => drop(howManyToDrop, _list)\n\n  return listOrString.slice(howManyToDrop > 0 ? howManyToDrop : 0)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport assert from 'assert'\n\nimport { drop } from './drop.js'\n\ntest('with array', () => {\n  expect(drop(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'baz' ])\n  expect(drop(3, [ 'foo', 'bar', 'baz' ])).toEqual([])\n  expect(drop(4, [ 'foo', 'bar', 'baz' ])).toEqual([])\n})\n\ntest('with string', () => {\n  expect(drop(3, 'rambda')).toBe('bda')\n})\n\ntest('with non-positive count', () => {\n  expect(drop(0, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n  expect(drop(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n  expect(drop(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n})\n\ntest('should return copy', () => {\n  const xs = [ 1, 2, 3 ]\n\n  assert.notStrictEqual(drop(0, xs), xs)\n  assert.notStrictEqual(drop(-1, xs), xs)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {drop} from 'rambda'\n\nconst list = [1, 2, 3, 4]\nconst str = 'foobar'\nconst howMany = 2\n\ndescribe('R.drop - array', () => {\n  it('happy', () => {\n    const result = drop(howMany, list)\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = drop(howMany)(list)\n    result // $ExpectType number[]\n  })\n})\n\ndescribe('R.drop - string', () => {\n  it('happy', () => {\n    const result = drop(howMany, str)\n    result // $ExpectType string\n  })\n  it('curried', () => {\n    const result = drop(howMany)(str)\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#drop)\n\n### dropLast\n\n```typescript\n\ndropLast<T>(howMany: number, input: T[]): T[]\n```\n\nIt returns `howMany` items dropped from the end of list or string `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.dropLast(2%2C%20%5B'foo'%2C%20'bar'%2C%20'baz'%5D)%20%2F%2F%20%3D%3E%20%5B'foo'%5D%0Aconst%20result%20%3D%20R.dropLast(2%2C%20'foobar')%20%20%2F%2F%20%3D%3E%20'foob'\">Try this <strong>R.dropLast</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ndropLast<T>(howMany: number, input: T[]): T[];\ndropLast(howMany: number, input: string): string;\ndropLast<T>(howMany: number): {\n  <T>(input: T[]): T[];\n  (input: string): string;\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.dropLast</strong> source</summary>\n\n```javascript\nexport function dropLast(howManyToDrop, listOrString){\n  if (arguments.length === 1){\n    return _listOrString => dropLast(howManyToDrop, _listOrString)\n  }\n\n  return howManyToDrop > 0 ?\n    listOrString.slice(0, -howManyToDrop) :\n    listOrString.slice()\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport assert from 'assert'\n\nimport { dropLast } from './dropLast.js'\n\ntest('with array', () => {\n  expect(dropLast(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'foo' ])\n  expect(dropLast(3, [ 'foo', 'bar', 'baz' ])).toEqual([])\n  expect(dropLast(4, [ 'foo', 'bar', 'baz' ])).toEqual([])\n})\n\ntest('with string', () => {\n  expect(dropLast(3, 'rambda')).toBe('ram')\n})\n\ntest('with non-positive count', () => {\n  expect(dropLast(0, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n  expect(dropLast(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n  expect(dropLast(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n})\n\ntest('should return copy', () => {\n  const xs = [ 1, 2, 3 ]\n\n  assert.notStrictEqual(dropLast(0, xs), xs)\n  assert.notStrictEqual(dropLast(-1, xs), xs)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {dropLast} from 'rambda'\n\nconst list = [1, 2, 3, 4]\nconst str = 'foobar'\nconst howMany = 2\n\ndescribe('R.dropLast - array', () => {\n  it('happy', () => {\n    const result = dropLast(howMany, list)\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = dropLast(howMany)(list)\n    result // $ExpectType number[]\n  })\n})\n\ndescribe('R.dropLast - string', () => {\n  it('happy', () => {\n    const result = dropLast(howMany, str)\n    result // $ExpectType string\n  })\n  it('curried', () => {\n    const result = dropLast(howMany)(str)\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dropLast)\n\n### dropLastWhile\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%2C%205%5D%3B%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3E%3D%203%0A%0Aconst%20result%20%3D%20dropLastWhile(predicate%2C%20list)%3B%0A%2F%2F%20%3D%3E%20%5B1%2C%202%5D\">Try this <strong>R.dropLastWhile</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dropLastWhile)\n\n### dropRepeats\n\n```typescript\n\ndropRepeats<T>(list: T[]): T[]\n```\n\nIt removes any successive duplicates according to `R.equals`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.dropRepeats(%5B%0A%20%201%2C%20%0A%20%201%2C%20%0A%20%20%7Ba%3A%201%7D%2C%20%0A%20%20%7Ba%3A1%7D%2C%20%0A%20%201%0A%5D)%0A%2F%2F%20%3D%3E%20%5B1%2C%20%7Ba%3A%201%7D%2C%201%5D\">Try this <strong>R.dropRepeats</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ndropRepeats<T>(list: T[]): T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.dropRepeats</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { equals } from './equals.js'\n\nexport function dropRepeats(list){\n  if (!isArray(list)){\n    throw new Error(`${ list } is not a list`)\n  }\n\n  const toReturn = []\n\n  list.reduce((prev, current) => {\n    if (!equals(prev, current)){\n      toReturn.push(current)\n    }\n\n    return current\n  }, undefined)\n\n  return toReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { dropRepeats as dropRepeatsRamda } from 'ramda'\n\nimport { compareCombinations } from './_internals/testUtils.js'\nimport { add } from './add.js'\nimport { dropRepeats } from './dropRepeats.js'\n\nconst list = [ 1, 2, 2, 2, 3, 4, 4, 5, 5, 3, 2, 2, { a : 1 }, { a : 1 } ]\nconst listClean = [ 1, 2, 3, 4, 5, 3, 2, { a : 1 } ]\n\ntest('happy', () => {\n  const result = dropRepeats(list)\n  expect(result).toEqual(listClean)\n})\n\nconst possibleLists = [\n  [ add(1), async () => {}, [ 1 ], [ 1 ], [ 2 ], [ 2 ] ],\n  [ add(1), add(1), add(2) ],\n  [],\n  1,\n  /foo/g,\n  Promise.resolve(1),\n]\n\ndescribe('brute force', () => {\n  compareCombinations({\n    firstInput : possibleLists,\n    callback   : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n        {\n          \"ERRORS_MESSAGE_MISMATCH\": 0,\n          \"ERRORS_TYPE_MISMATCH\": 0,\n          \"RESULTS_MISMATCH\": 1,\n          \"SHOULD_NOT_THROW\": 3,\n          \"SHOULD_THROW\": 0,\n          \"TOTAL_TESTS\": 6,\n        }\n      `)\n    },\n    fn      : dropRepeats,\n    fnRamda : dropRepeatsRamda,\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {dropRepeats} from 'rambda'\n\ndescribe('R.dropRepeats', () => {\n  it('happy', () => {\n    const result = dropRepeats([1, 2, 2, 3])\n\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dropRepeats)\n\n### dropRepeatsBy\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.dropRepeatsBy(%0A%20%20Math.abs%2C%0A%20%20%5B1%2C%20-1%2C%202%2C%203%2C%20-3%5D%0A)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%2C%203%5D\">Try this <strong>R.dropRepeatsBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dropRepeatsBy)\n\n### dropRepeatsWith\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%7Ba%3A1%2Cb%3A2%7D%2C%20%7Ba%3A1%2Cb%3A3%7D%2C%20%7Ba%3A2%2C%20b%3A4%7D%5D%0Aconst%20result%20%3D%20R.dropRepeatsWith(R.prop('a')%2C%20list)%0A%0A%2F%2F%20%3D%3E%20%5B%7Ba%3A1%2Cb%3A2%7D%2C%20%7Ba%3A2%2C%20b%3A4%7D%5D\">Try this <strong>R.dropRepeatsWith</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dropRepeatsWith)\n\n### dropWhile\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3C%203%0Aconst%20result%20%3D%20R.dropWhile(predicate%2C%20list)%0A%2F%2F%20%3D%3E%20%5B3%2C%204%5D\">Try this <strong>R.dropWhile</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#dropWhile)\n\n### either\n\n```typescript\n\neither(firstPredicate: Pred, secondPredicate: Pred): Pred\n```\n\nIt returns a new `predicate` function from `firstPredicate` and `secondPredicate` inputs.\n\nThis `predicate` function will return `true`, if any of the two input predicates return `true`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20firstPredicate%20%3D%20x%20%3D%3E%20x%20%3E%2010%0Aconst%20secondPredicate%20%3D%20x%20%3D%3E%20x%20%25%202%20%3D%3D%3D%200%0Aconst%20predicate%20%3D%20R.either(firstPredicate%2C%20secondPredicate)%0A%0Aconst%20result%20%3D%20%5B%0A%20%20predicate(15)%2C%0A%20%20predicate(8)%2C%0A%20%20predicate(7)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%2C%20false%5D\">Try this <strong>R.either</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\neither(firstPredicate: Pred, secondPredicate: Pred): Pred;\neither<T>(firstPredicate: Predicate<T>, secondPredicate: Predicate<T>): Predicate<T>;\neither<T>(firstPredicate: Predicate<T>): (secondPredicate: Predicate<T>) => Predicate<T>;\neither(firstPredicate: Pred): (secondPredicate: Pred) => Pred;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.either</strong> source</summary>\n\n```javascript\nexport function either(firstPredicate, secondPredicate){\n  if (arguments.length === 1){\n    return _secondPredicate => either(firstPredicate, _secondPredicate)\n  }\n\n  return (...input) =>\n    Boolean(firstPredicate(...input) || secondPredicate(...input))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { either } from './either.js'\n\ntest('with multiple inputs', () => {\n  const between = function (\n    a, b, c\n  ){\n    return a < b && b < c\n  }\n  const total20 = function (\n    a, b, c\n  ){\n    return a + b + c === 20\n  }\n  const fn = either(between, total20)\n  expect(fn(\n    7, 8, 5\n  )).toBeTrue()\n})\n\ntest('skip evaluation of the second expression', () => {\n  let effect = 'not evaluated'\n  const F = function (){\n    return true\n  }\n  const Z = function (){\n    effect = 'Z got evaluated'\n  }\n  either(F, Z)()\n\n  expect(effect).toBe('not evaluated')\n})\n\ntest('case 1', () => {\n  const firstFn = val => val > 0\n  const secondFn = val => val * 5 > 10\n\n  expect(either(firstFn, secondFn)(1)).toBeTrue()\n})\n\ntest('case 2', () => {\n  const firstFn = val => val > 0\n  const secondFn = val => val === -10\n  const fn = either(firstFn)(secondFn)\n\n  expect(fn(-10)).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {either} from 'rambda'\n\ndescribe('R.either', () => {\n  it('with passed type', () => {\n    const fn = either<number>(\n      x => x > 1,\n      x => x % 2 === 0\n    )\n    fn // $ExpectType Predicate<number>\n    const result = fn(2) // $ExpectType boolean\n    result // $ExpectType boolean\n  })\n  it('with passed type - curried', () => {\n    const fn = either<number>(x => x > 1)(x => x % 2 === 0)\n    fn // $ExpectType Predicate<number>\n    const result = fn(2)\n    result // $ExpectType boolean\n  })\n  it('no type passed', () => {\n    const fn = either(\n      x => {\n        x // $ExpectType any\n        return x > 1\n      },\n      x => {\n        x // $ExpectType any\n        return x % 2 === 0\n      }\n    )\n    const result = fn(2)\n    result // $ExpectType boolean\n  })\n  it('no type passed - curried', () => {\n    const fn = either((x: number) => {\n      x // $ExpectType number\n      return x > 1\n    })((x: number) => {\n      x // $ExpectType number\n      return x % 2 === 0\n    })\n    const result = fn(2)\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#either)\n\n### empty\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5BR.empty(%5B1%2C2%2C3%5D)%2C%20R.empty('foo')%2C%20R.empty(%7Bx%3A%201%2C%20y%3A%202%7D)%5D%0A%2F%2F%20%3D%3E%20%5B%5B%5D%2C%20''%2C%20%7B%7D%5D\">Try this <strong>R.empty</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#empty)\n\n### endsWith\n\n```typescript\n\nendsWith<T extends string>(question: T, str: string): boolean\n```\n\nWhen iterable is a string, then it behaves as `String.prototype.endsWith`.\nWhen iterable is a list, then it uses R.equals to determine if the target list ends in the same way as the given target.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20str%20%3D%20'foo-bar'%0Aconst%20list%20%3D%20%5B%7Ba%3A1%7D%2C%20%7Ba%3A2%7D%2C%20%7Ba%3A3%7D%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.endsWith('bar'%2C%20str)%2C%0A%20%20R.endsWith(%5B%7Ba%3A1%7D%2C%20%7Ba%3A2%7D%5D%2C%20list)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%5D\">Try this <strong>R.endsWith</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nendsWith<T extends string>(question: T, str: string): boolean;\nendsWith<T extends string>(question: T): (str: string) => boolean;\nendsWith<T>(question: T[], list: T[]): boolean;\nendsWith<T>(question: T[]): (list: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.endsWith</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { equals } from './equals.js'\n\nexport function endsWith(target, iterable){\n  if (arguments.length === 1) return _iterable => endsWith(target, _iterable)\n\n  if (typeof iterable === 'string'){\n    return iterable.endsWith(target)\n  }\n  if (!isArray(target)) return false\n\n  const diff = iterable.length - target.length\n  let correct = true\n  const filtered = target.filter((x, index) => {\n    if (!correct) return false\n    const result = equals(x, iterable[ index + diff ])\n    if (!result) correct = false\n\n    return result\n  })\n\n  return filtered.length === target.length\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { endsWith as endsWithRamda } from 'ramda'\n\nimport { compareCombinations } from './_internals/testUtils.js'\nimport { endsWith } from './endsWith.js'\n\ntest('with string', () => {\n  expect(endsWith('bar', 'foo-bar')).toBeTrue()\n  expect(endsWith('baz')('foo-bar')).toBeFalse()\n})\n\ntest('use R.equals with array', () => {\n  const list = [ { a : 1 }, { a : 2 }, { a : 3 } ]\n  expect(endsWith({ a : 3 }, list)).toBeFalse(),\n  expect(endsWith([ { a : 3 } ], list)).toBeTrue()\n  expect(endsWith([ { a : 2 }, { a : 3 } ], list)).toBeTrue()\n  expect(endsWith(list, list)).toBeTrue()\n  expect(endsWith([ { a : 1 } ], list)).toBeFalse()\n})\n\nexport const possibleTargets = [\n  NaN,\n  [ NaN ],\n  /foo/,\n  [ /foo/ ],\n  Promise.resolve(1),\n  [ Promise.resolve(1) ],\n  Error('foo'),\n  [ Error('foo') ],\n]\n\nexport const possibleIterables = [\n  [ Promise.resolve(1), Promise.resolve(2) ],\n  [ /foo/, /bar/ ],\n  [ NaN ],\n  [ Error('foo'), Error('bar') ],\n]\n\ndescribe('brute force', () => {\n  compareCombinations({\n    fn          : endsWith,\n    fnRamda     : endsWithRamda,\n    firstInput  : possibleTargets,\n    secondInput : possibleIterables,\n    callback    : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n        {\n          \"ERRORS_MESSAGE_MISMATCH\": 0,\n          \"ERRORS_TYPE_MISMATCH\": 0,\n          \"RESULTS_MISMATCH\": 0,\n          \"SHOULD_NOT_THROW\": 0,\n          \"SHOULD_THROW\": 0,\n          \"TOTAL_TESTS\": 32,\n        }\n      `)\n    },\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {endsWith} from 'rambda'\n\ndescribe('R.endsWith - array', () => {\n  const target = [{a: 2}]\n  const input = [{a: 1}, {a: 2}]\n  it('happy', () => {\n    const result = endsWith(target, input)\n    result // $ExpectType boolean\n  })\n  it('curried', () => {\n    const result = endsWith(target)(input)\n    result // $ExpectType boolean\n  })\n})\n\ndescribe('R.endsWith - string', () => {\n  const target = 'bar'\n  const input = 'foo bar'\n  it('happy', () => {\n    const result = endsWith(target, input)\n    result // $ExpectType boolean\n  })\n  it('curried', () => {\n    const result = endsWith(target)(input)\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#endsWith)\n\n### eqBy\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.eqBy(Math.abs%2C%205%2C%20-5)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.eqBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#eqBy)\n\n### eqProps\n\nIt returns `true` if property `prop` in `obj1` is equal to property `prop` in `obj2` according to `R.equals`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj1%20%3D%20%7Ba%3A%201%2C%20b%3A2%7D%0Aconst%20obj2%20%3D%20%7Ba%3A%201%2C%20b%3A3%7D%0Aconst%20result%20%3D%20R.eqProps('a'%2C%20obj1%2C%20obj2)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.eqProps</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#eqProps)\n\n### equals\n\n```typescript\n\nequals<T>(x: T, y: T): boolean\n```\n\nIt deeply compares `x` and `y` and returns `true` if they are equal.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.equals(%0A%20%20%5B1%2C%20%7Ba%3A2%7D%2C%20%5B%7Bb%3A%203%7D%5D%5D%2C%0A%20%20%5B1%2C%20%7Ba%3A2%7D%2C%20%5B%7Bb%3A%203%7D%5D%5D%0Aconst%20result%20%3D%20)%20%2F%2F%20%3D%3E%20true\">Try this <strong>R.equals</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nequals<T>(x: T, y: T): boolean;\nequals<T>(x: T): (y: T) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.equals</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { type } from './type.js'\n\nexport function _lastIndexOf(valueToFind, list){\n  if (!isArray(list))\n    throw new Error(`Cannot read property 'indexOf' of ${ list }`)\n\n  const typeOfValue = type(valueToFind)\n  if (![ 'Array', 'NaN', 'Object', 'RegExp' ].includes(typeOfValue))\n    return list.lastIndexOf(valueToFind)\n\n  const { length } = list\n  let index = length\n  let foundIndex = -1\n\n  while (--index > -1 && foundIndex === -1)\n    if (equals(list[ index ], valueToFind))\n      foundIndex = index\n\n  return foundIndex\n}\n\nexport function _indexOf(valueToFind, list){\n  if (!isArray(list))\n    throw new Error(`Cannot read property 'indexOf' of ${ list }`)\n\n  const typeOfValue = type(valueToFind)\n  if (![ 'Array', 'NaN', 'Object', 'RegExp' ].includes(typeOfValue))\n    return list.indexOf(valueToFind)\n\n  let index = -1\n  let foundIndex = -1\n  const { length } = list\n\n  while (++index < length && foundIndex === -1)\n    if (equals(list[ index ], valueToFind))\n      foundIndex = index\n\n  return foundIndex\n}\n\nfunction _arrayFromIterator(iter){\n  const list = []\n  let next\n  while (!(next = iter.next()).done)\n    list.push(next.value)\n\n  return list\n}\n\nfunction _compareSets(a, b){\n  if (a.size !== b.size)\n    return false\n\n  const aList = _arrayFromIterator(a.values())\n  const bList = _arrayFromIterator(b.values())\n\n  const filtered = aList.filter(aInstance => _indexOf(aInstance, bList) === -1)\n\n  return filtered.length === 0\n}\n\nfunction compareErrors(a, b){\n  if (a.message !== b.message) return false\n  if (a.toString !== b.toString) return false\n\n  return a.toString() === b.toString()\n}\n\nfunction parseDate(maybeDate){\n  if (!maybeDate.toDateString) return [ false ]\n\n  return [ true, maybeDate.getTime() ]\n}\n\nfunction parseRegex(maybeRegex){\n  if (maybeRegex.constructor !== RegExp) return [ false ]\n\n  return [ true, maybeRegex.toString() ]\n}\n\nexport function equals(a, b){\n  if (arguments.length === 1) return _b => equals(a, _b)\n\n  if (Object.is(a, b)) return true\n\n  const aType = type(a)\n\n  if (aType !== type(b)) return false\n  if (aType === 'Function')\n    return a.name === undefined ? false : a.name === b.name\n\n  if ([ 'NaN', 'Null', 'Undefined' ].includes(aType)) return true\n\n  if ([ 'BigInt', 'Number' ].includes(aType)){\n    if (Object.is(-0, a) !== Object.is(-0, b)) return false\n\n    return a.toString() === b.toString()\n  }\n\n  if ([ 'Boolean', 'String' ].includes(aType))\n    return a.toString() === b.toString()\n\n  if (aType === 'Array'){\n    const aClone = Array.from(a)\n    const bClone = Array.from(b)\n\n    if (aClone.toString() !== bClone.toString())\n      return false\n\n    let loopArrayFlag = true\n    aClone.forEach((aCloneInstance, aCloneIndex) => {\n      if (loopArrayFlag)\n        if (\n          aCloneInstance !== bClone[ aCloneIndex ] &&\n          !equals(aCloneInstance, bClone[ aCloneIndex ])\n        )\n          loopArrayFlag = false\n\n    })\n\n    return loopArrayFlag\n  }\n\n  const aRegex = parseRegex(a)\n  const bRegex = parseRegex(b)\n\n  if (aRegex[ 0 ])\n    return bRegex[ 0 ] ? aRegex[ 1 ] === bRegex[ 1 ] : false\n  else if (bRegex[ 0 ]) return false\n\n  const aDate = parseDate(a)\n  const bDate = parseDate(b)\n\n  if (aDate[ 0 ])\n    return bDate[ 0 ] ? aDate[ 1 ] === bDate[ 1 ] : false\n  else if (bDate[ 0 ]) return false\n\n  if (a instanceof Error){\n    if (!(b instanceof Error)) return false\n\n    return compareErrors(a, b)\n  }\n\n  if (aType === 'Set')\n    return _compareSets(a, b)\n\n  if (aType === 'Object'){\n    const aKeys = Object.keys(a)\n\n    if (aKeys.length !== Object.keys(b).length)\n      return false\n\n    let loopObjectFlag = true\n    aKeys.forEach(aKeyInstance => {\n      if (loopObjectFlag){\n        const aValue = a[ aKeyInstance ]\n        const bValue = b[ aKeyInstance ]\n\n        if (aValue !== bValue && !equals(aValue, bValue))\n          loopObjectFlag = false\n\n      }\n    })\n\n    return loopObjectFlag\n  }\n\n  return false\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { equals as equalsRamda } from 'ramda'\n\nimport { compareCombinations } from './_internals/testUtils.js'\nimport { variousTypes } from './benchmarks/_utils.js'\nimport { equals } from './equals.js'\n\ntest('compare functions', () => {\n  function foo(){}\n  function bar(){}\n  const baz = () => {}\n\n  const expectTrue = equals(foo, foo)\n  const expectFalseFirst = equals(foo, bar)\n  const expectFalseSecond = equals(foo, baz)\n\n  expect(expectTrue).toBeTrue()\n  expect(expectFalseFirst).toBeFalse()\n  expect(expectFalseSecond).toBeFalse()\n})\n\ntest('with array of objects', () => {\n  const list1 = [ { a : 1 }, [ { b : 2 } ] ]\n  const list2 = [ { a : 1 }, [ { b : 2 } ] ]\n  const list3 = [ { a : 1 }, [ { b : 3 } ] ]\n\n  expect(equals(list1, list2)).toBeTrue()\n  expect(equals(list1, list3)).toBeFalse()\n})\n\ntest('with regex', () => {\n  expect(equals(/s/, /s/)).toBeTrue()\n  expect(equals(/s/, /d/)).toBeFalse()\n  expect(equals(/a/gi, /a/gi)).toBeTrue()\n  expect(equals(/a/gim, /a/gim)).toBeTrue()\n  expect(equals(/a/gi, /a/i)).toBeFalse()\n})\n\ntest('not a number', () => {\n  expect(equals([ NaN ], [ NaN ])).toBeTrue()\n})\n\ntest('new number', () => {\n  expect(equals(new Number(0), new Number(0))).toBeTrue()\n  expect(equals(new Number(0), new Number(1))).toBeFalse()\n  expect(equals(new Number(1), new Number(0))).toBeFalse()\n})\n\ntest('new string', () => {\n  expect(equals(new String(''), new String(''))).toBeTrue()\n  expect(equals(new String(''), new String('x'))).toBeFalse()\n  expect(equals(new String('x'), new String(''))).toBeFalse()\n  expect(equals(new String('foo'), new String('foo'))).toBeTrue()\n  expect(equals(new String('foo'), new String('bar'))).toBeFalse()\n  expect(equals(new String('bar'), new String('foo'))).toBeFalse()\n})\n\ntest('new Boolean', () => {\n  expect(equals(new Boolean(true), new Boolean(true))).toBeTrue()\n  expect(equals(new Boolean(false), new Boolean(false))).toBeTrue()\n  expect(equals(new Boolean(true), new Boolean(false))).toBeFalse()\n  expect(equals(new Boolean(false), new Boolean(true))).toBeFalse()\n})\n\ntest('new Error', () => {\n  expect(equals(new Error('XXX'), {})).toBeFalse()\n  expect(equals(new Error('XXX'), new TypeError('XXX'))).toBeFalse()\n  expect(equals(new Error('XXX'), new Error('YYY'))).toBeFalse()\n  expect(equals(new Error('XXX'), new Error('XXX'))).toBeTrue()\n  expect(equals(new Error('XXX'), new TypeError('YYY'))).toBeFalse()\n  expect(equals(new Error('XXX'), new Error('XXX'))).toBeTrue()\n})\n\ntest('with dates', () => {\n  expect(equals(new Date(0), new Date(0))).toBeTrue()\n  expect(equals(new Date(1), new Date(1))).toBeTrue()\n  expect(equals(new Date(0), new Date(1))).toBeFalse()\n  expect(equals(new Date(1), new Date(0))).toBeFalse()\n  expect(equals(new Date(0), {})).toBeFalse()\n  expect(equals({}, new Date(0))).toBeFalse()\n})\n\ntest('ramda spec', () => {\n  expect(equals({}, {})).toBeTrue()\n\n  expect(equals({\n    a : 1,\n    b : 2,\n  },\n  {\n    a : 1,\n    b : 2,\n  })).toBeTrue()\n\n  expect(equals({\n    a : 2,\n    b : 3,\n  },\n  {\n    a : 2,\n    b : 3,\n  })).toBeTrue()\n\n  expect(equals({\n    a : 2,\n    b : 3,\n  },\n  {\n    a : 3,\n    b : 3,\n  })).toBeFalse()\n\n  expect(equals({\n    a : 2,\n    b : 3,\n    c : 1,\n  },\n  {\n    a : 2,\n    b : 3,\n  })).toBeFalse()\n})\n\ntest('works with boolean tuple', () => {\n  expect(equals([ true, false ], [ true, false ])).toBeTrue()\n  expect(equals([ true, false ], [ true, true ])).toBeFalse()\n})\n\ntest('works with equal objects within array', () => {\n  const objFirst = {\n    a : {\n      b : 1,\n      c : 2,\n      d : [ 1 ],\n    },\n  }\n  const objSecond = {\n    a : {\n      b : 1,\n      c : 2,\n      d : [ 1 ],\n    },\n  }\n\n  const x = [ 1, 2, objFirst, null, '', [] ]\n  const y = [ 1, 2, objSecond, null, '', [] ]\n  expect(equals(x, y)).toBeTrue()\n})\n\ntest('works with different objects within array', () => {\n  const objFirst = { a : { b : 1 } }\n  const objSecond = { a : { b : 2 } }\n\n  const x = [ 1, 2, objFirst, null, '', [] ]\n  const y = [ 1, 2, objSecond, null, '', [] ]\n  expect(equals(x, y)).toBeFalse()\n})\n\ntest('works with undefined as second argument', () => {\n  expect(equals(1, undefined)).toBeFalse()\n\n  expect(equals(undefined, undefined)).toBeTrue()\n})\n\ntest('compare sets', () => {\n  const toCompareDifferent = new Set([ { a : 1 }, { a : 2 } ])\n  const toCompareSame = new Set([ { a : 1 }, { a : 2 }, { a : 1 } ])\n  const testSet = new Set([ { a : 1 }, { a : 2 }, { a : 1 } ])\n  expect(equals(toCompareSame, testSet)).toBeTruthy()\n  expect(equals(toCompareDifferent, testSet)).toBeFalsy()\n  expect(equalsRamda(toCompareSame, testSet)).toBeTruthy()\n  expect(equalsRamda(toCompareDifferent, testSet)).toBeFalsy()\n})\n\ntest('compare simple sets', () => {\n  const testSet = new Set([ '2', '3', '3', '2', '1' ])\n  expect(equals(new Set([ '3', '2', '1' ]), testSet)).toBeTruthy()\n  expect(equals(new Set([ '3', '2', '0' ]), testSet)).toBeFalsy()\n})\n\ntest('various examples', () => {\n  expect(equals([ 1, 2, 3 ])([ 1, 2, 3 ])).toBeTrue()\n\n  expect(equals([ 1, 2, 3 ], [ 1, 2 ])).toBeFalse()\n\n  expect(equals(1, 1)).toBeTrue()\n\n  expect(equals(1, '1')).toBeFalse()\n\n  expect(equals({}, {})).toBeTrue()\n\n  expect(equals({\n    a : 1,\n    b : 2,\n  },\n  {\n    a : 1,\n    b : 2,\n  })).toBeTrue()\n\n  expect(equals({\n    a : 1,\n    b : 2,\n  },\n  {\n    a : 1,\n    b : 1,\n  })).toBeFalse()\n\n  expect(equals({\n    a : 1,\n    b : false,\n  },\n  {\n    a : 1,\n    b : 1,\n  })).toBeFalse()\n\n  expect(equals({\n    a : 1,\n    b : 2,\n  },\n  {\n    a : 1,\n    b : 2,\n    c : 3,\n  })).toBeFalse()\n\n  expect(equals({\n    x : {\n      a : 1,\n      b : 2,\n    },\n  },\n  {\n    x : {\n      a : 1,\n      b : 2,\n      c : 3,\n    },\n  })).toBeFalse()\n\n  expect(equals({\n    a : 1,\n    b : 2,\n  },\n  {\n    a : 1,\n    b : 3,\n  })).toBeFalse()\n\n  expect(equals({ a : { b : { c : 1 } } }, { a : { b : { c : 1 } } })).toBeTrue()\n\n  expect(equals({ a : { b : { c : 1 } } }, { a : { b : { c : 2 } } })).toBeFalse()\n\n  expect(equals({ a : {} }, { a : {} })).toBeTrue()\n\n  expect(equals('', '')).toBeTrue()\n\n  expect(equals('foo', 'foo')).toBeTrue()\n\n  expect(equals('foo', 'bar')).toBeFalse()\n\n  expect(equals(0, false)).toBeFalse()\n\n  expect(equals(/\\s/g, null)).toBeFalse()\n\n  expect(equals(null, null)).toBeTrue()\n\n  expect(equals(false)(null)).toBeFalse()\n})\n\ntest('with custom functions', () => {\n  function foo(){\n    return 1\n  }\n  foo.prototype.toString = () => ''\n  const result = equals(foo, foo)\n\n  expect(result).toBeTrue()\n})\n\ntest('with classes', () => {\n  class Foo{}\n  const foo = new Foo()\n  const result = equals(foo, foo)\n\n  expect(result).toBeTrue()\n})\n\ntest('with negative zero', () => {\n  expect(equals(-0, -0)).toBeTrue()\n  expect(equals(-0, 0)).toBeFalse()\n  expect(equals(0, 0)).toBeTrue()\n  expect(equals(-0, 1)).toBeFalse()\n})\n\ntest('with big int', () => {\n  const a = BigInt(9007199254740991)\n  const b = BigInt(9007199254740991)\n  const c = BigInt(7007199254740991)\n  expect(equals(a, b)).toBeTrue()\n  expect(equals(a, c)).toBeFalse()\n})\n\ndescribe('brute force', () => {\n  compareCombinations({\n    callback : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n{\n  \"ERRORS_MESSAGE_MISMATCH\": 0,\n  \"ERRORS_TYPE_MISMATCH\": 0,\n  \"RESULTS_MISMATCH\": 0,\n  \"SHOULD_NOT_THROW\": 0,\n  \"SHOULD_THROW\": 0,\n  \"TOTAL_TESTS\": 289,\n}\n`)\n    },\n    firstInput  : variousTypes,\n    fn          : equals,\n    fnRamda     : equalsRamda,\n    secondInput : variousTypes,\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {equals} from 'rambda'\n\ndescribe('R.equals', () => {\n  it('happy', () => {\n    const result = equals(4, 1)\n    result // $ExpectType boolean\n  })\n  it('with object', () => {\n    const foo = {a: 1}\n    const bar = {a: 2}\n    const result = equals(foo, bar)\n    result // $ExpectType boolean\n  })\n  it('curried', () => {\n    const result = equals(4)(1)\n\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#equals)\n\n### evolve\n\n```typescript\n\nevolve<T, U>(rules: ((x: T) => U)[], list: T[]): U[]\n```\n\nIt takes object or array of functions as set of rules. These `rules` are applied to the `iterable` input to produce the result.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20rules%20%3D%20%7B%0A%20%20foo%20%3A%20add(1)%2C%0A%20%20bar%20%3A%20add(-1)%2C%0A%7D%0Aconst%20input%20%3D%20%7B%0A%20%20a%20%20%20%3A%201%2C%0A%20%20foo%20%3A%202%2C%0A%20%20bar%20%3A%203%2C%0A%7D%0Aconst%20result%20%3D%20evolve(rules%2C%20input)%0Aconst%20expected%20%3D%20%7B%0A%20%20a%20%20%20%3A%201%2C%0A%20%20foo%20%3A%203%2C%0A%20%20bar%20%3A%202%2C%0A%7D)%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.evolve</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nevolve<T, U>(rules: ((x: T) => U)[], list: T[]): U[];\nevolve<T, U>(rules: ((x: T) => U)[]) : (list: T[]) => U[];\nevolve<E extends Evolver, V extends Evolvable<E>>(rules: E, obj: V): Evolve<V, E>;\nevolve<E extends Evolver>(rules: E): <V extends Evolvable<E>>(obj: V) => Evolve<V, E>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.evolve</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { mapArray, mapObject } from './map.js'\nimport { type } from './type.js'\n\nexport function evolveArray(rules, list){\n  return mapArray(\n    (x, i) => {\n      if (type(rules[ i ]) === 'Function'){\n        return rules[ i ](x)\n      }\n\n      return x\n    },\n    list,\n    true\n  )\n}\n\nexport function evolveObject(rules, iterable){\n  return mapObject((x, prop) => {\n    if (type(x) === 'Object'){\n      const typeRule = type(rules[ prop ])\n      if (typeRule === 'Function'){\n        return rules[ prop ](x)\n      }\n      if (typeRule === 'Object'){\n        return evolve(rules[ prop ], x)\n      }\n\n      return x\n    }\n    if (type(rules[ prop ]) === 'Function'){\n      return rules[ prop ](x)\n    }\n\n    return x\n  }, iterable)\n}\n\nexport function evolve(rules, iterable){\n  if (arguments.length === 1){\n    return _iterable => evolve(rules, _iterable)\n  }\n  const rulesType = type(rules)\n  const iterableType = type(iterable)\n\n  if (iterableType !== rulesType){\n    throw new Error('iterableType !== rulesType')\n  }\n\n  if (![ 'Object', 'Array' ].includes(rulesType)){\n    throw new Error(`'iterable' and 'rules' are from wrong type ${ rulesType }`)\n  }\n\n  if (iterableType === 'Object'){\n    return evolveObject(rules, iterable)\n  }\n\n  return evolveArray(rules, iterable)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { evolve as evolveRamda } from 'ramda'\n\nimport { add } from '../rambda.js'\nimport { compareCombinations, compareToRamda } from './_internals/testUtils.js'\nimport { evolve } from './evolve.js'\n\ntest('happy', () => {\n  const rules = {\n    foo    : add(1),\n    nested : { bar : x => Object.keys(x).length },\n  }\n  const input = {\n    a      : 1,\n    foo    : 2,\n    nested : { bar : { z : 3 } },\n  }\n  const result = evolve(rules, input)\n  expect(result).toEqual({\n    a      : 1,\n    foo    : 3,\n    nested : { bar : 1 },\n  })\n})\n\ntest('nested rule is wrong', () => {\n  const rules = {\n    foo    : add(1),\n    nested : { bar : 10 },\n  }\n  const input = {\n    a      : 1,\n    foo    : 2,\n    nested : { bar : { z : 3 } },\n  }\n  const result = evolve(rules)(input)\n  expect(result).toEqual({\n    a      : 1,\n    foo    : 3,\n    nested : { bar : { z : 3 } },\n  })\n})\n\ntest('is recursive', () => {\n  const rules = {\n    nested : {\n      second : add(-1),\n      third  : add(1),\n    },\n  }\n  const object = {\n    first  : 1,\n    nested : {\n      second : 2,\n      third  : 3,\n    },\n  }\n  const expected = {\n    first  : 1,\n    nested : {\n      second : 1,\n      third  : 4,\n    },\n  }\n  const result = evolve(rules, object)\n  expect(result).toEqual(expected)\n})\n\ntest('ignores primitive values', () => {\n  const rules = {\n    n : 2,\n    m : 'foo',\n  }\n  const object = {\n    n : 0,\n    m : 1,\n  }\n  const expected = {\n    n : 0,\n    m : 1,\n  }\n  const result = evolve(rules, object)\n  expect(result).toEqual(expected)\n})\n\ntest('with array', () => {\n  const rules = [ add(1), add(-1) ]\n  const list = [ 100, 1400 ]\n  const expected = [ 101, 1399 ]\n  const result = evolve(rules, list)\n  expect(result).toEqual(expected)\n})\n\nconst rulesObject = { a : add(1) }\nconst rulesList = [ add(1) ]\nconst possibleIterables = [ null, undefined, '', 42, [], [ 1 ], { a : 1 } ]\nconst possibleRules = [ ...possibleIterables, rulesList, rulesObject ]\n\ndescribe('brute force', () => {\n  compareCombinations({\n    firstInput : possibleRules,\n    callback   : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n        {\n          \"ERRORS_MESSAGE_MISMATCH\": 0,\n          \"ERRORS_TYPE_MISMATCH\": 4,\n          \"RESULTS_MISMATCH\": 0,\n          \"SHOULD_NOT_THROW\": 51,\n          \"SHOULD_THROW\": 0,\n          \"TOTAL_TESTS\": 63,\n        }\n      `)\n    },\n    secondInput : possibleIterables,\n    fn          : evolve,\n    fnRamda     : evolveRamda,\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {evolve, add} from 'rambda'\n\ndescribe('R.evolve', () => {\n  it('happy', () => {\n    const input = {\n      foo: 2,\n      nested: {\n        a: 1,\n        bar: 3,\n      },\n    }\n    const rules = {\n      foo: add(1),\n      nested: {\n        a: add(-1),\n        bar: add(1),\n      },\n    }\n    const result = evolve(rules, input)\n    const curriedResult = evolve(rules)(input)\n\n    result.nested.a // $ExpectType number\n    curriedResult.nested.a // $ExpectType number\n    result.nested.bar // $ExpectType number\n    result.foo // $ExpectType number\n  })\n  it('with array', () => {\n    const rules = [String, String]\n    const input = [100, 1400]\n    const result = evolve(rules, input)\n    const curriedResult = evolve(rules)(input)\n    result // $ExpectType string[]\n    curriedResult // $ExpectType string[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#evolve)\n\n### F\n\n```typescript\n\nF(): boolean\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20F()%20%2F%2F%20%3D%3E%20false\">Try this <strong>R.F</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nF(): boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.F</strong> source</summary>\n\n```javascript\nexport function F(){\n  return false\n}\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#F)\n\n### filter\n\n```typescript\n\nfilter<T>(predicate: Predicate<T>): (input: T[]) => T[]\n```\n\nIt filters list or object `input` using a `predicate` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B3%2C%204%2C%203%2C%202%5D%0Aconst%20listPredicate%20%3D%20x%20%3D%3E%20x%20%3E%202%0A%0Aconst%20object%20%3D%20%7Babc%3A%20'fo'%2C%20xyz%3A%20'bar'%2C%20baz%3A%20'foo'%7D%0Aconst%20objectPredicate%20%3D%20(x%2C%20prop)%20%3D%3E%20x.length%20%2B%20prop.length%20%3E%205%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.filter(listPredicate%2C%20list)%2C%0A%20%20R.filter(objectPredicate%2C%20object)%0A%5D%0A%2F%2F%20%3D%3E%20%5B%20%5B3%2C%204%5D%2C%20%7B%20xyz%3A%20'bar'%2C%20baz%3A%20'foo'%7D%20%5D\">Try this <strong>R.filter</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nfilter<T>(predicate: Predicate<T>): (input: T[]) => T[];\nfilter<T>(predicate: Predicate<T>, input: T[]): T[];\nfilter<T, U>(predicate: ObjectPredicate<T>): (x: Dictionary<T>) => Dictionary<T>;\nfilter<T>(predicate: ObjectPredicate<T>, x: Dictionary<T>): Dictionary<T>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.filter</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function filterObject(predicate, obj){\n  const willReturn = {}\n\n  for (const prop in obj){\n    if (predicate(\n      obj[ prop ], prop, obj\n    )){\n      willReturn[ prop ] = obj[ prop ]\n    }\n  }\n\n  return willReturn\n}\n\nexport function filterArray(\n  predicate, list, indexed = false\n){\n  let index = 0\n  const len = list.length\n  const willReturn = []\n\n  while (index < len){\n    const predicateResult = indexed ?\n      predicate(list[ index ], index) :\n      predicate(list[ index ])\n    if (predicateResult){\n      willReturn.push(list[ index ])\n    }\n\n    index++\n  }\n\n  return willReturn\n}\n\nexport function filter(predicate, iterable){\n  if (arguments.length === 1)\n    return _iterable => filter(predicate, _iterable)\n  if (!iterable){\n    throw new Error('Incorrect iterable input')\n  }\n\n  if (isArray(iterable)) return filterArray(\n    predicate, iterable, false\n  )\n\n  return filterObject(predicate, iterable)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { filter as filterRamda } from 'ramda'\n\nimport { filter } from './filter.js'\nimport { T } from './T.js'\n\nconst sampleObject = {\n  a : 1,\n  b : 2,\n  c : 3,\n  d : 4,\n}\n\ntest('happy', () => {\n  const isEven = n => n % 2 === 0\n\n  expect(filter(isEven, [ 1, 2, 3, 4 ])).toEqual([ 2, 4 ])\n  expect(filter(isEven, {\n    a : 1,\n    b : 2,\n    d : 3,\n  })).toEqual({ b : 2 })\n})\n\ntest('predicate when input is object', () => {\n  const obj = {\n    a : 1,\n    b : 2,\n  }\n  const predicate = (\n    val, prop, inputObject\n  ) => {\n    expect(inputObject).toEqual(obj)\n    expect(typeof prop).toBe('string')\n\n    return val < 2\n  }\n  expect(filter(predicate, obj)).toEqual({ a : 1 })\n})\n\ntest('with object', () => {\n  const isEven = n => n % 2 === 0\n  const result = filter(isEven, sampleObject)\n  const expectedResult = {\n    b : 2,\n    d : 4,\n  }\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('bad inputs difference between Ramda and Rambda', () => {\n  expect(() => filter(T, null)).toThrowWithMessage(Error,\n    'Incorrect iterable input')\n  expect(() => filter(T)(undefined)).toThrowWithMessage(Error,\n    'Incorrect iterable input')\n  expect(() => filterRamda(T, null)).toThrowWithMessage(TypeError,\n    'Cannot read properties of null (reading \\'fantasy-land/filter\\')')\n  expect(() => filterRamda(T, undefined)).toThrowWithMessage(TypeError,\n    'Cannot read properties of undefined (reading \\'fantasy-land/filter\\')')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {filter} from 'rambda'\n\nconst list = [1, 2, 3]\nconst obj = {a: 1, b: 2}\n\ndescribe('R.filter with array', () => {\n  it('happy', () => {\n    const result = filter<number>(x => {\n      x // $ExpectType number\n      return x > 1\n    }, list)\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = filter<number>(x => {\n      x // $ExpectType number\n      return x > 1\n    })(list)\n    result // $ExpectType number[]\n  })\n})\n\ndescribe('R.filter with objects', () => {\n  it('happy', () => {\n    const result = filter<number>((val, prop, origin) => {\n      val // $ExpectType number\n      prop // $ExpectType string\n      origin // $ExpectType Dictionary<number>\n\n      return val > 1\n    }, obj)\n    result // $ExpectType Dictionary<number>\n  })\n  it('curried version requires second dummy type', () => {\n    const result = filter<number, any>((val, prop, origin) => {\n      val // $ExpectType number\n      prop // $ExpectType string\n      origin // $ExpectType Dictionary<number>\n\n      return val > 1\n    })(obj)\n    result // $ExpectType Dictionary<number>\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#filter)\n\n### find\n\n```typescript\n\nfind<T>(predicate: (x: T) => boolean, list: T[]): T | undefined\n```\n\nIt returns the first element of `list` that satisfy the `predicate`.\n\nIf there is no such element, it returns `undefined`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20predicate%20%3D%20x%20%3D%3E%20R.type(x.foo)%20%3D%3D%3D%20'Number'%0Aconst%20list%20%3D%20%5B%7Bfoo%3A%20'bar'%7D%2C%20%7Bfoo%3A%201%7D%5D%0A%0Aconst%20result%20%3D%20R.find(predicate%2C%20list)%0A%2F%2F%20%3D%3E%20%7Bfoo%3A%201%7D\">Try this <strong>R.find</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nfind<T>(predicate: (x: T) => boolean, list: T[]): T | undefined;\nfind<T>(predicate: (x: T) => boolean): (list: T[]) => T | undefined;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.find</strong> source</summary>\n\n```javascript\nexport function find(predicate, list){\n  if (arguments.length === 1) return _list => find(predicate, _list)\n\n  let index = 0\n  const len = list.length\n\n  while (index < len){\n    const x = list[ index ]\n    if (predicate(x)){\n      return x\n    }\n\n    index++\n  }\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { find } from './find.js'\nimport { propEq } from './propEq.js'\n\nconst list = [ { a : 1 }, { a : 2 }, { a : 3 } ]\n\ntest('happy', () => {\n  const fn = propEq(2, 'a')\n  expect(find(fn, list)).toEqual({ a : 2 })\n})\n\ntest('with curry', () => {\n  const fn = propEq(4, 'a')\n  expect(find(fn)(list)).toBeUndefined()\n})\n\ntest('with empty list', () => {\n  expect(find(() => true, [])).toBeUndefined()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {find} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.find', () => {\n  it('happy', () => {\n    const predicate = (x: number) => x > 2\n    const result = find(predicate, list)\n    result // $ExpectType number | undefined\n  })\n  it('curried', () => {\n    const predicate = (x: number) => x > 2\n    const result = find(predicate)(list)\n    result // $ExpectType number | undefined\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#find)\n\n### findIndex\n\n```typescript\n\nfindIndex<T>(predicate: (x: T) => boolean, list: T[]): number\n```\n\nIt returns the index of the first element of `list` satisfying the `predicate` function.\n\nIf there is no such element, then `-1` is returned.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20predicate%20%3D%20x%20%3D%3E%20R.type(x.foo)%20%3D%3D%3D%20'Number'%0Aconst%20list%20%3D%20%5B%7Bfoo%3A%20'bar'%7D%2C%20%7Bfoo%3A%201%7D%5D%0A%0Aconst%20result%20%3D%20R.findIndex(predicate%2C%20list)%0A%2F%2F%20%3D%3E%201\">Try this <strong>R.findIndex</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nfindIndex<T>(predicate: (x: T) => boolean, list: T[]): number;\nfindIndex<T>(predicate: (x: T) => boolean): (list: T[]) => number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.findIndex</strong> source</summary>\n\n```javascript\nexport function findIndex(predicate, list){\n  if (arguments.length === 1) return _list => findIndex(predicate, _list)\n\n  const len = list.length\n  let index = -1\n\n  while (++index < len){\n    if (predicate(list[ index ])){\n      return index\n    }\n  }\n\n  return -1\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { findIndex } from './findIndex.js'\nimport { propEq } from './propEq.js'\n\nconst list = [ { a : 1 }, { a : 2 }, { a : 3 } ]\n\ntest('happy', () => {\n  expect(findIndex(propEq(2, 'a'), list)).toBe(1)\n  expect(findIndex(propEq(1, 'a'))(list)).toBe(0)\n  expect(findIndex(propEq(4, 'a'))(list)).toBe(-1)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {findIndex} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.findIndex', () => {\n  it('happy', () => {\n    const predicate = (x: number) => x > 2\n    const result = findIndex(predicate, list)\n    result // $ExpectType number\n  })\n  it('curried', () => {\n    const predicate = (x: number) => x > 2\n    const result = findIndex(predicate)(list)\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#findIndex)\n\n### findLast\n\n```typescript\n\nfindLast<T>(fn: (x: T) => boolean, list: T[]): T | undefined\n```\n\nIt returns the last element of `list` satisfying the `predicate` function.\n\nIf there is no such element, then `undefined` is returned.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20predicate%20%3D%20x%20%3D%3E%20R.type(x.foo)%20%3D%3D%3D%20'Number'%0Aconst%20list%20%3D%20%5B%7Bfoo%3A%200%7D%2C%20%7Bfoo%3A%201%7D%5D%0A%0Aconst%20result%20%3D%20R.findLast(predicate%2C%20list)%0A%2F%2F%20%3D%3E%20%7Bfoo%3A%201%7D\">Try this <strong>R.findLast</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nfindLast<T>(fn: (x: T) => boolean, list: T[]): T | undefined;\nfindLast<T>(fn: (x: T) => boolean): (list: T[]) => T | undefined;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.findLast</strong> source</summary>\n\n```javascript\nexport function findLast(predicate, list){\n  if (arguments.length === 1) return _list => findLast(predicate, _list)\n\n  let index = list.length\n\n  while (--index >= 0){\n    if (predicate(list[ index ])){\n      return list[ index ]\n    }\n  }\n\n  return undefined\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { findLast } from './findLast.js'\n\ntest('happy', () => {\n  const result = findLast(x => x > 1, [ 1, 1, 1, 2, 3, 4, 1 ])\n  expect(result).toBe(4)\n\n  expect(findLast(x => x === 0, [ 0, 1, 1, 2, 3, 4, 1 ])).toBe(0)\n})\n\ntest('with curry', () => {\n  expect(findLast(x => x > 1)([ 1, 1, 1, 2, 3, 4, 1 ])).toBe(4)\n})\n\nconst obj1 = { x : 100 }\nconst obj2 = { x : 200 }\nconst a = [ 11, 10, 9, 'cow', obj1, 8, 7, 100, 200, 300, obj2, 4, 3, 2, 1, 0 ]\nconst even = function (x){\n  return x % 2 === 0\n}\nconst gt100 = function (x){\n  return x > 100\n}\nconst isStr = function (x){\n  return typeof x === 'string'\n}\nconst xGt100 = function (o){\n  return o && o.x > 100\n}\n\ntest('ramda 1', () => {\n  expect(findLast(even, a)).toBe(0)\n  expect(findLast(gt100, a)).toBe(300)\n  expect(findLast(isStr, a)).toBe('cow')\n  expect(findLast(xGt100, a)).toEqual(obj2)\n})\n\ntest('ramda 2', () => {\n  expect(findLast(even, [ 'zing' ])).toBeUndefined()\n})\n\ntest('ramda 3', () => {\n  expect(findLast(even, [ 2, 3, 5 ])).toBe(2)\n})\n\ntest('ramda 4', () => {\n  expect(findLast(even, [])).toBeUndefined()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {findLast} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.findLast', () => {\n  it('happy', () => {\n    const predicate = (x: number) => x > 2\n    const result = findLast(predicate, list)\n    result // $ExpectType number | undefined\n  })\n  it('curried', () => {\n    const predicate = (x: number) => x > 2\n    const result = findLast(predicate)(list)\n    result // $ExpectType number | undefined\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#findLast)\n\n### findLastIndex\n\n```typescript\n\nfindLastIndex<T>(predicate: (x: T) => boolean, list: T[]): number\n```\n\nIt returns the index of the last element of `list` satisfying the `predicate` function.\n\nIf there is no such element, then `-1` is returned.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20predicate%20%3D%20x%20%3D%3E%20R.type(x.foo)%20%3D%3D%3D%20'Number'%0Aconst%20list%20%3D%20%5B%7Bfoo%3A%200%7D%2C%20%7Bfoo%3A%201%7D%5D%0A%0Aconst%20result%20%3D%20R.findLastIndex(predicate%2C%20list)%0A%2F%2F%20%3D%3E%201\">Try this <strong>R.findLastIndex</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nfindLastIndex<T>(predicate: (x: T) => boolean, list: T[]): number;\nfindLastIndex<T>(predicate: (x: T) => boolean): (list: T[]) => number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.findLastIndex</strong> source</summary>\n\n```javascript\nexport function findLastIndex(fn, list){\n  if (arguments.length === 1) return _list => findLastIndex(fn, _list)\n\n  let index = list.length\n\n  while (--index >= 0){\n    if (fn(list[ index ])){\n      return index\n    }\n  }\n\n  return -1\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { findLastIndex } from './findLastIndex.js'\n\ntest('happy', () => {\n  const result = findLastIndex(x => x > 1, [ 1, 1, 1, 2, 3, 4, 1 ])\n\n  expect(result).toBe(5)\n\n  expect(findLastIndex(x => x === 0, [ 0, 1, 1, 2, 3, 4, 1 ])).toBe(0)\n})\n\ntest('with curry', () => {\n  expect(findLastIndex(x => x > 1)([ 1, 1, 1, 2, 3, 4, 1 ])).toBe(5)\n})\n\nconst obj1 = { x : 100 }\nconst obj2 = { x : 200 }\nconst a = [ 11, 10, 9, 'cow', obj1, 8, 7, 100, 200, 300, obj2, 4, 3, 2, 1, 0 ]\nconst even = function (x){\n  return x % 2 === 0\n}\nconst gt100 = function (x){\n  return x > 100\n}\nconst isStr = function (x){\n  return typeof x === 'string'\n}\nconst xGt100 = function (o){\n  return o && o.x > 100\n}\n\ntest('ramda 1', () => {\n  expect(findLastIndex(even, a)).toBe(15)\n  expect(findLastIndex(gt100, a)).toBe(9)\n  expect(findLastIndex(isStr, a)).toBe(3)\n  expect(findLastIndex(xGt100, a)).toBe(10)\n})\n\ntest('ramda 2', () => {\n  expect(findLastIndex(even, [ 'zing' ])).toBe(-1)\n})\n\ntest('ramda 3', () => {\n  expect(findLastIndex(even, [ 2, 3, 5 ])).toBe(0)\n})\n\ntest('ramda 4', () => {\n  expect(findLastIndex(even, [])).toBe(-1)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {findLastIndex} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.findLastIndex', () => {\n  it('happy', () => {\n    const predicate = (x: number) => x > 2\n    const result = findLastIndex(predicate, list)\n    result // $ExpectType number\n  })\n  it('curried', () => {\n    const predicate = (x: number) => x > 2\n    const result = findLastIndex(predicate)(list)\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#findLastIndex)\n\n### flatten\n\n```typescript\n\nflatten<T>(list: any[]): T[]\n```\n\nIt deeply flattens an array.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.flatten(%5B%0A%20%201%2C%20%0A%20%202%2C%20%0A%20%20%5B3%2C%2030%2C%20%5B300%5D%5D%2C%20%0A%20%20%5B4%5D%0A%5D)%0A%2F%2F%20%3D%3E%20%5B%201%2C%202%2C%203%2C%2030%2C%20300%2C%204%20%5D\">Try this <strong>R.flatten</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nflatten<T>(list: any[]): T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.flatten</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function flatten(list, input){\n  const willReturn = input === undefined ? [] : input\n\n  for (let i = 0; i < list.length; i++){\n    if (isArray(list[ i ])){\n      flatten(list[ i ], willReturn)\n    } else {\n      willReturn.push(list[ i ])\n    }\n  }\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { flatten } from './flatten.js'\n\ntest('happy', () => {\n  expect(flatten([ 1, 2, 3, [ [ [ [ [ 4 ] ] ] ] ] ])).toEqual([ 1, 2, 3, 4 ])\n\n  expect(flatten([ 1, [ 2, [ [ 3 ] ] ], [ 4 ] ])).toEqual([ 1, 2, 3, 4 ])\n\n  expect(flatten([ 1, [ 2, [ [ [ 3 ] ] ] ], [ 4 ] ])).toEqual([ 1, 2, 3, 4 ])\n\n  expect(flatten([ 1, 2, [ 3, 4 ], 5, [ 6, [ 7, 8, [ 9, [ 10, 11 ], 12 ] ] ] ])).toEqual([ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 ])\n})\n\ntest('readme example', () => {\n  const result = flatten([ 1, 2, [ 3, 30, [ 300 ] ], [ 4 ] ])\n  expect(result).toEqual([ 1, 2, 3, 30, 300, 4 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {flatten} from 'rambda'\n\ndescribe('flatten', () => {\n  it('happy', () => {\n    const result = flatten<number>([1, 2, [3, [4]]])\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#flatten)\n\n### flip\n\nIt returns function which calls `fn` with exchanged first and second argument.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20subtractFlip%20%3D%20R.flip(R.subtract)%0A%0Aconst%20result%20%3D%20%5B%0A%20%20subtractFlip(1%2C7)%2C%0A%20%20R.subtract(1%2C%206)%0A%5D%20%20%0A%2F%2F%20%3D%3E%20%5B6%2C%20-6%5D\">Try this <strong>R.flip</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#flip)\n\n### forEach\n\n```typescript\n\nforEach<T>(fn: Iterator<T, void>, list: T[]): T[]\n```\n\nIt applies `iterable` function over all members of `list` and returns `list`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20sideEffect%20%3D%20%7B%7D%0Aconst%20result%20%3D%20R.forEach(%0A%20%20x%20%3D%3E%20sideEffect%5B%60foo%24%7Bx%7D%60%5D%20%3D%20x%0A)(%5B1%2C%202%5D)%0A%0AsideEffect%20%2F%2F%20%3D%3E%20%7Bfoo1%3A%201%2C%20foo2%3A%202%7D%0Aresult%20%2F%2F%20%3D%3E%20%5B1%2C%202%5D\">Try this <strong>R.forEach</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nforEach<T>(fn: Iterator<T, void>, list: T[]): T[];\nforEach<T>(fn: Iterator<T, void>): (list: T[]) => T[];\nforEach<T>(fn: ObjectIterator<T, void>, list: Dictionary<T>): Dictionary<T>;\nforEach<T, U>(fn: ObjectIterator<T, void>): (list: Dictionary<T>) => Dictionary<T>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.forEach</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { forEachObjIndexedFn } from './forEachObjIndexed.js'\n\nexport function forEach(fn, iterable){\n  if (arguments.length === 1) return _list => forEach(fn, _list)\n  if (iterable === undefined) return\n\n  if (isArray(iterable)){\n    let index = 0\n    const len = iterable.length\n\n    while (index < len){\n      fn(iterable[ index ])\n      index++\n    }\n  } else return forEachObjIndexedFn(fn, iterable)\n\n  return iterable\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { forEach } from './forEach.js'\nimport { type } from './type.js'\n\ntest('happy', () => {\n  const sideEffect = {}\n  forEach(x => sideEffect[ `foo${ x }` ] = x + 10)([ 1, 2 ])\n\n  expect(sideEffect).toEqual({\n    foo1 : 11,\n    foo2 : 12,\n  })\n})\n\ntest('iterate over object', () => {\n  const obj = {\n    a : 1,\n    b : [ 1, 2 ],\n    c : { d : 7 },\n    f : 'foo',\n  }\n  const result = {}\n  const returned = forEach((\n    val, prop, inputObj\n  ) => {\n    expect(type(inputObj)).toBe('Object')\n    result[ prop ] = `${ prop }-${ type(val) }`\n  })(obj)\n\n  const expected = {\n    a : 'a-Number',\n    b : 'b-Array',\n    c : 'c-Object',\n    f : 'f-String',\n  }\n\n  expect(result).toEqual(expected)\n  expect(returned).toEqual(obj)\n})\n\ntest('with empty list', () => {\n  const list = []\n  const result = forEach(x => x * x)(list)\n\n  expect(result).toEqual(list)\n})\n\ntest('with wrong input', () => {\n  const list = undefined\n  const result = forEach(x => x * x)(list)\n\n  expect(result).toBeUndefined()\n})\n\ntest('returns the input', () => {\n  const list = [ 1, 2, 3 ]\n  const result = forEach(x => x * x)(list)\n\n  expect(result).toEqual(list)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {forEach} from 'rambda'\n\nconst list = [1, 2, 3]\nconst obj = {a: 1, b: 2}\n\ndescribe('R.forEach with arrays', () => {\n  it('happy', () => {\n    const result = forEach(a => {\n      a // $ExpectType number\n    }, list)\n    result // $ExpectType number[]\n  })\n  it('curried require an explicit typing', () => {\n    const result = forEach<number>(a => {\n      a // $ExpectType number\n    })(list)\n    result // $ExpectType number[]\n  })\n})\n\ndescribe('R.forEach with objects', () => {\n  it('happy', () => {\n    const result = forEach((a, b, c) => {\n      a // $ExpectType number\n      b // $ExpectType string\n      c // $ExpectType Dictionary<number>\n      return `${a}`\n    }, obj)\n    result // $ExpectType Dictionary<number>\n  })\n  it('curried require an input typing and a dummy third typing', () => {\n    // Required in order all typings to work\n    const result = forEach<number, any>((a, b, c) => {\n      a // $ExpectType number\n      b // $ExpectType string\n      c // $ExpectType Dictionary<number>\n    })(obj)\n    result // $ExpectType Dictionary<number>\n  })\n  it('iterator without property', () => {\n    const result = forEach(a => {\n      a // $ExpectType number\n    }, obj)\n    result // $ExpectType Dictionary<number>\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#forEach)\n\n### forEachObjIndexed\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#forEachObjIndexed)\n\n### fromPairs\n\nIt transforms a `listOfPairs` to an object.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20listOfPairs%20%3D%20%5B%20%5B%20'a'%2C%201%20%5D%2C%20%5B%20'b'%2C%202%20%5D%2C%20%5B%20'c'%2C%20%5B%203%2C%204%20%5D%20%5D%20%5D%0Aconst%20expected%20%3D%20%7B%0A%20%20a%20%3A%201%2C%0A%20%20b%20%3A%202%2C%0A%20%20c%20%3A%20%5B%203%2C%204%20%5D%2C%0A%7D%0A%0Aconst%20result%20%3D%20R.fromPairs(listOfPairs)%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.fromPairs</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#fromPairs)\n\n### groupBy\n\nIt splits `list` according to a provided `groupFn` function and returns an object.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%20'a'%2C%20'b'%2C%20'aa'%2C%20'bb'%20%5D%0Aconst%20groupFn%20%3D%20x%20%3D%3E%20x.length%0A%0Aconst%20result%20%3D%20R.groupBy(groupFn%2C%20list)%0A%2F%2F%20%3D%3E%20%7B%20'1'%3A%20%5B'a'%2C%20'b'%5D%2C%20'2'%3A%20%5B'aa'%2C%20'bb'%5D%20%7D\">Try this <strong>R.groupBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#groupBy)\n\n### groupWith\n\nIt returns separated version of list or string `input`, where separation is done with equality `compareFn` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20isConsecutive%20%3D%20(x%2C%20y)%20%3D%3E%20x%20%3D%3D%3D%20y%0Aconst%20list%20%3D%20%5B1%2C%202%2C%202%2C%201%2C%201%2C%202%5D%0A%0Aconst%20result%20%3D%20R.groupWith(isConsecutive%2C%20list)%0A%2F%2F%20%3D%3E%20%5B%5B1%5D%2C%20%5B2%2C2%5D%2C%20%5B1%2C1%5D%2C%20%5B2%5D%5D\">Try this <strong>R.groupWith</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#groupWith)\n\n### gt\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5BR.gt(2%2C%201)%2C%20R.gt(2%2C%203)%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.gt</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#gt)\n\n### gte\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5BR.gte(2%2C%201)%2C%20R.gte(2%2C%202)%2C%20R.gte(2%2C%203)%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%2C%20false%5D\">Try this <strong>R.gte</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#gte)\n\n### has\n\n```typescript\n\nhas<T>(prop: string, obj: T): boolean\n```\n\nIt returns `true` if `obj` has property `prop`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A%201%7D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.has('a'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.has('b'%2C%20Record%3Cstring%2C%20unknown%3E)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.has</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nhas<T>(prop: string, obj: T): boolean;\nhas(prop: string): <T>(obj: T) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.has</strong> source</summary>\n\n```javascript\nexport function has(prop, obj){\n  if (arguments.length === 1) return _obj => has(prop, _obj)\n\n  if (!obj) return false\n\n  return obj.hasOwnProperty(prop)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { has } from './has.js'\n\ntest('happy', () => {\n  expect(has('a')({ a : 1 })).toBeTrue()\n  expect(has('b', { a : 1 })).toBeFalse()\n})\n\ntest('with non-object', () => {\n  expect(has('a', undefined)).toBeFalse()\n  expect(has('a', null)).toBeFalse()\n  expect(has('a', true)).toBeFalse()\n  expect(has('a', '')).toBeFalse()\n  expect(has('a', /a/)).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {has} from 'rambda'\n\ndescribe('R.has', () => {\n  it('happy', () => {\n    const result = has('foo', {a: 1})\n    const curriedResult = has('bar')({a: 1})\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#has)\n\n### hasIn\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.hasIn('a'%2C%20%7Ba%3A%201%7D)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.hasIn</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#hasIn)\n\n### hasPath\n\n```typescript\n\nhasPath<T>(\n  path: string | string[],\n  input: object\n): boolean\n```\n\nIt will return true, if `input` object has truthy `path`(calculated with `R.path`).\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20path%20%3D%20'a.b'%0Aconst%20pathAsArray%20%3D%20%5B'a'%2C%20'b'%5D%0Aconst%20obj%20%3D%20%7Ba%3A%20%7Bb%3A%20%5B%5D%7D%7D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.hasPath(path%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.hasPath(pathAsArray%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.hasPath('a.c'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%2C%20false%5D\">Try this <strong>R.hasPath</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nhasPath<T>(\n  path: string | string[],\n  input: object\n): boolean;\nhasPath<T>(\n  path: string | string[]\n): (input: object) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.hasPath</strong> source</summary>\n\n```javascript\nimport { path } from './path.js'\n\nexport function hasPath(pathInput, obj){\n  if (arguments.length === 1){\n    return objHolder => hasPath(pathInput, objHolder)\n  }\n\n  return path(pathInput, obj) !== undefined\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { hasPath } from './hasPath.js'\n\ntest('when true', () => {\n  const path = 'a.b'\n  const obj = { a : { b : [] } }\n\n  const result = hasPath(path)(obj)\n  const expectedResult = true\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('when false', () => {\n  const path = 'a.b'\n  const obj = {}\n\n  const result = hasPath(path, obj)\n  const expectedResult = false\n\n  expect(result).toEqual(expectedResult)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {hasPath} from 'rambda'\n\ndescribe('R.hasPath', () => {\n  it('string path', () => {\n    const obj = {a: {b: 1}}\n    const result = hasPath('a.b', obj)\n    const curriedResult = hasPath('a.c')(obj)\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n  it('array path', () => {\n    const obj = {a: {b: 1}}\n    const result = hasPath(['a', 'b'], obj)\n    const curriedResult = hasPath(['a', 'c'])(obj)\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#hasPath)\n\n### head\n\n```typescript\n\nhead(str: string): string\n```\n\nIt returns the first element of list or string `input`. It returns `undefined` if array has length of 0.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.head(%5B1%2C%202%2C%203%5D)%2C%0A%20%20R.head('foo')%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B1%2C%20'f'%5D\">Try this <strong>R.head</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nhead(str: string): string;\nhead(str: ''): undefined;\nhead(list: readonly[]): undefined;\nhead<T>(list: never[]): undefined;\nhead<T extends unknown[]>(array: T): FirstArrayElement<T>\nhead<T extends readonly unknown[]>(array: T): FirstArrayElement<T>\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.head</strong> source</summary>\n\n```javascript\nexport function head(listOrString){\n  if (typeof listOrString === 'string') return listOrString[ 0 ] || ''\n\n  return listOrString[ 0 ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { head } from './head.js'\n\ntest('head', () => {\n  expect(head([ 'fi', 'fo', 'fum' ])).toBe('fi')\n  expect(head([])).toBeUndefined()\n  expect(head('foo')).toBe('f')\n  expect(head('')).toBe('')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {\n  emptyList,\n  emptyString,\n  mixedList,\n  mixedListConst,\n  numberList,\n  numberListConst,\n  string,\n} from '_internals/typescriptTestUtils'\nimport {head, last} from 'rambda'\n\ndescribe('R.head', () => {\n  it('string', () => {\n    head(string) // $ExpectType string\n    last(string) // $ExpectType string\n  })\n  it('empty string', () => {\n    head(emptyString) // $ExpectType undefined\n    last(emptyString) // $ExpectType undefined\n  })\n  it('array', () => {\n    head(numberList) // $ExpectType number\n    head(numberListConst) // $ExpectType 1\n\n    last(numberList) // $ExpectType number\n    last(numberListConst) // $ExpectType 3\n  })\n  it('empty array', () => {\n    const list = [] as const\n    head(emptyList) // $ExpectType undefined\n    head(list) // $ExpectType undefined\n    last(emptyList) // $ExpectType undefined\n    last(list) // $ExpectType undefined\n  })\n\n  it('mixed', () => {\n    head(mixedList) // $ExpectType string | number\n    head(mixedListConst) // $ExpectType 1\n    last(mixedList) // $ExpectType string | number\n    last(mixedListConst) // $ExpectType \"bar\"\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#head)\n\n### identical\n\nIt returns `true` if its arguments `a` and `b` are identical.\n\nOtherwise, it returns `false`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20objA%20%3D%20%7Ba%3A%201%7D%3B%0Aconst%20objB%20%3D%20%7Ba%3A%201%7D%3B%0AR.identical(objA%2C%20objA)%3B%20%2F%2F%20%3D%3E%20true%0AR.identical(objA%2C%20objB)%3B%20%2F%2F%20%3D%3E%20false%0AR.identical(1%2C%201)%3B%20%2F%2F%20%3D%3E%20true%0AR.identical(1%2C%20'1')%3B%20%2F%2F%20%3D%3E%20false%0AR.identical(%5B%5D%2C%20%5B%5D)%3B%20%2F%2F%20%3D%3E%20false%0AR.identical(0%2C%20-0)%3B%20%2F%2F%20%3D%3E%20false%0Aconst%20result%20%3D%20R.identical(NaN%2C%20NaN)%3B%20%2F%2F%20%3D%3E%20true\">Try this <strong>R.identical</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#identical)\n\n### identity\n\n```typescript\n\nidentity<T>(input: T): T\n```\n\nIt just passes back the supplied `input` argument.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.identity(7)%20%2F%2F%20%3D%3E%207\">Try this <strong>R.identity</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nidentity<T>(input: T): T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.identity</strong> source</summary>\n\n```javascript\nexport function identity(x){\n  return x\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { identity } from './identity.js'\n\ntest('happy', () => {\n  expect(identity(7)).toBe(7)\n  expect(identity(true)).toBeTrue()\n  expect(identity({ a : 1 })).toEqual({ a : 1 })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {identity} from 'rambda'\n\ndescribe('R.identity', () => {\n  it('happy', () => {\n    const result = identity(4)\n    result // $ExpectType 4\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#identity)\n\n### ifElse\n\n```typescript\n\nifElse<T, TFiltered extends T, TOnTrueResult, TOnFalseResult>(\n  pred: (a: T) => a is TFiltered,\n  onTrue: (a: TFiltered) => TOnTrueResult,\n  onFalse: (a: Exclude<T, TFiltered>) => TOnFalseResult,\n): (a: T) => TOnTrueResult | TOnFalseResult\n```\n\nIt expects `condition`, `onTrue` and `onFalse` functions as inputs and it returns a new function with example name of `fn`. \n\nWhen `fn`` is called with `input` argument, it will return either `onTrue(input)` or `onFalse(input)` depending on `condition(input)` evaluation.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20R.ifElse(%0A%20x%20%3D%3E%20x%3E10%2C%0A%20x%20%3D%3E%20x*2%2C%0A%20x%20%3D%3E%20x*10%0A)%0A%0Aconst%20result%20%3D%20%5B%20fn(8)%2C%20fn(18)%20%5D%0A%2F%2F%20%3D%3E%20%5B80%2C%2036%5D\">Try this <strong>R.ifElse</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nifElse<T, TFiltered extends T, TOnTrueResult, TOnFalseResult>(\n  pred: (a: T) => a is TFiltered,\n  onTrue: (a: TFiltered) => TOnTrueResult,\n  onFalse: (a: Exclude<T, TFiltered>) => TOnFalseResult,\n): (a: T) => TOnTrueResult | TOnFalseResult;\nifElse<TArgs extends any[], TOnTrueResult, TOnFalseResult>(fn: (...args: TArgs) => boolean, onTrue: (...args: TArgs) => TOnTrueResult, onFalse: (...args: TArgs) => TOnFalseResult): (...args: TArgs) => TOnTrueResult | TOnFalseResult;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.ifElse</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nfunction ifElseFn(\n  condition, onTrue, onFalse\n){\n  return (...input) => {\n\t\tconst conditionResult =\n      typeof condition === 'boolean' ? condition : condition(...input)\n    if (Boolean(conditionResult) ){\n      return onTrue(...input)\n    }\n\n    return onFalse(...input)\n  }\n}\n\nexport const ifElse = curry(ifElseFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { always } from './always.js'\nimport { has } from './has.js'\nimport { identity } from './identity.js'\nimport { ifElse } from './ifElse.js'\nimport { prop } from './prop.js'\nimport * as R from 'ramda'\n\nconst condition = has('foo')\nconst v = function (a){\n  return typeof a === 'number'\n}\nconst t = function (a){\n  return a + 1\n}\nconst ifFn = x => prop('foo', x).length\nconst elseFn = () => false\n\ntest('happy', () => {\n  const fn = ifElse(condition, ifFn)(elseFn)\n\n  expect(fn({ foo : 'bar' })).toBe(3)\n  expect(fn({ fo : 'bar' })).toBeFalse()\n})\n\ntest('ramda spec', () => {\n  const ifIsNumber = ifElse(v)\n  expect(ifIsNumber(t, identity)(15)).toBe(16)\n  expect(ifIsNumber(t, identity)('hello')).toBe('hello')\n})\n\ntest('pass all arguments', () => {\n  const identity = function (a){\n    return a\n  }\n  const v = function (){\n    return true\n  }\n  const onTrue = function (a, b){\n    expect(a).toBe(123)\n    expect(b).toBe('abc')\n  }\n  ifElse(\n    v, onTrue, identity\n  )(123, 'abc')\n})\n\ntest('accept constant as condition', () => {\n  const fn = ifElse(true)(always(true))(always(false))\n\n  expect(fn()).toBeTrue()\n})\n\ntest('accept constant as condition - case 2', () => {\n  const fn = ifElse(\n    false, always(true), always(false)\n  )\n\n  expect(fn()).toBeFalse()\n})\n\ntest('curry 1', () => {\n  const fn = ifElse(condition, ifFn)(elseFn)\n\n  expect(fn({ foo : 'bar' })).toBe(3)\n  expect(fn({ fo : 'bar' })).toBeFalse()\n})\n\ntest('curry 2', () => {\n  const fn = ifElse(condition)(ifFn)(elseFn)\n\n  expect(fn({ foo : 'bar' })).toBe(3)\n  expect(fn({ fo : 'bar' })).toBeFalse()\n})\n\ntest('simple arity of 1', () => {\n  const condition = x => x > 5\n  const onTrue = x => x + 1\n  const onFalse = x => x + 10\n  const result = ifElse(\n    condition, onTrue, onFalse\n  )(1)\n  expect(result).toBe(11)\n})\n\ntest('simple arity of 2', () => {\n  const condition = (x, y) => x + y > 5\n  const onTrue = (x, y) => x + y + 1\n  const onFalse = (x, y) => x + y + 10\n  const result = ifElse(\n    condition, onTrue, onFalse\n  )(1, 10)\n  expect(result).toBe(12)\n})\n\ntest('bug 750', () => {\n\tconst value = 34;\n\n\tlet result = ifElse(\n\tR.identity,\n\tR.always('true'),\n\tR.always('false')\n\t)(value)\n\texpect(result).toBe('true')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {ifElse} from 'rambda'\n\ndescribe('R.ifElse', () => {\n  it('happy', () => {\n    const condition = (x: number) => x > 5\n    const onTrue = (x: number) => `foo${x}`\n    const onFalse = (x: number) => `bar${x}`\n    const fn = ifElse(condition, onTrue, onFalse)\n    fn // $ExpectType (x: number) => string\n    const result = fn(3)\n    result // $ExpectType string\n  })\n  it('arity of 2', () => {\n    const condition = (x: number, y: string) => x + y.length > 5\n    const onTrue = (x: number, y: string) => `foo${x}-${y}`\n    const onFalse = (x: number, y: string) => `bar${x}-${y}`\n    const fn = ifElse(condition, onTrue, onFalse)\n    fn // $ExpectType (x: number, y: string) => string\n    const result = fn(3, 'hello')\n    result // $ExpectType string\n  })\n  test('DefinitelyTyped#59291', () => {\n    const getLengthIfStringElseDouble = ifElse(\n      (a: string | number): a is string => true,\n      a => a.length,\n      a => a * 2\n    )\n\n    getLengthIfStringElseDouble('foo') // $ExpectType number\n    getLengthIfStringElseDouble(3) // $ExpectType number\n    const result = ifElse(\n      (a: {\n        foo?: string,\n        bar: number | string,\n      }): a is {foo: string, bar: string} => true,\n      (a): [string, string] => [a.foo, a.bar],\n      (a): [string | undefined, string | number] => [a.foo, a.bar]\n    )\n    result // $ExpectType (a: { foo?: string | undefined; bar: string | number; }) => [string, string] | [string | undefined, string | number]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#ifElse)\n\n### inc\n\nIt increments a number.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.inc(1)%20%2F%2F%20%3D%3E%202\">Try this <strong>R.inc</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#inc)\n\n### includes\n\n```typescript\n\nincludes<T extends string>(valueToFind: T, input: string): boolean\n```\n\nIf `input` is string, then this method work as native `String.includes`.\n\nIf `input` is array, then `R.equals` is used to define if `valueToFind` belongs to the list.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.includes('oo'%2C%20'foo')%2C%0A%20%20R.includes(%7Ba%3A%201%7D%2C%20%5B%7Ba%3A%201%7D%5D)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%20%5D\">Try this <strong>R.includes</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nincludes<T extends string>(valueToFind: T, input: string): boolean;\nincludes<T extends string>(valueToFind: T): (input: string) => boolean;\nincludes<T>(valueToFind: T, input: T[]): boolean;\nincludes<T>(valueToFind: T): (input: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.includes</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { _indexOf } from './equals.js'\n\nexport function includes(valueToFind, iterable){\n  if (arguments.length === 1)\n    return _iterable => includes(valueToFind, _iterable)\n  if (typeof iterable === 'string'){\n    return iterable.includes(valueToFind)\n  }\n  if (!iterable){\n    throw new TypeError(`Cannot read property \\'indexOf\\' of ${ iterable }`)\n  }\n  if (!isArray(iterable)) return false\n\n  return _indexOf(valueToFind, iterable) > -1\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { includes as includesRamda } from 'ramda'\n\nimport { includes } from './includes.js'\n\ntest('with string as iterable', () => {\n  const str = 'foo bar'\n\n  expect(includes('bar')(str)).toBeTrue()\n  expect(includesRamda('bar')(str)).toBeTrue()\n  expect(includes('never', str)).toBeFalse()\n  expect(includesRamda('never', str)).toBeFalse()\n})\n\ntest('with array as iterable', () => {\n  const arr = [ 1, 2, 3 ]\n\n  expect(includes(2)(arr)).toBeTrue()\n  expect(includesRamda(2)(arr)).toBeTrue()\n\n  expect(includes(4, arr)).toBeFalse()\n  expect(includesRamda(4, arr)).toBeFalse()\n})\n\ntest('with list of objects as iterable', () => {\n  const arr = [ { a : 1 }, { b : 2 }, { c : 3 } ]\n\n  expect(includes({ c : 3 }, arr)).toBeTrue()\n  expect(includesRamda({ c : 3 }, arr)).toBeTrue()\n})\n\ntest('with NaN', () => {\n  const result = includes(NaN, [ NaN ])\n  const ramdaResult = includesRamda(NaN, [ NaN ])\n  expect(result).toBeTrue()\n  expect(ramdaResult).toBeTrue()\n})\n\ntest('with wrong input that does not throw', () => {\n  const result = includes(1, /foo/g)\n  const ramdaResult = includesRamda(1, /foo/g)\n  expect(result).toBeFalse()\n  expect(ramdaResult).toBeFalse()\n})\n\ntest('throws on wrong input - match ramda behaviour', () => {\n  expect(() => includes(2, null)).toThrowWithMessage(TypeError,\n    'Cannot read property \\'indexOf\\' of null')\n  expect(() => includesRamda(2, null)).toThrowWithMessage(TypeError,\n    'Cannot read properties of null (reading \\'indexOf\\')')\n  expect(() => includes(2, undefined)).toThrowWithMessage(TypeError,\n    'Cannot read property \\'indexOf\\' of undefined')\n  expect(() => includesRamda(2, undefined)).toThrowWithMessage(TypeError,\n    'Cannot read properties of undefined (reading \\'indexOf\\')')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {includes} from 'rambda'\n\nconst list = [{a: {b: '1'}}, {a: {c: '2'}}, {a: {b: '3'}}]\n\ndescribe('R.includes', () => {\n  it('happy', () => {\n    const result = includes({a: {b: '1'}}, list)\n    result // $ExpectType boolean\n    const result2 = includes('oo', ['f', 'oo'])\n    result2 // $ExpectType boolean\n  })\n  it('with string', () => {\n    const str = 'foo' as 'foo' | 'bar'\n    const result = includes('oo', str)\n    const curriedResult = includes('oo')(str)\n\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#includes)\n\n### indexBy\n\nIt generates object with properties provided by `condition` and values provided by `list` array.\n\nIf `condition` is a function, then all list members are passed through it.\n\nIf `condition` is a string, then all list members are passed through `R.path(condition)`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%20%7Bid%3A%2010%7D%2C%20%7Bid%3A%2020%7D%20%5D%0A%0Aconst%20withFunction%20%3D%20R.indexBy(%0A%20%20x%20%3D%3E%20x.id%2C%0A%20%20list%0A)%0Aconst%20withString%20%3D%20R.indexBy(%0A%20%20'id'%2C%0A%20%20list%0A)%0Aconst%20result%20%3D%20%5B%0A%20%20withFunction%2C%20%0A%20%20R.equals(withFunction%2C%20withString)%0A%5D%0A%2F%2F%20%3D%3E%20%5B%20%7B%2010%3A%20%7Bid%3A%2010%7D%2C%2020%3A%20%7Bid%3A%2020%7D%20%7D%2C%20true%20%5D\">Try this <strong>R.indexBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#indexBy)\n\n### indexOf\n\nIt returns the index of the first element of `list` equals to `valueToFind`.\n\nIf there is no such element, it returns `-1`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B0%2C%201%2C%202%2C%203%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.indexOf(2%2C%20list)%2C%0A%20%20R.indexOf(0%2C%20list)%0A%5D%0A%2F%2F%20%3D%3E%20%5B2%2C%20-1%5D\">Try this <strong>R.indexOf</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#indexOf)\n\n### init\n\n```typescript\n\ninit<T extends unknown[]>(input: T): T extends readonly [...infer U, any] ? U : [...T]\n```\n\nIt returns all but the last element of list or string `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.init(%5B1%2C%202%2C%203%5D)%20%2C%20%0A%20%20R.init('foo')%20%20%2F%2F%20%3D%3E%20'fo'%0A%5D%0A%2F%2F%20%3D%3E%20%5B%5B1%2C%202%5D%2C%20'fo'%5D\">Try this <strong>R.init</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ninit<T extends unknown[]>(input: T): T extends readonly [...infer U, any] ? U : [...T];\ninit(input: string): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.init</strong> source</summary>\n\n```javascript\nimport baseSlice from './_internals/baseSlice.js'\n\nexport function init(listOrString){\n  if (typeof listOrString === 'string') return listOrString.slice(0, -1)\n\n  return listOrString.length ?\n    baseSlice(\n      listOrString, 0, -1\n    ) :\n    []\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { init } from './init.js'\n\ntest('with array', () => {\n  expect(init([ 1, 2, 3 ])).toEqual([ 1, 2 ])\n  expect(init([ 1, 2 ])).toEqual([ 1 ])\n  expect(init([ 1 ])).toEqual([])\n  expect(init([])).toEqual([])\n  expect(init([])).toEqual([])\n  expect(init([ 1 ])).toEqual([])\n})\n\ntest('with string', () => {\n  expect(init('foo')).toBe('fo')\n  expect(init('f')).toBe('')\n  expect(init('')).toBe('')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {init} from 'rambda'\n\ndescribe('R.init', () => {\n  it('with string', () => {\n    const result = init('foo')\n\n    result // $ExpectType string\n  })\n  it('with list - one type', () => {\n    const result = init([1, 2, 3])\n\n    result // $ExpectType number[]\n  })\n  it('with list - mixed types', () => {\n    const result = init([1, 2, 3, 'foo', 'bar'])\n\n    result // $ExpectType (string | number)[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#init)\n\n### innerJoin\n\nIt returns a new list by applying a `predicate` function to all elements of `list1` and `list2` and keeping only these elements where `predicate` returns `true`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list1%20%3D%20%5B1%2C%202%2C%203%2C%204%2C%205%5D%0Aconst%20list2%20%3D%20%5B4%2C%205%2C%206%5D%0Aconst%20predicate%20%3D%20(x%2C%20y)%20%3D%3E%20x%20%3E%3D%20y%0Aconst%20result%20%3D%20R.innerJoin(predicate%2C%20list1%2C%20list2)%0A%2F%2F%20%3D%3E%20%5B4%2C%205%5D\">Try this <strong>R.innerJoin</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#innerJoin)\n\n### insert\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B'a'%2C%20'b'%2C%20'c'%2C%20'd'%2C%20'e'%5D%3B%0Aconst%20result%20%3D%20R.insert(2%2C%20'x'%2C%20list)%3B%0A%2F%2F%20%3D%3E%20%5B'a'%2C%20'b'%2C%20'x'%2C%20'c'%2C%20'd'%2C%20'e'%5D\">Try this <strong>R.insert</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#insert)\n\n### insertAll\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B'a'%2C%20'b'%2C%20'c'%2C%20'd'%2C%20'e'%5D%3B%0Aconst%20result%20%3D%20R.insertAll(2%2C%20%5B'x'%2C%20'y'%2C%20'z'%5D%2C%20list)%3B%0A%2F%2F%20%3D%3E%20%5B'a'%2C%20'b'%2C%20'x'%2C%20'y'%2C%20'z'%2C%20'c'%2C%20'd'%2C%20'e'%5D\">Try this <strong>R.insertAll</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#insertAll)\n\n### intersection\n\nIt loops through `listA` and `listB` and returns the intersection of the two according to `R.equals`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20listA%20%3D%20%5B%20%7B%20id%20%3A%201%20%7D%2C%20%7B%20id%20%3A%202%20%7D%2C%20%7B%20id%20%3A%203%20%7D%2C%20%7B%20id%20%3A%204%20%7D%20%5D%0Aconst%20listB%20%3D%20%5B%20%7B%20id%20%3A%203%20%7D%2C%20%7B%20id%20%3A%204%20%7D%2C%20%7B%20id%20%3A%205%20%7D%2C%20%7B%20id%20%3A%206%20%7D%20%5D%0A%0Aconst%20result%20%3D%20R.intersection(listA%2C%20listB)%0A%2F%2F%20%3D%3E%20%5B%7B%20id%20%3A%203%20%7D%2C%20%7B%20id%20%3A%204%20%7D%5D\">Try this <strong>R.intersection</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#intersection)\n\n### intersperse\n\nIt adds a `separator` between members of `list`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%200%2C%201%2C%202%2C%203%20%5D%0Aconst%20separator%20%3D%20'%7C'%0Aconst%20result%20%3D%20intersperse(separator%2C%20list)%0A%2F%2F%20%3D%3E%20%5B0%2C%20'%7C'%2C%201%2C%20'%7C'%2C%202%2C%20'%7C'%2C%203%5D\">Try this <strong>R.intersperse</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#intersperse)\n\n### is\n\nIt returns `true` if `x` is instance of `targetPrototype`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.is(String%2C%20'foo')%2C%20%20%0A%20%20R.is(Array%2C%201)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.is</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#is)\n\n### isEmpty\n\n```typescript\n\nisEmpty<T>(x: T): boolean\n```\n\nIt returns `true` if `x` is `empty`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.isEmpty('')%2C%0A%20%20R.isEmpty(%7B%20x%20%3A%200%20%7D)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.isEmpty</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nisEmpty<T>(x: T): boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.isEmpty</strong> source</summary>\n\n```javascript\nimport { type } from './type.js'\n\nexport function isEmpty(input){\n  const inputType = type(input)\n  if ([ 'Undefined', 'NaN', 'Number', 'Null' ].includes(inputType))\n    return false\n  if (!input) return true\n\n  if (inputType === 'Object'){\n    return Object.keys(input).length === 0\n  }\n\n  if (inputType === 'Array'){\n    return input.length === 0\n  }\n\n  return false\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { isEmpty } from './isEmpty.js'\n\ntest('happy', () => {\n  expect(isEmpty(undefined)).toBeFalse()\n  expect(isEmpty('')).toBeTrue()\n  expect(isEmpty(null)).toBeFalse()\n  expect(isEmpty(' ')).toBeFalse()\n  expect(isEmpty(new RegExp(''))).toBeFalse()\n  expect(isEmpty([])).toBeTrue()\n  expect(isEmpty([ [] ])).toBeFalse()\n  expect(isEmpty({})).toBeTrue()\n  expect(isEmpty({ x : 0 })).toBeFalse()\n  expect(isEmpty(0)).toBeFalse()\n  expect(isEmpty(NaN)).toBeFalse()\n  expect(isEmpty([ '' ])).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {isEmpty} from 'rambda'\n\ndescribe('R.isEmpty', () => {\n  it('happy', () => {\n    const result = isEmpty('foo')\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#isEmpty)\n\n### isNil\n\n```typescript\n\nisNil(x: any): x is null | undefined\n```\n\nIt returns `true` if `x` is either `null` or `undefined`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.isNil(null)%2C%0A%20%20R.isNil(1)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.isNil</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nisNil(x: any): x is null | undefined;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.isNil</strong> source</summary>\n\n```javascript\nexport function isNil(x){\n  return x === undefined || x === null\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { isNil } from './isNil.js'\n\ntest('happy', () => {\n  expect(isNil(null)).toBeTrue()\n\n  expect(isNil(undefined)).toBeTrue()\n\n  expect(isNil([])).toBeFalse()\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#isNil)\n\n### isNotEmpty\n\n```typescript\n\nisNotEmpty<T>(value: T[]): value is NonEmptyArray<T>\n```\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nisNotEmpty<T>(value: T[]): value is NonEmptyArray<T>;\nisNotEmpty<T>(value: readonly T[]): value is ReadonlyNonEmptyArray<T>;\nisNotEmpty(value: any): boolean;\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#isNotEmpty)\n\n### isNotNil\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.isNotNil(null)%2C%0A%20%20R.isNotNil(undefined)%2C%0A%20%20R.isNotNil(%5B%5D)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5Bfalse%2C%20false%2C%20true%5D\">Try this <strong>R.isNotNil</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#isNotNil)\n\n### join\n\n```typescript\n\njoin<T>(glue: string, list: T[]): string\n```\n\nIt returns a string of all `list` instances joined with a `glue`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.join('-'%2C%20%5B1%2C%202%2C%203%5D)%20%20%2F%2F%20%3D%3E%20'1-2-3'\">Try this <strong>R.join</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\njoin<T>(glue: string, list: T[]): string;\njoin<T>(glue: string): (list: T[]) => string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.join</strong> source</summary>\n\n```javascript\nexport function join(glue, list){\n  if (arguments.length === 1) return _list => join(glue, _list)\n\n  return list.join(glue)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { join } from './join.js'\n\ntest('curry', () => {\n  expect(join('|')([ 'foo', 'bar', 'baz' ])).toBe('foo|bar|baz')\n\n  expect(join('|', [ 1, 2, 3 ])).toBe('1|2|3')\n\n  const spacer = join(' ')\n\n  expect(spacer([ 'a', 2, 3.4 ])).toBe('a 2 3.4')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {join} from 'rambda'\n\ndescribe('R.join', () => {\n  it('happy', () => {\n    const result = join('|', [1, 2, 3])\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#join)\n\n### juxt\n\n```typescript\n\njuxt<A extends any[], R1>(fns: [(...a: A) => R1]): (...a: A) => [R1]\n```\n\nIt applies list of function to a list of inputs.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20getRange%20%3D%20juxt(%5B%20Math.min%2C%20Math.max%2C%20Math.min%20%5D)%0Aconst%20result%20%3D%20getRange(%0A%20%203%2C%204%2C%209%2C%20-3%0A)%0A%2F%2F%20%3D%3E%20%5B-3%2C%209%2C%20-3%5D\">Try this <strong>R.juxt</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\njuxt<A extends any[], R1>(fns: [(...a: A) => R1]): (...a: A) => [R1];\njuxt<A extends any[], R1, R2>(fns: [(...a: A) => R1, (...a: A) => R2]): (...a: A) => [R1, R2];\njuxt<A extends any[], R1, R2, R3>(fns: [(...a: A) => R1, (...a: A) => R2, (...a: A) => R3]): (...a: A) => [R1, R2, R3];\njuxt<A extends any[], R1, R2, R3, R4>(fns: [(...a: A) => R1, (...a: A) => R2, (...a: A) => R3, (...a: A) => R4]): (...a: A) => [R1, R2, R3, R4];\njuxt<A extends any[], R1, R2, R3, R4, R5>(fns: [(...a: A) => R1, (...a: A) => R2, (...a: A) => R3, (...a: A) => R4, (...a: A) => R5]): (...a: A) => [R1, R2, R3, R4, R5];\njuxt<A extends any[], U>(fns: Array<(...args: A) => U>): (...args: A) => U[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.juxt</strong> source</summary>\n\n```javascript\nexport function juxt(listOfFunctions){\n  return (...args) => listOfFunctions.map(fn => fn(...args))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { juxt } from './juxt.js'\n\ntest('happy', () => {\n  const fn = juxt([ Math.min, Math.max, Math.min ])\n  const result = fn(\n    3, 4, 9, -3\n  )\n  expect(result).toEqual([ -3, 9, -3 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {juxt} from 'rambda'\n\ndescribe('R.juxt', () => {\n  it('happy', () => {\n    const fn = juxt([Math.min, Math.max])\n    const result = fn(3, 4, 9, -3)\n    result // $ExpectType [number, number]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#juxt)\n\n### keys\n\n```typescript\n\nkeys<T extends object>(x: T): (keyof T & string)[]\n```\n\nIt applies `Object.keys` over `x` and returns its keys.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.keys(%7Ba%3A1%2C%20b%3A2%7D)%20%20%2F%2F%20%3D%3E%20%5B'a'%2C%20'b'%5D\">Try this <strong>R.keys</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nkeys<T extends object>(x: T): (keyof T & string)[];\nkeys<T>(x: T): string[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.keys</strong> source</summary>\n\n```javascript\nexport function keys(x){\n  return Object.keys(x)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { keys } from './keys.js'\n\ntest('happy', () => {\n  expect(keys({ a : 1 })).toEqual([ 'a' ])\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#keys)\n\n### last\n\n```typescript\n\nlast(str: ''): undefined\n```\n\nIt returns the last element of `input`, as the `input` can be either a string or an array. It returns `undefined` if array has length of 0.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.last(%5B1%2C%202%2C%203%5D)%2C%0A%20%20R.last('foo')%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5B3%2C%20'o'%5D\">Try this <strong>R.last</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nlast(str: ''): undefined;\nlast(str: string): string;\nlast(list: readonly[]): undefined;\nlast(list: never[]): undefined;\nlast<T extends unknown[]>(array: T): LastArrayElement<T>;\nlast<T extends readonly unknown[]>(array: T): LastArrayElement<T>;\nlast(str: string): string | undefined;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.last</strong> source</summary>\n\n```javascript\nexport function last(listOrString){\n  if (typeof listOrString === 'string'){\n    return listOrString[ listOrString.length - 1 ] || ''\n  }\n\n  return listOrString[ listOrString.length - 1 ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { last } from './last.js'\n\ntest('with list', () => {\n  expect(last([ 1, 2, 3 ])).toBe(3)\n  expect(last([])).toBeUndefined()\n})\n\ntest('with string', () => {\n  expect(last('abc')).toBe('c')\n  expect(last('')).toBe('')\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#last)\n\n### lastIndexOf\n\n```typescript\n\nlastIndexOf<T>(target: T, list: T[]): number\n```\n\nIt returns the last index of `target` in `list` array.\n\n`R.equals` is used to determine equality between `target` and members of `list`.\n\nIf there is no such index, then `-1` is returned.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%2C%201%2C%202%2C%203%5D%0Aconst%20result%20%3D%20%5B%0A%20%20R.lastIndexOf(2%2C%20list)%2C%0A%20%20R.lastIndexOf(4%2C%20list)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5B4%2C%20-1%5D\">Try this <strong>R.lastIndexOf</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nlastIndexOf<T>(target: T, list: T[]): number;\nlastIndexOf<T>(target: T): (list: T[]) => number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.lastIndexOf</strong> source</summary>\n\n```javascript\nimport { _lastIndexOf } from './equals.js'\n\nexport function lastIndexOf(valueToFind, list){\n  if (arguments.length === 1){\n    return _list => _lastIndexOf(valueToFind, _list)\n  }\n\n  return _lastIndexOf(valueToFind, list)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { lastIndexOf as lastIndexOfRamda } from 'ramda'\n\nimport { compareCombinations } from './_internals/testUtils.js'\nimport { possibleIterables, possibleTargets } from './indexOf.spec.js'\nimport { lastIndexOf } from './lastIndexOf.js'\n\ntest('with NaN', () => {\n  expect(lastIndexOf(NaN, [ NaN ])).toBe(0)\n})\n\ntest('will throw with bad input', () => {\n  expect(lastIndexOfRamda([], true)).toBe(-1)\n  expect(() => indexOf([], true)).toThrowErrorMatchingInlineSnapshot('\"indexOf is not defined\"')\n})\n\ntest('without list of objects - no R.equals', () => {\n  expect(lastIndexOf(3, [ 1, 2, 3, 4 ])).toBe(2)\n  expect(lastIndexOf(10)([ 1, 2, 3, 4 ])).toBe(-1)\n})\n\ntest('list of objects uses R.equals', () => {\n  const listOfObjects = [ { a : 1 }, { b : 2 }, { c : 3 } ]\n  expect(lastIndexOf({ c : 4 }, listOfObjects)).toBe(-1)\n  expect(lastIndexOf({ c : 3 }, listOfObjects)).toBe(2)\n})\n\ntest('list of arrays uses R.equals', () => {\n  const listOfLists = [ [ 1 ], [ 2, 3 ], [ 2, 3, 4 ], [ 2, 3 ], [ 1 ], [] ]\n  expect(lastIndexOf([], listOfLists)).toBe(5)\n  expect(lastIndexOf([ 1 ], listOfLists)).toBe(4)\n  expect(lastIndexOf([ 2, 3, 4 ], listOfLists)).toBe(2)\n  expect(lastIndexOf([ 2, 3, 5 ], listOfLists)).toBe(-1)\n})\n\ntest('with string as iterable', () => {\n  expect(() => lastIndexOf('a', 'abc')).toThrowErrorMatchingInlineSnapshot('\"Cannot read property \\'indexOf\\' of abc\"')\n  expect(lastIndexOfRamda('a', 'abc')).toBe(0)\n})\n\ndescribe('brute force', () => {\n  compareCombinations({\n    fn          : lastIndexOf,\n    fnRamda     : lastIndexOfRamda,\n    firstInput  : possibleTargets,\n    secondInput : possibleIterables,\n    callback    : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n        {\n          \"ERRORS_MESSAGE_MISMATCH\": 0,\n          \"ERRORS_TYPE_MISMATCH\": 34,\n          \"RESULTS_MISMATCH\": 0,\n          \"SHOULD_NOT_THROW\": 51,\n          \"SHOULD_THROW\": 0,\n          \"TOTAL_TESTS\": 170,\n        }\n      `)\n    },\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {lastIndexOf} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.lastIndexOf', () => {\n  it('happy', () => {\n    const result = lastIndexOf(2, list)\n    result // $ExpectType number\n  })\n  it('curried', () => {\n    const result = lastIndexOf(2)(list)\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lastIndexOf)\n\n### length\n\n```typescript\n\nlength<T>(input: T[]): number\n```\n\nIt returns the `length` property of list or string `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.length(%5B1%2C%202%2C%203%2C%204%5D)%2C%0A%20%20R.length('foo')%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5B4%2C%203%5D\">Try this <strong>R.length</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nlength<T>(input: T[]): number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.length</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function length(x){\n  if (isArray(x)) return x.length\n  if (typeof x === 'string') return x.length\n\n  return NaN\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { length as lengthRamda } from 'ramda'\n\nimport { length } from './length.js'\n\ntest('happy', () => {\n  expect(length('foo')).toBe(3)\n  expect(length([ 1, 2, 3 ])).toBe(3)\n  expect(length([])).toBe(0)\n})\n\ntest('with empty string', () => {\n  expect(length('')).toBe(0)\n})\n\ntest('with bad input returns NaN', () => {\n  expect(length(0)).toBeNaN()\n  expect(length({})).toBeNaN()\n  expect(length(null)).toBeNaN()\n  expect(length(undefined)).toBeNaN()\n})\n\ntest('with length as property', () => {\n  const input1 = { length : '123' }\n  const input2 = { length : null }\n  const input3 = { length : '' }\n\n  expect(length(input1)).toBeNaN()\n  expect(lengthRamda(input1)).toBeNaN()\n  expect(length(input2)).toBeNaN()\n  expect(lengthRamda(input2)).toBeNaN()\n  expect(length(input3)).toBeNaN()\n  expect(lengthRamda(input3)).toBeNaN()\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#length)\n\n### lens\n\n```typescript\n\nlens<S, A>(getter: (s: S) => A, setter: (a: A, s: S) => S): Lens<S, A>\n```\n\nIt returns a `lens` for the given `getter` and `setter` functions. \n\nThe `getter` **gets** the value of the focus; the `setter` **sets** the value of the focus. \n\nThe setter should not mutate the data structure.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20xLens%20%3D%20R.lens(R.prop('x')%2C%20R.assoc('x'))%3B%0A%0AR.view(xLens%2C%20%7Bx%3A%201%2C%20y%3A%202%7D)%20%2F%2F%20%3D%3E%201%0AR.set(xLens%2C%204%2C%20%7Bx%3A%201%2C%20y%3A%202%7D)%20%2F%2F%20%3D%3E%20%7Bx%3A%204%2C%20y%3A%202%7D%0Aconst%20result%20%3D%20R.over(xLens%2C%20R.negate%2C%20%7Bx%3A%201%2C%20y%3A%202%7D)%20%2F%2F%20%3D%3E%20%7Bx%3A%20-1%2C%20y%3A%202%7D\">Try this <strong>R.lens</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nlens<S, A>(getter: (s: S) => A, setter: (a: A, s: S) => S): Lens<S, A>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.lens</strong> source</summary>\n\n```javascript\nexport function lens(getter, setter){\n  return function (functor){\n    return function (target){\n      return functor(getter(target)).map(focus => setter(focus, target))\n    }\n  }\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {lens, assoc, lensProp, view, lensIndex, over, lensPath} from 'rambda'\n\ninterface Input {\n  foo: string,\n}\nconst testObject: Input = {\n  foo: 'Jazz',\n}\n\ndescribe('R.lens', () => {\n  it('happy', () => {\n    const fn = lens<Input, string>((x: Input) => {\n      x.foo // $ExpectType string\n      return x.foo\n    }, assoc('name'))\n    fn // $ExpectType Lens<Input, string>\n  })\n})\n\ndescribe('R.lensProp', () => {\n  it('happy', () => {\n    const result = view<Input, string>(lensProp('foo'), testObject)\n    result // $ExpectType string\n  })\n  it('issue 740', () => {\n    // @ts-expect-error\n    over(lensProp('x'), (n) => String(n), {x: 1})\n  })\n})\n\ndescribe('R.lensIndex', () => {\n  const testList: Input[] = [{foo: 'bar'}, {foo: 'baz'}]\n  it('happy', () => {\n    const result = view<Input[], Input>(lensIndex(0), testList)\n    result // $ExpectType Input\n    result.foo // $ExpectType string\n  })\n})\n\ndescribe('R.lensPath', () => {\n  const path = lensPath(['bar', 'a'])\n  it('happy', () => {\n    const result = view<Input, string>(path, testObject)\n    result // $ExpectType string\n  })\n})\n\ndescribe('R.view', () => {\n  const fooLens = lens<Input, string>((x: Input) => {\n    return x.foo\n  }, assoc('foo'))\n  it('happt', () => {\n    const result = view<Input, string>(fooLens, testObject)\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lens)\n\n### lensIndex\n\n```typescript\n\nlensIndex<A>(n: number): Lens<A[], A>\n```\n\nIt returns a lens that focuses on specified `index`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B'a'%2C%20'b'%2C%20'c'%5D%0Aconst%20headLens%20%3D%20R.lensIndex(0)%0A%0AR.view(headLens%2C%20list)%20%2F%2F%20%3D%3E%20'a'%0AR.set(headLens%2C%20'x'%2C%20list)%20%2F%2F%20%3D%3E%20%5B'x'%2C%20'b'%2C%20'c'%5D%0Aconst%20result%20%3D%20R.over(headLens%2C%20R.toUpper%2C%20list)%20%2F%2F%20%3D%3E%20%5B'A'%2C%20'b'%2C%20'c'%5D\">Try this <strong>R.lensIndex</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nlensIndex<A>(n: number): Lens<A[], A>;\nlensIndex<A extends any[], N extends number>(n: N): Lens<A, A[N]>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.lensIndex</strong> source</summary>\n\n```javascript\nimport { lens } from './lens.js'\nimport { nth } from './nth.js'\nimport { update } from './update.js'\n\nexport function lensIndex(index){\n  return lens(nth(index), update(index))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { compose } from './compose.js'\nimport { keys } from './keys.js'\nimport { lensIndex } from './lensIndex.js'\nimport { over } from './over.js'\nimport { set } from './set.js'\nimport { view } from './view.js'\n\nconst testList = [ { a : 1 }, { b : 2 }, { c : 3 } ]\n\ntest('focuses list element at the specified index', () => {\n  expect(view(lensIndex(0), testList)).toEqual({ a : 1 })\n})\n\ntest('returns undefined if the specified index does not exist', () => {\n  expect(view(lensIndex(10), testList)).toBeUndefined()\n})\n\ntest('sets the list value at the specified index', () => {\n  expect(set(\n    lensIndex(0), 0, testList\n  )).toEqual([ 0, { b : 2 }, { c : 3 } ])\n})\n\ntest('applies function to the value at the specified list index', () => {\n  expect(over(\n    lensIndex(2), keys, testList\n  )).toEqual([ { a : 1 }, { b : 2 }, [ 'c' ] ])\n})\n\ntest('can be composed', () => {\n  const nestedList = [ 0, [ 10, 11, 12 ], 1, 2 ]\n  const composedLens = compose(lensIndex(1), lensIndex(0))\n\n  expect(view(composedLens, nestedList)).toBe(10)\n})\n\ntest('set s (get s) === s', () => {\n  expect(set(\n    lensIndex(0), view(lensIndex(0), testList), testList\n  )).toEqual(testList)\n})\n\ntest('get (set s v) === v', () => {\n  expect(view(lensIndex(0), set(\n    lensIndex(0), 0, testList\n  ))).toBe(0)\n})\n\ntest('get (set(set s v1) v2) === v2', () => {\n  expect(view(lensIndex(0),\n    set(\n      lensIndex(0), 11, set(\n        lensIndex(0), 10, testList\n      )\n    ))).toBe(11)\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lensIndex)\n\n### lensPath\n\nIt returns a lens that focuses on specified `path`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20lensPath%20%3D%20R.lensPath(%5B'x'%2C%200%2C%20'y'%5D)%0Aconst%20input%20%3D%20%7Bx%3A%20%5B%7By%3A%202%2C%20z%3A%203%7D%2C%20%7By%3A%204%2C%20z%3A%205%7D%5D%7D%0A%0AR.view(lensPath%2C%20input)%20%2F%2F%20%3D%3E%202%0A%0AR.set(lensPath%2C%201%2C%20input)%20%0A%2F%2F%20%3D%3E%20%7Bx%3A%20%5B%7By%3A%201%2C%20z%3A%203%7D%2C%20%7By%3A%204%2C%20z%3A%205%7D%5D%7D%0A%0Aconst%20result%20%3D%20R.over(xHeadYLens%2C%20R.negate%2C%20input)%20%0A%2F%2F%20%3D%3E%20%7Bx%3A%20%5B%7By%3A%20-2%2C%20z%3A%203%7D%2C%20%7By%3A%204%2C%20z%3A%205%7D%5D%7D\">Try this <strong>R.lensPath</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lensPath)\n\n### lensProp\n\n```typescript\n\nlensProp<S, K extends keyof S = keyof S>(prop: K): Lens<S, S[K]>\n```\n\nIt returns a lens that focuses on specified property `prop`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20xLens%20%3D%20R.lensProp('x')%3B%0Aconst%20input%20%3D%20%7Bx%3A%201%2C%20y%3A%202%7D%0A%0AR.view(xLens%2C%20input)%20%2F%2F%20%3D%3E%201%0A%0AR.set(xLens%2C%204%2C%20input)%20%0A%2F%2F%20%3D%3E%20%7Bx%3A%204%2C%20y%3A%202%7D%0A%0Aconst%20result%20%3D%20R.over(xLens%2C%20R.negate%2C%20input)%20%0A%2F%2F%20%3D%3E%20%7Bx%3A%20-1%2C%20y%3A%202%7D\">Try this <strong>R.lensProp</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nlensProp<S, K extends keyof S = keyof S>(prop: K): Lens<S, S[K]>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.lensProp</strong> source</summary>\n\n```javascript\nimport { assoc } from './assoc.js'\nimport { lens } from './lens.js'\nimport { prop } from './prop.js'\n\nexport function lensProp(key){\n  return lens(prop(key), assoc(key))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { compose } from './compose.js'\nimport { identity } from './identity.js'\nimport { inc } from './inc.js'\nimport { lensProp } from './lensProp.js'\nimport { over } from './over.js'\nimport { set } from './set.js'\nimport { view } from './view.js'\n\nconst testObj = {\n  a : 1,\n  b : 2,\n  c : 3,\n}\n\ntest('focuses object the specified object property', () => {\n  expect(view(lensProp('a'), testObj)).toBe(1)\n})\n\ntest('returns undefined if the specified property does not exist', () => {\n  expect(view(lensProp('X'), testObj)).toBeUndefined()\n})\n\ntest('sets the value of the object property specified', () => {\n  expect(set(\n    lensProp('a'), 0, testObj\n  )).toEqual({\n    a : 0,\n    b : 2,\n    c : 3,\n  })\n})\n\ntest('adds the property to the object if it doesn\\'t exist', () => {\n  expect(set(\n    lensProp('d'), 4, testObj\n  )).toEqual({\n    a : 1,\n    b : 2,\n    c : 3,\n    d : 4,\n  })\n})\n\ntest('applies function to the value of the specified object property', () => {\n  expect(over(\n    lensProp('a'), inc, testObj\n  )).toEqual({\n    a : 2,\n    b : 2,\n    c : 3,\n  })\n})\n\ntest('applies function to undefined and adds the property if it doesn\\'t exist', () => {\n  expect(over(\n    lensProp('X'), identity, testObj\n  )).toEqual({\n    a : 1,\n    b : 2,\n    c : 3,\n    X : undefined,\n  })\n})\n\ntest('can be composed', () => {\n  const nestedObj = {\n    a : { b : 1 },\n    c : 2,\n  }\n  const composedLens = compose(lensProp('a'), lensProp('b'))\n\n  expect(view(composedLens, nestedObj)).toBe(1)\n})\n\ntest('set s (get s) === s', () => {\n  expect(set(\n    lensProp('a'), view(lensProp('a'), testObj), testObj\n  )).toEqual(testObj)\n})\n\ntest('get (set s v) === v', () => {\n  expect(view(lensProp('a'), set(\n    lensProp('a'), 0, testObj\n  ))).toBe(0)\n})\n\ntest('get (set(set s v1) v2) === v2', () => {\n  expect(view(lensProp('a'),\n    set(\n      lensProp('a'), 11, set(\n        lensProp('a'), 10, testObj\n      )\n    ))).toBe(11)\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lensProp)\n\n### lt\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5BR.lt(2%2C%201)%2C%20R.lt(2%2C%203)%5D%0A%2F%2F%20%3D%3E%20%5Bfalse%2C%20true%5D\">Try this <strong>R.lt</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lt)\n\n### lte\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5BR.lte(2%2C%201)%2C%20R.lte(2%2C%202)%2C%20R.lte(2%2C%203)%5D%0A%2F%2F%20%3D%3E%20%5Bfalse%2C%20true%2C%20true%5D\">Try this <strong>R.lte</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#lte)\n\n### map\n\n```typescript\n\nmap<T, U>(fn: ObjectIterator<T, U>, iterable: Dictionary<T>): Dictionary<U>\n```\n\nIt returns the result of looping through `iterable` with `fn`.\n\nIt works with both array and object.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20x%20%3D%3E%20x%20*%202%0Aconst%20fnWhenObject%20%3D%20(val%2C%20prop)%3D%3E%7B%0A%20%20return%20%60%24%7Bprop%7D-%24%7Bval%7D%60%0A%7D%0A%0Aconst%20iterable%20%3D%20%5B1%2C%202%5D%0Aconst%20obj%20%3D%20%7Ba%3A%201%2C%20b%3A%202%7D%0A%0Aconst%20result%20%3D%20%5B%20%0A%20%20R.map(fn%2C%20iterable)%2C%0A%20%20R.map(fnWhenObject%2C%20obj)%0A%5D%0A%2F%2F%20%3D%3E%20%5B%20%5B2%2C%204%5D%2C%20%7Ba%3A%20'a-1'%2C%20b%3A%20'b-2'%7D%5D\">Try this <strong>R.map</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmap<T, U>(fn: ObjectIterator<T, U>, iterable: Dictionary<T>): Dictionary<U>;\nmap<T, U>(fn: Iterator<T, U>, iterable: T[]): U[];\nmap<T, U>(fn: Iterator<T, U>): (iterable: T[]) => U[];\nmap<T, U, S>(fn: ObjectIterator<T, U>): (iterable: Dictionary<T>) => Dictionary<U>;\nmap<T>(fn: Iterator<T, T>): (iterable: T[]) => T[];\nmap<T>(fn: Iterator<T, T>, iterable: T[]): T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.map</strong> source</summary>\n\n```javascript\nimport { INCORRECT_ITERABLE_INPUT } from './_internals/constants.js'\nimport { isArray } from './_internals/isArray.js'\nimport { keys } from './_internals/keys.js'\n\nexport function mapArray(\n  fn, list, isIndexed = false\n){\n  let index = 0\n  const willReturn = Array(list.length)\n\n  while (index < list.length){\n    willReturn[ index ] = isIndexed ? fn(list[ index ], index) : fn(list[ index ])\n\n    index++\n  }\n\n  return willReturn\n}\n\nexport function mapObject(fn, obj){\n  if (arguments.length === 1){\n    return _obj => mapObject(fn, _obj)\n  }\n  let index = 0\n  const objKeys = keys(obj)\n  const len = objKeys.length\n  const willReturn = {}\n\n  while (index < len){\n    const key = objKeys[ index ]\n    willReturn[ key ] = fn(\n      obj[ key ], key, obj\n    )\n    index++\n  }\n\n  return willReturn\n}\n\nexport const mapObjIndexed = mapObject\n\nexport function map(fn, iterable){\n  if (arguments.length === 1) return _iterable => map(fn, _iterable)\n  if (!iterable){\n    throw new Error(INCORRECT_ITERABLE_INPUT)\n  }\n\n  if (isArray(iterable)) return mapArray(fn, iterable)\n\n  return mapObject(fn, iterable)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { map as mapRamda } from 'ramda'\n\nimport { map } from './map.js'\n\nconst double = x => x * 2\n\ndescribe('with array', () => {\n  it('happy', () => {\n    expect(map(double, [ 1, 2, 3 ])).toEqual([ 2, 4, 6 ])\n  })\n\n  it('curried', () => {\n    expect(map(double)([ 1, 2, 3 ])).toEqual([ 2, 4, 6 ])\n  })\n})\n\ndescribe('with object', () => {\n  const obj = {\n    a : 1,\n    b : 2,\n  }\n\n  it('happy', () => {\n    expect(map(double, obj)).toEqual({\n      a : 2,\n      b : 4,\n    })\n  })\n\n  it('property as second and input object as third argument', () => {\n    const obj = {\n      a : 1,\n      b : 2,\n    }\n    const iterator = (\n      val, prop, inputObject\n    ) => {\n      expect(prop).toBeString()\n      expect(inputObject).toEqual(obj)\n\n      return val * 2\n    }\n\n    expect(map(iterator)(obj)).toEqual({\n      a : 2,\n      b : 4,\n    })\n  })\n})\n\ntest('bad inputs difference between Ramda and Rambda', () => {\n  expect(() => map(double, null)).toThrowErrorMatchingInlineSnapshot('\"Incorrect iterable input\"')\n  expect(() => map(double)(undefined)).toThrowErrorMatchingInlineSnapshot('\"Incorrect iterable input\"')\n  expect(() => mapRamda(double, null)).toThrowErrorMatchingInlineSnapshot('\"Cannot read properties of null (reading \\'fantasy-land/map\\')\"')\n  expect(() =>\n    mapRamda(double, undefined)).toThrowErrorMatchingInlineSnapshot('\"Cannot read properties of undefined (reading \\'fantasy-land/map\\')\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {map} from 'rambda'\n\ndescribe('R.map with arrays', () => {\n  it('iterable returns the same type as the input', () => {\n    const result = map<number>(\n      (x: number) => {\n        x // $ExpectType number\n        return x + 2\n      },\n      [1, 2, 3]\n    )\n    result // $ExpectType number[]\n  })\n  it('iterable returns the same type as the input - curried', () => {\n    const result = map<number>((x: number) => {\n      x // $ExpectType number\n      return x + 2\n    })([1, 2, 3])\n    result // $ExpectType number[]\n  })\n  it('iterable returns different type as the input', () => {\n    const result = map<number, string>(\n      (x: number) => {\n        x // $ExpectType number\n        return String(x)\n      },\n      [1, 2, 3]\n    )\n    result // $ExpectType string[]\n  })\n})\n\ndescribe('R.map with objects', () => {\n  it('iterable with all three arguments - curried', () => {\n    // It requires dummy third typing argument\n    // in order to identify compared to curry typings for arrays\n    // ============================================\n    const result = map<number, string, any>((a, b, c) => {\n      a // $ExpectType number\n      b // $ExpectType string\n      c // $ExpectType Dictionary<number>\n      return `${a}`\n    })({a: 1, b: 2})\n    result // $ExpectType Dictionary<string>\n  })\n  it('iterable with all three arguments', () => {\n    const result = map<number, string>(\n      (a, b, c) => {\n        a // $ExpectType number\n        b // $ExpectType string\n        c // $ExpectType Dictionary<number>\n        return `${a}`\n      },\n      {a: 1, b: 2}\n    )\n    result // $ExpectType Dictionary<string>\n  })\n  it('iterable with property argument', () => {\n    const result = map<number, string>(\n      (a, b) => {\n        a // $ExpectType number\n        b // $ExpectType string\n        return `${a}`\n      },\n      {a: 1, b: 2}\n    )\n    result // $ExpectType Dictionary<string>\n  })\n  it('iterable with no property argument', () => {\n    const result = map<number, string>(\n      a => {\n        a // $ExpectType number\n        return `${a}`\n      },\n      {a: 1, b: 2}\n    )\n    result // $ExpectType Dictionary<string>\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#map)\n\n### mapObjIndexed\n\n```typescript\n\nmapObjIndexed<T>(fn: ObjectIterator<T, T>, iterable: Dictionary<T>): Dictionary<T>\n```\n\nIt works the same way as `R.map` does for objects. It is added as Ramda also has this method.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20(val%2C%20prop)%20%3D%3E%20%7B%0A%20%20return%20%60%24%7Bprop%7D-%24%7Bval%7D%60%0A%7D%0A%0Aconst%20obj%20%3D%20%7Ba%3A%201%2C%20b%3A%202%7D%0A%0Aconst%20result%20%3D%20R.mapObjIndexed(fn%2C%20obj)%0A%2F%2F%20%3D%3E%20%7Ba%3A%20'a-1'%2C%20b%3A%20'b-2'%7D\">Try this <strong>R.mapObjIndexed</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmapObjIndexed<T>(fn: ObjectIterator<T, T>, iterable: Dictionary<T>): Dictionary<T>;\nmapObjIndexed<T, U>(fn: ObjectIterator<T, U>, iterable: Dictionary<T>): Dictionary<U>;\nmapObjIndexed<T>(fn: ObjectIterator<T, T>): (iterable: Dictionary<T>) => Dictionary<T>;\nmapObjIndexed<T, U>(fn: ObjectIterator<T, U>): (iterable: Dictionary<T>) => Dictionary<U>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {mapObjIndexed} from 'rambda'\n\nconst obj = {a: 1, b: 2, c: 3}\n\ndescribe('R.mapObjIndexed', () => {\n  it('without type transform', () => {\n    const result = mapObjIndexed((x, prop, obj) => {\n      x // $ExpectType number\n      prop // $ExpectType string\n      obj // $ExpectType Dictionary<number>\n      return x + 2\n    }, obj)\n    result // $ExpectType Dictionary<number>\n  })\n  it('without type transform - curried', () => {\n    const result = mapObjIndexed<number>((x, prop, obj) => {\n      x // $ExpectType number\n      prop // $ExpectType string\n      obj // $ExpectType Dictionary<number>\n      return x + 2\n    })(obj)\n    result // $ExpectType Dictionary<number>\n  })\n  it('change of type', () => {\n    const result = mapObjIndexed((x, prop, obj) => {\n      x // $ExpectType number\n      prop // $ExpectType string\n      obj // $ExpectType Dictionary<number>\n      return String(x + 2)\n    }, obj)\n    result // $ExpectType Dictionary<string>\n  })\n  it('change of type - curried', () => {\n    const result = mapObjIndexed<number, string>((x, prop, obj) => {\n      x // $ExpectType number\n      prop // $ExpectType string\n      obj // $ExpectType Dictionary<number>\n      return String(x + 2)\n    })(obj)\n    result // $ExpectType Dictionary<string>\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mapObjIndexed)\n\n### match\n\n```typescript\n\nmatch(regExpression: RegExp, str: string): string[]\n```\n\nCurried version of `String.prototype.match` which returns empty array, when there is no match.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.match('a'%2C%20'foo')%2C%0A%20%20R.match(%2F(%5Ba-z%5Da)%2Fg%2C%20'bananas')%0A%5D%0A%2F%2F%20%3D%3E%20%5B%5B%5D%2C%20%5B'ba'%2C%20'na'%2C%20'na'%5D%5D\">Try this <strong>R.match</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmatch(regExpression: RegExp, str: string): string[];\nmatch(regExpression: RegExp): (str: string) => string[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.match</strong> source</summary>\n\n```javascript\nexport function match(pattern, input){\n  if (arguments.length === 1) return _input => match(pattern, _input)\n\n  const willReturn = input.match(pattern)\n\n  return willReturn === null ? [] : willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { equals } from './equals.js'\nimport { match } from './match.js'\n\ntest('happy', () => {\n  expect(match(/a./g)('foo bar baz')).toEqual([ 'ar', 'az' ])\n})\n\ntest('fallback', () => {\n  expect(match(/a./g)('foo')).toEqual([])\n})\n\ntest('with string', () => {\n  expect(match('a', 'foo')).toEqual([])\n  expect(equals(match('o', 'foo'), [ 'o' ])).toBeTrue()\n})\n\ntest('throwing', () => {\n  expect(() => {\n    match(/a./g, null)\n  }).toThrowErrorMatchingInlineSnapshot('\"Cannot read properties of null (reading \\'match\\')\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {match} from 'rambda'\n\nconst str = 'foo bar'\n\ndescribe('R.match', () => {\n  it('happy', () => {\n    const result = match(/foo/, str)\n    result // $ExpectType string[]\n  })\n  it('curried', () => {\n    const result = match(/foo/)(str)\n    result // $ExpectType string[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#match)\n\n### mathMod\n\n`R.mathMod` behaves like the modulo operator should mathematically, unlike the `%` operator (and by extension, `R.modulo`). So while `-17 % 5` is `-2`, `mathMod(-17, 5)` is `3`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.mathMod(-17%2C%205)%2C%0A%20%20R.mathMod(17%2C%205)%2C%0A%20%20R.mathMod(17%2C%20-5)%2C%20%20%0A%20%20R.mathMod(17%2C%200)%20%20%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B3%2C%202%2C%20NaN%2C%20NaN%5D\">Try this <strong>R.mathMod</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mathMod)\n\n### max\n\nIt returns the greater value between `x` and `y`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.max(5%2C%207)%2C%20%20%0A%20%20R.max('bar'%2C%20'foo')%2C%20%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B7%2C%20'foo'%5D\">Try this <strong>R.max</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#max)\n\n### maxBy\n\nIt returns the greater value between `x` and `y` according to `compareFn` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20compareFn%20%3D%20Math.abs%0A%0Aconst%20result%20%3D%20R.maxBy(compareFn%2C%205%2C%20-7)%20%2F%2F%20%3D%3E%20-7\">Try this <strong>R.maxBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#maxBy)\n\n### mean\n\n```typescript\n\nmean(list: number[]): number\n```\n\nIt returns the mean value of `list` input.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.mean(%5B%202%2C%207%20%5D)%0A%2F%2F%20%3D%3E%204.5\">Try this <strong>R.mean</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmean(list: number[]): number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.mean</strong> source</summary>\n\n```javascript\nimport { sum } from './sum.js'\n\nexport function mean(list){\n  return sum(list) / list.length\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { mean } from './mean.js'\n\ntest('happy', () => {\n  expect(mean([ 2, 7 ])).toBe(4.5)\n})\n\ntest('with NaN', () => {\n  expect(mean([])).toBeNaN()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {mean} from 'rambda'\n\ndescribe('R.mean', () => {\n  it('happy', () => {\n    const result = mean([1, 2, 3])\n\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mean)\n\n### median\n\n```typescript\n\nmedian(list: number[]): number\n```\n\nIt returns the median value of `list` input.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.median(%5B%207%2C%202%2C%2010%2C%209%20%5D)%20%2F%2F%20%3D%3E%208\">Try this <strong>R.median</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmedian(list: number[]): number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.median</strong> source</summary>\n\n```javascript\nimport { mean } from './mean.js'\n\nexport function median(list){\n  const len = list.length\n  if (len === 0) return NaN\n  const width = 2 - len % 2\n  const idx = (len - width) / 2\n\n  return mean(Array.prototype.slice\n    .call(list, 0)\n    .sort((a, b) => {\n      if (a === b) return 0\n\n      return a < b ? -1 : 1\n    })\n    .slice(idx, idx + width))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { median } from './median.js'\n\ntest('happy', () => {\n  expect(median([ 2 ])).toBe(2)\n  expect(median([ 7, 2, 10, 2, 9 ])).toBe(7)\n})\n\ntest('with empty array', () => {\n  expect(median([])).toBeNaN()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {median} from 'rambda'\n\ndescribe('R.median', () => {\n  it('happy', () => {\n    const result = median([1, 2, 3])\n\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#median)\n\n### merge\n\nSame as `R.mergeRight`.\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#merge)\n\n### mergeAll\n\n```typescript\n\nmergeAll<T>(list: object[]): T\n```\n\nIt merges all objects of `list` array sequentially and returns the result.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%0A%20%20%7Ba%3A%201%7D%2C%0A%20%20%7Bb%3A%202%7D%2C%0A%20%20%7Bc%3A%203%7D%0A%5D%0Aconst%20result%20%3D%20R.mergeAll(list)%0Aconst%20expected%20%3D%20%7B%0A%20%20a%3A%201%2C%0A%20%20b%3A%202%2C%0A%20%20c%3A%203%0A%7D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.mergeAll</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmergeAll<T>(list: object[]): T;\nmergeAll(list: object[]): object;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.mergeAll</strong> source</summary>\n\n```javascript\nimport { map } from './map.js'\nimport { mergeRight } from './mergeRight.js'\n\nexport function mergeAll(arr){\n  let willReturn = {}\n  map(val => {\n    willReturn = mergeRight(willReturn, val)\n  }, arr)\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { mergeAll } from './mergeAll.js'\n\ntest('case 1', () => {\n  const arr = [ { a : 1 }, { b : 2 }, { c : 3 } ]\n  const expectedResult = {\n    a : 1,\n    b : 2,\n    c : 3,\n  }\n  expect(mergeAll(arr)).toEqual(expectedResult)\n})\n\ntest('case 2', () => {\n  expect(mergeAll([ { foo : 1 }, { bar : 2 }, { baz : 3 } ])).toEqual({\n    foo : 1,\n    bar : 2,\n    baz : 3,\n  })\n})\n\ndescribe('acts as if nil values are simply empty objects', () => {\n  it('if the first object is nil', () => {\n    expect(mergeAll([ null, { foo : 1 }, { foo : 2 }, { bar : 2 } ])).toEqual({\n      foo : 2,\n      bar : 2,\n    })\n  })\n\n  it('if the last object is nil', () => {\n    expect(mergeAll([ { foo : 1 }, { foo : 2 }, { bar : 2 }, undefined ])).toEqual({\n      foo : 2,\n      bar : 2,\n    })\n  })\n\n  it('if an intermediate object is nil', () => {\n    expect(mergeAll([ { foo : 1 }, { foo : 2 }, null, { bar : 2 } ])).toEqual({\n      foo : 2,\n      bar : 2,\n    })\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {mergeAll} from 'rambda'\n\ndescribe('R.mergeAll', () => {\n  it('with passing type', () => {\n    interface Output {\n      foo: number,\n      bar: number,\n    }\n    const result = mergeAll<Output>([{foo: 1}, {bar: 2}])\n    result.foo // $ExpectType number\n    result.bar // $ExpectType number\n  })\n\n  it('without passing type', () => {\n    const result = mergeAll([{foo: 1}, {bar: 2}])\n    result // $ExpectType unknown\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mergeAll)\n\n### mergeDeepLeft\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.mergeDeepLeft(%0A%20%20%7Ba%3A%20%7Bb%3A%201%7D%7D%2C%0A%20%20%7Ba%3A%20%7Bb%3A%202%2C%20c%3A%203%7D%7D%0A)%0A%2F%2F%20%3D%3E%20%7Ba%3A%20%7Bb%3A%201%2C%20c%3A%203%7D%7D\">Try this <strong>R.mergeDeepLeft</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mergeDeepLeft)\n\n### mergeDeepRight\n\n```typescript\n\nmergeDeepRight<Output>(target: object, newProps: object): Output\n```\n\nCreates a new object with the own properties of the first object merged with the own properties of the second object. If a key exists in both objects:\n\n  - and both values are objects, the two values will be recursively merged\n  - otherwise the value from the second object will be used.\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmergeDeepRight<Output>(target: object, newProps: object): Output;\nmergeDeepRight<Output>(target: object): (newProps: object) => Output;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.mergeDeepRight</strong> source</summary>\n\n```javascript\nimport { clone } from './clone.js'\nimport { type } from './type.js'\n\nexport function mergeDeepRight(target, source){\n  if (arguments.length === 1){\n    return sourceHolder => mergeDeepRight(target, sourceHolder)\n  }\n\n  const willReturn = clone(target)\n\n  Object.keys(source).forEach(key => {\n    if (type(source[ key ]) === 'Object'){\n      if (type(target[ key ]) === 'Object'){\n        willReturn[ key ] = mergeDeepRight(target[ key ], source[ key ])\n      } else {\n        willReturn[ key ] = source[ key ]\n      }\n    } else {\n      willReturn[ key ] = source[ key ]\n    }\n  })\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { mergeDeepRight } from './mergeDeepRight.js'\n\nconst student = {\n  name    : 'foo',\n  age     : 10,\n  contact : {\n    a     : 1,\n    email : 'foo@example.com',\n  },\n}\nconst teacher = {\n  age     : 40,\n  contact : { email : 'baz@example.com' },\n  songs   : { title : 'Remains the same' },\n}\n\ntest('when merging object with lists inside them', () => {\n  const a = {\n    a : [ 1, 2, 3 ],\n    b : [ 4, 5, 6 ],\n  }\n  const b = {\n    a : [ 7, 8, 9 ],\n    b : [ 10, 11, 12 ],\n  }\n  const result = mergeDeepRight(a, b)\n  const expected = {\n    a : [ 7, 8, 9 ],\n    b : [ 10, 11, 12 ],\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('happy', () => {\n  const result = mergeDeepRight(student, teacher)\n  const curryResult = mergeDeepRight(student)(teacher)\n  const expected = {\n    age     : 40,\n    name    : 'foo',\n    contact : {\n      a     : 1,\n      email : 'baz@example.com',\n    },\n    songs : { title : 'Remains the same' },\n  }\n\n  expect(result).toEqual(expected)\n  expect(curryResult).toEqual(expected)\n})\n\ntest('issue 650', () => {\n  expect(Object.keys(mergeDeepRight({ a : () => {} }, { b : () => {} }))).toEqual([\n    'a',\n    'b',\n  ])\n})\n\ntest('ramda compatible test 1', () => {\n  const a = {\n    w : 1,\n    x : 2,\n    y : { z : 3 },\n  }\n  const b = {\n    a : 4,\n    b : 5,\n    c : { d : 6 },\n  }\n  const result = mergeDeepRight(a, b)\n  const expected = {\n    w : 1,\n    x : 2,\n    y : { z : 3 },\n    a : 4,\n    b : 5,\n    c : { d : 6 },\n  }\n\n  expect(result).toEqual(expected)\n})\n\ntest('ramda compatible test 2', () => {\n  const a = {\n    a : {\n      b : 1,\n      c : 2,\n    },\n    y : 0,\n  }\n  const b = {\n    a : {\n      b : 3,\n      d : 4,\n    },\n    z : 0,\n  }\n  const result = mergeDeepRight(a, b)\n  const expected = {\n    a : {\n      b : 3,\n      c : 2,\n      d : 4,\n    },\n    y : 0,\n    z : 0,\n  }\n\n  expect(result).toEqual(expected)\n})\n\ntest('ramda compatible test 3', () => {\n  const a = {\n    w : 1,\n    x : { y : 2 },\n  }\n  const result = mergeDeepRight(a, { x : { y : 3 } })\n  const expected = {\n    w : 1,\n    x : { y : 3 },\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('functions are not discarded', () => {\n  const obj = { foo : () => {} }\n  expect(typeof mergeDeepRight(obj, {}).foo).toBe('function')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {mergeDeepRight} from 'rambda'\n\ninterface Output {\n  foo: {\n    bar: number,\n  },\n}\n\ndescribe('R.mergeDeepRight', () => {\n  const result = mergeDeepRight<Output>({foo: {bar: 1}}, {foo: {bar: 2}})\n  result.foo.bar // $ExpectType number\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mergeDeepRight)\n\n### mergeLeft\n\n```typescript\n\nmergeLeft<Output>(newProps: object, target: object): Output\n```\n\nSame as `R.merge`, but in opposite direction.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.mergeLeft(%0A%20%20%7Ba%3A%2010%7D%2C%0A%20%20%7Ba%3A%201%2C%20b%3A%202%7D%0A)%0A%2F%2F%20%3D%3E%20%7Ba%3A10%2C%20b%3A%202%7D\">Try this <strong>R.mergeLeft</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmergeLeft<Output>(newProps: object, target: object): Output;\nmergeLeft<Output>(newProps: object): (target: object) => Output;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.mergeLeft</strong> source</summary>\n\n```javascript\nimport { mergeRight } from './mergeRight.js'\n\nexport function mergeLeft(x, y){\n  if (arguments.length === 1) return _y => mergeLeft(x, _y)\n\n  return mergeRight(y, x)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { mergeLeft } from './mergeLeft.js'\n\nconst obj = {\n  foo : 1,\n  bar : 2,\n}\n\ntest('happy', () => {\n  expect(mergeLeft({ bar : 20 }, obj)).toEqual({\n    foo : 1,\n    bar : 20,\n  })\n})\n\ntest('curry', () => {\n  expect(mergeLeft({ baz : 3 })(obj)).toEqual({\n    foo : 1,\n    bar : 2,\n    baz : 3,\n  })\n})\n\ntest('when undefined or null instead of object', () => {\n  expect(mergeLeft(null, undefined)).toEqual({})\n  expect(mergeLeft(obj, null)).toEqual(obj)\n  expect(mergeLeft(obj, undefined)).toEqual(obj)\n  expect(mergeLeft(undefined, obj)).toEqual(obj)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {mergeLeft} from 'rambda'\n\ninterface Output {\n  foo: number,\n  bar: number,\n}\n\ndescribe('R.mergeLeft', () => {\n  const result = mergeLeft<Output>({foo: 1}, {bar: 2})\n  const curriedResult = mergeLeft<Output>({foo: 1})({bar: 2})\n\n  result.foo // $ExpectType number\n  result.bar // $ExpectType number\n  curriedResult.bar // $ExpectType number\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mergeLeft)\n\n### mergeRight\n\nIt creates a copy of `target` object with overwritten `newProps` properties. Previously known as `R.merge` but renamed after Ramda did the same.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20target%20%3D%20%7B%20'foo'%3A%200%2C%20'bar'%3A%201%20%7D%0Aconst%20newProps%20%3D%20%7B%20'foo'%3A%207%20%7D%0A%0Aconst%20result%20%3D%20R.mergeRight(target%2C%20newProps)%0A%2F%2F%20%3D%3E%20%7B%20'foo'%3A%207%2C%20'bar'%3A%201%20%7D\">Try this <strong>R.mergeRight</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mergeRight)\n\n### mergeWith\n\n```typescript\n\nmergeWith(fn: (x: any, z: any) => any, a: Record<string, unknown>, b: Record<string, unknown>): Record<string, unknown>\n```\n\nIt takes two objects and a function, which will be used when there is an overlap between the keys.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.mergeWith(%0A%20%20R.concat%2C%0A%20%20%7Bvalues%20%3A%20%5B%2010%2C%2020%20%5D%7D%2C%0A%20%20%7Bvalues%20%3A%20%5B%2015%2C%2035%20%5D%7D%0A)%0A%2F%2F%20%3D%3E%20%5B%2010%2C%2020%2C%2015%2C%2035%20%5D\">Try this <strong>R.mergeWith</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmergeWith(fn: (x: any, z: any) => any, a: Record<string, unknown>, b: Record<string, unknown>): Record<string, unknown>;\nmergeWith<Output>(fn: (x: any, z: any) => any, a: Record<string, unknown>, b: Record<string, unknown>): Output;\nmergeWith(fn: (x: any, z: any) => any, a: Record<string, unknown>): (b: Record<string, unknown>) => Record<string, unknown>;\nmergeWith<Output>(fn: (x: any, z: any) => any, a: Record<string, unknown>): (b: Record<string, unknown>) => Output;\nmergeWith(fn: (x: any, z: any) => any): <U, V>(a: U, b: V) => Record<string, unknown>;\nmergeWith<Output>(fn: (x: any, z: any) => any): <U, V>(a: U, b: V) => Output;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.mergeWith</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nexport function mergeWithFn(\n  mergeFn, aInput, bInput\n){\n  const a = aInput ?? {}\n  const b = bInput ?? {}\n  const willReturn = {}\n\n  Object.keys(a).forEach(key => {\n    if (b[ key ] === undefined) willReturn[ key ] = a[ key ]\n    else willReturn[ key ] = mergeFn(a[ key ], b[ key ])\n  })\n\n  Object.keys(b).forEach(key => {\n    if (willReturn[ key ] !== undefined) return\n\n    if (a[ key ] === undefined) willReturn[ key ] = b[ key ]\n    else willReturn[ key ] = mergeFn(a[ key ], b[ key ])\n  })\n\n  return willReturn\n}\n\nexport const mergeWith = curry(mergeWithFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { concat } from './concat.js'\nimport { mergeWithFn } from './mergeWith.js'\n\ntest('happy', () => {\n  const result = mergeWithFn(\n    concat,\n    {\n      a      : true,\n      values : [ 10, 20 ],\n    },\n    {\n      b      : true,\n      values : [ 15, 35 ],\n    }\n  )\n  const expected = {\n    a      : true,\n    b      : true,\n    values : [ 10, 20, 15, 35 ],\n  }\n  expect(result).toEqual(expected)\n})\n\n// https://github.com/ramda/ramda/pull/3222/files#diff-d925d9188b478d2f1d4b26012c6dddac374f9e9d7a336604d654b9a113bfc857\ndescribe('acts as if nil values are simply empty objects', () => {\n  it('if the first object is nil and the second empty', () => {\n    expect(mergeWithFn(\n      concat, undefined, {}\n    )).toEqual({})\n  })\n\n  it('if the first object is empty and the second nil', () => {\n    expect(mergeWithFn(\n      concat, {}, null\n    )).toEqual({})\n  })\n\n  it('if both objects are nil', () => {\n    expect(mergeWithFn(\n      concat, undefined, null\n    )).toEqual({})\n  })\n\n  it('if the first object is not empty and the second is nil', () => {\n    expect(mergeWithFn(\n      concat, { a : 'a' }, null\n    )).toEqual({ a : 'a' })\n  })\n\n  it('if the first object is nil and the second is not empty', () => {\n    expect(mergeWithFn(\n      concat, undefined, { a : 'a' }\n    )).toEqual({ a : 'a' })\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {concat, mergeWith} from 'rambda'\n\ninterface Output {\n  a: boolean,\n  b: boolean,\n  values: number[],\n}\nconst A = {\n  a: true,\n  values: [10, 20],\n}\nconst B = {\n  b: true,\n  values: [15, 35],\n}\n\ndescribe('R.mergeWith', () => {\n  test('no curry | without explicit types', () => {\n    const result = mergeWith(concat, A, B)\n    result // $ExpectType Record<string, unknown>\n  })\n  test('no curry | with explicit types', () => {\n    const result = mergeWith<Output>(concat, A, B)\n    result // $ExpectType Output\n  })\n  test('curry 1 | without explicit types', () => {\n    const result = mergeWith(concat, A)(B)\n    result // $ExpectType Record<string, unknown>\n  })\n  test('curry 1 | with explicit types', () => {\n    const result = mergeWith<Output>(concat, A)(B)\n    result // $ExpectType Output\n  })\n  test('curry 2 | without explicit types', () => {\n    const result = mergeWith(concat)(A, B)\n    result // $ExpectType Record<string, unknown>\n  })\n  test('curry 2 | with explicit types', () => {\n    const result = mergeWith<Output>(concat)(A, B)\n    result // $ExpectType Output\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#mergeWith)\n\n### min\n\nIt returns the lesser value between `x` and `y`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.min(5%2C%207)%2C%20%20%0A%20%20R.min('bar'%2C%20'foo')%2C%20%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B5%2C%20'bar'%5D\">Try this <strong>R.min</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#min)\n\n### minBy\n\nIt returns the lesser value between `x` and `y` according to `compareFn` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20compareFn%20%3D%20Math.abs%0A%0Aconst%20result%20%3D%20R.minBy(compareFn%2C%20-5%2C%202)%20%2F%2F%20%3D%3E%20-5\">Try this <strong>R.minBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#minBy)\n\n### modify\n\n```typescript\n\nmodify<K extends PropertyKey, T>(prop: K, fn: (value: T) => T): <U extends Record<K, T>>(object: U) => U\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.modify()%0A%2F%2F%20%3D%3E\">Try this <strong>R.modify</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nmodify<K extends PropertyKey, T>(prop: K, fn: (value: T) => T): <U extends Record<K, T>>(object: U) => U;\nmodify<U, K extends keyof U>(prop: K, fn: (value: U[K]) => U[K], object: U): U;\nmodify<K extends PropertyKey>(prop: K): {\n  <T>(fn: (value: T) => T): <U extends Record<K, T>>(object: U) => U;\n  <T, U extends Record<K, T>>(fn: (value: T) => T, object: U): U;\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.modify</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { isIterable } from './_internals/isIterable.js'\nimport { curry } from './curry.js'\nimport { updateFn } from './update.js'\n\nfunction modifyFn(\n  property, fn, iterable\n){\n  if (!isIterable(iterable)) return iterable\n  if (iterable[ property ] === undefined) return iterable\n  if (isArray(iterable)){\n    return updateFn(\n      property, fn(iterable[ property ]), iterable\n    )\n  }\n\n  return {\n    ...iterable,\n    [ property ] : fn(iterable[ property ]),\n  }\n}\n\nexport const modify = curry(modifyFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { modify as modifyRamda } from 'ramda'\n\nimport { compareCombinations, FALSY_VALUES } from './_internals/testUtils.js'\nimport { add } from './add.js'\nimport { compose } from './compose.js'\nimport { modify } from './modify.js'\n\nconst person = {\n  name : 'foo',\n  age  : 20,\n}\n\ntest('happy', () => {\n  expect(modify(\n    'age', x => x + 1, person\n  )).toEqual({\n    name : 'foo',\n    age  : 21,\n  })\n})\n\ntest('property is missing', () => {\n  expect(modify(\n    'foo', x => x + 1, person\n  )).toEqual(person)\n})\n\ntest('adjust if `array` at the given key with the `transformation` function', () => {\n  expect(modify(\n    1, add(1), [ 100, 1400 ]\n  )).toEqual([ 100, 1401 ])\n})\n\ndescribe('ignores transformations if the input value is not Array and Object', () => {\n  ;[ 42, undefined, null, '' ].forEach(value => {\n    it(`${ value }`, () => {\n      expect(modify(\n        'a', add(1), value\n      )).toEqual(value)\n    })\n  })\n})\n\nconst possibleProperties = [ ...FALSY_VALUES, 'foo', 0 ]\nconst possibleTransformers = [\n  ...FALSY_VALUES,\n  add(1),\n  add('foo'),\n  compose,\n  String,\n]\nconst possibleObjects = [\n  ...FALSY_VALUES,\n  {},\n  [ 1, 2, 3 ],\n  {\n    a   : 1,\n    foo : 2,\n  },\n  {\n    a   : 1,\n    foo : [ 1 ],\n  },\n  {\n    a   : 1,\n    foo : 'bar',\n  },\n]\n\ndescribe('brute force', () => {\n  compareCombinations({\n    fn          : modify,\n    fnRamda     : modifyRamda,\n    firstInput  : possibleProperties,\n    secondInput : possibleTransformers,\n    thirdInput  : possibleObjects,\n    callback    : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n        {\n          \"ERRORS_MESSAGE_MISMATCH\": 0,\n          \"ERRORS_TYPE_MISMATCH\": 0,\n          \"RESULTS_MISMATCH\": 0,\n          \"SHOULD_NOT_THROW\": 0,\n          \"SHOULD_THROW\": 0,\n          \"TOTAL_TESTS\": 630,\n        }\n      `)\n    },\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport { add, identity, map, modify, pipe, toUpper } from 'rambda';\n\ntype Obj = {\n\tfoo: string;\n\tbar: number;\n};\n\ndescribe('R.modify', () => {\n\tit('ramda tests', () => {\n\t\tconst result1 = modify('foo', toUpper, {} as Obj);\n\t\tresult1; // $ExpectType Obj\n\n\t\tconst result2 = modify('bar', add(1), {} as Obj);\n\t\tresult2; // $ExpectType Obj\n\n\t\tconst result3 = modify('foo', toUpper)({} as Obj);\n\t\tresult3; // $ExpectType Obj\n\n\t\tconst result4 = modify('bar', add(1))({} as Obj);\n\t\tresult4; // $ExpectType Obj\n\n\t\tconst result5 = modify('foo')(toUpper)({} as Obj);\n\t\tresult5; // $ExpectType Obj\n\n\t\tconst result6 = modify('bar')(add(1))({} as Obj);\n\t\tresult6; // $ExpectType Obj\n\n\t\tconst result7 = modify('foo')(toUpper, {} as Obj);\n\t\tresult7; // $ExpectType Obj\n\n\t\tconst result8 = modify('bar')(add(1), {} as Obj);\n\t\tresult8; // $ExpectType Obj\n\n\t\tconst result9 = modify('foo', identity, {} as Obj);\n\t\tresult9; // $ExpectType Obj\n\n\t\t// @ts-expect-error\n\t\tmodify('foo', add(1), {} as Obj);\n\t\t// @ts-expect-error\n\t\tmodify('bar', toUpper, {} as Obj);\n\n\t\tconst f = pipe(map<Obj, Obj>(modify('foo', toUpper)));\n\n\t\tf([] as Obj[]); // $ExpectType Obj[]\n\t});\n});\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#modify)\n\n### modifyPath\n\nIt changes a property of object on the base of provided path and transformer function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.modifyPath('a.b.c'%2C%20x%3D%3E%20x%2B1%2C%20%7Ba%3A%7Bb%3A%20%7Bc%3A1%7D%7D%7D)%0A%2F%2F%20%3D%3E%20%7Ba%3A%7Bb%3A%20%7Bc%3A2%7D%7D%7D\">Try this <strong>R.modifyPath</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#modifyPath)\n\n### modulo\n\nCurried version of `x%y`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.modulo(17%2C%203)%20%2F%2F%20%3D%3E%202\">Try this <strong>R.modulo</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#modulo)\n\n### move\n\nIt returns a copy of `list` with exchanged `fromIndex` and `toIndex` elements.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%5D%0Aconst%20result%20%3D%20R.move(0%2C%201%2C%20list)%0A%2F%2F%20%3D%3E%20%5B2%2C%201%2C%203%5D\">Try this <strong>R.move</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#move)\n\n### multiply\n\nCurried version of `x*y`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.multiply(2%2C%204)%20%2F%2F%20%3D%3E%208\">Try this <strong>R.multiply</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#multiply)\n\n### negate\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.negate(420)%2F%2F%20%3D%3E%20-420\">Try this <strong>R.negate</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#negate)\n\n### none\n\n```typescript\n\nnone<T>(predicate: (x: T) => boolean, list: T[]): boolean\n```\n\nIt returns `true`, if all members of array `list` returns `false`, when applied as argument to `predicate` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%200%2C%201%2C%202%2C%203%2C%204%20%5D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3E%206%0A%0Aconst%20result%20%3D%20R.none(predicate%2C%20arr)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.none</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nnone<T>(predicate: (x: T) => boolean, list: T[]): boolean;\nnone<T>(predicate: (x: T) => boolean): (list: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.none</strong> source</summary>\n\n```javascript\nexport function none(predicate, list){\n  if (arguments.length === 1) return _list => none(predicate, _list)\n\n  for (let i = 0; i < list.length; i++){\n    if (predicate(list[ i ])) return false\n  }\n\n  return true\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { none } from './none.js'\n\nconst isEven = n => n % 2 === 0\n\ntest('when true', () => {\n  expect(none(isEven, [ 1, 3, 5, 7 ])).toBeTrue()\n})\n\ntest('when false curried', () => {\n  expect(none(input => input > 1, [ 1, 2, 3 ])).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {none} from 'rambda'\n\ndescribe('R.none', () => {\n  it('happy', () => {\n    const result = none(\n      x => {\n        x // $ExpectType number\n        return x > 0\n      },\n      [1, 2, 3]\n    )\n    result // $ExpectType boolean\n  })\n  it('curried needs a type', () => {\n    const result = none<number>(x => {\n      x // $ExpectType number\n      return x > 0\n    })([1, 2, 3])\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#none)\n\n### not\n\n```typescript\n\nnot(input: any): boolean\n```\n\nIt returns a boolean negated version of `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.not(false)%20%2F%2F%20true\">Try this <strong>R.not</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nnot(input: any): boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.not</strong> source</summary>\n\n```javascript\nexport function not(input){\n  return !input\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { not } from './not.js'\n\ntest('not', () => {\n  expect(not(false)).toBeTrue()\n  expect(not(true)).toBeFalse()\n  expect(not(0)).toBeTrue()\n  expect(not(1)).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {not} from 'rambda'\n\ndescribe('R.not', () => {\n  it('happy', () => {\n    const result = not(4)\n\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#not)\n\n### nth\n\n```typescript\n\nnth(index: number, input: string): string\n```\n\nCurried version of `input[index]`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%5D%0Aconst%20str%20%3D%20'foo'%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.nth(2%2C%20list)%2C%0A%20%20R.nth(6%2C%20list)%2C%0A%20%20R.nth(0%2C%20str)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5B3%2C%20undefined%2C%20'f'%5D\">Try this <strong>R.nth</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nnth(index: number, input: string): string;\t\nnth<T>(index: number, input: T[]): T | undefined;\t\nnth(n: number): {\n  <T>(input: T[]): T | undefined;\n  (input: string): string;\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.nth</strong> source</summary>\n\n```javascript\nexport function nth(index, input){\n  if (arguments.length === 1) return _input => nth(index, _input)\n\n  const idx = index < 0 ? input.length + index : index\n\n  return Object.prototype.toString.call(input) === '[object String]' ?\n    input.charAt(idx) :\n    input[ idx ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { nth } from './nth.js'\n\ntest('happy', () => {\n  expect(nth(2, [ 1, 2, 3, 4 ])).toBe(3)\n})\n\ntest('with curry', () => {\n  expect(nth(2)([ 1, 2, 3, 4 ])).toBe(3)\n})\n\ntest('with string and correct index', () => {\n  expect(nth(2)('foo')).toBe('o')\n})\n\ntest('with string and invalid index', () => {\n  expect(nth(20)('foo')).toBe('')\n})\n\ntest('with negative index', () => {\n  expect(nth(-3)([ 1, 2, 3, 4 ])).toBe(2)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {nth} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.nth', () => {\n  it('happy', () => {\n    const result = nth(4, list)\n\n    result // $ExpectType number | undefined\n  })\n  it('curried', () => {\n    const result = nth(1)(list)\n\n    result // $ExpectType number | undefined\n  })\n})\n\ndescribe('R.nth - string', () => {\n  const str = 'abc'\n  it('happy', () => {\n    const result = nth(4, str)\n\n    result // $ExpectType string\n  })\n  it('curried', () => {\n    const result = nth(1)(str)\n\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#nth)\n\n### objOf\n\nIt creates an object with a single key-value pair.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.objOf('foo'%2C%20'bar')%0A%2F%2F%20%3D%3E%20%7Bfoo%3A%20'bar'%7D\">Try this <strong>R.objOf</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#objOf)\n\n### of\n\n```typescript\n\nof<T>(x: T): T[]\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.of(null)%3B%20%2F%2F%20%3D%3E%20%5Bnull%5D%0Aconst%20result%20%3D%20R.of(%5B42%5D)%3B%20%2F%2F%20%3D%3E%20%5B%5B42%5D%5D\">Try this <strong>R.of</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nof<T>(x: T): T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.of</strong> source</summary>\n\n```javascript\nexport function of(value){\n  return [ value ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { of } from './of.js'\n\ntest('happy', () => {\n  expect(of(3)).toEqual([ 3 ])\n\n  expect(of(null)).toEqual([ null ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {of} from 'rambda'\n\nconst list = [1, 2, 3]\n\ndescribe('R.of', () => {\n  it('happy', () => {\n    const result = of(4)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = of(list)\n\n    result // $ExpectType number[][]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#of)\n\n### omit\n\n```typescript\n\nomit<T, K extends string>(propsToOmit: K[], obj: T): Omit<T, K>\n```\n\nIt returns a partial copy of an `obj` without `propsToOmit` properties.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A%201%2C%20b%3A%202%2C%20c%3A%203%7D%0Aconst%20propsToOmit%20%3D%20'a%2Cc%2Cd'%0Aconst%20propsToOmitList%20%3D%20%5B'a'%2C%20'c'%2C%20'd'%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.omit(propsToOmit%2C%20Record%3Cstring%2C%20unknown%3E)%2C%20%0A%20%20R.omit(propsToOmitList%2C%20Record%3Cstring%2C%20unknown%3E)%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B%7Bb%3A%202%7D%2C%20%7Bb%3A%202%7D%5D\">Try this <strong>R.omit</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nomit<T, K extends string>(propsToOmit: K[], obj: T): Omit<T, K>;\nomit<K extends string>(propsToOmit: K[]): <T>(obj: T) => Omit<T, K>;\nomit<T, U>(propsToOmit: string, obj: T): U;\nomit<T, U>(propsToOmit: string): (obj: T) => U;\nomit<T>(propsToOmit: string, obj: object): T;\nomit<T>(propsToOmit: string): (obj: object) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.omit</strong> source</summary>\n\n```javascript\nimport { createPath } from './_internals/createPath.js'\nimport { includes } from './_internals/includes.js'\n\nexport function omit(propsToOmit, obj){\n  if (arguments.length === 1) return _obj => omit(propsToOmit, _obj)\n\n  if (obj === null || obj === undefined)\n    return undefined\n\n  const propsToOmitValue = createPath(propsToOmit, ',')\n  const willReturn = {}\n\n  for (const key in obj)\n    if (!includes(key, propsToOmitValue))\n      willReturn[ key ] = obj[ key ]\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { omit } from './omit.js'\n\ntest('with string as condition', () => {\n  const obj = {\n    a : 1,\n    b : 2,\n    c : 3,\n  }\n  const result = omit('a,c', obj)\n  const resultCurry = omit('a,c')(obj)\n  const expectedResult = { b : 2 }\n\n  expect(result).toEqual(expectedResult)\n  expect(resultCurry).toEqual(expectedResult)\n})\n\ntest.only('with number as property to omit', () => {\n  const obj = {\n    1 : 1,\n    b : 2,\n  }\n  const result = omit([ 1 ], obj)\n  expect(result).toEqual({ b : 2 })\n})\n\ntest('with null', () => {\n  expect(omit('a,b', null)).toBeUndefined()\n})\n\ntest('happy', () => {\n  expect(omit([ 'a', 'c' ])({\n    a : 'foo',\n    b : 'bar',\n    c : 'baz',\n  })).toEqual({ b : 'bar' })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {omit} from 'rambda'\n\ndescribe('R.omit with array as props input', () => {\n  it('allow Typescript to infer object type', () => {\n    const input = {a: 'foo', b: 2, c: 3, d: 4}\n    const result = omit(['b,c'], input)\n\n    result.a // $ExpectType string\n    result.d // $ExpectType number\n\n    const curriedResult = omit(['a,c'], input)\n\n    curriedResult.a // $ExpectType string\n    curriedResult.d // $ExpectType number\n  })\n\n  it('declare type of input object', () => {\n    interface Input {\n      a: string,\n      b: number,\n      c: number,\n      d: number,\n    }\n    const input: Input = {a: 'foo', b: 2, c: 3, d: 4}\n    const result = omit(['b,c'], input)\n    result // $ExpectType Omit<Input, \"b,c\">\n\n    result.a // $ExpectType string\n    result.d // $ExpectType number\n\n    const curriedResult = omit(['a,c'], input)\n\n    curriedResult.a // $ExpectType string\n    curriedResult.d // $ExpectType number\n  })\n})\n\ndescribe('R.omit with string as props input', () => {\n  interface Output {\n    b: number,\n    d: number,\n  }\n\n  it('explicitly declare output', () => {\n    const result = omit<Output>('a,c', {a: 1, b: 2, c: 3, d: 4})\n    result // $ExpectType Output\n    result.b // $ExpectType number\n\n    const curriedResult = omit<Output>('a,c')({a: 1, b: 2, c: 3, d: 4})\n\n    curriedResult.b // $ExpectType number\n  })\n\n  it('explicitly declare input and output', () => {\n    interface Input {\n      a: number,\n      b: number,\n      c: number,\n      d: number,\n    }\n    const result = omit<Input, Output>('a,c', {a: 1, b: 2, c: 3, d: 4})\n    result // $ExpectType Output\n    result.b // $ExpectType number\n\n    const curriedResult = omit<Input, Output>('a,c')({\n      a: 1,\n      b: 2,\n      c: 3,\n      d: 4,\n    })\n\n    curriedResult.b // $ExpectType number\n  })\n\n  it('without passing type', () => {\n    const result = omit('a,c', {a: 1, b: 2, c: 3, d: 4})\n    result // $ExpectType unknown\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#omit)\n\n### on\n\nIt passes the two inputs through `unaryFn` and then the results are passed as inputs the the `binaryFn` to receive the final result(`binaryFn(unaryFn(FIRST_INPUT), unaryFn(SECOND_INPUT))`). \n\nThis method is also known as P combinator.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.on((a%2C%20b)%20%3D%3E%20a%20%2B%20b%2C%20R.prop('a')%2C%20%7Bb%3A0%2C%20a%3A1%7D%2C%20%7Ba%3A2%7D)%0A%2F%2F%20%3D%3E%203\">Try this <strong>R.on</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#on)\n\n### once\n\n```typescript\n\nonce<T extends AnyFunction, C = unknown>(fn: T, context?: C): T\n```\n\nIt returns a function, which invokes only once `fn` function.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?let%20result%20%3D%200%0Aconst%20addOnce%20%3D%20R.once((x)%20%3D%3E%20result%20%3D%20result%20%2B%20x)%0A%0AaddOnce(1)%0Aconst%20result%20%3D%20addOnce(1)%0A%2F%2F%20%3D%3E%201\">Try this <strong>R.once</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nonce<T extends AnyFunction, C = unknown>(fn: T, context?: C): T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.once</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nfunction onceFn(fn, context){\n  let result\n\n  return function (){\n    if (fn){\n      result = fn.apply(context || this, arguments)\n      fn = null\n    }\n\n    return result\n  }\n}\n\nexport function once(fn, context){\n  if (arguments.length === 1){\n    const wrap = onceFn(fn, context)\n\n    return curry(wrap)\n  }\n\n  return onceFn(fn, context)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { once } from './once.js'\n\ntest('with counter', () => {\n  let counter = 0\n  const runOnce = once(x => {\n    counter++\n\n    return x + 2\n  })\n  expect(runOnce(1)).toBe(3)\n  runOnce(1)\n  runOnce(1)\n  runOnce(1)\n  expect(counter).toBe(1)\n})\n\ntest('happy path', () => {\n  const addOneOnce = once((\n    a, b, c\n  ) => a + b + c, 1)\n\n  expect(addOneOnce(\n    10, 20, 30\n  )).toBe(60)\n  expect(addOneOnce(40)).toBe(60)\n})\n\ntest('with context', () => {\n  const context = { name: 'fris' }\n  const getNameOnce = once(function (){\n    return this.name\n  }, context)\n\n  expect(getNameOnce()).toBe('fris')\n  expect(getNameOnce()).toBe('fris')\n  expect(getNameOnce()).toBe('fris')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {once} from 'rambda'\n\ndescribe('R.once', () => {\n  it('happy', () => {\n    const runOnce = once((x: number) => {\n      return x + 2\n    })\n\n    const result = runOnce(1)\n    result // $ExpectType number\n  })\n  it('with context', () => {\n    const runOnce = once(function (this: any, x: number) {\n      return x + 2\n    })\n\n    const result = runOnce.call({}, 1)\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#once)\n\n### or\n\nLogical OR\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?R.or(false%2C%20true)%3B%20%2F%2F%20%3D%3E%20true%0AR.or(false%2C%20false)%3B%20%2F%2F%20%3D%3E%20false%0Aconst%20result%20%3D%20R.or(false%2C%20'foo')%3B%20%2F%2F%20%3D%3E%20'foo'\">Try this <strong>R.or</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#or)\n\n### over\n\n```typescript\n\nover<S, A>(lens: Lens<S, A>): {\n  (fn: (a: A) => A): (value: S) => S\n```\n\nIt returns a copied **Object** or **Array** with modified value received by applying function `fn` to `lens` focus.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20headLens%20%3D%20R.lensIndex(0)%0A%20%0Aconst%20result%20%3D%20R.over(headLens%2C%20R.toUpper%2C%20%5B'foo'%2C%20'bar'%2C%20'baz'%5D)%20%2F%2F%20%3D%3E%20%5B'FOO'%2C%20'bar'%2C%20'baz'%5D\">Try this <strong>R.over</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nover<S, A>(lens: Lens<S, A>): {\n  (fn: (a: A) => A): (value: S) => S;\n  (fn: (a: A) => A, value: S): S;\n};\nover<S, A>(lens: Lens<S, A>, fn: (a: A) => A): (value: S) => S;\nover<S, A>(lens: Lens<S, A>, fn: (a: A) => A, value: S): S;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.over</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nconst Identity = x => ({\n  x,\n  map : fn => Identity(fn(x)),\n})\n\nfunction overFn(\n  lens, fn, object\n){\n  return lens(x => Identity(fn(x)))(object).x\n}\n\nexport const over = curry(overFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { assoc } from './assoc.js'\nimport { lens } from './lens.js'\nimport { lensIndex } from './lensIndex.js'\nimport { lensPath } from './lensPath.js'\nimport { over } from './over.js'\nimport { prop } from './prop.js'\nimport { toUpper } from './toUpper.js'\n\nconst testObject = {\n  foo : 'bar',\n  baz : {\n    a : 'x',\n    b : 'y',\n  },\n}\n\ntest('assoc lens', () => {\n  const assocLens = lens(prop('foo'), assoc('foo'))\n  const result = over(\n    assocLens, toUpper, testObject\n  )\n  const expected = {\n    ...testObject,\n    foo : 'BAR',\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('path lens', () => {\n  const pathLens = lensPath('baz.a')\n  const result = over(\n    pathLens, toUpper, testObject\n  )\n  const expected = {\n    ...testObject,\n    baz : {\n      a : 'X',\n      b : 'y',\n    },\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('index lens', () => {\n  const indexLens = lensIndex(0)\n  const result = over(indexLens, toUpper)([ 'foo', 'bar' ])\n  expect(result).toEqual([ 'FOO', 'bar' ])\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#over)\n\n### partial\n\n```typescript\n\npartial<V0, V1, T>(fn: (x0: V0, x1: V1) => T, args: [V0]): (x1: V1) => T\n```\n\nIt is very similar to `R.curry`, but you can pass initial arguments when you create the curried function.\n\n`R.partial` will keep returning a function until all the arguments that the function `fn` expects are passed.\nThe name comes from the fact that you partially inject the inputs.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20(title%2C%20firstName%2C%20lastName)%20%3D%3E%20%7B%0A%20%20return%20title%20%2B%20'%20'%20%2B%20firstName%20%2B%20'%20'%20%2B%20lastName%20%2B%20'!'%0A%7D%0A%0Aconst%20canPassAnyNumberOfArguments%20%3D%20R.partial(fn%2C%20'Hello')%0Aconst%20ramdaStyle%20%3D%20R.partial(fn%2C%20%5B'Hello'%5D)%0A%0Aconst%20finalFn%20%3D%20canPassAnyNumberOfArguments('Foo')%0A%0Aconst%20result%20%3D%20finalFn('Bar')%20%2F%2F%20%3D%3E%20%20'Hello%2C%20Foo%20Bar!'\">Try this <strong>R.partial</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npartial<V0, V1, T>(fn: (x0: V0, x1: V1) => T, args: [V0]): (x1: V1) => T;\npartial<V0, V1, V2, T>(fn: (x0: V0, x1: V1, x2: V2) => T, args: [V0, V1]): (x2: V2) => T;\npartial<V0, V1, V2, T>(fn: (x0: V0, x1: V1, x2: V2) => T, args: [V0]): (x1: V1, x2: V2) => T;\npartial<V0, V1, V2, V3, T>(\n  fn: (x0: V0, x1: V1, x2: V2, x3: V3) => T,\n  args: [V0, V1, V2],\n): (x2: V3) => T;\npartial<V0, V1, V2, V3, T>(\n  fn: (x0: V0, x1: V1, x2: V2, x3: V3) => T,\n  args: [V0, V1],\n): (x2: V2, x3: V3) => T;\npartial<V0, V1, V2, V3, T>(\n  fn: (x0: V0, x1: V1, x2: V2, x3: V3) => T,\n  args: [V0],\n): (x1: V1, x2: V2, x3: V3) => T;\npartial<T>(fn: (...a: any[]) => T, args: any[]): (...a: any[]) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.partial</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function partial(fn, ...args){\n  const len = fn.length\n\n  // If a single array argument is given, those are the args (a la Ramda).\n  // Otherwise, the variadic arguments are the args.\n  const argList = args.length === 1 && isArray(args[0]) ? args[0] : args\n\n  return (...rest) => {\n    if (argList.length + rest.length >= len){\n      return fn(...argList, ...rest)\n    }\n\n    return partial(fn, ...[ ...argList, ...rest ])\n  }\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { partial } from './partial.js'\nimport { type } from './type.js'\n\nconst greet = (\n  salutation, title, firstName, lastName\n) =>\n  [salutation, title, firstName, lastName]\n\ntest('happy', () => {\n  const canPassAnyNumberOfArguments = partial(\n    greet, 'Hello', 'Ms.'\n  )\n  const fn = canPassAnyNumberOfArguments('foo')\n  const sayHello = partial(greet, [ 'Hello' ])\n  const sayHelloRamda = partial(sayHello, [ 'Ms.' ])\n\n  expect(type(fn)).toBe('Function')\n\n  expect(fn('bar')).toStrictEqual(['Hello', 'Ms.', 'foo', 'bar'])\n  expect(sayHelloRamda('foo', 'bar')).toStrictEqual(['Hello', 'Ms.', 'foo', 'bar'])\n})\n\ntest('extra arguments are ignored', () => {\n  const canPassAnyNumberOfArguments = partial(\n    greet, 'Hello', 'Ms.'\n  )\n  const fn = canPassAnyNumberOfArguments('foo')\n\n  expect(type(fn)).toBe('Function')\n\n  expect(fn(\n    'bar', 1, 2\n  )).toStrictEqual(['Hello', 'Ms.', 'foo', 'bar'])\n})\n\ntest('when array is input', () => {\n  const fooFn = (\n    a, b, c, d\n  ) => ({\n    a,\n    b,\n    c,\n    d,\n  })\n  const barFn = partial(\n    fooFn, [ 1, 2 ], []\n  )\n\n  expect(barFn(1, 2)).toEqual({\n    a : [ 1, 2 ],\n    b : [],\n    c : 1,\n    d : 2,\n  })\n})\n\ntest('ramda spec', () => {\n  const sayHello = partial(greet, 'Hello')\n  const sayHelloToMs = partial(sayHello, 'Ms.')\n\n  expect(sayHelloToMs('Jane', 'Jones')).toStrictEqual(['Hello', 'Ms.', 'Jane', 'Jones'])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {partial} from 'rambda'\n\ndescribe('R.partial', () => {\n  it('happy', () => {\n    function fn(\n      aString: string,\n      aNumber: number,\n      aBoolean: boolean,\n      aNull: null\n    ) {\n      return {aString, aNumber, aBoolean, aNull}\n    }\n\n    // @ts-expect-error\n    partial(fn, 1)\n\n    const fn1 = partial(fn, ['a'])\n    partial(fn1, ['b'])\n\n    const fn2 = partial(fn1, [2])\n    const result = fn2(true, null)\n    result // $ExpectType { aString: string; aNumber: number; aBoolean: boolean; aNull: null; }\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#partial)\n\n### partialObject\n\n```typescript\n\npartialObject<Input, PartialInput, Output>(\n  fn: (input: Input) => Output, \n  partialInput: PartialInput,\n): (input: Pick<Input, Exclude<keyof Input, keyof PartialInput>>) => Output\n```\n\n`R.partialObject` is a curry helper designed specifically for functions accepting object as a single argument.\n\nInitially the function knows only a part from the whole input object and then `R.partialObject` helps in preparing the function for the second part, when it receives the rest of the input.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20(%7B%20a%2C%20b%2C%20c%20%7D)%20%3D%3E%20a%20%2B%20b%20%2B%20c%0Aconst%20curried%20%3D%20R.partialObject(fn%2C%20%7B%20a%20%3A%201%20%7D)%0Aconst%20result%20%3D%20curried(%7B%0A%20%20b%20%3A%202%2C%0A%20%20c%20%3A%203%2C%0A%7D)%0A%2F%2F%20%3D%3E%206\">Try this <strong>R.partialObject</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npartialObject<Input, PartialInput, Output>(\n  fn: (input: Input) => Output, \n  partialInput: PartialInput,\n): (input: Pick<Input, Exclude<keyof Input, keyof PartialInput>>) => Output;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.partialObject</strong> source</summary>\n\n```javascript\nimport { mergeDeepRight } from './mergeDeepRight.js'\n\nexport function partialObject(fn, input){\n  return nextInput => fn(mergeDeepRight(nextInput, input))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { delay } from './delay.js'\nimport { partialObject } from './partialObject.js'\nimport { type } from './type.js'\n\ntest('with plain function', () => {\n  const fn = ({ a, b, c }) => a + b + c\n  const curried = partialObject(fn, { a : 1 })\n\n  expect(type(curried)).toBe('Function')\n  expect(curried({\n    b : 2,\n    c : 3,\n  })).toBe(6)\n})\n\ntest('with function that throws an error', () => {\n  const fn = ({ a, b, c }) => {\n    throw new Error('foo')\n  }\n  const curried = partialObject(fn, { a : 1 })\n\n  expect(type(curried)).toBe('Function')\n  expect(() =>\n    curried({\n      b : 2,\n      c : 3,\n    })).toThrowErrorMatchingInlineSnapshot('\"foo\"')\n})\n\ntest('with async', async () => {\n  const fn = async ({ a, b, c }) => {\n    await delay(100)\n\n    return a + b + c\n  }\n\n  const curried = partialObject(fn, { a : 1 })\n\n  const result = await curried({\n    b : 2,\n    c : 3,\n  })\n\n  expect(result).toBe(6)\n})\n\ntest('async function throwing an error', async () => {\n  const fn = async ({ a, b, c }) => {\n    await delay(100)\n    throw new Error('foo')\n  }\n\n  const curried = partialObject(fn, { a : 1 })\n\n  try {\n    await curried({\n      b : 2,\n      c : 3,\n    })\n    expect(true).toBeFalsy()\n  } catch (e){\n    expect(e.message).toBe('foo')\n  }\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {partialObject, delay} from 'rambda'\n\ndescribe('R.partialObject', () => {\n  it('happy', () => {\n    interface Input {\n      a: number,\n      b: number,\n      c: string,\n    }\n    const fn = ({a, b, c}: Input) => a + b + c\n    const curried = partialObject(fn, {a: 1})\n    const result = curried({\n      b: 2,\n      c: 'foo',\n    })\n    result // $ExpectType string\n  })\n  it('asynchronous', async() => {\n    interface Input {\n      a: number,\n      b: number,\n      c: string,\n    }\n    const fn = async({a, b, c}: Input) => {\n      await delay(100)\n      return a + b + c\n    }\n    const curried = partialObject(fn, {a: 1})\n    const result = await curried({\n      b: 2,\n      c: 'foo',\n    })\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#partialObject)\n\n### partition\n\n```typescript\n\npartition<T>(\n  predicate: Predicate<T>,\n  input: T[]\n): [T[], T[]]\n```\n\nIt will return array of two objects/arrays according to `predicate` function. The first member holds all instances of `input` that pass the `predicate` function, while the second member - those who doesn't.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%5D%0Aconst%20obj%20%3D%20%7Ba%3A%201%2C%20b%3A%202%2C%20c%3A%203%7D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3E%202%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.partition(predicate%2C%20list)%2C%0A%20%20R.partition(predicate%2C%20Record%3Cstring%2C%20unknown%3E)%0A%5D%0Aconst%20expected%20%3D%20%5B%0A%20%20%5B%5B3%5D%2C%20%5B1%2C%202%5D%5D%2C%0A%20%20%5B%7Bc%3A%203%7D%2C%20%20%7Ba%3A%201%2C%20b%3A%202%7D%5D%2C%0A%5D%0A%2F%2F%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.partition</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npartition<T>(\n  predicate: Predicate<T>,\n  input: T[]\n): [T[], T[]];\npartition<T>(\n  predicate: Predicate<T>\n): (input: T[]) => [T[], T[]];\npartition<T>(\n  predicate: (x: T, prop?: string) => boolean,\n  input: { [key: string]: T}\n): [{ [key: string]: T}, { [key: string]: T}];\npartition<T>(\n  predicate: (x: T, prop?: string) => boolean\n): (input: { [key: string]: T}) => [{ [key: string]: T}, { [key: string]: T}];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.partition</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function partitionObject(predicate, iterable){\n  const yes = {}\n  const no = {}\n  Object.entries(iterable).forEach(([ prop, value ]) => {\n    if (predicate(value, prop)){\n      yes[ prop ] = value\n    } else {\n      no[ prop ] = value\n    }\n  })\n\n  return [ yes, no ]\n}\n\nexport function partitionArray(\n  predicate, list, indexed = false\n){\n  const yes = []\n  const no = []\n  let counter = -1\n\n  while (counter++ < list.length - 1){\n    if (\n      indexed ? predicate(list[ counter ], counter) : predicate(list[ counter ])\n    ){\n      yes.push(list[ counter ])\n    } else {\n      no.push(list[ counter ])\n    }\n  }\n\n  return [ yes, no ]\n}\n\nexport function partition(predicate, iterable){\n  if (arguments.length === 1){\n    return listHolder => partition(predicate, listHolder)\n  }\n  if (!isArray(iterable)) return partitionObject(predicate, iterable)\n\n  return partitionArray(predicate, iterable)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { partition } from './partition.js'\n\ntest('with array', () => {\n  const predicate = x => x > 2\n  const list = [ 1, 2, 3, 4 ]\n\n  const result = partition(predicate, list)\n  const expectedResult = [\n    [ 3, 4 ],\n    [ 1, 2 ],\n  ]\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('with object', () => {\n  const predicate = (value, prop) => {\n    expect(typeof prop).toBe('string')\n\n    return value > 2\n  }\n  const hash = {\n    a : 1,\n    b : 2,\n    c : 3,\n    d : 4,\n  }\n\n  const result = partition(predicate)(hash)\n  const expectedResult = [\n    {\n      c : 3,\n      d : 4,\n    },\n    {\n      a : 1,\n      b : 2,\n    },\n  ]\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('readme example', () => {\n  const list = [ 1, 2, 3 ]\n  const obj = {\n    a : 1,\n    b : 2,\n    c : 3,\n  }\n  const predicate = x => x > 2\n\n  const result = [ partition(predicate, list), partition(predicate, obj) ]\n  const expected = [\n    [ [ 3 ], [ 1, 2 ] ],\n    [\n      { c : 3 },\n      {\n        a : 1,\n        b : 2,\n      },\n    ],\n  ]\n  expect(result).toEqual(expected)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {partition} from 'rambda'\n\ndescribe('R.partition', () => {\n  it('with array', () => {\n    const predicate = (x: number) => {\n      return x > 2\n    }\n    const list = [1, 2, 3, 4]\n\n    const result = partition(predicate, list)\n    const curriedResult = partition(predicate)(list)\n    result // $ExpectType [number[], number[]]\n    curriedResult // $ExpectType [number[], number[]]\n  })\n\n  /*\n    revert to old version of `dtslint` and `R.partition` typing\n    as there is diff between VSCode types(correct) and dtslint(incorrect)\n    \n    it('with object', () => {\n      const predicate = (value: number, prop?: string) => {\n        return value > 2\n      }\n      const hash = {\n        a: 1,\n        b: 2,\n        c: 3,\n        d: 4,\n      }\n  \n      const result = partition(predicate, hash)\n      const curriedResult = partition(predicate)(hash)\n      result[0] // $xExpectType { [key: string]: number; }\n      result[1] // $xExpectType { [key: string]: number; }\n      curriedResult[0] // $xExpectType { [key: string]: number; }\n      curriedResult[1] // $xExpectType { [key: string]: number; }\n    })\n    */\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#partition)\n\n### path\n\n```typescript\n\npath<S, K0 extends keyof S = keyof S>(path: [K0], obj: S): S[K0]\n```\n\nIf `pathToSearch` is `'a.b'` then it will return `1` if `obj` is `{a:{b:1}}`.\n\nIt will return `undefined`, if such path is not found.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A%20%7Bb%3A%201%7D%7D%0Aconst%20pathToSearch%20%3D%20'a.b'%0Aconst%20pathToSearchList%20%3D%20%5B'a'%2C%20'b'%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.path(pathToSearch%2C%20obj)%2C%0A%20%20R.path(pathToSearchList%2C%20obj)%2C%0A%20%20R.path('a.b.c.d'%2C%20obj)%0A%5D%0A%2F%2F%20%3D%3E%20%5B1%2C%201%2C%20undefined%5D\">Try this <strong>R.path</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npath<S, K0 extends keyof S = keyof S>(path: [K0], obj: S): S[K0];\npath<S, K0 extends keyof S = keyof S, K1 extends keyof S[K0] = keyof S[K0]>(path: [K0, K1], obj: S): S[K0][K1];\npath<\n    S,\n    K0 extends keyof S = keyof S,\n    K1 extends keyof S[K0] = keyof S[K0],\n    K2 extends keyof S[K0][K1] = keyof S[K0][K1]\n>(path: [K0, K1, K2], obj: S): S[K0][K1][K2];\npath<\n    S,\n    K0 extends keyof S = keyof S,\n    K1 extends keyof S[K0] = keyof S[K0],\n    K2 extends keyof S[K0][K1] = keyof S[K0][K1],\n    K3 extends keyof S[K0][K1][K2] = keyof S[K0][K1][K2],\n>(path: [K0, K1, K2, K3], obj: S): S[K0][K1][K2][K3];\npath<\n    S,\n    K0 extends keyof S = keyof S,\n    K1 extends keyof S[K0] = keyof S[K0],\n    K2 extends keyof S[K0][K1] = keyof S[K0][K1],\n    K3 extends keyof S[K0][K1][K2] = keyof S[K0][K1][K2],\n    K4 extends keyof S[K0][K1][K2][K3] = keyof S[K0][K1][K2][K3],\n>(path: [K0, K1, K2, K3, K4], obj: S): S[K0][K1][K2][K3][K4];\npath<\n    S,\n    K0 extends keyof S = keyof S,\n    K1 extends keyof S[K0] = keyof S[K0],\n    K2 extends keyof S[K0][K1] = keyof S[K0][K1],\n    K3 extends keyof S[K0][K1][K2] = keyof S[K0][K1][K2],\n    K4 extends keyof S[K0][K1][K2][K3] = keyof S[K0][K1][K2][K3],\n    K5 extends keyof S[K0][K1][K2][K3][K4] = keyof S[K0][K1][K2][K3][K4],\n>(path: [K0, K1, K2, K3, K4, K5], obj: S): S[K0][K1][K2][K3][K4][K5];\npath<T>(pathToSearch: string, obj: any): T | undefined;\npath<T>(pathToSearch: string): (obj: any) => T | undefined;\npath<T>(pathToSearch: RamdaPath): (obj: any) => T | undefined;\npath<T>(pathToSearch: RamdaPath, obj: any): T | undefined;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.path</strong> source</summary>\n\n```javascript\nimport { createPath } from './_internals/createPath.js'\n\nexport function pathFn(pathInput, obj){\n  let willReturn = obj\n  let counter = 0\n\n  const pathArrValue = createPath(pathInput)\n\n  while (counter < pathArrValue.length){\n    if (willReturn === null || willReturn === undefined){\n      return undefined\n    }\n    if (willReturn[ pathArrValue[ counter ] ] === null) return undefined\n\n    willReturn = willReturn[ pathArrValue[ counter ] ]\n    counter++\n  }\n\n  return willReturn\n}\n\nexport function path(pathInput, obj){\n  if (arguments.length === 1) return _obj => path(pathInput, _obj)\n\n  if (obj === null || obj === undefined){\n    return undefined\n  }\n\n  return pathFn(pathInput, obj)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { path } from './path.js'\n\ntest('with array inside object', () => {\n  const obj = { a : { b : [ 1, { c : 1 } ] } }\n\n  expect(path('a.b.1.c', obj)).toBe(1)\n})\n\ntest('works with undefined', () => {\n  const obj = { a : { b : { c : 1 } } }\n\n  expect(path('a.b.c.d.f', obj)).toBeUndefined()\n  expect(path('foo.babaz', undefined)).toBeUndefined()\n  expect(path('foo.babaz')(undefined)).toBeUndefined()\n})\n\ntest('works with string instead of array', () => {\n  expect(path('foo.bar.baz')({ foo : { bar : { baz : 'yes' } } })).toBe('yes')\n})\n\ntest('path', () => {\n  expect(path([ 'foo', 'bar', 'baz' ])({ foo : { bar : { baz : 'yes' } } })).toBe('yes')\n  expect(path([ 'foo', 'bar', 'baz' ])(null)).toBeUndefined()\n  expect(path([ 'foo', 'bar', 'baz' ])({ foo : { bar : 'baz' } })).toBeUndefined()\n})\n\ntest('with number string in between', () => {\n\texpect(path(['a','1','b'], {a: [{b: 1}, {b: 2}]})).toBe(2)\n})\n\ntest('null is not a valid path', () => {\n  expect(path('audio_tracks', {\n    a            : 1,\n    audio_tracks : null,\n  })).toBeUndefined()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {path} from 'rambda'\n\nconst input = {a: {b: {c: true}}}\n\ndescribe('R.path with string as path', () => {\n  it('without specified output type', () => {\n    // $ExpectType unknown\n    path('a.b.c', input)\n    // $ExpectType unknown\n    path('a.b.c')(input)\n  })\n  it('with specified output type', () => {\n    // $ExpectType boolean | undefined\n    path<boolean>('a.b.c', input)\n    // $ExpectType boolean | undefined\n    path<boolean>('a.b.c')(input)\n  })\n})\n\ndescribe('R.path with list as path', () => {\n  it('with array as path', () => {\n    // $ExpectType boolean\n    path(['a', 'b', 'c'], input)\n    // $ExpectType unknown\n    path(['a', 'b', 'c'])(input)\n  })\n  test('shallow property', () => {\n    // $ExpectType number\n    path(['a'], {a: 1})\n\n    // $ExpectType unknown\n    path(['b'], {a: 1})\n  })\n  test('deep property', () => {\n    const testObject = {a: {b: {c: {d: {e: {f: 1}}}}}}\n    const result = path(['a', 'b', 'c', 'd', 'e', 'f'], testObject)\n    // $ExpectType number\n    result\n    const curriedResult = path(['a', 'b', 'c', 'd', 'e', 'f'])(testObject)\n    // $ExpectType unknown\n    curriedResult\n  })\n  test('issue #668 - path is not correct', () => {\n    const object = {\n      is: {\n        a: 'path',\n      },\n    }\n    const result = path(['is', 'not', 'a'], object)\n    // $ExpectType unknown\n    result\n    const curriedResult = path(['is', 'not', 'a'])(object)\n    // $ExpectType unknown\n    curriedResult\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#path)\n\n### pathEq\n\n```typescript\n\npathEq(pathToSearch: Path, target: any, input: any): boolean\n```\n\nIt returns `true` if `pathToSearch` of `input` object is equal to `target` value.\n\n`pathToSearch` is passed to `R.path`, which means that it can be either a string or an array. Also equality between `target` and the found value is determined by `R.equals`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20path%20%3D%20'a.b'%0Aconst%20target%20%3D%20%7Bc%3A%201%7D%0Aconst%20input%20%3D%20%7Ba%3A%20%7Bb%3A%20%7Bc%3A%201%7D%7D%7D%0A%0Aconst%20result%20%3D%20R.pathEq(%0A%20%20path%2C%0A%20%20target%2C%0A%20%20input%0A)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.pathEq</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npathEq(pathToSearch: Path, target: any, input: any): boolean;\npathEq(pathToSearch: Path, target: any): (input: any) => boolean;\npathEq(pathToSearch: Path): (target: any) => (input: any) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.pathEq</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { equals } from './equals.js'\nimport { path } from './path.js'\n\nfunction pathEqFn(\n  pathToSearch, target, input\n){\n  return equals(path(pathToSearch, input), target)\n}\n\nexport const pathEq = curry(pathEqFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { pathEq } from './pathEq.js'\n\ntest('when true', () => {\n  const path = 'a.b'\n  const obj = { a : { b : { c : 1 } } }\n  const target = { c : 1 }\n\n  expect(pathEq(\n    path, target, obj\n  )).toBeTrue()\n})\n\ntest('when false', () => {\n  const path = 'a.b'\n  const obj = { a : { b : 1 } }\n  const target = 2\n\n  expect(pathEq(path, target)(obj)).toBeFalse()\n})\n\ntest('when wrong path', () => {\n  const path = 'foo.bar'\n  const obj = { a : { b : 1 } }\n  const target = 2\n\n  expect(pathEq(\n    path, target, obj\n  )).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {pathEq} from 'rambda'\n\ndescribe('R.pathEq', () => {\n  it('with string path', () => {\n    const pathToSearch = 'a.b.c'\n    const input = {a: {b: {c: 1}}}\n    const target = {c: 1}\n\n    const result = pathEq(pathToSearch, input, target)\n    const curriedResult = pathEq(pathToSearch, input, target)\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n\n  it('with array path', () => {\n    const pathToSearch = ['a', 'b', 'c']\n    const input = {a: {b: {c: 1}}}\n    const target = {c: 1}\n\n    const result = pathEq(pathToSearch, input, target)\n    const curriedResult = pathEq(pathToSearch, input, target)\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n})\n\ndescribe('with ramda specs', () => {\n  const testPath = ['x', 0, 'y']\n  const testObj = {\n    x: [\n      {y: 2, z: 3},\n      {y: 4, z: 5},\n    ],\n  }\n\n  const result1 = pathEq(testPath, 2, testObj)\n  const result2 = pathEq(testPath, 2)(testObj)\n  const result3 = pathEq(testPath)(2)(testObj)\n  result1 // $ExpectType boolean\n  result2 // $ExpectType boolean\n  result3 // $ExpectType boolean\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pathEq)\n\n### pathOr\n\n```typescript\n\npathOr<T>(defaultValue: T, pathToSearch: Path, obj: any): T\n```\n\nIt reads `obj` input and returns either `R.path(pathToSearch, Record<string, unknown>)` result or `defaultValue` input.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20defaultValue%20%3D%20'DEFAULT_VALUE'%0Aconst%20pathToSearch%20%3D%20'a.b'%0Aconst%20pathToSearchList%20%3D%20%5B'a'%2C%20'b'%5D%0A%0Aconst%20obj%20%3D%20%7B%0A%20%20a%20%3A%20%7B%0A%20%20%20%20b%20%3A%201%0A%20%20%7D%0A%7D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.pathOr(DEFAULT_VALUE%2C%20pathToSearch%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pathOr(DEFAULT_VALUE%2C%20pathToSearchList%2C%20Record%3Cstring%2C%20unknown%3E)%2C%20%0A%20%20R.pathOr(DEFAULT_VALUE%2C%20'a.b.c'%2C%20Record%3Cstring%2C%20unknown%3E)%0A%5D%0A%2F%2F%20%3D%3E%20%5B1%2C%201%2C%20'DEFAULT_VALUE'%5D\">Try this <strong>R.pathOr</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npathOr<T>(defaultValue: T, pathToSearch: Path, obj: any): T;\npathOr<T>(defaultValue: T, pathToSearch: Path): (obj: any) => T;\npathOr<T>(defaultValue: T): (pathToSearch: Path) => (obj: any) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.pathOr</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { defaultTo } from './defaultTo.js'\nimport { path } from './path.js'\n\nfunction pathOrFn(\n  defaultValue, pathInput, obj\n){\n  return defaultTo(defaultValue, path(pathInput, obj))\n}\n\nexport const pathOr = curry(pathOrFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { pathOr } from './pathOr.js'\n\ntest('with undefined', () => {\n  const result = pathOr(\n    'foo', 'x.y', { x : { y : 1 } }\n  )\n\n  expect(result).toBe(1)\n})\n\ntest('with null', () => {\n  const result = pathOr(\n    'foo', 'x.y', null\n  )\n\n  expect(result).toBe('foo')\n})\n\ntest('with NaN', () => {\n  const result = pathOr(\n    'foo', 'x.y', NaN\n  )\n\n  expect(result).toBe('foo')\n})\n\ntest('curry case (x)(y)(z)', () => {\n  const result = pathOr('foo')('x.y.z')({ x : { y : { a : 1 } } })\n\n  expect(result).toBe('foo')\n})\n\ntest('curry case (x)(y,z)', () => {\n  const result = pathOr('foo', 'x.y.z')({ x : { y : { a : 1 } } })\n\n  expect(result).toBe('foo')\n})\n\ntest('curry case (x,y)(z)', () => {\n  const result = pathOr('foo')('x.y.z', { x : { y : { a : 1 } } })\n\n  expect(result).toBe('foo')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {pathOr} from 'rambda'\n\ndescribe('R.pathOr', () => {\n  it('with string path', () => {\n    const x = pathOr<string>('foo', 'x.y', {x: {y: 'bar'}})\n    x // $ExpectType string\n  })\n  it('with array path', () => {\n    const x = pathOr<string>('foo', ['x', 'y'], {x: {y: 'bar'}})\n    x // $ExpectType string\n  })\n  it('without passing type looks bad', () => {\n    const x = pathOr('foo', 'x.y', {x: {y: 'bar'}})\n    x // $ExpectType \"foo\"\n  })\n  it('curried', () => {\n    const x = pathOr<string>('foo', 'x.y')({x: {y: 'bar'}})\n    x // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pathOr)\n\n### paths\n\n```typescript\n\npaths<Input, T>(pathsToSearch: Path[], obj: Input): (T | undefined)[]\n```\n\nIt loops over members of `pathsToSearch` as `singlePath` and returns the array produced by `R.path(singlePath, Record<string, unknown>)`.\n\nBecause it calls `R.path`, then `singlePath` can be either string or a list.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7B%0A%20%20a%20%3A%20%7B%0A%20%20%20%20b%20%3A%20%7B%0A%20%20%20%20%20%20c%20%3A%201%2C%0A%20%20%20%20%20%20d%20%3A%202%0A%20%20%20%20%7D%0A%20%20%7D%0A%7D%0A%0Aconst%20result%20%3D%20R.paths(%5B%0A%20%20'a.b.c'%2C%0A%20%20'a.b.d'%2C%0A%20%20'a.b.c.d.e'%2C%0A%5D%2C%20Record%3Cstring%2C%20unknown%3E)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%2C%20undefined%5D\">Try this <strong>R.paths</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npaths<Input, T>(pathsToSearch: Path[], obj: Input): (T | undefined)[];\npaths<Input, T>(pathsToSearch: Path[]): (obj: Input) => (T | undefined)[];\npaths<T>(pathsToSearch: Path[], obj: any): (T | undefined)[];\npaths<T>(pathsToSearch: Path[]): (obj: any) => (T | undefined)[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.paths</strong> source</summary>\n\n```javascript\nimport { path } from './path.js'\n\nexport function paths(pathsToSearch, obj){\n  if (arguments.length === 1){\n    return _obj => paths(pathsToSearch, _obj)\n  }\n\n  return pathsToSearch.map(singlePath => path(singlePath, obj))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { paths } from './paths.js'\n\nconst obj = {\n  a : {\n    b : {\n      c : 1,\n      d : 2,\n    },\n  },\n  p : [ { q : 3 } ],\n  x : {\n    y : 'FOO',\n    z : [ [ {} ] ],\n  },\n}\n\ntest('with string path + curry', () => {\n  const pathsInput = [ 'a.b.d', 'p.q' ]\n  const expected = [ 2, undefined ]\n  const result = paths(pathsInput, obj)\n  const curriedResult = paths(pathsInput)(obj)\n\n  expect(result).toEqual(expected)\n  expect(curriedResult).toEqual(expected)\n})\n\ntest('with array path', () => {\n  const result = paths([\n    [ 'a', 'b', 'c' ],\n    [ 'x', 'y' ],\n  ],\n  obj)\n\n  expect(result).toEqual([ 1, 'FOO' ])\n})\n\ntest('takes a paths that contains indices into arrays', () => {\n  expect(paths([\n    [ 'p', 0, 'q' ],\n    [ 'x', 'z', 0, 0 ],\n  ],\n  obj)).toEqual([ 3, {} ])\n  expect(paths([\n    [ 'p', 0, 'q' ],\n    [ 'x', 'z', 2, 1 ],\n  ],\n  obj)).toEqual([ 3, undefined ])\n})\n\ntest('gets a deep property\\'s value from objects', () => {\n  expect(paths([ [ 'a', 'b' ] ], obj)).toEqual([ obj.a.b ])\n  expect(paths([ [ 'p', 0 ] ], obj)).toEqual([ obj.p[ 0 ] ])\n})\n\ntest('returns undefined for items not found', () => {\n  expect(paths([ [ 'a', 'x', 'y' ] ], obj)).toEqual([ undefined ])\n  expect(paths([ [ 'p', 2 ] ], obj)).toEqual([ undefined ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {paths} from 'rambda'\n\ninterface Input {\n  a: number,\n  b: number,\n  c: number,\n}\n\nconst input: Input = {a: 1, b: 2, c: 3}\n\ndescribe('R.paths', () => {\n  it('with dot notation', () => {\n    const result = paths<number>(['a.b.c', 'foo.bar'], input)\n    result // $ExpectType (number | undefined)[]\n  })\n\n  it('without type', () => {\n    const result = paths(['a.b.c', 'foo.bar'], input)\n    result // $ExpectType unknown[]\n  })\n\n  it('with array as path', () => {\n    const result = paths<number>([['a', 'b', 'c'], ['foo.bar']], input)\n    result // $ExpectType (number | undefined)[]\n  })\n\n  it('curried', () => {\n    const result = paths<number>([['a', 'b', 'c'], ['foo.bar']])(input)\n    result // $ExpectType (number | undefined)[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#paths)\n\n### pathSatisfies\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.pathSatisfies(%0A%20%20x%20%3D%3E%20x%20%3E%200%2C%0A%20%20%5B'a'%2C%20'b'%2C%20'c'%5D%2C%0A%20%20%7Ba%3A%20%7Bb%3A%20%7Bc%3A%201%7D%7D%7D%0A)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.pathSatisfies</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pathSatisfies)\n\n### pick\n\n```typescript\n\npick<T, K extends string | number | symbol>(propsToPick: K[], input: T): Pick<T, Exclude<keyof T, Exclude<keyof T, K>>>\n```\n\nIt returns a partial copy of an `input` containing only `propsToPick` properties.\n\n`input` can be either an object or an array.\n\nString annotation of `propsToPick` is one of the differences between `Rambda` and `Ramda`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7B%0A%20%20a%20%3A%201%2C%0A%20%20b%20%3A%20false%2C%0A%20%20foo%3A%20'cherry'%0A%7D%0Aconst%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20propsToPick%20%3D%20'a%2Cfoo'%0Aconst%20propsToPickList%20%3D%20%5B'a'%2C%20'foo'%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.pick(propsToPick%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pick(propsToPickList%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pick('a%2Cbar'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pick('bar'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pick(%5B0%2C%203%2C%205%5D%2C%20list)%2C%0A%20%20R.pick('0%2C3%2C5'%2C%20list)%2C%0A%5D%0A%0Aconst%20expected%20%3D%20%5B%0A%20%20%7Ba%3A1%2C%20foo%3A%20'cherry'%7D%2C%0A%20%20%7Ba%3A1%2C%20foo%3A%20'cherry'%7D%2C%0A%20%20%7Ba%3A1%7D%2C%0A%20%20%7B%7D%2C%0A%20%20%7B0%3A%201%2C%203%3A%204%7D%2C%0A%20%20%7B0%3A%201%2C%203%3A%204%7D%2C%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.pick</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npick<T, K extends string | number | symbol>(propsToPick: K[], input: T): Pick<T, Exclude<keyof T, Exclude<keyof T, K>>>;\npick<K extends string | number | symbol>(propsToPick: K[]): <T>(input: T) => Pick<T, Exclude<keyof T, Exclude<keyof T, K>>>;\npick<T, U>(propsToPick: string, input: T): U;\npick<T, U>(propsToPick: string): (input: T) => U;\npick<T>(propsToPick: string, input: object): T;\npick<T>(propsToPick: string): (input: object) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.pick</strong> source</summary>\n\n```javascript\nimport { createPath } from './_internals/createPath.js'\n\nexport function pick(propsToPick, input){\n  if (arguments.length === 1) return _input => pick(propsToPick, _input)\n\n  if (input === null || input === undefined){\n    return undefined\n  }\n  const keys = createPath(propsToPick, ',')\n  const willReturn = {}\n  let counter = 0\n\n  while (counter < keys.length){\n    if (keys[ counter ] in input){\n      willReturn[ keys[ counter ] ] = input[ keys[ counter ] ]\n    }\n    counter++\n  }\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { pick } from './pick.js'\n\nconst obj = {\n  a : 1,\n  b : 2,\n  c : 3,\n}\n\ntest('props to pick is a string', () => {\n  const result = pick('a,c', obj)\n  const resultCurry = pick('a,c')(obj)\n  const expectedResult = {\n    a : 1,\n    c : 3,\n  }\n\n  expect(result).toEqual(expectedResult)\n  expect(resultCurry).toEqual(expectedResult)\n})\n\ntest('when prop is missing', () => {\n  const result = pick('a,d,f', obj)\n  expect(result).toEqual({ a : 1 })\n})\n\ntest('with list indexes as props', () => {\n  const list = [ 1, 2, 3 ]\n  const expected = {\n    0 : 1,\n    2 : 3,\n  }\n  expect(pick([ 0, 2, 3 ], list)).toEqual(expected)\n  expect(pick('0,2,3', list)).toEqual(expected)\n})\n\ntest('props to pick is an array', () => {\n  expect(pick([ 'a', 'c' ])({\n    a : 'foo',\n    b : 'bar',\n    c : 'baz',\n  })).toEqual({\n    a : 'foo',\n    c : 'baz',\n  })\n\n  expect(pick([ 'a', 'd', 'e', 'f' ])({\n    a : 'foo',\n    b : 'bar',\n    c : 'baz',\n  })).toEqual({ a : 'foo' })\n\n  expect(pick('a,d,e,f')(null)).toBeUndefined()\n})\n\ntest('works with list as input and number as props - props to pick is an array', () => {\n  const result = pick([ 1, 2 ], [ 'a', 'b', 'c', 'd' ])\n  expect(result).toEqual({\n    1 : 'b',\n    2 : 'c',\n  })\n})\n\ntest('works with list as input and number as props - props to pick is a string', () => {\n  const result = pick('1,2', [ 'a', 'b', 'c', 'd' ])\n  expect(result).toEqual({\n    1 : 'b',\n    2 : 'c',\n  })\n})\n\ntest('with symbol', () => {\n  const symbolProp = Symbol('s')\n  expect(pick([ symbolProp ], { [ symbolProp ] : 'a' })).toMatchInlineSnapshot(`\n{\n  Symbol(s): \"a\",\n}\n`)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {pick} from 'rambda'\n\nconst input = {a: 'foo', b: 2, c: 3, d: 4}\n\ndescribe('R.pick with array as props input', () => {\n  it('without passing type', () => {\n    const result = pick(['a', 'c'], input)\n    result.a // $ExpectType string\n    result.c // $ExpectType number\n  })\n})\n\ndescribe('R.pick with string as props input', () => {\n  interface Input {\n    a: string,\n    b: number,\n    c: number,\n    d: number,\n  }\n  interface Output {\n    a: string,\n    c: number,\n  }\n  it('explicitly declare output', () => {\n    const result = pick<Output>('a,c', input)\n    result // $ExpectType Output\n    result.a // $ExpectType string\n    result.c // $ExpectType number\n\n    const curriedResult = pick<Output>('a,c')(input)\n\n    curriedResult.a // $ExpectType string\n  })\n\n  it('explicitly declare input and output', () => {\n    const result = pick<Input, Output>('a,c', input)\n    result // $ExpectType Output\n    result.a // $ExpectType string\n\n    const curriedResult = pick<Input, Output>('a,c')(input)\n\n    curriedResult.a // $ExpectType string\n  })\n\n  it('without passing type', () => {\n    const result = pick('a,c', input)\n    result // $ExpectType unknown\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pick)\n\n### pickAll\n\n```typescript\n\npickAll<T, K extends keyof T>(propsToPicks: K[], input: T): Pick<T, K>\n```\n\nSame as `R.pick` but it won't skip the missing props, i.e. it will assign them to `undefined`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7B%0A%20%20a%20%3A%201%2C%0A%20%20b%20%3A%20false%2C%0A%20%20foo%3A%20'cherry'%0A%7D%0Aconst%20propsToPick%20%3D%20'a%2Cfoo%2Cbar'%0Aconst%20propsToPickList%20%3D%20%5B'a'%2C%20'foo'%2C%20'bar'%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.pickAll(propsToPick%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pickAll(propsToPickList%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pickAll('a%2Cbar'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.pickAll('bar'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%5D%0Aconst%20expected%20%3D%20%5B%0A%20%20%7Ba%3A1%2C%20foo%3A%20'cherry'%2C%20bar%3A%20undefined%7D%2C%0A%20%20%7Ba%3A1%2C%20foo%3A%20'cherry'%2C%20bar%3A%20undefined%7D%2C%0A%20%20%7Ba%3A1%2C%20bar%3A%20undefined%7D%2C%0A%20%20%7Bbar%3A%20undefined%7D%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.pickAll</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npickAll<T, K extends keyof T>(propsToPicks: K[], input: T): Pick<T, K>;\npickAll<T, U>(propsToPicks: string[], input: T): U;\npickAll(propsToPicks: string[]): <T, U>(input: T) => U;\npickAll<T, U>(propsToPick: string, input: T): U;\npickAll<T, U>(propsToPick: string): (input: T) => U;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.pickAll</strong> source</summary>\n\n```javascript\nimport { createPath } from './_internals/createPath.js'\n\nexport function pickAll(propsToPick, obj){\n  if (arguments.length === 1) return _obj => pickAll(propsToPick, _obj)\n\n  if (obj === null || obj === undefined){\n    return undefined\n  }\n  const keysValue = createPath(propsToPick, ',')\n  const willReturn = {}\n  let counter = 0\n\n  while (counter < keysValue.length){\n    if (keysValue[ counter ] in obj){\n      willReturn[ keysValue[ counter ] ] = obj[ keysValue[ counter ] ]\n    } else {\n      willReturn[ keysValue[ counter ] ] = undefined\n    }\n    counter++\n  }\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { pickAll } from './pickAll.js'\n\ntest('when input is undefined or null', () => {\n  expect(pickAll('a', null)).toBeUndefined()\n  expect(pickAll('a', undefined)).toBeUndefined()\n})\n\ntest('with string as condition', () => {\n  const obj = {\n    a : 1,\n    b : 2,\n    c : 3,\n  }\n  const result = pickAll('a,c', obj)\n  const resultCurry = pickAll('a,c')(obj)\n  const expectedResult = {\n    a : 1,\n    b : undefined,\n    c : 3,\n  }\n\n  expect(result).toEqual(expectedResult)\n  expect(resultCurry).toEqual(expectedResult)\n})\n\ntest('with array as condition', () => {\n  expect(pickAll([ 'a', 'b', 'c' ], {\n    a : 'foo',\n    c : 'baz',\n  })).toEqual({\n    a : 'foo',\n    b : undefined,\n    c : 'baz',\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {pickAll} from 'rambda'\n\ninterface Input {\n  a: string,\n  b: number,\n  c: number,\n  d: number,\n}\ninterface Output {\n  a?: string,\n  c?: number,\n}\nconst input = {a: 'foo', b: 2, c: 3, d: 4}\n\ndescribe('R.pickAll with array as props input', () => {\n  it('without passing type', () => {\n    const result = pickAll(['a', 'c'], input)\n    result.a // $ExpectType string\n    result.c // $ExpectType number\n  })\n  it('without passing type + curry', () => {\n    const result = pickAll(['a', 'c'])(input)\n    result // $ExpectType unknown\n  })\n  it('explicitly passing types', () => {\n    const result = pickAll<Input, Output>(['a', 'c'], input)\n    result.a // $ExpectType string | undefined\n    result.c // $ExpectType number | undefined\n  })\n})\n\ndescribe('R.pickAll with string as props input', () => {\n  it('without passing type', () => {\n    const result = pickAll('a,c', input)\n    result // $ExpectType unknown\n  })\n  it('without passing type + curry', () => {\n    const result = pickAll('a,c')(input)\n    result // $ExpectType unknown\n  })\n  it('explicitly passing types', () => {\n    const result = pickAll<Input, Output>('a,c', input)\n    result.a // $ExpectType string | undefined\n    result.c // $ExpectType number | undefined\n  })\n  it('explicitly passing types + curry', () => {\n    const result = pickAll<Input, Output>('a,c')(input)\n    result.a // $ExpectType string | undefined\n    result.c // $ExpectType number | undefined\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pickAll)\n\n### pickBy\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.pickBy(%0A%20%20x%20%3D%3E%20x%20%3E%201%2C%0A%20%20%7Ba%3A%201%2C%20b%3A%202%2C%20c%3A%203%7D%0A)%0A%2F%2F%20%3D%3E%20%7Bb%3A%202%2C%20c%3A%203%7D\">Try this <strong>R.pickBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pickBy)\n\n### pipe\n\nIt performs left-to-right function composition.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.pipe(%0A%20%20R.filter(val%20%3D%3E%20val%20%3E%202)%2C%0A%20%20R.map(a%20%3D%3E%20a%20*%202)%0A)(%5B1%2C%202%2C%203%2C%204%5D)%0A%0A%2F%2F%20%3D%3E%20%5B6%2C%208%5D\">Try this <strong>R.pipe</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pipe)\n\n### pluck\n\n```typescript\n\npluck<K extends keyof T, T>(property: K, list: T[]): T[K][]\n```\n\nIt returns list of the values of `property` taken from the all objects inside `list`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%7Ba%3A%201%7D%2C%20%7Ba%3A%202%7D%2C%20%7Bb%3A%203%7D%5D%0Aconst%20property%20%3D%20'a'%0A%0Aconst%20result%20%3D%20R.pluck(property%2C%20list)%20%0A%2F%2F%20%3D%3E%20%5B1%2C%202%5D\">Try this <strong>R.pluck</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npluck<K extends keyof T, T>(property: K, list: T[]): T[K][];\npluck<T>(property: number, list: { [k: number]: T }[]):  T[];\npluck<P extends string>(property: P): <T>(list: Record<P, T>[]) => T[];\npluck(property: number): <T>(list: { [k: number]: T }[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.pluck</strong> source</summary>\n\n```javascript\nimport { map } from './map.js'\n\nexport function pluck(property, list){\n  if (arguments.length === 1) return _list => pluck(property, _list)\n\n  const willReturn = []\n\n  map(x => {\n    if (x[ property ] !== undefined){\n      willReturn.push(x[ property ])\n    }\n  }, list)\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { pluck } from './pluck.js'\n\ntest('happy', () => {\n  expect(pluck('a')([ { a : 1 }, { a : 2 }, { b : 1 } ])).toEqual([ 1, 2 ])\n})\n\ntest('with undefined', () => {\n  expect(pluck(undefined)([ { a : 1 }, { a : 2 }, { b : 1 } ])).toEqual([ ])\n})\n\ntest('with number', () => {\n  const input = [\n    [ 1, 2 ],\n    [ 3, 4 ],\n  ]\n\n  expect(pluck(0, input)).toEqual([ 1, 3 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {pluck} from 'rambda'\n\ndescribe('R.pluck', () => {\n  it('with object', () => {\n    interface ListMember {\n      a: number,\n      b: string,\n    }\n    const input: ListMember[] = [\n      {a: 1, b: 'foo'},\n      {a: 2, b: 'bar'},\n    ]\n    const resultA = pluck('a', input)\n    const resultB = pluck('b')(input)\n    resultA // $ExpectType number[]\n    resultB // $ExpectType string[]\n  })\n\n  it('with array', () => {\n    const input = [\n      [1, 2],\n      [3, 4],\n      [5, 6],\n    ]\n    const result = pluck(0, input)\n    const resultCurry = pluck(0)(input)\n    result // $ExpectType number[]\n    resultCurry // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#pluck)\n\n### prepend\n\n```typescript\n\nprepend<T>(xToPrepend: T, iterable: T[]): T[]\n```\n\nIt adds element `x` at the beginning of `list`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.prepend('foo'%2C%20%5B'bar'%2C%20'baz'%5D)%0A%2F%2F%20%3D%3E%20%5B'foo'%2C%20'bar'%2C%20'baz'%5D\">Try this <strong>R.prepend</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nprepend<T>(xToPrepend: T, iterable: T[]): T[];\nprepend<T, U>(xToPrepend: T, iterable: IsFirstSubtypeOfSecond<T, U>[]) : U[];\nprepend<T>(xToPrepend: T): <U>(iterable: IsFirstSubtypeOfSecond<T, U>[]) => U[];\nprepend<T>(xToPrepend: T): (iterable: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.prepend</strong> source</summary>\n\n```javascript\nexport function prepend(x, input){\n  if (arguments.length === 1) return _input => prepend(x, _input)\n\n  if (typeof input === 'string') return [ x ].concat(input.split(''))\n\n  return [ x ].concat(input)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { prepend } from './prepend.js'\n\ntest('happy', () => {\n  expect(prepend('yes', [ 'foo', 'bar', 'baz' ])).toEqual([\n    'yes',\n    'foo',\n    'bar',\n    'baz',\n  ])\n})\n\ntest('with empty list', () => {\n  expect(prepend('foo')([])).toEqual([ 'foo' ])\n})\n\ntest('with string instead of array', () => {\n  expect(prepend('foo')('bar')).toEqual([ 'foo', 'b', 'a', 'r' ])\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#prepend)\n\n### product\n\n```typescript\n\nproduct(list: number[]): number\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.product(%5B%202%2C%203%2C%204%20%5D)%0A%2F%2F%20%3D%3E%2024)\">Try this <strong>R.product</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nproduct(list: number[]): number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.product</strong> source</summary>\n\n```javascript\nimport { multiply } from './multiply.js'\nimport { reduce } from './reduce.js'\n\nexport const product = reduce(multiply, 1)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { product } from './product.js'\n\ntest('happy', () => {\n  expect(product([ 2, 3, 4 ])).toBe(24)\n})\n\ntest('bad input', () => {\n  expect(product([ null ])).toBe(0)\n  expect(product([])).toBe(1)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {product} from 'rambda'\n\ndescribe('R.product', () => {\n  it('happy', () => {\n    const result = product([1, 2, 3])\n\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#product)\n\n### prop\n\n```typescript\n\nprop<_, P extends keyof never, T>(p: P, value: T): Prop<T, P>\n```\n\nIt returns the value of property `propToFind` in `obj`.\n\nIf there is no such property, it returns `undefined`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.prop('x'%2C%20%7Bx%3A%20100%7D)%2C%20%0A%20%20R.prop('x'%2C%20%7Ba%3A%201%7D)%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B100%2C%20undefined%5D\">Try this <strong>R.prop</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nprop<_, P extends keyof never, T>(p: P, value: T): Prop<T, P>;\nprop<V>(p: keyof never, value: unknown): V;\nprop<_, P extends keyof never>(p: P): <T>(value: T) => Prop<T, P>;\nprop<V>(p: keyof never): (value: unknown) => V;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.prop</strong> source</summary>\n\n```javascript\nexport function propFn(searchProperty, obj){\n  if (!obj) return undefined\n\n  return obj[ searchProperty ]\n}\n\nexport function prop(searchProperty, obj){\n  if (arguments.length === 1) return _obj => prop(searchProperty, _obj)\n\n  return propFn(searchProperty, obj)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { prop } from './prop.js'\n\ntest('prop', () => {\n  expect(prop('foo')({ foo : 'baz' })).toBe('baz')\n\n  expect(prop('bar')({ foo : 'baz' })).toBeUndefined()\n\n  expect(prop('bar')(null)).toBeUndefined()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {prop} from 'rambda'\n\ndescribe('R.prop', () => {\n  interface Foo {\n    a: number,\n    b: string,\n    c?: number,\n  }\n  const obj: Foo = {a: 1, b: 'foo'}\n\n  it('issue #553', () => {\n    const result = {\n      a: prop('a', obj),\n      b: prop('b', obj),\n      c: prop('c', obj),\n    }\n    const curriedResult = {\n      a: prop('a')(obj),\n      b: prop('b')(obj),\n      c: prop('c')(obj),\n    }\n\n    result // $ExpectType { a: number; b: string; c: number | undefined; }\n    curriedResult // $ExpectType { a: number; b: string; c: number | undefined; }\n  })\n})\n\ndescribe('with number as prop', () => {\n  const list = [1, 2, 3]\n  const index = 1\n  it('happy', () => {\n    const result = prop(index, list)\n\n    result // $ExpectType number\n  })\n  it('curried require explicit type', () => {\n    const result = prop<number>(index)(list)\n\n    result // $ExpectType number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#prop)\n\n### propEq\n\n```typescript\n\npropEq<K extends string | number>(valueToMatch: any, propToFind: K, obj: Record<K, any>): boolean\n```\n\nIt returns true if `obj` has property `propToFind` and its value is equal to `valueToMatch`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7B%20foo%3A%20'bar'%20%7D%0Aconst%20secondObj%20%3D%20%7B%20foo%3A%201%20%7D%0A%0Aconst%20propToFind%20%3D%20'foo'%0Aconst%20valueToMatch%20%3D%20'bar'%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.propEq(propToFind%2C%20valueToMatch%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.propEq(propToFind%2C%20valueToMatch%2C%20secondRecord%3Cstring%2C%20unknown%3E)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.propEq</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npropEq<K extends string | number>(valueToMatch: any, propToFind: K, obj: Record<K, any>): boolean;\npropEq<K extends string | number>(valueToMatch: any, propToFind: K): (obj: Record<K, any>) => boolean;\npropEq(valueToMatch: any): {\n  <K extends string | number>(propToFind: K, obj: Record<K, any>): boolean;\n  <K extends string | number>(propToFind: K): (obj: Record<K, any>) => boolean;\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.propEq</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { equals } from './equals.js'\nimport { prop } from './prop.js'\n\nfunction propEqFn(\n  valueToMatch, propToFind, obj\n){\n  if (!obj) return false\n\n  return equals(valueToMatch, prop(propToFind, obj))\n}\n\nexport const propEq = curry(propEqFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { BAR, FOO } from './_internals/testUtils.js'\nimport { propEq } from './propEq.js'\n\ntest('happy', () => {\n  const obj = { [ FOO ] : BAR }\n  expect(propEq(BAR, FOO)(obj)).toBeTrue()\n  expect(propEq(1, FOO)(obj)).toBeFalse()\n  expect(propEq(1)(FOO)(obj)).toBeFalse()\n  expect(propEq(\n    1, 1, null\n  )).toBeFalse()\n})\n\ntest('returns false if called with a null or undefined object', () => {\n  expect(propEq(\n    'name', 'Abby', null\n  )).toBeFalse()\n  expect(propEq(\n    'name', 'Abby', undefined\n  )).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {propEq} from 'rambda'\n\nconst property = 'foo'\nconst numberProperty = 1\nconst value = 'bar'\nconst obj = {[property]: value}\nconst objWithNumberIndex = {[numberProperty]: value}\n\ndescribe('R.propEq', () => {\n  it('happy', () => {\n    const result = propEq(value, property, obj)\n    result // $ExpectType boolean\n  })\n\n  it('number is property', () => {\n    const result = propEq(value, 1, objWithNumberIndex)\n    result // $ExpectType boolean\n  })\n\n  it('with optional property', () => {\n    interface MyType {\n      optional?: string | number,\n    }\n\n    const myObject: MyType = {}\n    const valueToFind = '1111'\n    // @ts-expect-error\n    propEq(valueToFind, 'optional', myObject)\n  })\n\n  it('imported from @types/ramda', () => {\n    interface A {\n      foo: string | null,\n    }\n    const obj: A = {\n      foo: 'bar',\n    }\n    const value = ''\n    const result = propEq(value, 'foo')(obj)\n    result // $ExpectType boolean\n\n    // @ts-expect-error\n    propEq(value, 'bar')(obj)\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#propEq)\n\n### propIs\n\n```typescript\n\npropIs<C extends AnyFunction, K extends keyof any>(type: C, name: K, obj: any): obj is Record<K, ReturnType<C>>\n```\n\nIt returns `true` if `property` of `obj` is from `target` type.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A1%2C%20b%3A%20'foo'%7D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.propIs(Number%2C%20'a'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.propIs(String%2C%20'b'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.propIs(Number%2C%20'b'%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%2C%20false%5D\">Try this <strong>R.propIs</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npropIs<C extends AnyFunction, K extends keyof any>(type: C, name: K, obj: any): obj is Record<K, ReturnType<C>>;\npropIs<C extends AnyConstructor, K extends keyof any>(type: C, name: K, obj: any): obj is Record<K, InstanceType<C>>;\npropIs<C extends AnyFunction, K extends keyof any>(type: C, name: K): (obj: any) => obj is Record<K, ReturnType<C>>;\npropIs<C extends AnyConstructor, K extends keyof any>(type: C, name: K): (obj: any) => obj is Record<K, InstanceType<C>>;\npropIs<C extends AnyFunction>(type: C): {\n    <K extends keyof any>(name: K, obj: any): obj is Record<K, ReturnType<C>>;\n    <K extends keyof any>(name: K): (obj: any) => obj is Record<K, ReturnType<C>>;\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.propIs</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { is } from './is.js'\n\nfunction propIsFn(\n  targetPrototype, property, obj\n){\n  return is(targetPrototype, obj[ property ])\n}\n\nexport const propIs = curry(propIsFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { propIs } from './propIs.js'\n\nconst obj = {\n  a : 1,\n  b : 'foo',\n}\n\ntest('when true', () => {\n  expect(propIs(\n    Number, 'a', obj\n  )).toBeTrue()\n  expect(propIs(\n    String, 'b', obj\n  )).toBeTrue()\n})\n\ntest('when false', () => {\n  expect(propIs(\n    String, 'a', obj\n  )).toBeFalse()\n  expect(propIs(\n    Number, 'b', obj\n  )).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {propIs} from 'rambda'\n\nconst property = 'a'\nconst obj = {a: 1}\n\ndescribe('R.propIs', () => {\n  it('happy', () => {\n    const result = propIs(Number, property, obj)\n    result // $ExpectType boolean\n  })\n\n  it('curried', () => {\n    const result = propIs(Number, property)(obj)\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#propIs)\n\n### propOr\n\n```typescript\n\npropOr<T, P extends string>(defaultValue: T, property: P, obj: Partial<Record<P, T>> | undefined): T\n```\n\nIt returns either `defaultValue` or the value of `property` in `obj`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A%201%7D%0Aconst%20defaultValue%20%3D%20'DEFAULT_VALUE'%0Aconst%20property%20%3D%20'a'%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.propOr(defaultValue%2C%20property%2C%20Record%3Cstring%2C%20unknown%3E)%2C%0A%20%20R.propOr(defaultValue%2C%20'foo'%2C%20Record%3Cstring%2C%20unknown%3E)%0A%5D%0A%2F%2F%20%3D%3E%20%5B1%2C%20'DEFAULT_VALUE'%5D\">Try this <strong>R.propOr</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npropOr<T, P extends string>(defaultValue: T, property: P, obj: Partial<Record<P, T>> | undefined): T;\npropOr<T, P extends string>(defaultValue: T, property: P): (obj: Partial<Record<P, T>> | undefined) => T;\npropOr<T>(defaultValue: T): {\n  <P extends string>(property: P, obj: Partial<Record<P, T>> | undefined): T;\n  <P extends string>(property: P): (obj: Partial<Record<P, T>> | undefined) => T;\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.propOr</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { defaultTo } from './defaultTo.js'\n\nfunction propOrFn(\n  defaultValue, property, obj\n){\n  if (!obj) return defaultValue\n\n  return defaultTo(defaultValue, obj[ property ])\n}\n\nexport const propOr = curry(propOrFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { propOr } from './propOr.js'\n\ntest('propOr (result)', () => {\n  const obj = { a : 1 }\n  expect(propOr(\n    'default', 'a', obj\n  )).toBe(1)\n  expect(propOr(\n    'default', 'notExist', obj\n  )).toBe('default')\n  expect(propOr(\n    'default', 'notExist', null\n  )).toBe('default')\n})\n\ntest('propOr (currying)', () => {\n  const obj = { a : 1 }\n  expect(propOr('default')('a', obj)).toBe(1)\n  expect(propOr('default', 'a')(obj)).toBe(1)\n  expect(propOr('default')('notExist', obj)).toBe('default')\n  expect(propOr('default', 'notExist')(obj)).toBe('default')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {propOr} from 'rambda'\n\nconst obj = {foo: 'bar'}\nconst property = 'foo'\nconst fallback = 'fallback'\n\ndescribe('R.propOr', () => {\n  it('happy', () => {\n    const result = propOr(fallback, property, obj)\n    result // $ExpectType string\n  })\n  it('curry 1', () => {\n    const result = propOr(fallback)(property, obj)\n    result // $ExpectType string\n  })\n  it('curry 2', () => {\n    const result = propOr(fallback, property)(obj)\n    result // $ExpectType string\n  })\n  it('curry 3', () => {\n    const result = propOr(fallback)(property)(obj)\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#propOr)\n\n### props\n\n```typescript\n\nprops<P extends string, T>(propsToPick: P[], obj: Record<P, T>): T[]\n```\n\nIt takes list with properties `propsToPick` and returns a list with property values in `obj`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.props(%0A%20%20%5B'a'%2C%20'b'%5D%2C%20%0A%20%20%7Ba%3A1%2C%20c%3A3%7D%0A)%0A%2F%2F%20%3D%3E%20%5B1%2C%20undefined%5D\">Try this <strong>R.props</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nprops<P extends string, T>(propsToPick: P[], obj: Record<P, T>): T[];\nprops<P extends string>(propsToPick: P[]): <T>(obj: Record<P, T>) => T[];\nprops<P extends string, T>(propsToPick: P[]): (obj: Record<P, T>) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.props</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { mapArray } from './map.js'\n\nexport function props(propsToPick, obj){\n  if (arguments.length === 1){\n    return _obj => props(propsToPick, _obj)\n  }\n  if (!isArray(propsToPick)){\n    throw new Error('propsToPick is not a list')\n  }\n\n  return mapArray(prop => obj[ prop ], propsToPick)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { props } from './props.js'\n\nconst obj = {\n  a : 1,\n  b : 2,\n}\nconst propsToPick = [ 'a', 'c' ]\n\ntest('happy', () => {\n  const result = props(propsToPick, obj)\n  expect(result).toEqual([ 1, undefined ])\n})\n\ntest('curried', () => {\n  const result = props(propsToPick)(obj)\n  expect(result).toEqual([ 1, undefined ])\n})\n\ntest('wrong input', () => {\n  expect(() => props(null)(obj)).toThrowErrorMatchingInlineSnapshot('\"propsToPick is not a list\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {props} from 'rambda'\n\nconst obj = {a: 1, b: 2}\n\ndescribe('R.props', () => {\n  it('happy', () => {\n    const result = props(['a', 'b'], obj)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = props(['a', 'b'])(obj)\n\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#props)\n\n### propSatisfies\n\n```typescript\n\npropSatisfies<T>(predicate: Predicate<T>, property: string, obj: Record<string, T>): boolean\n```\n\nIt returns `true` if the object property satisfies a given predicate.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A%20%7Bb%3A1%7D%7D%0Aconst%20property%20%3D%20'a'%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%3F.b%20%3D%3D%3D%201%0A%0Aconst%20result%20%3D%20R.propSatisfies(predicate%2C%20property%2C%20Record%3Cstring%2C%20unknown%3E)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.propSatisfies</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\npropSatisfies<T>(predicate: Predicate<T>, property: string, obj: Record<string, T>): boolean;\npropSatisfies<T>(predicate: Predicate<T>, property: string): (obj: Record<string, T>) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.propSatisfies</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { prop } from './prop.js'\n\nfunction propSatisfiesFn(\n  predicate, property, obj\n){\n  return predicate(prop(property, obj))\n}\n\nexport const propSatisfies = curry(propSatisfiesFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { propSatisfies } from './propSatisfies.js'\n\nconst obj = { a : 1 }\n\ntest('when true', () => {\n  expect(propSatisfies(\n    x => x > 0, 'a', obj\n  )).toBeTrue()\n})\n\ntest('when false', () => {\n  expect(propSatisfies(x => x < 0, 'a')(obj)).toBeFalse()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {propSatisfies} from 'rambda'\n\nconst obj = {a: 1}\n\ndescribe('R.propSatisfies', () => {\n  it('happy', () => {\n    const result = propSatisfies(x => x > 0, 'a', obj)\n\n    result // $ExpectType boolean\n  })\n  it('curried requires explicit type', () => {\n    const result = propSatisfies<number>(x => x > 0, 'a')(obj)\n\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#propSatisfies)\n\n### range\n\n```typescript\n\nrange(startInclusive: number, endExclusive: number): number[]\n```\n\nIt returns list of numbers between `startInclusive` to `endExclusive` markers.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.range(0%2C%205)%0A%2F%2F%20%3D%3E%20%5B0%2C%201%2C%202%2C%203%2C%204%5D\">Try this <strong>R.range</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nrange(startInclusive: number, endExclusive: number): number[];\nrange(startInclusive: number): (endExclusive: number) => number[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.range</strong> source</summary>\n\n```javascript\nexport function range(start, end){\n  if (arguments.length === 1) return _end => range(start, _end)\n\n  if (Number.isNaN(Number(start)) || Number.isNaN(Number(end))){\n    throw new TypeError('Both arguments to range must be numbers')\n  }\n\n  if (end < start) return []\n\n  const len = end - start\n  const willReturn = Array(len)\n\n  for (let i = 0; i < len; i++){\n    willReturn[ i ] = start + i\n  }\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { range } from './range.js'\n\ntest('happy', () => {\n  expect(range(0, 10)).toEqual([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ])\n})\n\ntest('end range is bigger than start range', () => {\n  expect(range(7, 3)).toEqual([])\n  expect(range(5, 5)).toEqual([])\n})\n\ntest('with bad input', () => {\n  const throwMessage = 'Both arguments to range must be numbers'\n  expect(() => range('a', 6)).toThrowWithMessage(Error, throwMessage)\n  expect(() => range(6, 'z')).toThrowWithMessage(Error, throwMessage)\n})\n\ntest('curry', () => {\n  expect(range(0)(10)).toEqual([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {range} from 'rambda'\n\ndescribe('R.range', () => {\n  it('happy', () => {\n    const result = range(1, 4)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = range(1)(4)\n\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#range)\n\n### reduce\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%5D%0Aconst%20initialValue%20%3D%2010%0Aconst%20reducer%20%3D%20(prev%2C%20current)%20%3D%3E%20prev%20*%20current%0A%0Aconst%20result%20%3D%20R.reduce(reducer%2C%20initialValue%2C%20list)%0A%2F%2F%20%3D%3E%2060\">Try this <strong>R.reduce</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#reduce)\n\n### reduceBy\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.reduceBy(%0A%20%20(acc%2C%20elem)%20%3D%3E%20acc%20%2B%20elem%2C%0A%20%200%2C%0A%20%20x%20%3D%3E%20x%20%3E%202%20%3F%20'big'%20%3A%20'small'%2C%0A%20%20%5B1%2C%202%2C%203%2C%204%2C%205%5D%0A)%0A%2F%2F%20%3D%3E%20%7B%20big%3A%2012%2C%20small%3A%203%20%7D\">Try this <strong>R.reduceBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#reduceBy)\n\n### reject\n\n```typescript\n\nreject<T>(predicate: Predicate<T>, list: T[]): T[]\n```\n\nIt has the opposite effect of `R.filter`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20obj%20%3D%20%7Ba%3A%201%2C%20b%3A%202%7D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3E%201%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.reject(predicate%2C%20list)%2C%0A%20%20R.reject(predicate%2C%20Record%3Cstring%2C%20unknown%3E)%0A%5D%0A%2F%2F%20%3D%3E%20%5B%5B1%5D%2C%20%7Ba%3A%201%7D%5D\">Try this <strong>R.reject</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nreject<T>(predicate: Predicate<T>, list: T[]): T[];\nreject<T>(predicate: Predicate<T>): (list: T[]) => T[];\nreject<T>(predicate: Predicate<T>, obj: Dictionary<T>): Dictionary<T>;\nreject<T, U>(predicate: Predicate<T>): (obj: Dictionary<T>) => Dictionary<T>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.reject</strong> source</summary>\n\n```javascript\nimport { filter } from './filter.js'\n\nexport function reject(predicate, list){\n  if (arguments.length === 1) return _list => reject(predicate, _list)\n\n  return filter(x => !predicate(x), list)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { reject } from './reject.js'\n\nconst isOdd = n => n % 2 === 1\n\ntest('with array', () => {\n  expect(reject(isOdd)([ 1, 2, 3, 4 ])).toEqual([ 2, 4 ])\n})\n\ntest('with object', () => {\n  const obj = {\n    a : 1,\n    b : 2,\n    c : 3,\n    d : 4,\n  }\n  expect(reject(isOdd, obj)).toEqual({\n    b : 2,\n    d : 4,\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {reject} from 'rambda'\n\ndescribe('R.reject with array', () => {\n  it('happy', () => {\n    const result = reject(\n      x => {\n        x // $ExpectType number\n        return x > 1\n      },\n      [1, 2, 3]\n    )\n    result // $ExpectType number[]\n  })\n  it('curried require explicit type', () => {\n    const result = reject<number>(x => {\n      x // $ExpectType number\n      return x > 1\n    })([1, 2, 3])\n    result // $ExpectType number[]\n  })\n})\n\ndescribe('R.reject with objects', () => {\n  it('happy', () => {\n    const result = reject(\n      x => {\n        x // $ExpectType number\n\n        return x > 1\n      },\n      {a: 1, b: 2}\n    )\n    result // $ExpectType Dictionary<number>\n  })\n  it('curried require dummy type', () => {\n    const result = reject<number, any>(x => {\n      return x > 1\n    })({a: 1, b: 2})\n    result // $ExpectType Dictionary<number>\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#reject)\n\n### removeIndex\n\n```typescript\n\nremoveIndex<T>(index: number, list: T[]): T[]\n```\n\nIt returns a copy of `list` input with removed `index`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20result%20%3D%20R.removeIndex(1%2C%20list)%0A%2F%2F%20%3D%3E%20%5B1%2C%203%2C%204%5D\">Try this <strong>R.removeIndex</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nremoveIndex<T>(index: number, list: T[]): T[];\nremoveIndex(index: number): <T>(list: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.removeIndex</strong> source</summary>\n\n```javascript\nexport function removeIndex(index, list){\n  if (arguments.length === 1) return _list => removeIndex(index, _list)\n  if (index <= 0) return list.slice(1)\n  if (index >= list.length - 1) return list.slice(0, list.length - 1)\n\n  return [ ...list.slice(0, index), ...list.slice(index + 1) ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { removeIndex } from './removeIndex.js'\n\nconst list = [ 1, 2, 3, 4 ]\n\ntest('first or before first index', () => {\n  expect(removeIndex(-2, list)).toEqual([ 2, 3, 4 ])\n  expect(removeIndex(-2)(list)).toEqual([ 2, 3, 4 ])\n})\n\ntest('last or after last index', () => {\n  expect(removeIndex(4, list)).toEqual([ 1, 2, 3 ])\n  expect(removeIndex(10, list)).toEqual([ 1, 2, 3 ])\n})\n\ntest('middle index', () => {\n  expect(removeIndex(1, list)).toEqual([ 1, 3, 4 ])\n  expect(removeIndex(2, list)).toEqual([ 1, 2, 4 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {removeIndex} from 'rambda'\n\ndescribe('R.removeIndex', () => {\n  it('happy', () => {\n    const result = removeIndex(1, [1, 2, 3])\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = removeIndex(1)([1, 2, 3])\n\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#removeIndex)\n\n### repeat\n\n```typescript\n\nrepeat<T>(x: T): (timesToRepeat: number) => T[]\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.repeat('foo'%2C%203)%0A%2F%2F%20%3D%3E%20%5B'foo'%2C%20'foo'%2C%20'foo'%5D\">Try this <strong>R.repeat</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nrepeat<T>(x: T): (timesToRepeat: number) => T[];\nrepeat<T>(x: T, timesToRepeat: number): T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.repeat</strong> source</summary>\n\n```javascript\nexport function repeat(x, timesToRepeat){\n  if (arguments.length === 1){\n    return _timesToRepeat => repeat(x, _timesToRepeat)\n  }\n\n  return Array(timesToRepeat).fill(x)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { repeat } from './repeat.js'\n\ntest('repeat', () => {\n  expect(repeat('')(3)).toEqual([ '', '', '' ])\n  expect(repeat('foo', 3)).toEqual([ 'foo', 'foo', 'foo' ])\n\n  const obj = {}\n  const arr = repeat(obj, 3)\n\n  expect(arr).toEqual([ {}, {}, {} ])\n\n  expect(arr[ 0 ] === arr[ 1 ]).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {repeat} from 'rambda'\n\ndescribe('R.repeat', () => {\n  it('happy', () => {\n    const result = repeat(4, 7)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = repeat(4)(7)\n\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#repeat)\n\n### replace\n\n```typescript\n\nreplace(strOrRegex: RegExp | string, replacer: RegExpReplacer, str: string): string\n```\n\nIt replaces `strOrRegex` found in `str` with `replacer`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20strOrRegex%20%3D%20%2Fo%2Fg%0A%0Aconst%20result%20%3D%20R.replace(strOrRegex%2C%20'%7C0%7C'%2C%20'foo')%0A%2F%2F%20%3D%3E%20'f%7C0%7C%7C0%7C'\">Try this <strong>R.replace</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nreplace(strOrRegex: RegExp | string, replacer: RegExpReplacer, str: string): string;\nreplace(strOrRegex: RegExp | string, replacer: RegExpReplacer): (str: string) => string;\nreplace(strOrRegex: RegExp | string): (replacer: RegExpReplacer) => (str: string) => string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.replace</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nfunction replaceFn(\n  pattern, replacer, str\n){\n  return str.replace(pattern, replacer)\n}\n\nexport const replace = curry(replaceFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { replace } from './replace.js'\n\ntest('happy', () => {\n  expect(replace(\n    /\\s/g, '|', 'foo bar baz'\n  )).toBe('foo|bar|baz')\n})\n\ntest('with function as replacer input', () => {\n  expect(replace(\n    /\\s/g,\n    (\n      match, offset, str\n    ) => {\n      expect(match).toBe(' ')\n      expect([ 3, 7 ].includes(offset)).toBeTrue()\n      expect(str).toBe('foo bar baz')\n\n      return '|'\n    },\n    'foo bar baz'\n  )).toBe('foo|bar|baz')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {replace} from 'rambda'\n\nconst str = 'foo bar foo'\nconst replacer = 'bar'\n\ndescribe('R.replace', () => {\n  it('happy', () => {\n    const result = replace(/foo/g, replacer, str)\n\n    result // $ExpectType string\n  })\n  it('with string as search pattern', () => {\n    const result = replace('foo', replacer, str)\n\n    result // $ExpectType string\n  })\n  it('with function as replacer', () => {\n    const result = replace('f(o)o', (m: string, p1: string, offset: number) => {\n      m // $ExpectType string\n      p1 // $ExpectType string\n      offset // $ExpectType number\n      return p1\n    }, str)\n\n    result // $ExpectType string\n  })\n})\n\ndescribe('R.replace - curried', () => {\n  it('happy', () => {\n    const result = replace(/foo/g, replacer)(str)\n\n    result // $ExpectType string\n  })\n  it('with string as search pattern', () => {\n    const result = replace('foo', replacer)(str)\n\n    result // $ExpectType string\n  })\n  it('with function as replacer', () => {\n    const result = replace('f(o)o')((m: string, p1: string, offset: number) => {\n      m // $ExpectType string\n      p1 // $ExpectType string\n      offset // $ExpectType number\n      return p1\n    })(str)\n\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#replace)\n\n### reverse\n\n```typescript\n\nreverse<T>(input: T[]): T[]\n```\n\nIt returns a reversed copy of list or string `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.reverse('foo')%2C%0A%20%20R.reverse(%5B1%2C%202%2C%203%5D)%0A%5D%0A%2F%2F%20%3D%3E%20%5B'oof'%2C%20%5B3%2C%202%2C%201%5D\">Try this <strong>R.reverse</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nreverse<T>(input: T[]): T[];\nreverse(input: string): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.reverse</strong> source</summary>\n\n```javascript\nexport function reverse(listOrString) {\n  if (typeof listOrString === 'string') {\n    return listOrString.split('').reverse().join('')\n  }\n\n  const clone = listOrString.slice()\n\n  return clone.reverse()\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport {reverse} from './reverse.js'\n\ntest('happy', () => {\n  expect(reverse([1, 2, 3])).toEqual([3, 2, 1])\n})\n\ntest('with string', () => {\n  expect(reverse('baz')).toBe('zab')\n})\n\ntest(\"it doesn't mutate\", () => {\n  const arr = [1, 2, 3]\n\n  expect(reverse(arr)).toEqual([3, 2, 1])\n\n  expect(arr).toEqual([1, 2, 3])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {reverse} from 'rambda'\n\nconst list = [1, 2, 3, 4, 5]\n\ndescribe('R.reverse', () => {\n  it('happy', () => {\n    const result = reverse(list)\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#reverse)\n\n### set\n\n```typescript\n\nset<S, A>(lens: Lens<S, A>): {\n  (a: A): (obj: S) => S\n  (a: A, obj: S): S\n}\n```\n\nIt returns a copied **Object** or **Array** with modified `lens` focus set to `replacer` value.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20input%20%3D%20%7Bx%3A%201%2C%20y%3A%202%7D%0Aconst%20xLens%20%3D%20R.lensProp('x')%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.set(xLens%2C%204%2C%20input)%2C%0A%20%20R.set(xLens%2C%208%2C%20input)%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B%7Bx%3A%204%2C%20y%3A%202%7D%2C%20%7Bx%3A%208%2C%20y%3A%202%7D%5D\">Try this <strong>R.set</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nset<S, A>(lens: Lens<S, A>): {\n  (a: A): (obj: S) => S\n  (a: A, obj: S): S\n};\nset<S, A>(lens: Lens<S, A>, a: A): (obj: S) => S;\nset<S, A>(lens: Lens<S, A>, a: A, obj: S): S;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.set</strong> source</summary>\n\n```javascript\nimport {always} from './always.js'\nimport {curry} from './curry.js'\nimport {over} from './over.js'\n\nfunction setFn(lens, replacer, x) {\n  return over(lens, always(replacer), x)\n}\n\nexport const set = curry(setFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport {assoc} from './assoc.js'\nimport {lens} from './lens.js'\nimport {lensIndex} from './lensIndex.js'\nimport {lensPath} from './lensPath.js'\nimport {prop} from './prop.js'\nimport {set} from './set.js'\n\nconst testObject = {\n  foo: 'bar',\n  baz: {\n    a: 'x',\n    b: 'y',\n  },\n}\n\ntest('assoc lens', () => {\n  const assocLens = lens(prop('foo'), assoc('foo'))\n  const result = set(assocLens, 'FOO', testObject)\n  const expected = {\n    ...testObject,\n    foo: 'FOO',\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('path lens', () => {\n  const pathLens = lensPath('baz.a')\n  const result = set(pathLens, 'z', testObject)\n  const expected = {\n    ...testObject,\n    baz: {\n      a: 'z',\n      b: 'y',\n    },\n  }\n  expect(result).toEqual(expected)\n})\n\ntest('index lens', () => {\n  const indexLens = lensIndex(0)\n\n  const result = set(indexLens, 3, [1, 2])\n  expect(result).toEqual([3, 2])\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#set)\n\n### slice\n\n```typescript\n\nslice(from: number, to: number, input: string): string\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B0%2C%201%2C%202%2C%203%2C%204%2C%205%5D%0Aconst%20str%20%3D%20'FOO_BAR'%0Aconst%20from%20%3D%201%0Aconst%20to%20%3D%204%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.slice(from%2C%20to%2C%20str)%2C%0A%20%20R.slice(from%2C%20to%2C%20list)%0A%5D%0A%2F%2F%20%3D%3E%20%5B'OO_'%2C%20%5B1%2C%202%2C%203%5D%5D\">Try this <strong>R.slice</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nslice(from: number, to: number, input: string): string;\nslice<T>(from: number, to: number, input: T[]): T[];\nslice(from: number, to: number): {\n  (input: string): string;\n  <T>(input: T[]): T[];\n};\nslice(from: number): {\n  (to: number, input: string): string;\n  <T>(to: number, input: T[]): T[];\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.slice</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nfunction sliceFn(\n  from, to, list\n){\n  return list.slice(from, to)\n}\n\nexport const slice = curry(sliceFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { slice } from './slice.js'\n\ntest('slice', () => {\n  expect(slice(\n    1, 3, [ 'a', 'b', 'c', 'd' ]\n  )).toEqual([ 'b', 'c' ])\n  expect(slice(\n    1, Infinity, [ 'a', 'b', 'c', 'd' ]\n  )).toEqual([ 'b', 'c', 'd' ])\n  expect(slice(\n    0, -1, [ 'a', 'b', 'c', 'd' ]\n  )).toEqual([ 'a', 'b', 'c' ])\n  expect(slice(\n    -3, -1, [ 'a', 'b', 'c', 'd' ]\n  )).toEqual([ 'b', 'c' ])\n  expect(slice(\n    0, 3, 'ramda'\n  )).toBe('ram')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {slice} from 'rambda'\n\nconst list = [1, 2, 3, 4, 5]\n\ndescribe('R.slice', () => {\n  it('happy', () => {\n    const result = slice(1, 3, list)\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = slice(1, 3)(list)\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#slice)\n\n### sort\n\n```typescript\n\nsort<T>(sortFn: (a: T, b: T) => number, list: T[]): T[]\n```\n\nIt returns copy of `list` sorted by `sortFn` function, where `sortFn` needs to return only `-1`, `0` or `1`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%0A%20%20%7Ba%3A%202%7D%2C%0A%20%20%7Ba%3A%203%7D%2C%0A%20%20%7Ba%3A%201%7D%0A%5D%0Aconst%20sortFn%20%3D%20(x%2C%20y)%20%3D%3E%20%7B%0A%20%20return%20x.a%20%3E%20y.a%20%3F%201%20%3A%20-1%0A%7D%0A%0Aconst%20result%20%3D%20R.sort(sortFn%2C%20list)%0Aconst%20expected%20%3D%20%5B%0A%20%20%7Ba%3A%201%7D%2C%0A%20%20%7Ba%3A%202%7D%2C%0A%20%20%7Ba%3A%203%7D%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.sort</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsort<T>(sortFn: (a: T, b: T) => number, list: T[]): T[];\nsort<T>(sortFn: (a: T, b: T) => number): (list: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.sort</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\n\nexport function sort(sortFn, list){\n  if (arguments.length === 1) return _list => sort(sortFn, _list)\n\n  return cloneList(list).sort(sortFn)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { sort } from './sort.js'\n\nconst fn = (a, b) => a > b ? 1 : -1\n\ntest('sort', () => {\n  expect(sort((a, b) => a - b)([ 2, 3, 1 ])).toEqual([ 1, 2, 3 ])\n})\n\ntest('it doesn\\'t mutate', () => {\n  const list = [ 'foo', 'bar', 'baz' ]\n\n  expect(sort(fn, list)).toEqual([ 'bar', 'baz', 'foo' ])\n\n  expect(list[ 0 ]).toBe('foo')\n  expect(list[ 1 ]).toBe('bar')\n  expect(list[ 2 ]).toBe('baz')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {sort} from 'rambda'\n\nconst list = [3, 0, 5, 2, 1]\n\nfunction sortFn(a: number, b: number): number {\n  return a > b ? 1 : -1\n}\n\ndescribe('R.sort', () => {\n  it('happy', () => {\n    const result = sort(sortFn, list)\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = sort(sortFn)(list)\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#sort)\n\n### sortBy\n\n```typescript\n\nsortBy<T>(sortFn: (a: T) => Ord, list: T[]): T[]\n```\n\nIt returns copy of `list` sorted by `sortFn` function, where `sortFn` function returns a value to compare, i.e. it doesn't need to return only `-1`, `0` or `1`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%0A%20%20%7Ba%3A%202%7D%2C%0A%20%20%7Ba%3A%203%7D%2C%0A%20%20%7Ba%3A%201%7D%0A%5D%0Aconst%20sortFn%20%3D%20x%20%3D%3E%20x.a%0A%0Aconst%20result%20%3D%20R.sortBy(sortFn%2C%20list)%0Aconst%20expected%20%3D%20%5B%0A%20%20%7Ba%3A%201%7D%2C%0A%20%20%7Ba%3A%202%7D%2C%0A%20%20%7Ba%3A%203%7D%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.sortBy</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsortBy<T>(sortFn: (a: T) => Ord, list: T[]): T[];\nsortBy<T>(sortFn: (a: T) => Ord): (list: T[]) => T[];\nsortBy(sortFn: (a: any) => Ord): <T>(list: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.sortBy</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\n\nexport function sortBy(sortFn, list){\n  if (arguments.length === 1) return _list => sortBy(sortFn, _list)\n\n  const clone = cloneList(list)\n\n  return clone.sort((a, b) => {\n    const aSortResult = sortFn(a)\n    const bSortResult = sortFn(b)\n\n    if (aSortResult === bSortResult) return 0\n\n    return aSortResult < bSortResult ? -1 : 1\n  })\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { compose } from './compose.js'\nimport { prop } from './prop.js'\nimport { sortBy } from './sortBy.js'\nimport { toLower } from './toLower.js'\n\ntest('happy', () => {\n  const input = [ { a : 2 }, { a : 1 }, { a : 1 }, { a : 3 } ]\n  const expected = [ { a : 1 }, { a : 1 }, { a : 2 }, { a : 3 } ]\n\n  const result = sortBy(x => x.a)(input)\n  expect(result).toEqual(expected)\n})\n\ntest('with compose', () => {\n  const alice = {\n    name : 'ALICE',\n    age  : 101,\n  }\n  const bob = {\n    name : 'Bob',\n    age  : -10,\n  }\n  const clara = {\n    name : 'clara',\n    age  : 314.159,\n  }\n  const people = [ clara, bob, alice ]\n  const sortByNameCaseInsensitive = sortBy(compose(toLower, prop('name')))\n\n  expect(sortByNameCaseInsensitive(people)).toEqual([ alice, bob, clara ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {sortBy, pipe} from 'rambda'\n\ninterface Input {\n  a: number,\n}\n\ndescribe('R.sortBy', () => {\n  it('passing type to sort function', () => {\n    function fn(x: any): number {\n      return x.a\n    }\n    function fn2(x: Input): number {\n      return x.a\n    }\n\n    const input = [{a: 2}, {a: 1}, {a: 0}]\n    const result = sortBy(fn, input)\n    const curriedResult = sortBy(fn2)(input)\n\n    result // $ExpectType { a: number; }[]\n    curriedResult // $ExpectType Input[]\n    result[0].a // $ExpectType number\n    curriedResult[0].a // $ExpectType number\n  })\n  it('passing type to sort function and list', () => {\n    function fn(x: Input): number {\n      return x.a\n    }\n\n    const input: Input[] = [{a: 2}, {a: 1}, {a: 0}]\n    const result = sortBy(fn, input)\n    const curriedResult = sortBy(fn)(input)\n\n    result // $ExpectType Input[]\n    curriedResult // $ExpectType Input[]\n    result[0].a // $ExpectType number\n  })\n  it('with R.pipe', () => {\n    interface Obj {\n      value: number,\n    }\n    const fn = pipe(sortBy<Obj>(x => x.value))\n\n    const result = fn([{value: 1}, {value: 2}])\n    result // $ExpectType Obj[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#sortBy)\n\n### sortWith\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.sortWith(%5B%0A%20%20%20%20(a%2C%20b)%20%3D%3E%20a.a%20%3D%3D%3D%20b.a%20%3F%200%20%3A%20a.a%20%3E%20b.a%20%3F%201%20%3A%20-1%2C%0A%20%20%20%20(a%2C%20b)%20%3D%3E%20a.b%20%3D%3D%3D%20b.b%20%3F%200%20%3A%20a.b%20%3E%20b.b%20%3F%201%20%3A%20-1%2C%0A%5D%2C%20%5B%0A%20%20%7Ba%3A%201%2C%20b%3A%202%7D%2C%0A%20%20%7Ba%3A%202%2C%20b%3A%201%7D%2C%0A%20%20%7Ba%3A%202%2C%20b%3A%202%7D%2C%0A%20%20%7Ba%3A%201%2C%20b%3A%201%7D%2C%0A%5D)%0Aconst%20expected%20%3D%20%5B%0A%20%20%7Ba%3A%201%2C%20b%3A%201%7D%2C%0A%20%20%7Ba%3A%201%2C%20b%3A%202%7D%2C%0A%20%20%7Ba%3A%202%2C%20b%3A%201%7D%2C%0A%20%20%7Ba%3A%202%2C%20b%3A%202%7D%2C%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.sortWith</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#sortWith)\n\n### split\n\n```typescript\n\nsplit(separator: string | RegExp): (str: string) => string[]\n```\n\nCurried version of `String.prototype.split`\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20str%20%3D%20'foo%7Cbar%7Cbaz'%0Aconst%20separator%20%3D%20'%7C'%0Aconst%20result%20%3D%20R.split(separator%2C%20str)%0A%2F%2F%20%3D%3E%20%5B%20'foo'%2C%20'bar'%2C%20'baz'%20%5D\">Try this <strong>R.split</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsplit(separator: string | RegExp): (str: string) => string[];\nsplit(separator: string | RegExp, str: string): string[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.split</strong> source</summary>\n\n```javascript\nexport function split(separator, str){\n  if (arguments.length === 1) return _str => split(separator, _str)\n\n  return str.split(separator)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { split } from './split.js'\n\nconst str = 'foo|bar|baz'\nconst splitChar = '|'\nconst expected = [ 'foo', 'bar', 'baz' ]\n\ntest('happy', () => {\n  expect(split(splitChar, str)).toEqual(expected)\n})\n\ntest('curried', () => {\n  expect(split(splitChar)(str)).toEqual(expected)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {split} from 'rambda'\n\nconst str = 'foo|bar|baz'\nconst splitChar = '|'\n\ndescribe('R.split', () => {\n  it('happy', () => {\n    const result = split(splitChar, str)\n\n    result // $ExpectType string[]\n  })\n  it('curried', () => {\n    const result = split(splitChar)(str)\n\n    result // $ExpectType string[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#split)\n\n### splitAt\n\n```typescript\n\nsplitAt<T>(index: number, input: T[]): [T[], T[]]\n```\n\nIt splits string or array at a given index.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%201%2C%202%2C%203%20%5D%0Aconst%20result%20%3D%20R.splitAt(2%2C%20list)%0A%2F%2F%20%3D%3E%20%5B%5B%201%2C%202%20%5D%2C%20%5B%203%20%5D%5D\">Try this <strong>R.splitAt</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsplitAt<T>(index: number, input: T[]): [T[], T[]];\nsplitAt(index: number, input: string): [string, string];\nsplitAt(index: number): {\n    <T>(input: T[]): [T[], T[]];\n    (input: string): [string, string];\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.splitAt</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { drop } from './drop.js'\nimport { maybe } from './maybe.js'\nimport { take } from './take.js'\n\nexport function splitAt(index, input){\n  if (arguments.length === 1){\n    return _list => splitAt(index, _list)\n  }\n  if (!input) throw new TypeError(`Cannot read property 'slice' of ${ input }`)\n\n  if (!isArray(input) && typeof input !== 'string') return [ [], [] ]\n\n  const correctIndex = maybe(\n    index < 0,\n    input.length + index < 0 ? 0 : input.length + index,\n    index\n  )\n\n  return [ take(correctIndex, input), drop(correctIndex, input) ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { splitAt as splitAtRamda } from 'ramda'\n\nimport { splitAt } from './splitAt.js'\n\nconst list = [ 1, 2, 3 ]\nconst str = 'foo bar'\n\ntest('with array', () => {\n  const result = splitAt(2, list)\n  expect(result).toEqual([ [ 1, 2 ], [ 3 ] ])\n})\n\ntest('with array - index is negative number', () => {\n  const result = splitAt(-6, list)\n  expect(result).toEqual([ [], list ])\n})\n\ntest('with array - index is out of scope', () => {\n  const result = splitAt(4, list)\n  expect(result).toEqual([ [ 1, 2, 3 ], [] ])\n})\n\ntest('with string', () => {\n  const result = splitAt(4, str)\n  expect(result).toEqual([ 'foo ', 'bar' ])\n})\n\ntest('with string - index is negative number', () => {\n  const result = splitAt(-2, str)\n  expect(result).toEqual([ 'foo b', 'ar' ])\n})\n\ntest('with string - index is out of scope', () => {\n  const result = splitAt(10, str)\n  expect(result).toEqual([ str, '' ])\n})\n\ntest('with array - index is out of scope', () => {\n  const result = splitAt(4)(list)\n  expect(result).toEqual([ [ 1, 2, 3 ], [] ])\n})\n\nconst badInputs = [ 1, true, /foo/g, {} ]\nconst throwingBadInputs = [ null, undefined ]\n\ntest('with bad inputs', () => {\n  throwingBadInputs.forEach(badInput => {\n    expect(() => splitAt(1, badInput)).toThrowWithMessage(TypeError,\n      `Cannot read property 'slice' of ${ badInput }`)\n    expect(() => splitAtRamda(1, badInput)).toThrowWithMessage(TypeError,\n      `Cannot read properties of ${ badInput } (reading 'slice')`)\n  })\n\n  badInputs.forEach(badInput => {\n    const result = splitAt(1, badInput)\n    const ramdaResult = splitAtRamda(1, badInput)\n    expect(result).toEqual(ramdaResult)\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {splitAt} from 'rambda'\n\nconst index = 1\nconst str = 'foo'\nconst list = [1, 2, 3]\n\ndescribe('R.splitAt with array', () => {\n  it('happy', () => {\n    const result = splitAt(index, list)\n\n    result // $ExpectType [number[], number[]]\n  })\n  it('curried', () => {\n    const result = splitAt(index)(list)\n\n    result // $ExpectType [number[], number[]]\n  })\n})\n\ndescribe('R.splitAt with string', () => {\n  it('happy', () => {\n    const result = splitAt(index, str)\n\n    result // $ExpectType [string, string]\n  })\n  it('curried', () => {\n    const result = splitAt(index)(str)\n\n    result // $ExpectType [string, string]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#splitAt)\n\n### splitEvery\n\n```typescript\n\nsplitEvery<T>(sliceLength: number, input: T[]): (T[])[]\n```\n\nIt splits `input` into slices of `sliceLength`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.splitEvery(2%2C%20%5B1%2C%202%2C%203%5D)%2C%20%0A%20%20R.splitEvery(3%2C%20'foobar')%20%0A%5D%0A%0Aconst%20expected%20%3D%20%5B%0A%20%20%5B%5B1%2C%202%5D%2C%20%5B3%5D%5D%2C%0A%20%20%5B'foo'%2C%20'bar'%5D%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.splitEvery</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsplitEvery<T>(sliceLength: number, input: T[]): (T[])[];\nsplitEvery(sliceLength: number, input: string): string[];\nsplitEvery(sliceLength: number): {\n  (input: string): string[];\n  <T>(input: T[]): (T[])[];\n};\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.splitEvery</strong> source</summary>\n\n```javascript\nexport function splitEvery(sliceLength, listOrString){\n  if (arguments.length === 1){\n    return _listOrString => splitEvery(sliceLength, _listOrString)\n  }\n\n  if (sliceLength < 1){\n    throw new Error('First argument to splitEvery must be a positive integer')\n  }\n\n  const willReturn = []\n  let counter = 0\n\n  while (counter < listOrString.length){\n    willReturn.push(listOrString.slice(counter, counter += sliceLength))\n  }\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { splitEvery } from './splitEvery.js'\n\ntest('happy', () => {\n  expect(splitEvery(3, [ 1, 2, 3, 4, 5, 6, 7 ])).toEqual([\n    [ 1, 2, 3 ],\n    [ 4, 5, 6 ],\n    [ 7 ],\n  ])\n\n  expect(splitEvery(3)('foobarbaz')).toEqual([ 'foo', 'bar', 'baz' ])\n})\n\ntest('with bad input', () => {\n  expect(() =>\n    expect(splitEvery(0)('foo')).toEqual([ 'f', 'o', 'o' ])).toThrowErrorMatchingInlineSnapshot('\"First argument to splitEvery must be a positive integer\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {splitEvery} from 'rambda'\n\nconst list = [1, 2, 3, 4, 5, 6, 7]\n\ndescribe('R.splitEvery', () => {\n  it('happy', () => {\n    const result = splitEvery(3, list)\n\n    result // $ExpectType number[][]\n  })\n  it('curried', () => {\n    const result = splitEvery(3)(list)\n\n    result // $ExpectType number[][]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#splitEvery)\n\n### splitWhen\n\n```typescript\n\nsplitWhen<T, U>(predicate: Predicate<T>, list: U[]): (U[])[]\n```\n\nIt splits `list` to two arrays according to a `predicate` function. \n\nThe first array contains all members of `list` before `predicate` returns `true`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%201%2C%202%5D%0Aconst%20result%20%3D%20R.splitWhen(R.equals(2)%2C%20list)%0A%2F%2F%20%3D%3E%20%5B%5B1%5D%2C%20%5B2%2C%201%2C%202%5D%5D\">Try this <strong>R.splitWhen</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsplitWhen<T, U>(predicate: Predicate<T>, list: U[]): (U[])[];\nsplitWhen<T>(predicate: Predicate<T>): <U>(list: U[]) => (U[])[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.splitWhen</strong> source</summary>\n\n```javascript\nexport function splitWhen(predicate, input){\n  if (arguments.length === 1){\n    return _input => splitWhen(predicate, _input)\n  }\n  if (!input)\n    throw new TypeError(`Cannot read property 'length' of ${ input }`)\n\n  const preFound = []\n  const postFound = []\n  let found = false\n  let counter = -1\n\n  while (counter++ < input.length - 1){\n    if (found){\n      postFound.push(input[ counter ])\n    } else if (predicate(input[ counter ])){\n      postFound.push(input[ counter ])\n      found = true\n    } else {\n      preFound.push(input[ counter ])\n    }\n  }\n\n  return [ preFound, postFound ]\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { splitWhen as splitWhenRamda } from 'ramda'\n\nimport { equals } from './equals.js'\nimport { splitWhen } from './splitWhen.js'\n\nconst list = [ 1, 2, 1, 2 ]\n\ntest('happy', () => {\n  const result = splitWhen(equals(2), list)\n  expect(result).toEqual([ [ 1 ], [ 2, 1, 2 ] ])\n})\n\ntest('when predicate returns false', () => {\n  const result = splitWhen(equals(3))(list)\n  expect(result).toEqual([ list, [] ])\n})\n\nconst badInputs = [ 1, true, /foo/g, {} ]\nconst throwingBadInputs = [ null, undefined ]\n\ntest('with bad inputs', () => {\n  throwingBadInputs.forEach(badInput => {\n    expect(() => splitWhen(equals(2), badInput)).toThrowWithMessage(TypeError,\n      `Cannot read property 'length' of ${ badInput }`)\n    expect(() => splitWhenRamda(equals(2), badInput)).toThrowWithMessage(TypeError,\n      `Cannot read properties of ${ badInput } (reading 'length')`)\n  })\n\n  badInputs.forEach(badInput => {\n    const result = splitWhen(equals(2), badInput)\n    const ramdaResult = splitWhenRamda(equals(2), badInput)\n    expect(result).toEqual(ramdaResult)\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {splitWhen} from 'rambda'\n\nconst list = [1, 2, 1, 2]\nconst predicate = (x: number) => x === 2\n\ndescribe('R.splitWhen', () => {\n  it('happy', () => {\n    const result = splitWhen(predicate, list)\n\n    result // $ExpectType number[][]\n  })\n  it('curried', () => {\n    const result = splitWhen(predicate)(list)\n\n    result // $ExpectType number[][]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#splitWhen)\n\n### startsWith\n\n```typescript\n\nstartsWith<T extends string>(question: T, input: string): boolean\n```\n\nWhen iterable is a string, then it behaves as `String.prototype.startsWith`.\nWhen iterable is a list, then it uses R.equals to determine if the target list starts in the same way as the given target.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20str%20%3D%20'foo-bar'%0Aconst%20list%20%3D%20%5B%7Ba%3A1%7D%2C%20%7Ba%3A2%7D%2C%20%7Ba%3A3%7D%5D%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.startsWith('foo'%2C%20str)%2C%0A%20%20R.startsWith(%5B%7Ba%3A1%7D%2C%20%7Ba%3A2%7D%5D%2C%20list)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20true%5D\">Try this <strong>R.startsWith</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nstartsWith<T extends string>(question: T, input: string): boolean;\nstartsWith<T extends string>(question: T): (input: string) => boolean;\nstartsWith<T>(question: T[], input: T[]): boolean;\nstartsWith<T>(question: T[]): (input: T[]) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.startsWith</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\nimport { equals } from './equals.js'\n\nexport function startsWith(question, iterable){\n  if (arguments.length === 1)\n    return _iterable => startsWith(question, _iterable)\n\n  if (typeof iterable === 'string'){\n    return iterable.startsWith(question)\n  }\n  if (!isArray(question)) return false\n\n  let correct = true\n  const filtered = question.filter((x, index) => {\n    if (!correct) return false\n    const result = equals(x, iterable[ index ])\n    if (!result) correct = false\n\n    return result\n  })\n\n  return filtered.length === question.length\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { startsWith as startsWithRamda } from 'ramda'\n\nimport { compareCombinations } from './_internals/testUtils.js'\nimport { possibleIterables, possibleTargets } from './endsWith.spec.js'\nimport { startsWith } from './startsWith.js'\n\ntest('with string', () => {\n  expect(startsWith('foo', 'foo-bar')).toBeTrue()\n  expect(startsWith('baz')('foo-bar')).toBeFalse()\n})\n\ntest('use R.equals with array', () => {\n  const list = [ { a : 1 }, { a : 2 }, { a : 3 } ]\n  expect(startsWith({ a : 1 }, list)).toBeFalse()\n  expect(startsWith([ { a : 1 } ], list)).toBeTrue()\n  expect(startsWith([ { a : 1 }, { a : 2 } ], list)).toBeTrue()\n  expect(startsWith(list, list)).toBeTrue()\n  expect(startsWith([ { a : 2 } ], list)).toBeFalse()\n})\n\ndescribe('brute force', () => {\n  compareCombinations({\n    fn          : startsWith,\n    fnRamda     : startsWithRamda,\n    firstInput  : possibleTargets,\n    secondInput : possibleIterables,\n    callback    : errorsCounters => {\n      expect(errorsCounters).toMatchInlineSnapshot(`\n        {\n          \"ERRORS_MESSAGE_MISMATCH\": 0,\n          \"ERRORS_TYPE_MISMATCH\": 0,\n          \"RESULTS_MISMATCH\": 0,\n          \"SHOULD_NOT_THROW\": 0,\n          \"SHOULD_THROW\": 0,\n          \"TOTAL_TESTS\": 32,\n        }\n      `)\n    },\n  })\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {startsWith} from 'rambda'\n\ndescribe('R.startsWith - array', () => {\n  const question = [{a: 1}]\n  const iterable = [{a: 1}, {a: 2}]\n  it('happy', () => {\n    const result = startsWith(question, iterable)\n    result // $ExpectType boolean\n  })\n  it('curried', () => {\n    const result = startsWith(question)(iterable)\n    result // $ExpectType boolean\n  })\n})\n\ndescribe('R.startsWith - string', () => {\n  const question = 'foo'\n  const iterable = 'foo bar'\n  it('happy', () => {\n    const result = startsWith(question, iterable)\n    result // $ExpectType boolean\n  })\n  it('curried', () => {\n    const result = startsWith(question)(iterable)\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#startsWith)\n\n### subtract\n\nCurried version of `x - y`\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20x%20%3D%203%0Aconst%20y%20%3D%201%0A%0Aconst%20result%20%3D%20R.subtract(x%2C%20y)%20%0A%2F%2F%20%3D%3E%202\">Try this <strong>R.subtract</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#subtract)\n\n### sum\n\n```typescript\n\nsum(list: number[]): number\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.sum(%5B1%2C%202%2C%203%2C%204%2C%205%5D)%20%0A%2F%2F%20%3D%3E%2015\">Try this <strong>R.sum</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsum(list: number[]): number;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.sum</strong> source</summary>\n\n```javascript\nexport function sum(list){\n  return list.reduce((prev, current) => prev + current, 0)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { sum } from './sum.js'\n\ntest('happy', () => {\n  expect(sum([ 1, 2, 3, 4, 5 ])).toBe(15)\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#sum)\n\n### swap\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.swap(1%2C%202%2C%20%5B1%2C%202%2C%203%5D)%0A%2F%2F%20%3D%3E%20%5B1%2C%203%2C%202%5D\">Try this <strong>R.swap</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#swap)\n\n### symmetricDifference\n\n```typescript\n\nsymmetricDifference<T>(x: T[], y: T[]): T[]\n```\n\nIt returns a merged list of `x` and `y` with all equal elements removed.\n\n`R.equals` is used to determine equality.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20x%20%3D%20%5B%201%2C%202%2C%203%2C%204%20%5D%0Aconst%20y%20%3D%20%5B%203%2C%204%2C%205%2C%206%20%5D%0A%0Aconst%20result%20%3D%20R.symmetricDifference(x%2C%20y)%0A%2F%2F%20%3D%3E%20%5B%201%2C%202%2C%205%2C%206%20%5D\">Try this <strong>R.symmetricDifference</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nsymmetricDifference<T>(x: T[], y: T[]): T[];\nsymmetricDifference<T>(x: T[]): <T>(y: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.symmetricDifference</strong> source</summary>\n\n```javascript\nimport { concat } from './concat.js'\nimport { filter } from './filter.js'\nimport { includes } from './includes.js'\n\nexport function symmetricDifference(x, y){\n  if (arguments.length === 1){\n    return _y => symmetricDifference(x, _y)\n  }\n\n  return concat(filter(value => !includes(value, y), x),\n    filter(value => !includes(value, x), y))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { symmetricDifference } from './symmetricDifference.js'\n\ntest('symmetricDifference', () => {\n  const list1 = [ 1, 2, 3, 4 ]\n  const list2 = [ 3, 4, 5, 6 ]\n  expect(symmetricDifference(list1)(list2)).toEqual([ 1, 2, 5, 6 ])\n\n  expect(symmetricDifference([], [])).toEqual([])\n})\n\ntest('symmetricDifference with objects', () => {\n  const list1 = [ { id : 1 }, { id : 2 }, { id : 3 }, { id : 4 } ]\n  const list2 = [ { id : 3 }, { id : 4 }, { id : 5 }, { id : 6 } ]\n  expect(symmetricDifference(list1)(list2)).toEqual([\n    { id : 1 },\n    { id : 2 },\n    { id : 5 },\n    { id : 6 },\n  ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {symmetricDifference} from 'rambda'\n\ndescribe('R.symmetricDifference', () => {\n  it('happy', () => {\n    const list1 = [1, 2, 3, 4]\n    const list2 = [3, 4, 5, 6]\n    const result = symmetricDifference(list1, list2)\n\n    result // $ExpectType number[]\n  })\n\n  it('curried', () => {\n    const list1 = [{id: 1}, {id: 2}, {id: 3}, {id: 4}]\n    const list2 = [{id: 3}, {id: 4}, {id: 5}, {id: 6}]\n    const result = symmetricDifference(list1)(list2)\n\n    result // $ExpectType { id: number; }[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#symmetricDifference)\n\n### T\n\n```typescript\n\nT(): boolean\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.T()%20%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.T</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nT(): boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.T</strong> source</summary>\n\n```javascript\nexport function T(){\n  return true\n}\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#T)\n\n### tail\n\n```typescript\n\ntail<T extends unknown[]>(input: T): T extends [any, ...infer U] ? U : [...T]\n```\n\nIt returns all but the first element of `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20R.tail(%5B1%2C%202%2C%203%5D)%2C%20%20%0A%20%20R.tail('foo')%20%0A%5D%0A%2F%2F%20%3D%3E%20%5B%5B2%2C%203%5D%2C%20'oo'%5D\">Try this <strong>R.tail</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntail<T extends unknown[]>(input: T): T extends [any, ...infer U] ? U : [...T];\ntail(input: string): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.tail</strong> source</summary>\n\n```javascript\nimport { drop } from './drop.js'\n\nexport function tail(listOrString){\n  return drop(1, listOrString)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { tail } from './tail.js'\n\ntest('tail', () => {\n  expect(tail([ 1, 2, 3 ])).toEqual([ 2, 3 ])\n  expect(tail([ 1, 2 ])).toEqual([ 2 ])\n  expect(tail([ 1 ])).toEqual([])\n  expect(tail([])).toEqual([])\n\n  expect(tail('abc')).toBe('bc')\n  expect(tail('ab')).toBe('b')\n  expect(tail('a')).toBe('')\n  expect(tail('')).toBe('')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {tail} from 'rambda'\n\ndescribe('R.tail', () => {\n  it('with string', () => {\n    const result = tail('foo')\n\n    result // $ExpectType string\n  })\n  it('with list - one type', () => {\n    const result = tail([1, 2, 3])\n\n    result // $ExpectType number[]\n  })\n  it('with list - mixed types', () => {\n    const result = tail(['foo', 'bar', 1, 2, 3])\n\n    result // $ExpectType (string | number)[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#tail)\n\n### take\n\n```typescript\n\ntake<T>(howMany: number, input: T): T extends string ? string : T\n```\n\nIt returns the first `howMany` elements of `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20howMany%20%3D%202%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.take(howMany%2C%20%5B1%2C%202%2C%203%5D)%2C%0A%20%20R.take(howMany%2C%20'foobar')%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5B%5B1%2C%202%5D%2C%20'fo'%5D\">Try this <strong>R.take</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntake<T>(howMany: number, input: T): T extends string ? string : T;\ntake<T>(howMany: number) : (input: T) => T extends string ? string : T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.take</strong> source</summary>\n\n```javascript\nimport baseSlice from './_internals/baseSlice.js'\n\nexport function take(howMany, listOrString){\n  if (arguments.length === 1)\n    return _listOrString => take(howMany, _listOrString)\n  if (howMany < 0) return listOrString.slice()\n  if (typeof listOrString === 'string') return listOrString.slice(0, howMany)\n\n  return baseSlice(\n    listOrString, 0, howMany\n  )\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { take } from './take.js'\n\ntest('happy', () => {\n  const arr = [ 'foo', 'bar', 'baz' ]\n\n  expect(take(1, arr)).toEqual([ 'foo' ])\n\n  expect(arr).toEqual([ 'foo', 'bar', 'baz' ])\n\n  expect(take(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar' ])\n  expect(take(3, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])\n  expect(take(4, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])\n  expect(take(3)('rambda')).toBe('ram')\n})\n\ntest('with negative index', () => {\n  expect(take(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n  expect(take(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n})\n\ntest('with zero index', () => {\n  expect(take(0, [ 1, 2, 3 ])).toEqual([])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {take} from 'rambda'\n\nconst list = [1, 2, 3, 4]\nconst str = 'foobar'\nconst howMany = 2\n\ndescribe('R.take - array', () => {\n  it('happy', () => {\n    const result = take(howMany, list)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = take<number[]>(howMany)(list)\n\n    result // $ExpectType number[]\n  })\n})\n\ndescribe('R.take - string', () => {\n  it('happy', () => {\n    const result = take(howMany, str)\n\n    result // $ExpectType string\n  })\n  it('curried', () => {\n    const result = take<string>(howMany)(str)\n\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#take)\n\n### takeLast\n\n```typescript\n\ntakeLast<T>(howMany: number, input: T): T extends string ? string : T\n```\n\nIt returns the last `howMany` elements of `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20howMany%20%3D%202%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.takeLast(howMany%2C%20%5B1%2C%202%2C%203%5D)%2C%0A%20%20R.takeLast(howMany%2C%20'foobar')%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5B%5B2%2C%203%5D%2C%20'ar'%5D\">Try this <strong>R.takeLast</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntakeLast<T>(howMany: number, input: T): T extends string ? string : T;\ntakeLast<T>(howMany: number) : (input: T) => T extends string ? string : T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.takeLast</strong> source</summary>\n\n```javascript\nimport baseSlice from './_internals/baseSlice.js'\n\nexport function takeLast(howMany, listOrString){\n  if (arguments.length === 1)\n    return _listOrString => takeLast(howMany, _listOrString)\n\n  const len = listOrString.length\n  if (howMany < 0) return listOrString.slice()\n  let numValue = howMany > len ? len : howMany\n\n  if (typeof listOrString === 'string')\n    return listOrString.slice(len - numValue)\n\n  numValue = len - numValue\n\n  return baseSlice(\n    listOrString, numValue, len\n  )\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { takeLast } from './takeLast.js'\n\ntest('with arrays', () => {\n  expect(takeLast(1, [ 'foo', 'bar', 'baz' ])).toEqual([ 'baz' ])\n\n  expect(takeLast(2)([ 'foo', 'bar', 'baz' ])).toEqual([ 'bar', 'baz' ])\n\n  expect(takeLast(3, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])\n\n  expect(takeLast(4, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])\n\n  expect(takeLast(10, [ 'foo', 'bar', 'baz' ])).toEqual([ 'foo', 'bar', 'baz' ])\n})\n\ntest('with strings', () => {\n  expect(takeLast(3, 'rambda')).toBe('bda')\n\n  expect(takeLast(7, 'rambda')).toBe('rambda')\n})\n\ntest('with negative index', () => {\n  expect(takeLast(-1, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n  expect(takeLast(-Infinity, [ 1, 2, 3 ])).toEqual([ 1, 2, 3 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {filter, piped, takeLast} from 'rambda'\n\nconst list = [1, 2, 3, 4]\nconst str = 'foobar'\nconst howMany = 2\n\ndescribe('R.takeLast - array', () => {\n  it('happy', () => {\n    const result = takeLast(howMany, list)\n\n    result // $ExpectType number[]\n  })\n  it('curried', () => {\n    const result = takeLast<number[]>(howMany)(list)\n\n    result // $ExpectType number[]\n  })\n\tit('real case', () => {\n\t\tconst data = ['foo', 'bar', 'baz', 'qux']\n\t\tconst result = piped(\n\t\t\tdata,\n\t\t\tfilter(\n\t\t\t\tx => x.length >= 100\n\t\t\t),\n\t\t\ttakeLast(2),\n\t\t)\n\t\tresult // $ExpectType string[]\n\t})\n})\n\ndescribe('R.takeLast - string', () => {\n  it('happy', () => {\n    const result = takeLast(howMany, str)\n\n    result // $ExpectType string\n  })\n  it('curried', () => {\n    const result = takeLast<string>(howMany)(str)\n\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#takeLast)\n\n### takeLastWhile\n\n```typescript\n\ntakeLastWhile(predicate: (x: string) => boolean, input: string): string\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.takeLastWhile(%0A%20%20x%20%3D%3E%20x%20%3E%202%2C%0A%20%20%5B1%2C%202%2C%203%2C%204%5D%0A)%0A%2F%2F%20%3D%3E%20%5B3%2C%204%5D\">Try this <strong>R.takeLastWhile</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntakeLastWhile(predicate: (x: string) => boolean, input: string): string;\ntakeLastWhile(predicate: (x: string) => boolean): (input: string) => string;\ntakeLastWhile<T>(predicate: (x: T) => boolean, input: T[]): T[];\ntakeLastWhile<T>(predicate: (x: T) => boolean): <T>(input: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.takeLastWhile</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function takeLastWhile(predicate, input){\n  if (arguments.length === 1){\n    return _input => takeLastWhile(predicate, _input)\n  }\n  if (input.length === 0) return input\n\n  const toReturn = []\n  let counter = input.length\n\n  while (counter){\n    const item = input[ --counter ]\n    if (!predicate(item)){\n      break\n    }\n    toReturn.push(item)\n  }\n\n  return isArray(input) ? toReturn.reverse() : toReturn.reverse().join('')\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { takeLastWhile } from './takeLastWhile.js'\nconst assert = require('assert')\n\nconst list = [ 1, 2, 3, 4 ]\n\ntest('happy', () => {\n  const predicate = x => x > 2\n  const result = takeLastWhile(predicate, list)\n  expect(result).toEqual([ 3, 4 ])\n})\n\ntest('predicate is always true', () => {\n  const predicate = () => true\n  const result = takeLastWhile(predicate)(list)\n  expect(result).toEqual(list)\n})\n\ntest('predicate is always false', () => {\n  const predicate = () => false\n  const result = takeLastWhile(predicate, list)\n  expect(result).toEqual([])\n})\n\ntest('with string', () => {\n  const result = takeLastWhile(x => x !== 'F', 'FOOBAR')\n  expect(result).toBe('OOBAR')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {takeLastWhile} from 'rambda'\n\nconst list = [1, 2, 3]\nconst str = 'FOO'\n\ndescribe('R.takeLastWhile', () => {\n  it('with array', () => {\n    const result = takeLastWhile(x => x > 1, list)\n\n    result // $ExpectType number[]\n  })\n  it('with array - curried', () => {\n    const result = takeLastWhile(x => x > 1, list)\n\n    result // $ExpectType number[]\n  })\n  it('with string', () => {\n    const result = takeLastWhile(x => x !== 'F', str)\n\n    result // $ExpectType string\n  })\n  it('with string - curried', () => {\n    const result = takeLastWhile(x => x !== 'F')(str)\n\n    result // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#takeLastWhile)\n\n### takeWhile\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20predicate%20%3D%20x%20%3D%3E%20x%20%3C%203%0A%0Aconst%20result%20%3D%20R.takeWhile(predicate%2C%20list)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%5D\">Try this <strong>R.takeWhile</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#takeWhile)\n\n### tap\n\n```typescript\n\ntap<T>(fn: (x: T) => void, input: T): T\n```\n\nIt applies function `fn` to input `x` and returns `x`. \n\nOne use case is debugging in the middle of `R.compose`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%202%2C%203%5D%0A%0AR.compose(%0A%20%20R.map(x%20%3D%3E%20x%20*%202)%0A%20%20R.tap(console.log)%2C%0A%20%20R.filter(x%20%3D%3E%20x%20%3E%201)%0A)(list)%0A%2F%2F%20%3D%3E%20%602%60%20and%20%603%60%20will%20be%20logged\">Try this <strong>R.tap</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntap<T>(fn: (x: T) => void, input: T): T;\ntap<T>(fn: (x: T) => void): (input: T) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.tap</strong> source</summary>\n\n```javascript\nexport function tap(fn, x){\n  if (arguments.length === 1) return _x => tap(fn, _x)\n\n  fn(x)\n\n  return x\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { tap } from './tap.js'\n\ntest('tap', () => {\n  let a = 1\n  const sayX = x => a = x\n\n  expect(tap(sayX, 100)).toBe(100)\n  expect(tap(sayX)(100)).toBe(100)\n  expect(a).toBe(100)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {tap, pipe} from 'rambda'\n\ndescribe('R.tap', () => {\n  it('happy', () => {\n    pipe(\n      tap(x => {\n        x // $ExpectType number[]\n      }),\n      (x: number[]) => x.length\n    )([1, 2])\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#tap)\n\n### test\n\n```typescript\n\ntest(regExpression: RegExp): (str: string) => boolean\n```\n\nIt determines whether `str` matches `regExpression`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.test(%2F%5Ef%2F%2C%20'foo')%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.test</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntest(regExpression: RegExp): (str: string) => boolean;\ntest(regExpression: RegExp, str: string): boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.test</strong> source</summary>\n\n```javascript\nexport function test(pattern, str){\n  if (arguments.length === 1) return _str => test(pattern, _str)\n\n  if (typeof pattern === 'string'){\n    throw new TypeError(`R.test requires a value of type RegExp as its first argument; received \"${ pattern }\"`)\n  }\n\n  return str.search(pattern) !== -1\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { test as testMethod } from './test.js'\n\ntest('happy', () => {\n  expect(testMethod(/^x/, 'xyz')).toBeTrue()\n\n  expect(testMethod(/^y/)('xyz')).toBeFalse()\n})\n\ntest('throws if first argument is not regex', () => {\n  expect(() => testMethod('foo', 'bar')).toThrowErrorMatchingInlineSnapshot('\"R.test requires a value of type RegExp as its first argument; received \"foo\"\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {test} from 'rambda'\n\nconst input = 'foo   '\nconst regex = /foo/\n\ndescribe('R.test', () => {\n  it('happy', () => {\n    const result = test(regex, input)\n\n    result // $ExpectType boolean\n  })\n  it('curried', () => {\n    const result = test(regex)(input)\n\n    result // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#test)\n\n### times\n\n```typescript\n\ntimes<T>(fn: (i: number) => T, howMany: number): T[]\n```\n\nIt returns the result of applying function `fn` over members of range array.\n\nThe range array includes numbers between `0` and `howMany`(exclusive).\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20x%20%3D%3E%20x%20*%202%0Aconst%20howMany%20%3D%205%0A%0Aconst%20result%20%3D%20R.times(fn%2C%20howMany)%0A%2F%2F%20%3D%3E%20%5B0%2C%202%2C%204%2C%206%2C%208%5D\">Try this <strong>R.times</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntimes<T>(fn: (i: number) => T, howMany: number): T[];\ntimes<T>(fn: (i: number) => T): (howMany: number) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.times</strong> source</summary>\n\n```javascript\nimport { isInteger } from './_internals/isInteger.js'\nimport { map } from './map.js'\nimport { range } from './range.js'\n\nexport function times(fn, howMany){\n  if (arguments.length === 1) return _howMany => times(fn, _howMany)\n  if (!isInteger(howMany) || howMany < 0){\n    throw new RangeError('n must be an integer')\n  }\n\n  return map(fn, range(0, howMany))\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport assert from 'assert'\n\nimport { identity } from './identity.js'\nimport { times } from './times.js'\n\ntest('happy', () => {\n  const result = times(identity, 5)\n\n  expect(result).toEqual([ 0, 1, 2, 3, 4 ])\n})\n\ntest('with bad input', () => {\n  assert.throws(() => {\n    times(3)('cheers!')\n  }, RangeError)\n  assert.throws(() => {\n    times(identity, -1)\n  }, RangeError)\n})\n\ntest('curry', () => {\n  const result = times(identity)(5)\n\n  expect(result).toEqual([ 0, 1, 2, 3, 4 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {times, identity} from 'rambda'\n\ndescribe('R.times', () => {\n  it('happy', () => {\n    const result = times(identity, 5)\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#times)\n\n### toLower\n\n```typescript\n\ntoLower<S extends string>(str: S): Lowercase<S>\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.toLower('FOO')%0A%2F%2F%20%3D%3E%20'foo'\">Try this <strong>R.toLower</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntoLower<S extends string>(str: S): Lowercase<S>;\ntoLower(str: string): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.toLower</strong> source</summary>\n\n```javascript\nexport function toLower(str){\n  return str.toLowerCase()\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { toLower } from './toLower.js'\n\ntest('toLower', () => {\n  expect(toLower('FOO|BAR|BAZ')).toBe('foo|bar|baz')\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#toLower)\n\n### toPairs\n\n```typescript\n\ntoPairs<O extends object, K extends Extract<keyof O, string | number>>(obj: O): Array<{ [key in K]: [`${key}`, O[key]] }[K]>\n```\n\nIt transforms an object to a list.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%7B%0A%20%20a%20%3A%201%2C%0A%20%20b%20%3A%202%2C%0A%20%20c%20%3A%20%5B%203%2C%204%20%5D%2C%0A%7D%0Aconst%20expected%20%3D%20%5B%20%5B%20'a'%2C%201%20%5D%2C%20%5B%20'b'%2C%202%20%5D%2C%20%5B%20'c'%2C%20%5B%203%2C%204%20%5D%20%5D%20%5D%0A%0Aconst%20result%20%3D%20R.toPairs(list)%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.toPairs</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntoPairs<O extends object, K extends Extract<keyof O, string | number>>(obj: O): Array<{ [key in K]: [`${key}`, O[key]] }[K]>;\ntoPairs<S>(obj: Record<string | number, S>): Array<[string, S]>;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.toPairs</strong> source</summary>\n\n```javascript\nexport function toPairs(obj){\n  return Object.entries(obj)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { toPairs } from './toPairs.js'\n\nconst obj = {\n  a : 1,\n  b : 2,\n  c : [ 3, 4 ],\n}\nconst expected = [\n  [ 'a', 1 ],\n  [ 'b', 2 ],\n  [ 'c', [ 3, 4 ] ],\n]\n\ntest('happy', () => {\n  expect(toPairs(obj)).toEqual(expected)\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#toPairs)\n\n### toString\n\n```typescript\n\ntoString(x: unknown): string\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.toString(%5B1%2C%202%5D)%20%0A%2F%2F%20%3D%3E%20'1%2C2'\">Try this <strong>R.toString</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntoString(x: unknown): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.toString</strong> source</summary>\n\n```javascript\nexport function toString(x){\n  return x.toString()\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { toString } from './toString.js'\n\ntest('happy', () => {\n  expect(toString([ 1, 2, 3 ])).toBe('1,2,3')\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#toString)\n\n### toUpper\n\n```typescript\n\ntoUpper<S extends string>(str: S): Uppercase<S>\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.toUpper('foo')%0A%2F%2F%20%3D%3E%20'FOO'\">Try this <strong>R.toUpper</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntoUpper<S extends string>(str: S): Uppercase<S>;\ntoUpper(str: string): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.toUpper</strong> source</summary>\n\n```javascript\nexport function toUpper(str){\n  return str.toUpperCase()\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { toUpper } from './toUpper.js'\n\ntest('toUpper', () => {\n  expect(toUpper('foo|bar|baz')).toBe('FOO|BAR|BAZ')\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#toUpper)\n\n### transpose\n\n```typescript\n\ntranspose<T>(list: (T[])[]): (T[])[]\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%5B10%2C%2011%5D%2C%20%5B20%5D%2C%20%5B%5D%2C%20%5B30%2C%2031%2C%2032%5D%5D%0Aconst%20expected%20%3D%20%5B%5B10%2C%2020%2C%2030%5D%2C%20%5B11%2C%2031%5D%2C%20%5B32%5D%5D%0A%0Aconst%20result%20%3D%20R.transpose(list)%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.transpose</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntranspose<T>(list: (T[])[]): (T[])[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.transpose</strong> source</summary>\n\n```javascript\nimport { isArray } from './_internals/isArray.js'\n\nexport function transpose(array){\n  return array.reduce((acc, el) => {\n    el.forEach((nestedEl, i) =>\n      isArray(acc[ i ]) ? acc[ i ].push(nestedEl) : acc.push([ nestedEl ]))\n\n    return acc\n  }, [])\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { transpose } from './transpose.js'\n\ntest('happy', () => {\n  const input = [\n    [ 'a', 1 ],\n    [ 'b', 2 ],\n    [ 'c', 3 ],\n  ]\n\n  expect(transpose(input)).toEqual([\n    [ 'a', 'b', 'c' ],\n    [ 1, 2, 3 ],\n  ])\n})\n\ntest('when rows are shorter', () => {\n  const actual = transpose([ [ 10, 11 ], [ 20 ], [], [ 30, 31, 32 ] ])\n  const expected = [ [ 10, 20, 30 ], [ 11, 31 ], [ 32 ] ]\n  expect(actual).toEqual(expected)\n})\n\ntest('with empty array', () => {\n  expect(transpose([])).toEqual([])\n})\n\ntest('array with falsy values', () => {\n  const actual = transpose([\n    [ true, false, undefined, null ],\n    [ null, undefined, false, true ],\n  ])\n  const expected = [\n    [ true, null ],\n    [ false, undefined ],\n    [ undefined, false ],\n    [ null, true ],\n  ]\n  expect(actual).toEqual(expected)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {transpose} from 'rambda'\n\nconst input = [\n  ['a', 1],\n  ['b', 2],\n  ['c', 3],\n]\n\ndescribe('R.transpose', () => {\n  it('happy', () => {\n    const result = transpose(input)\n\n    result // $ExpectType (string | number)[][]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#transpose)\n\n### trim\n\n```typescript\n\ntrim(str: string): string\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.trim('%20%20foo%20%20')%20%0A%2F%2F%20%3D%3E%20'foo'\">Try this <strong>R.trim</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\ntrim(str: string): string;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.trim</strong> source</summary>\n\n```javascript\nexport function trim(str){\n  return str.trim()\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { trim } from './trim.js'\n\ntest('trim', () => {\n  expect(trim(' foo ')).toBe('foo')\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#trim)\n\n### tryCatch\n\nIt returns function that runs `fn` in `try/catch` block. If there was an error, then `fallback` is used to return the result. Note that `fn` can be value or asynchronous/synchronous function(unlike `Ramda` where fallback can only be a synchronous function).\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20x%20%3D%3E%20x.foo%0A%0Aconst%20result%20%3D%20%5B%0A%20%20R.tryCatch(fn%2C%20false)(null)%2C%0A%20%20R.tryCatch(fn%2C%20false)(%7Bfoo%3A%20'bar'%7D)%0A%5D%0A%2F%2F%20%3D%3E%20%5Bfalse%2C%20'bar'%5D\">Try this <strong>R.tryCatch</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#tryCatch)\n\n### type\n\nIt accepts any input and it returns its type.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.type(()%20%3D%3E%20%7B%7D)%20%2F%2F%20%3D%3E%20'Function'%0AR.type(async%20()%20%3D%3E%20%7B%7D)%20%2F%2F%20%3D%3E%20'Async'%0AR.type(%5B%5D)%20%2F%2F%20%3D%3E%20'Array'%0AR.type(%7B%7D)%20%2F%2F%20%3D%3E%20'Object'%0AR.type('foo')%20%2F%2F%20%3D%3E%20'String'%0AR.type(1)%20%2F%2F%20%3D%3E%20'Number'%0AR.type(true)%20%2F%2F%20%3D%3E%20'Boolean'%0AR.type(null)%20%2F%2F%20%3D%3E%20'Null'%0AR.type(%2F%5BA-z%5D%2F)%20%2F%2F%20%3D%3E%20'RegExp'%0AR.type('foo'*1)%20%2F%2F%20%3D%3E%20'NaN'%0A%0Aconst%20delay%20%3D%20ms%20%3D%3E%20new%20Promise(resolve%20%3D%3E%20%7B%0A%20%20setTimeout(function%20()%20%7B%0A%20%20%20%20resolve()%0A%20%20%7D%2C%20ms)%0A%7D)%0AR.type(delay)%20%2F%2F%20%3D%3E%20'Promise'\">Try this <strong>R.type</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#type)\n\n### unapply\n\n```typescript\n\nunapply<T = any>(fn: (args: any[]) => T): (...args: any[]) => T\n```\n\nIt calls a function `fn` with the list of values of the returned function. \n\n`R.unapply` is the opposite of `R.apply` method.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.unapply(JSON.stringify)(1%2C%202%2C%203)%0A%2F%2F%3D%3E%20'%5B1%2C2%2C3%5D'\">Try this <strong>R.unapply</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nunapply<T = any>(fn: (args: any[]) => T): (...args: any[]) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.unapply</strong> source</summary>\n\n```javascript\nexport function unapply(fn){\n  return function (...args){\n    return fn.call(this, args)\n  }\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { apply } from './apply.js'\nimport { converge } from './converge.js'\nimport { identity } from './identity.js'\nimport { prop } from './prop.js'\nimport { sum } from './sum.js'\nimport { unapply } from './unapply.js'\n\ntest('happy', () => {\n  const fn = unapply(identity)\n  expect(fn(\n    1, 2, 3\n  )).toEqual([ 1, 2, 3 ])\n  expect(fn()).toEqual([])\n})\n\ntest('returns a function which is always passed one argument', () => {\n  const fn = unapply(function (){\n    return arguments.length\n  })\n  expect(fn('x')).toBe(1)\n  expect(fn('x', 'y')).toBe(1)\n  expect(fn(\n    'x', 'y', 'z'\n  )).toBe(1)\n})\n\ntest('forwards arguments to decorated function as an array', () => {\n  const fn = unapply(xs => '[' + xs + ']')\n  expect(fn(2)).toBe('[2]')\n  expect(fn(2, 4)).toBe('[2,4]')\n  expect(fn(\n    2, 4, 6\n  )).toBe('[2,4,6]')\n})\n\ntest('returns a function with length 0', () => {\n  const fn = unapply(identity)\n  expect(fn).toHaveLength(0)\n})\n\ntest('is the inverse of R.apply', () => {\n  let a, b, c, d, e, f, g, n\n  const rand = function (){\n    return Math.floor(200 * Math.random()) - 100\n  }\n\n  f = Math.max\n  g = unapply(apply(f))\n  n = 1\n  while (n <= 100){\n    a = rand()\n    b = rand()\n    c = rand()\n    d = rand()\n    e = rand()\n    expect(f(\n      a, b, c, d, e\n    )).toEqual(g(\n      a, b, c, d, e\n    ))\n    n += 1\n  }\n\n  f = function (xs){\n    return '[' + xs + ']'\n  }\n  g = apply(unapply(f))\n  n = 1\n  while (n <= 100){\n    a = rand()\n    b = rand()\n    c = rand()\n    d = rand()\n    e = rand()\n    expect(f([ a, b, c, d, e ])).toEqual(g([ a, b, c, d, e ]))\n    n += 1\n  }\n})\n\ntest('it works with converge', () => {\n  const fn = unapply(sum)\n  const convergeFn = converge(fn, [ prop('a'), prop('b'), prop('c') ])\n  const obj = {\n    a : 1337,\n    b : 42,\n    c : 1,\n  }\n  const expected = 1337 + 42 + 1\n  expect(convergeFn(obj)).toEqual(expected)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {join, unapply, sum} from 'rambda'\n\ndescribe('R.unapply', () => {\n  it('happy', () => {\n    const fn = unapply(sum)\n\n    fn(1, 2, 3) // $ExpectType number\n  })\n\n  it('joins a string', () => {\n    const fn = unapply(join(''))\n\n    fn('s', 't', 'r', 'i', 'n', 'g') // $ExpectType string\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#unapply)\n\n### union\n\n```typescript\n\nunion<T>(x: T[], y: T[]): T[]\n```\n\nIt takes two lists and return a new list containing a merger of both list with removed duplicates. \n\n`R.equals` is used to compare for duplication.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.union(%5B1%2C2%2C3%5D%2C%20%5B3%2C4%2C5%5D)%3B%0A%2F%2F%20%3D%3E%20%5B1%2C%202%2C%203%2C%204%2C%205%5D\">Try this <strong>R.union</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nunion<T>(x: T[], y: T[]): T[];\nunion<T>(x: T[]): (y: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.union</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\nimport { includes } from './includes.js'\n\nexport function union(x, y){\n  if (arguments.length === 1) return _y => union(x, _y)\n\n  const toReturn = cloneList(x)\n\n  y.forEach(yInstance => {\n    if (!includes(yInstance, x)) toReturn.push(yInstance)\n  })\n\n  return toReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { union } from './union.js'\n\ntest('happy', () => {\n  expect(union([ 1, 2 ], [ 2, 3 ])).toEqual([ 1, 2, 3 ])\n})\n\ntest('with list of objects', () => {\n  const list1 = [ { a : 1 }, { a : 2 } ]\n  const list2 = [ { a : 2 }, { a : 3 } ]\n  const result = union(list1)(list2)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {union} from 'rambda'\n\ndescribe('R.union', () => {\n  it('happy', () => {\n    const result = union([1, 2], [2, 3])\n\n    result // $ExpectType number[]\n  })\n  it('with array of objects - case 1', () => {\n    const list1 = [{a: 1}, {a: 2}]\n    const list2 = [{a: 2}, {a: 3}]\n    const result = union(list1, list2)\n    result // $ExpectType { a: number; }[]\n  })\n  it('with array of objects - case 2', () => {\n    const list1 = [{a: 1, b: 1}, {a: 2}]\n    const list2 = [{a: 2}, {a: 3, b: 3}]\n    const result = union(list1, list2)\n    result[0].a // $ExpectType number\n    result[0].b // $ExpectType number | undefined\n  })\n})\n\ndescribe('R.union - curried', () => {\n  it('happy', () => {\n    const result = union([1, 2])([2, 3])\n\n    result // $ExpectType number[]\n  })\n  it('with array of objects - case 1', () => {\n    const list1 = [{a: 1}, {a: 2}]\n    const list2 = [{a: 2}, {a: 3}]\n    const result = union(list1)(list2)\n    result // $ExpectType { a: number; }[]\n  })\n  it('with array of objects - case 2', () => {\n    const list1 = [{a: 1, b: 1}, {a: 2}]\n    const list2 = [{a: 2}, {a: 3, b: 3}]\n    const result = union(list1)(list2)\n    result[0].a // $ExpectType number\n    result[0].b // $ExpectType number | undefined\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#union)\n\n### uniq\n\n```typescript\n\nuniq<T>(list: T[]): T[]\n```\n\nIt returns a new array containing only one copy of each element of `list`.\n\n`R.equals` is used to determine equality.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B1%2C%201%2C%20%7Ba%3A%201%7D%2C%20%7Ba%3A%202%7D%2C%20%7Ba%3A1%7D%5D%0A%0Aconst%20result%20%3D%20R.uniq(list)%0A%2F%2F%20%3D%3E%20%5B1%2C%20%7Ba%3A%201%7D%2C%20%7Ba%3A%202%7D%5D\">Try this <strong>R.uniq</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nuniq<T>(list: T[]): T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.uniq</strong> source</summary>\n\n```javascript\nimport { _Set } from './_internals/set.js'\n\nexport function uniq(list){\n  const set = new _Set()\n  const willReturn = []\n  list.forEach(item => {\n    if (set.checkUniqueness(item)){\n      willReturn.push(item)\n    }\n  })\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { uniq } from './uniq.js'\n\ntest('happy', () => {\n  const list = [ 1, 2, 3, 3, 3, 1, 2, 0 ]\n  expect(uniq(list)).toEqual([ 1, 2, 3, 0 ])\n})\n\ntest('with object', () => {\n  const list = [ { a : 1 }, { a : 2 }, { a : 1 }, { a : 2 } ]\n  expect(uniq(list)).toEqual([ { a : 1 }, { a : 2 } ])\n})\n\ntest('with nested array', () => {\n  expect(uniq([ [ 42 ], [ 42 ] ])).toEqual([ [ 42 ] ])\n})\n\ntest('with booleans', () => {\n  expect(uniq([ [ false ], [ false ], [ true ] ])).toEqual([ [ false ], [ true ] ])\n})\n\ntest('with falsy values', () => {\n  expect(uniq([ undefined, null ])).toEqual([ undefined, null ])\n})\n\ntest('can distinct between string and number', () => {\n  expect(uniq([ 1, '1' ])).toEqual([ 1, '1' ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {uniq} from 'rambda'\n\ndescribe('R.uniq', () => {\n  it('happy', () => {\n    const result = uniq([1, 2, 3, 3, 3, 1, 2, 0])\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#uniq)\n\n### uniqBy\n\nIt applies uniqueness to input list based on function that defines what to be used for comparison between elements.\n\n`R.equals` is used to determine equality.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%7Ba%3A1%7D%2C%20%7Ba%3A2%7D%2C%20%7Ba%3A1%7D%5D%0Aconst%20result%20%3D%20R.uniqBy(x%20%3D%3E%20x%2C%20list)%0A%0A%2F%2F%20%3D%3E%20%5B%7Ba%3A1%7D%2C%20%7Ba%3A2%7D%5D\">Try this <strong>R.uniqBy</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#uniqBy)\n\n### uniqWith\n\n```typescript\n\nuniqWith<T, U>(predicate: (x: T, y: T) => boolean, list: T[]): T[]\n```\n\nIt returns a new array containing only one copy of each element in `list` according to `predicate` function.\n\nThis predicate should return true, if two elements are equal.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list%20%3D%20%5B%0A%20%20%7Bid%3A%200%2C%20title%3A'foo'%7D%2C%0A%20%20%7Bid%3A%201%2C%20title%3A'bar'%7D%2C%0A%20%20%7Bid%3A%202%2C%20title%3A'baz'%7D%2C%0A%20%20%7Bid%3A%203%2C%20title%3A'foo'%7D%2C%0A%20%20%7Bid%3A%204%2C%20title%3A'bar'%7D%2C%0A%5D%0A%0Aconst%20expected%20%3D%20%5B%0A%20%20%7Bid%3A%200%2C%20title%3A'foo'%7D%2C%0A%20%20%7Bid%3A%201%2C%20title%3A'bar'%7D%2C%0A%20%20%7Bid%3A%202%2C%20title%3A'baz'%7D%2C%0A%5D%0A%0Aconst%20predicate%20%3D%20(x%2Cy)%20%3D%3E%20x.title%20%3D%3D%3D%20y.title%0A%0Aconst%20result%20%3D%20R.uniqWith(predicate%2C%20list)%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.uniqWith</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nuniqWith<T, U>(predicate: (x: T, y: T) => boolean, list: T[]): T[];\nuniqWith<T, U>(predicate: (x: T, y: T) => boolean): (list: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.uniqWith</strong> source</summary>\n\n```javascript\nfunction includesWith(\n  predicate, target, list\n){\n  let willReturn = false\n  let index = -1\n\n  while (++index < list.length && !willReturn){\n    const value = list[ index ]\n\n    if (predicate(target, value)){\n      willReturn = true\n    }\n  }\n\n  return willReturn\n}\n\nexport function uniqWith(predicate, list){\n  if (arguments.length === 1) return _list => uniqWith(predicate, _list)\n\n  let index = -1\n  const willReturn = []\n\n  while (++index < list.length){\n    const value = list[ index ]\n\n    if (!includesWith(\n      predicate, value, willReturn\n    )){\n      willReturn.push(value)\n    }\n  }\n\n  return willReturn\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { uniqWith as uniqWithRamda } from 'ramda'\n\nimport { uniqWith } from './uniqWith.js'\n\nconst list = [ { a : 1 }, { a : 1 } ]\n\ntest('happy', () => {\n  const fn = (x, y) => x.a === y.a\n\n  const result = uniqWith(fn, list)\n  expect(result).toEqual([ { a : 1 } ])\n})\n\ntest('with list of strings', () => {\n  const fn = (x, y) => x.length === y.length\n  const list = [ '0', '11', '222', '33', '4', '55' ]\n  const result = uniqWith(fn)(list)\n  const resultRamda = uniqWithRamda(fn, list)\n  expect(result).toEqual([ '0', '11', '222' ])\n  expect(resultRamda).toEqual([ '0', '11', '222' ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {uniqWith} from 'rambda'\n\ndescribe('R.uniqWith', () => {\n  it('happy', () => {\n    const list = [{a: 1}, {a: 1}]\n\n    const fn = (x: any, y: any) => x.a === y.a\n\n    const result = uniqWith(fn, list)\n    result // $ExpectType { a: number; }[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#uniqWith)\n\n### unless\n\n```typescript\n\nunless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U, x: T): T | U\n```\n\nThe method returns function that will be called with argument `input`.\n\nIf `predicate(input)` returns `false`, then the end result will be the outcome of `whenFalse(input)`.\n\nIn the other case, the final output will be the `input` itself.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20fn%20%3D%20R.unless(%0A%20%20x%20%3D%3E%20x%20%3E%202%2C%0A%20%20x%20%3D%3E%20x%20%2B%2010%0A)%0A%0Aconst%20result%20%3D%20%5B%0A%20%20fn(1)%2C%0A%20%20fn(5)%0A%5D%0A%2F%2F%20%3D%3E%20%5B11%2C%205%5D\">Try this <strong>R.unless</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nunless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U, x: T): T | U;\nunless<T, U>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => U): (x: T) => T | U;\nunless<T>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => T, x: T): T;\nunless<T>(predicate: (x: T) => boolean, whenFalseFn: (x: T) => T): (x: T) => T;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.unless</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nfunction unlessFn(\n  predicate, whenFalseFn, input\n){\n  if (predicate(input)) return input\n\n  return whenFalseFn(input)\n}\n\nexport const unless = curry(unlessFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { inc } from './inc.js'\nimport { isNil } from './isNil.js'\nimport { unless } from './unless.js'\n\ntest('happy', () => {\n  const safeInc = unless(isNil, inc)\n  expect(safeInc(null)).toBeNull()\n  expect(safeInc(1)).toBe(2)\n})\n\ntest('curried', () => {\n  const safeIncCurried = unless(isNil)(inc)\n  expect(safeIncCurried(null)).toBeNull()\n})\n\ntest('with 3 inputs', () => {\n  let result = unless(x => x.startsWith('/'), x=> x.concat('/'), '/api')\n  expect(result).toBe('/api')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {unless, inc} from 'rambda'\n\ndescribe('R.unless', () => {\n  it('happy', () => {\n    const fn = unless(x => x > 5, inc)\n    const result = fn(1)\n    result // $ExpectType number\n  })\n  it('with one explicit type', () => {\n    const result = unless(\n      x => {\n        x // $ExpectType number\n        return x > 5\n      },\n      x => {\n        x // $ExpectType number\n        return x + 1\n      },\n      1\n    )\n    result // $ExpectType number\n  })\n  it('with two different explicit types', () => {\n    const result = unless(\n      x => {\n        x // $ExpectType number\n        return x > 5\n      },\n      x => {\n        x // $ExpectType number\n        return `${x}-foo`\n      },\n      1\n    )\n    result // $ExpectType string | number\n  })\n})\n\ndescribe('R.unless - curried', () => {\n  it('happy', () => {\n    const fn = unless(x => x > 5, inc)\n    const result = fn(1)\n    result // $ExpectType number\n  })\n  it('with one explicit type', () => {\n    const fn = unless<number>(\n      x => {\n        x // $ExpectType number\n        return x > 5\n      },\n      x => {\n        x // $ExpectType number\n        return x + 1\n      }\n    )\n    const result = fn(1)\n    result // $ExpectType number\n  })\n  it('with two different explicit types', () => {\n    const fn = unless<number, string>(\n      x => {\n        x // $ExpectType number\n        return x > 5\n      },\n      x => {\n        x // $ExpectType number\n        return `${x}-foo`\n      }\n    )\n    const result = fn(1)\n    result // $ExpectType string | number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#unless)\n\n### unnest\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20R.unnest(%5B1%2C%20%5B2%5D%2C%20%5B%5B3%5D%5D%5D)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%2C%20%5B3%5D%5D\">Try this <strong>R.unnest</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#unnest)\n\n### unwind\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7B%0A%20%20a%3A%201%2C%0A%20%20b%3A%20%5B2%2C%203%5D%2C%0A%7D%0Aconst%20result%20%3D%20R.unwind('b'%2C%20obj)%0Aconst%20expected%20%3D%20%5B%7Ba%3A1%2C%20b%3A2%7D%2C%20%7Ba%3A1%2C%20b%3A3%7D%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.unwind</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#unwind)\n\n### update\n\n```typescript\n\nupdate<T>(index: number, newValue: T, list: T[]): T[]\n```\n\nIt returns a copy of `list` with updated element at `index` with `newValue`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20index%20%3D%202%0Aconst%20newValue%20%3D%2088%0Aconst%20list%20%3D%20%5B1%2C%202%2C%203%2C%204%2C%205%5D%0A%0Aconst%20result%20%3D%20R.update(index%2C%20newValue%2C%20list)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%2C%2088%2C%204%2C%205%5D\">Try this <strong>R.update</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nupdate<T>(index: number, newValue: T, list: T[]): T[];\nupdate<T>(index: number, newValue: T): (list: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.update</strong> source</summary>\n\n```javascript\nimport { cloneList } from './_internals/cloneList.js'\nimport { curry } from './curry.js'\n\nexport function updateFn(\n  index, newValue, list\n){\n  const clone = cloneList(list)\n  if (index === -1) return clone.fill(newValue, index)\n\n  return clone.fill(\n    newValue, index, index + 1\n  )\n}\n\nexport const update = curry(updateFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { update } from './update.js'\n\nconst list = [ 1, 2, 3 ]\n\ntest('happy', () => {\n  const newValue = 8\n  const index = 1\n  const result = update(\n    index, newValue, list\n  )\n  const curriedResult = update(index, newValue)(list)\n  const tripleCurriedResult = update(index)(newValue)(list)\n\n  const expected = [ 1, 8, 3 ]\n  expect(result).toEqual(expected)\n  expect(curriedResult).toEqual(expected)\n  expect(tripleCurriedResult).toEqual(expected)\n})\n\ntest('list has no such index', () => {\n  const newValue = 8\n  const index = 10\n  const result = update(\n    index, newValue, list\n  )\n\n  expect(result).toEqual(list)\n})\n\ntest('with negative index', () => {\n  expect(update(\n    -1, 10, [ 1 ]\n  )).toEqual([ 10 ])\n  expect(update(\n    -1, 10, []\n  )).toEqual([])\n  expect(update(\n    -1, 10, list\n  )).toEqual([ 1, 2, 10 ])\n  expect(update(\n    -2, 10, list\n  )).toEqual([ 1, 10, 3 ])\n  expect(update(\n    -3, 10, list\n  )).toEqual([ 10, 2, 3 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {update} from 'rambda'\n\ndescribe('R.update', () => {\n  it('happy', () => {\n    const result = update(1, 0, [1, 2, 3])\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#update)\n\n### values\n\n```typescript\n\nvalues<T extends object, K extends keyof T>(obj: T): T[K][]\n```\n\nWith correct input, this is nothing more than `Object.values(Record<string, unknown>)`. If `obj` is not an object, then it returns an empty array.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20obj%20%3D%20%7Ba%3A1%2C%20b%3A2%7D%0A%0Aconst%20result%20%3D%20R.values(Record%3Cstring%2C%20unknown%3E)%0A%2F%2F%20%3D%3E%20%5B1%2C%202%5D\">Try this <strong>R.values</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nvalues<T extends object, K extends keyof T>(obj: T): T[K][];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.values</strong> source</summary>\n\n```javascript\nimport { type } from './type.js'\n\nexport function values(obj){\n  if (type(obj) !== 'Object') return []\n  return Object.values(obj)\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { values } from './values.js'\n\ntest('happy', () => {\n  expect(values({\n    a : 1,\n    b : 2,\n    c : 3,\n  })).toEqual([ 1, 2, 3 ])\n})\n\ntest('with bad input', () => {\n  expect(values(null)).toEqual([])\n  expect(values(undefined)).toEqual([])\n  expect(values(55)).toEqual([])\n  expect(values('foo')).toEqual([])\n  expect(values(true)).toEqual([])\n  expect(values(false)).toEqual([])\n  expect(values(NaN)).toEqual([])\n  expect(values(Infinity)).toEqual([])\n  expect(values([])).toEqual([])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {values} from 'rambda'\n\ndescribe('R.values', () => {\n  it('happy', () => {\n    const result = values({\n      a: 1,\n      b: 2,\n      c: 3,\n    })\n    result // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#values)\n\n### view\n\n```typescript\n\nview<S, A>(lens: Lens<S, A>): (obj: S) => A\n```\n\nIt returns the value of `lens` focus over `target` object.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20lens%20%3D%20R.lensProp('x')%0A%0AR.view(lens%2C%20%7Bx%3A%201%2C%20y%3A%202%7D)%20%2F%2F%20%3D%3E%201%0Aconst%20result%20%3D%20R.view(lens%2C%20%7Bx%3A%204%2C%20y%3A%202%7D)%20%2F%2F%20%3D%3E%204\">Try this <strong>R.view</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nview<S, A>(lens: Lens<S, A>): (obj: S) => A;\nview<S, A>(lens: Lens<S, A>, obj: S): A;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.view</strong> source</summary>\n\n```javascript\nconst Const = x => ({\n  x,\n  map : fn => Const(x),\n})\n\nexport function view(lens, target){\n  if (arguments.length === 1) return _target => view(lens, _target)\n\n  return lens(Const)(target).x\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { assoc } from './assoc.js'\nimport { lens } from './lens.js'\nimport { prop } from './prop.js'\nimport { view } from './view.js'\n\nconst testObject = { foo : 'Led Zeppelin' }\nconst assocLens = lens(prop('foo'), assoc('foo'))\n\ntest('happy', () => {\n  expect(view(assocLens, testObject)).toBe('Led Zeppelin')\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#view)\n\n### when\n\n```typescript\n\nwhen<T, U>(predicate: (x: T) => boolean, whenTrueFn: (a: T) => U, input: T): T | U\n```\n\nIt pass `input` to `predicate` function and if the result is `true`, it will return the result of `whenTrueFn(input)`. \nIf the `predicate` returns `false`, then it will simply return `input`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20predicate%20%3D%20x%20%3D%3E%20typeof%20x%20%3D%3D%3D%20'number'%0Aconst%20whenTrueFn%20%3D%20R.add(11)%0A%0Aconst%20fn%20%3D%20when(predicate%2C%20whenTrueResult)%0A%0Aconst%20positiveInput%20%3D%2088%0Aconst%20negativeInput%20%3D%20'foo'%0A%0Aconst%20result%20%3D%20%5B%0A%20%20fn(positiveInput)%2C%0A%20%20fn(positiveInput)%2C%0A%5D%0A%0Aconst%20expected%20%3D%20%5B%0A%20%2099%2C%0A%20%20'foo'%2C%0A%5D%0A%2F%2F%20%3D%3E%20%60result%60%20is%20equal%20to%20%60expected%60\">Try this <strong>R.when</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nwhen<T, U>(predicate: (x: T) => boolean, whenTrueFn: (a: T) => U, input: T): T | U;\nwhen<T, U>(predicate: (x: T) => boolean, whenTrueFn: (a: T) => U): (input: T) => T | U;\nwhen<T, U>(predicate: (x: T) => boolean): ((whenTrueFn: (a: T) => U) => (input: T) => T | U);\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.when</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\n\nfunction whenFn(\n  predicate, whenTrueFn, input\n){\n  if (!predicate(input)) return input\n\n  return whenTrueFn(input)\n}\n\nexport const when = curry(whenFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { add } from './add.js'\nimport { when } from './when.js'\n\nconst predicate = x => typeof x === 'number'\n\ntest('happy', () => {\n  const fn = when(predicate, add(11))\n  expect(fn(11)).toBe(22)\n  expect(fn('foo')).toBe('foo')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {when} from 'rambda'\n\nconst predicate = (x: number) => x > 2\nconst whenTrueFn = (x: number) => String(x)\n\ndescribe('R.when', () => {\n  it('happy', () => {\n    const result = when(predicate, whenTrueFn, 1)\n    result // $ExpectType string | 1\n  })\n\n  it('curry 1', () => {\n    const fn = when(predicate, whenTrueFn)\n    const result = fn(1)\n    result // $ExpectType string | number\n  })\n\n  it('curry 2 require explicit types', () => {\n    const fn = when<number, string>(predicate)(whenTrueFn)\n    const result = fn(1)\n    result // $ExpectType string | number\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#when)\n\n### where\n\n```typescript\n\nwhere<T, U>(conditions: T, input: U): boolean\n```\n\nIt returns `true` if all each property in `conditions` returns `true` when applied to corresponding property in `input` object.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20condition%20%3D%20R.where(%7B%0A%20%20a%20%3A%20x%20%3D%3E%20typeof%20x%20%3D%3D%3D%20%22string%22%2C%0A%20%20b%20%3A%20x%20%3D%3E%20x%20%3D%3D%3D%204%0A%7D)%0Aconst%20input%20%3D%20%7B%0A%20%20a%20%3A%20%22foo%22%2C%0A%20%20b%20%3A%204%2C%0A%20%20c%20%3A%2011%2C%0A%7D%0A%0Aconst%20result%20%3D%20condition(input)%20%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.where</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nwhere<T, U>(conditions: T, input: U): boolean;\nwhere<T>(conditions: T): <U>(input: U) => boolean;\nwhere<ObjFunc2, U>(conditions: ObjFunc2, input: U): boolean;\nwhere<ObjFunc2>(conditions: ObjFunc2): <U>(input: U) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.where</strong> source</summary>\n\n```javascript\nexport function where(conditions, input){\n  if (input === undefined){\n    return _input => where(conditions, _input)\n  }\n  let flag = true\n  for (const prop in conditions){\n    if (!flag) continue\n    const result = conditions[ prop ](input[ prop ])\n    if (flag && result === false){\n      flag = false\n    }\n  }\n\n  return flag\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { equals } from './equals.js'\nimport { where } from './where.js'\n\ntest('when true', () => {\n  const result = where({\n    a : equals('foo'),\n    b : equals('bar'),\n  },\n  {\n    a : 'foo',\n    b : 'bar',\n    x : 11,\n    y : 19,\n  })\n\n  expect(result).toBeTrue()\n})\n\ntest('when false | early exit', () => {\n  let counter = 0\n  const equalsFn = expected => input => {\n    console.log(expected, 'expected')\n    counter++\n\n    return input === expected\n  }\n  const predicate = where({\n    a : equalsFn('foo'),\n    b : equalsFn('baz'),\n  })\n  expect(predicate({\n    a : 'notfoo',\n    b : 'notbar',\n  })).toBeFalse()\n  expect(counter).toBe(1)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {where, equals} from 'rambda'\n\ndescribe('R.where', () => {\n  it('happy', () => {\n    const input = {\n      a: 'foo',\n      b: 'bar',\n      x: 11,\n      y: 19,\n    }\n    const conditions = {\n      a: equals('foo'),\n      b: equals('bar'),\n    }\n    const result = where(conditions, input)\n    const curriedResult = where(conditions)(input)\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#where)\n\n### whereAny\n\nSame as `R.where`, but it will return `true` if at least one condition check returns `true`.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20conditions%20%3D%20%7B%0A%20%20a%3A%20a%20%3D%3E%20a%20%3E%201%2C%0A%20%20b%3A%20b%20%3D%3E%20b%20%3E%202%2C%0A%7D%0Aconst%20result%20%3D%20%5B%0A%20%20R.whereAny(conditions%2C%20%7Bb%3A3%7D)%2C%0A%20%20R.whereAny(conditions%2C%20%7Bc%3A4%7D)%0A%5D%0A%2F%2F%20%3D%3E%20%5Btrue%2C%20false%5D\">Try this <strong>R.whereAny</strong> example in Rambda REPL</a>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#whereAny)\n\n### whereEq\n\n```typescript\n\nwhereEq<T, U>(condition: T, input: U): boolean\n```\n\nIt will return `true` if all of `input` object fully or partially include `rule` object.\n\n`R.equals` is used to determine equality.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20condition%20%3D%20%7B%20a%20%3A%20%7B%20b%20%3A%201%20%7D%20%7D%0Aconst%20input%20%3D%20%7B%0A%20%20a%20%3A%20%7B%20b%20%3A%201%20%7D%2C%0A%20%20c%20%3A%202%0A%7D%0A%0Aconst%20result%20%3D%20whereEq(condition%2C%20input)%0A%2F%2F%20%3D%3E%20true\">Try this <strong>R.whereEq</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nwhereEq<T, U>(condition: T, input: U): boolean;\nwhereEq<T>(condition: T): <U>(input: U) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.whereEq</strong> source</summary>\n\n```javascript\nimport { equals } from './equals.js'\nimport { filter } from './filter.js'\n\nexport function whereEq(condition, input){\n  if (arguments.length === 1){\n    return _input => whereEq(condition, _input)\n  }\n\n  const result = filter((conditionValue, conditionProp) =>\n    equals(conditionValue, input[ conditionProp ]),\n  condition)\n\n  return Object.keys(result).length === Object.keys(condition).length\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { whereEq } from './whereEq.js'\n\ntest('when true', () => {\n  const condition = { a : 1 }\n  const input = {\n    a : 1,\n    b : 2,\n  }\n\n  const result = whereEq(condition, input)\n  const expectedResult = true\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('when false', () => {\n  const condition = { a : 1 }\n  const input = { b : 2 }\n\n  const result = whereEq(condition, input)\n  const expectedResult = false\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('with nested object', () => {\n  const condition = { a : { b : 1 } }\n  const input = {\n    a : { b : 1 },\n    c : 2,\n  }\n\n  const result = whereEq(condition)(input)\n  const expectedResult = true\n\n  expect(result).toEqual(expectedResult)\n})\n\ntest('with wrong input', () => {\n  const condition = { a : { b : 1 } }\n\n  expect(() => whereEq(condition, null)).toThrowErrorMatchingInlineSnapshot('\"Cannot read properties of null (reading \\'a\\')\"')\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {whereEq} from 'rambda'\n\ndescribe('R.whereEq', () => {\n  it('happy', () => {\n    const result = whereEq({a: {b: 2}}, {b: 2})\n    const curriedResult = whereEq({a: {b: 2}})({b: 2})\n    result // $ExpectType boolean\n    curriedResult // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#whereEq)\n\n### without\n\n```typescript\n\nwithout<T>(matchAgainst: T[], source: T[]): T[]\n```\n\nIt will return a new array, based on all members of `source` list that are not part of `matchAgainst` list.\n\n`R.equals` is used to determine equality.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20source%20%3D%20%5B1%2C%202%2C%203%2C%204%5D%0Aconst%20matchAgainst%20%3D%20%5B2%2C%203%5D%0A%0Aconst%20result%20%3D%20R.without(matchAgainst%2C%20source)%0A%2F%2F%20%3D%3E%20%5B1%2C%204%5D\">Try this <strong>R.without</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nwithout<T>(matchAgainst: T[], source: T[]): T[];\nwithout<T>(matchAgainst: T[]): (source: T[]) => T[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.without</strong> source</summary>\n\n```javascript\nimport { _indexOf } from './equals.js'\nimport { reduce } from './reduce.js'\n\nexport function without(matchAgainst, source){\n  if (source === undefined){\n    return _source => without(matchAgainst, _source)\n  }\n\n  return reduce(\n    (prev, current) =>\n      _indexOf(current, matchAgainst) > -1 ? prev : prev.concat(current),\n    [],\n    source\n  )\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { without as withoutRamda } from 'ramda'\n\nimport { without } from './without.js'\n\ntest('should return a new list without values in the first argument', () => {\n  const itemsToOmit = [ 'A', 'B', 'C' ]\n  const collection = [ 'A', 'B', 'C', 'D', 'E', 'F' ]\n\n  expect(without(itemsToOmit, collection)).toEqual([ 'D', 'E', 'F' ])\n  expect(without(itemsToOmit)(collection)).toEqual([ 'D', 'E', 'F' ])\n})\n\ntest('with list of objects', () => {\n  const itemsToOmit = [ { a : 1 }, { c : 3 } ]\n  const collection = [ { a : 1 }, { b : 2 }, { c : 3 }, { d : 4 } ]\n  const expected = [ { b : 2 }, { d : 4 } ]\n\n  expect(without(itemsToOmit, collection)).toEqual(expected)\n  expect(withoutRamda(itemsToOmit, collection)).toEqual(expected)\n})\n\ntest('ramda accepts string as target input while rambda throws', () => {\n  expect(withoutRamda('0:1', [ '0', '0:1' ])).toEqual([ '0:1' ])\n  expect(() =>\n    without('0:1', [ '0', '0:1' ])).toThrowErrorMatchingInlineSnapshot('\"Cannot read property \\'indexOf\\' of 0:1\"')\n  expect(without([ '0:1' ], [ '0', '0:1' ])).toEqual([ '0' ])\n})\n\ntest('ramda test', () => {\n  expect(without([ 1, 2 ])([ 1, 2, 1, 3, 4 ])).toEqual([ 3, 4 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {without} from 'rambda'\n\nconst itemsToOmit = ['A', 'B', 'C']\nconst collection = ['A', 'B', 'C', 'D', 'E', 'F']\n\ndescribe('R.without', () => {\n  it('happy', () => {\n    const result = without(itemsToOmit, collection)\n\n    result // $ExpectType string[]\n  })\n  it('curried', () => {\n    const result = without(itemsToOmit)(collection)\n\n    result // $ExpectType string[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#without)\n\n### xor\n\n```typescript\n\nxor(x: boolean, y: boolean): boolean\n```\n\nLogical XOR\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20result%20%3D%20%5B%0A%20%20xor(true%2C%20true)%2C%0A%20%20xor(false%2C%20false)%2C%0A%20%20xor(false%2C%20true)%2C%0A%5D%0A%2F%2F%20%3D%3E%20%5Bfalse%2C%20false%2C%20true%5D\">Try this <strong>R.xor</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nxor(x: boolean, y: boolean): boolean;\nxor(y: boolean): (y: boolean) => boolean;\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.xor</strong> source</summary>\n\n```javascript\nexport function xor(a, b){\n  if (arguments.length === 1) return _b => xor(a, _b)\n\n  return Boolean(a) && !b || Boolean(b) && !a\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { xor } from './xor.js'\n\ntest('compares two values with exclusive or', () => {\n  expect(xor(true, true)).toBeFalse()\n  expect(xor(true, false)).toBeTrue()\n  expect(xor(false, true)).toBeTrue()\n  expect(xor(false, false)).toBeFalse()\n})\n\ntest('when both values are truthy, it should return false', () => {\n  expect(xor(true, 'foo')).toBeFalse()\n  expect(xor(42, true)).toBeFalse()\n  expect(xor('foo', 42)).toBeFalse()\n  expect(xor({}, true)).toBeFalse()\n  expect(xor(true, [])).toBeFalse()\n  expect(xor([], {})).toBeFalse()\n  expect(xor(new Date(), true)).toBeFalse()\n  expect(xor(true, Infinity)).toBeFalse()\n  expect(xor(Infinity, new Date())).toBeFalse()\n})\n\ntest('when both values are falsy, it should return false', () => {\n  expect(xor(null, false)).toBeFalse()\n  expect(xor(false, undefined)).toBeFalse()\n  expect(xor(undefined, null)).toBeFalse()\n  expect(xor(0, false)).toBeFalse()\n  expect(xor(false, NaN)).toBeFalse()\n  expect(xor(NaN, 0)).toBeFalse()\n  expect(xor('', false)).toBeFalse()\n})\n\ntest('when one argument is truthy and the other is falsy, it should return true', () => {\n  expect(xor('foo', null)).toBeTrue()\n  expect(xor(null, 'foo')).toBeTrue()\n  expect(xor(undefined, 42)).toBeTrue()\n  expect(xor(42, undefined)).toBeTrue()\n  expect(xor(Infinity, NaN)).toBeTrue()\n  expect(xor(NaN, Infinity)).toBeTrue()\n  expect(xor({}, '')).toBeTrue()\n  expect(xor('', {})).toBeTrue()\n  expect(xor(new Date(), 0)).toBeTrue()\n  expect(xor(0, new Date())).toBeTrue()\n  expect(xor([], null)).toBeTrue()\n  expect(xor(undefined, [])).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {xor} from 'rambda'\n\ndescribe('R.xor', () => {\n  it('happy', () => {\n    xor(true, false) // $ExpectType boolean\n  })\n  it('curry', () => {\n    xor(true)(false) // $ExpectType boolean\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#xor)\n\n### zip\n\n```typescript\n\nzip<K, V>(x: K[], y: V[]): KeyValuePair<K, V>[]\n```\n\nIt will return a new array containing tuples of equally positions items from both `x` and `y` lists. \n\nThe returned list will be truncated to match the length of the shortest supplied list.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20x%20%3D%20%5B1%2C%202%5D%0Aconst%20y%20%3D%20%5B'A'%2C%20'B'%5D%0AR.zip(x%2C%20y)%0A%2F%2F%20%3D%3E%20%5B%5B1%2C%20'A'%5D%2C%20%5B2%2C%20'B'%5D%5D%0A%0A%2F%2F%20truncates%20to%20shortest%20list%0Aconst%20result%20%3D%20R.zip(%5B...x%2C%203%5D%2C%20%5B'A'%2C%20'B'%5D)%0A%2F%2F%20%3D%3E%20%5B%5B1%2C%20'A'%5D%2C%20%5B2%2C%20'B'%5D%5D\">Try this <strong>R.zip</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nzip<K, V>(x: K[], y: V[]): KeyValuePair<K, V>[];\nzip<K>(x: K[]): <V>(y: V[]) => KeyValuePair<K, V>[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.zip</strong> source</summary>\n\n```javascript\nexport function zip(left, right){\n  if (arguments.length === 1) return _right => zip(left, _right)\n\n  const result = []\n  const length = Math.min(left.length, right.length)\n\n  for (let i = 0; i < length; i++){\n    result[ i ] = [ left[ i ], right[ i ] ]\n  }\n\n  return result\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { zip } from './zip.js'\n\nconst array1 = [ 1, 2, 3 ]\nconst array2 = [ 'A', 'B', 'C' ]\n\ntest('should return an array', () => {\n  const actual = zip(array1)(array2)\n  expect(actual).toBeInstanceOf(Array)\n})\n\ntest('should return and array or tuples', () => {\n  const expected = [\n    [ 1, 'A' ],\n    [ 2, 'B' ],\n    [ 3, 'C' ],\n  ]\n  const actual = zip(array1, array2)\n  expect(actual).toEqual(expected)\n})\n\ntest('should truncate result to length of shorted input list', () => {\n  const expectedA = [\n    [ 1, 'A' ],\n    [ 2, 'B' ],\n  ]\n  const actualA = zip([ 1, 2 ], array2)\n  expect(actualA).toEqual(expectedA)\n\n  const expectedB = [\n    [ 1, 'A' ],\n    [ 2, 'B' ],\n  ]\n  const actualB = zip(array1, [ 'A', 'B' ])\n  expect(actualB).toEqual(expectedB)\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {zip} from 'rambda'\n\ndescribe('R.zip', () => {\n  it('happy', () => {\n    const array1 = [1, 2, 3]\n    const array2 = ['A', 'B', 'C']\n\n    const result = zip(array1)(array2)\n    result // $ExpectType KeyValuePair<number, string>[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#zip)\n\n### zipObj\n\n```typescript\n\nzipObj<T, K extends string>(keys: K[], values: T[]): { [P in K]: T }\n```\n\nIt will return a new object with keys of `keys` array and values of `values` array.\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20keys%20%3D%20%5B'a'%2C%20'b'%2C%20'c'%5D%0A%0AR.zipObj(keys%2C%20%5B1%2C%202%2C%203%5D)%0A%2F%2F%20%3D%3E%20%7Ba%3A%201%2C%20b%3A%202%2C%20c%3A%203%7D%0A%0A%2F%2F%20truncates%20to%20shortest%20list%0Aconst%20result%20%3D%20R.zipObj(keys%2C%20%5B1%2C%202%5D)%0A%2F%2F%20%3D%3E%20%7Ba%3A%201%2C%20b%3A%202%7D\">Try this <strong>R.zipObj</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nzipObj<T, K extends string>(keys: K[], values: T[]): { [P in K]: T };\nzipObj<K extends string>(keys: K[]): <T>(values: T[]) => { [P in K]: T };\nzipObj<T, K extends number>(keys: K[], values: T[]): { [P in K]: T };\nzipObj<K extends number>(keys: K[]): <T>(values: T[]) => { [P in K]: T };\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.zipObj</strong> source</summary>\n\n```javascript\nimport { take } from './take.js'\n\nexport function zipObj(keys, values){\n  if (arguments.length === 1) return yHolder => zipObj(keys, yHolder)\n\n  return take(values.length, keys).reduce((\n    prev, xInstance, i\n  ) => {\n    prev[ xInstance ] = values[ i ]\n\n    return prev\n  }, {})\n}\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { equals } from './equals.js'\nimport { zipObj } from './zipObj.js'\n\ntest('zipObj', () => {\n  expect(zipObj([ 'a', 'b', 'c' ], [ 1, 2, 3 ])).toEqual({\n    a : 1,\n    b : 2,\n    c : 3,\n  })\n})\n\ntest('0', () => {\n  expect(zipObj([ 'a', 'b' ])([ 1, 2, 3 ])).toEqual({\n    a : 1,\n    b : 2,\n  })\n})\n\ntest('1', () => {\n  expect(zipObj([ 'a', 'b', 'c' ])([ 1, 2 ])).toEqual({\n    a : 1,\n    b : 2,\n  })\n})\n\ntest('ignore extra keys', () => {\n  const result = zipObj([ 'a', 'b', 'c', 'd', 'e', 'f' ], [ 1, 2, 3 ])\n  const expected = {\n    a : 1,\n    b : 2,\n    c : 3,\n  }\n\n  expect(equals(result, expected)).toBeTrue()\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {zipObj} from 'rambda'\n\ndescribe('R.zipObj', () => {\n  it('happy', () => {\n    // this is wrong since 24.10.2020 `@types/ramda` changes\n    const result = zipObj(['a', 'b', 'c', 'd'], [1, 2, 3])\n    ;[result.a, result.b, result.c, result.d] // $ExpectType number[]\n  })\n  it('imported from @types/ramda', () => {\n    const result = zipObj(['a', 'b', 'c'], [1, 2, 3])\n    const curriedResult = zipObj(['a', 'b', 'c'])([1, 2, 3])\n    ;[result.a, result.b, result.c] // $ExpectType number[]\n    ;[curriedResult.a, curriedResult.b, curriedResult.c] // $ExpectType number[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#zipObj)\n\n### zipWith\n\n```typescript\n\nzipWith<T, U, TResult>(fn: (x: T, y: U) => TResult, list1: T[], list2: U[]): TResult[]\n```\n\n<a title=\"redirect to Rambda Repl site\" href=\"https://rambda.now.sh?const%20list1%20%3D%20%5B%2010%2C%2020%2C%2030%2C%2040%20%5D%0Aconst%20list2%20%3D%20%5B%20100%2C%20200%20%5D%0A%0Aconst%20result%20%3D%20R.zipWith(%0A%20%20R.add%2C%20list1%2C%20list2%0A)%0A%2F%2F%20%3D%3E%20%5B110%2C%20220%5D\">Try this <strong>R.zipWith</strong> example in Rambda REPL</a>\n\n<details>\n\n<summary>All TypeScript definitions</summary>\n\n```typescript\nzipWith<T, U, TResult>(fn: (x: T, y: U) => TResult, list1: T[], list2: U[]): TResult[];\nzipWith<T, U, TResult>(fn: (x: T, y: U) => TResult, list1: T[]): (list2: U[]) => TResult[];\nzipWith<T, U, TResult>(fn: (x: T, y: U) => TResult): (list1: T[], list2: U[]) => TResult[];\n```\n\n</details>\n\n<details>\n\n<summary><strong>R.zipWith</strong> source</summary>\n\n```javascript\nimport { curry } from './curry.js'\nimport { take } from './take.js'\n\nfunction zipWithFn(\n  fn, x, y\n){\n  return take(x.length > y.length ? y.length : x.length, x).map((xInstance, i) => fn(xInstance, y[ i ]))\n}\n\nexport const zipWith = curry(zipWithFn)\n```\n\n</details>\n\n<details>\n\n<summary><strong>Tests</strong></summary>\n\n```javascript\nimport { add } from './add.js'\nimport { zipWith } from './zipWith.js'\n\nconst list1 = [ 1, 2, 3 ]\nconst list2 = [ 10, 20, 30, 40 ]\nconst list3 = [ 100, 200 ]\n\ntest('when second list is shorter', () => {\n  const result = zipWith(\n    add, list1, list3\n  )\n  expect(result).toEqual([ 101, 202 ])\n})\n\ntest('when second list is longer', () => {\n  const result = zipWith(\n    add, list1, list2\n  )\n  expect(result).toEqual([ 11, 22, 33 ])\n})\n```\n\n</details>\n\n<details>\n\n<summary><strong>TypeScript</strong> test</summary>\n\n```typescript\nimport {zipWith} from 'rambda'\n\nconst list1 = [1, 2]\nconst list2 = [10, 20, 30]\n\ndescribe('R.zipWith', () => {\n  it('happy', () => {\n    const result = zipWith(\n      (x, y) => {\n        x // $ExpectType number\n        y // $ExpectType number\n        return `${x}-${y}`\n      },\n      list1,\n      list2\n    )\n\n    result // $ExpectType string[]\n  })\n  it('curried', () => {\n    const result = zipWith((x, y) => {\n      x // $ExpectType unknown\n      y // $ExpectType unknown\n      return `${x}-${y}`\n    })(list1, list2)\n\n    result // $ExpectType string[]\n  })\n})\n```\n\n</details>\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#zipWith)\n\n## ❯ CHANGELOG\n\n9.4.2 \n\n- Fix TS issue when `R.take` is used as part of `R.pipe`.\n\nMoving away from `Ramda` types which are problematic in this case:\n\n```typescript\nconst data = ['foo', 'bar', 'baz', 'qux']\nconst result = piped(\n\tdata,\n\tfilter(\n\t\tx => x.length >= 2\n\t),\n\ttakeLast(2),\n)\n```\n\n9.4.1\n\n- Fix bug with `R.differenceWith` when two arrays has same length - [Issue #750](https://github.com/selfrefactor/rambda/issues/757)\n\n- Allow path input to not be transformed when string numbers are there - [Issue #750](https://github.com/selfrefactor/rambda/issues/750)\n\n9.4.0\n\n- Fix `deno` release\n\n- Fix too strict `true` condition in `R.ifElse` - [Issue #750](https://github.com/selfrefactor/rambda/issues/750)\n\n- Change `R.groupBy` typings to match `@types/ramda` typings\n\n9.3.0\n\n- Breaking change in relation to TS typings of `R.assoc`, `R.dissoc` and `R.modify` - https://github.com/ramda/types/pull/37\n\n- Add `R.isNotEmpty` as it is new method in `Ramda`\n\n- Fix `R.head`/`R.last` TS definition - It returns `undefined` if array has length of 0. Before \n\n9.2.1\n\n- Broken `Deno` build - [Issue #731](https://github.com/selfrefactor/rambda/issues/731)\n\n9.2.0\n\n- `R.once` TS type definition miss to context argument and its type - [Issue #728](https://github.com/selfrefactor/rambda/issues/728)\n\n- Fix implementation of `R.unless` function - https://github.com/selfrefactor/rambda/pull/726 \n\n9.1.1\n\n- Faster R.equals with Object.is short circuit - https://github.com/selfrefactor/rambda/pull/725\n\n- Fix R.cond transform is unary - https://github.com/selfrefactor/rambda/issues/720\n\n9.1.0\n\nAdd these methods\n\n- insert\n- insertAll\n- lt\n- lte\n- isNotNil\n- pickBy\n- pathSatisfies\n- swap\n- mergeDeepLeft\n\n9.0.1\n\n- Fix bad TS typings, due to missing declaration - [Issue #716](https://github.com/selfrefactor/rambda/issues/716)\n\n9.0.0\n\nBreaking change in TS definitions of `lenses` as now they are synced to `Ramda` types.\n\n- Add `R.sortWith` - [Issue #707](https://github.com/selfrefactor/rambda/issues/707)\n\n- Add `R.innerJoin`, `R.gt`, `R.gte`, `R.reduceBy`, `R.hasIn`\n\n8.6.0\n\n- Wrong typing for `R.dissocPath` - [Issue #709](https://github.com/selfrefactor/rambda/issues/709)\n\n- Update build dependencies\n\n8.5.0\n\n- Revert changes in `R.anyPass` introduced in `8.4.0` release. The reason is that the change was breaking the library older than `5.2.0` TypeScript.\n\n- Wrong `R.partial` TS definition  - [Issue #705](https://github.com/selfrefactor/rambda/issues/705)\n\n- Add `R.dropRepeatsBy`\n\n- Add `R.empty`\n\n- Add `R.eqBy`\n\n- Add `R.forEachObjIndexed`\n\n8.4.0\n\n- Add `R.dissocPath`\n\n- Fix TS definitions of `R.head/R.last` and add missing handle of empty string\n\n- Add `R.removeIndex` - method was before only in `Rambdax`, but now since `R.dissocPath` is using it, it is added to main library.\n\n- Allow `R.omit` to pass numbers as part of properties to omit, i.e. `R.omit(['a', 1], {a: {1: 1, 2: 2}})`\n\n- R.keys always returns strings - [MR #700](https://github.com/selfrefactor/rambda/pull/700)\n\n- Improve `R.prepend/R.append` type interference - [MR #699](https://github.com/selfrefactor/rambda/pull/699)\n\n- Change `R.reduce` TS definitions so index is always received - [MR #696](https://github.com/selfrefactor/rambda/pull/696)\n\n- Functions as a type guard in `R.anyPass` TS definitions - [MR #695](https://github.com/selfrefactor/rambda/pull/695)\n\n- Fix R.append's curried type - [MR #694](https://github.com/selfrefactor/rambda/pull/694)\n\n- Fix cannot compare errors in `Deno` with `R.equals` - [Issue #704](https://github.com/selfrefactor/rambda/issues/704).\n\n- Fix cannot compare `BigInt` with `R.equals` \n\n8.3.0\n\nAdd the following methods:\n\n- binary\n- call\n- collectBy\n- comparator\n- composeWith\n\n8.2.0\n\nAdd the following methods:\n\n- addIndex\n- addIndexRight\n- ap\n- aperture\n- applyTo\n- ascend\n- descend\n\n8.1.0\n\n- Fix input order of TS definitions for `R.propEq` method  - [Issue #688](https://github.com/selfrefactor/rambda/issues/688). The issue was due to 8.0.0 was shipped with TS definitions of `7.5.0` release.\n\n- Add `R.differenceWith` method  - [Issue #91](https://github.com/selfrefactor/rambdax/issues/91)\n\n8.0.0\n\n- handle falsy values in merge methods - https://github.com/ramda/ramda/pull/3222\n\n- `R.head`/`R.last` don't return `undefined` for non-empty arrays\n\n- `R.type` supports dates in TS definition - `Rambda` already did support dates in JS.\n\n- Improve typings of `R.endsWith/startsWith` with regard to `string` input. - [PR #622](https://github.com/selfrefactor/rambda/pull/622)\n\n- Handle list as falsy value in `R.reduce` - [Ramda MR](https://github.com/ramda/ramda/pull/2997/files)\n\n- `R.nop` is removed - it will be moved to `Rambdax` as `R.noop`\n\n- `R.includes` is no longer using string literal in TypeScript definitions\n\n> Reason for breaking change - synchronize with Ramda `0.29.0` release:\n\n- change order of `R.propEq` - [Ramda MR](https://github.com/ramda/ramda/pull/2938/files)\n\n7.5.0\n\n- IMPORTANT: Remove `export` property in `package.json` in order to allow `Rambda`  support for projects with `\"type\": \"module\"` in `package.json` - [Issue #667](https://github.com/selfrefactor/rambda/issues/657)\n\n- Add `R.unnest` - [Rambdax issue 89](https://github.com/selfrefactor/rambdax/issues/89)\n\n- `R.uniq` is not using `R.equals` as Ramda does - [Issue #88](https://github.com/selfrefactor/rambdax/issues/88)\n\n- Fix `R.path(['non','existing','path'], obj)` TS definition as 7.4.0 release caused TS errors - [Issue #668](https://github.com/selfrefactor/rambda/issues/668)\n\n7.4.0\n\n- Synchronize with `@types/ramda` - `R.prop`, `R.path`, `R.pickAll`\n\n- Remove `esm` Rollup output due to tree-shaking issues.\n\n- Upgrade all dev dependencies.\n\n7.3.0\n\n- Important - changing import declaration in `package.json` in order to fix tree-shaking issue - [Issue #647](https://github.com/selfrefactor/rambda/issues/647)\n\n- Add `R.modify`\n\n- Allow multiple inputs in TypeScript versions of `R.anyPass` and `R.allPass` - [Issue #642](https://github.com/selfrefactor/rambda/issues/604)\n\n- Using wrong clone of object in `R.mergeDeepRight` - [Issue #650](https://github.com/selfrefactor/rambda/issues/650)\n\n- Missing early return in `R.where` - [Issue #648](https://github.com/selfrefactor/rambda/issues/648)\n\n- `R.allPass` doesn't accept more than 1 parameters for function predicates- [Issue #604](https://github.com/selfrefactor/rambda/issues/604)\n\n7.2.1\n\n- Remove bad typings of `R.propIs` which caused the library to cannot be build with TypeScript. \n\n- Drop support for `Wallaby` as per [https://github.com/wallabyjs/public/issues/3037](https://github.com/wallabyjs/public/issues/3037)\n\n7.2.0\n\n- Wrong `R.update` if index is `-1` - [PR #593](https://github.com/selfrefactor/rambda/pull/593)\n\n- Wrong curried typings in `R.anyPass` - [Issue #642](https://github.com/selfrefactor/rambda/issues/642)\n\n- `R.modifyPath` not exported - [Issue #640](https://github.com/selfrefactor/rambda/issues/640)\n\n- Add new method `R.uniqBy`. Implementation is coming from [Ramda MR#2641](https://github.com/ramda/ramda/pull/2641)\n\n- Apply the following changes from `@types/rambda`:\n\n-- [https://github.com/DefinitelyTyped/DefinitelyTyped/commit/bab47272d52fc7bb81e85da36dbe9c905a04d067](add `AnyFunction` and `AnyConstructor`)\n\n-- Improve `R.ifElse` typings - https://github.com/DefinitelyTyped/DefinitelyTyped/pull/59291\n\n-- Make `R.propEq` safe for `null/undefined` arguments - https://github.com/ramda/ramda/pull/2594/files\n\n7.1.4\n\n- `R.mergeRight` not found on `Deno` import - [Issue #633](https://github.com/selfrefactor/rambda/issues/633)\n\n7.1.0\n\n- Add `R.mergeRight` - introduced by Ramda's latest release. While Ramda renames `R.merge`, Rambda will keep `R.merge`.\n\n- Rambda's `pipe/compose` doesn't return proper length of composed function which leads to issue with `R.applySpec`. It was fixed by using Ramda's `pipe/compose` logic - [Issue #627](https://github.com/selfrefactor/rambda/issues/627)\n\n- Replace `Async` with `Promise` as return type of `R.type`.\n\n- Add new types as TypeScript output for `R.type` - \"Map\", \"WeakMap\", \"Generator\", \"GeneratorFunction\", \"BigInt\", \"ArrayBuffer\"\n\n- Add `R.juxt` method\n\n- Add `R.propSatisfies` method\n\n- Add new methods after `Ramda` version upgrade to `0.28.0`:\n\n-- R.count\n-- R.modifyPath\n-- R.on\n-- R.whereAny\n-- R.partialObject\n\n7.0.3\n\nRambda.none has wrong logic introduced in version `7.0.0` - [Issue #625](https://github.com/selfrefactor/rambda/issues/625)\n\n7.0.2\n\nRambda doesn't work with `pnpm` due to wrong export configuration - [Issue #619](https://github.com/selfrefactor/rambda/issues/619)\n\n7.0.1\n\n- Wrong ESM export configuration in `package.json` - [Issue #614](https://github.com/selfrefactor/rambda/issues/614)\n\n7.0.0\n\n- Breaking change - sync `R.compose`/`R.pipe` with `@types/ramda`. That is significant change so as safeguard, it will lead a major bump. Important - this lead to raising required TypeScript version to `4.2.2`. In other words, to use `Rambda` you'll need TypeScript version `4.2.2` or newer.\n\nRelated commit in `@types/ramda` - https://github.com/DefinitelyTyped/DefinitelyTyped/commit/286eff4f76d41eb8f091e7437eabd8a60d97fc1f#diff-4f74803fa83a81e47cb17a7d8a4e46a7e451f4d9e5ce2f1bd7a70a72d91f4bc1\n\nThere are several other changes in `@types/ramda` as stated in [this comment](https://github.com/ramda/ramda/issues/2976#issuecomment-990408945). This leads to change of typings for the following methods in **Rambda**:\n\n-- R.unless\n\n-- R.toString\n\n-- R.ifElse\n\n-- R.always\n\n-- R.complement\n\n-- R.cond\n\n-- R.is\n\n-- R.sortBy\n\n-- R.dissoc\n\n-- R.toPairs\n\n-- R.assoc\n\n-- R.toLower\n\n-- R.toUpper\n\n- One more reason for the breaking change is changing of export declarations in `package.json` based on [this blog post](https://devblogs.microsoft.com/typescript/announcing-typescript-4-5-beta/#packagejson-exports-imports-and-self-referencing) and [this merged Ramda's PR](https://github.com/ramda/ramda/pull/2999). This also led to renaming of `babel.config.js` to `babel.config.cjs`. \n\n- Add `R.apply`, `R.bind` and `R.unapply`\n\n- `R.startsWith/R.endsWith` now support lists as inputs. This way, it matches current Ramda behavior. \n\n- Remove unused typing for `R.chain`.\n\n- `R.map`/`R.filter` no longer accept bad inputs as iterable. This way, Rambda behaves more like Ramda, which also throws.\n\n- Make `R.lastIndexOf` follow the logic of `R.indexOf`.\n\n- Change `R.type` logic to Ramda logic. This way, `R.type` can return `Error` and `Set` as results.\n\n- Add missing logic in `R.equals` to compare sets - [Issue #599](https://github.com/selfrefactor/rambda/issues/599)\n\n- Improve list cloning - [Issue #595](https://github.com/selfrefactor/rambda/issues/595)\n\n- Handle multiple inputs with `R.allPass` and `R.anyPass` - [Issue #604](https://github.com/selfrefactor/rambda/issues/604)\n\n- Fix `R.length` wrong logic with inputs as `{length: 123}` - [Issue #606](https://github.com/selfrefactor/rambda/issues/606).\n\n- Improve non-curry typings of `R.merge` by using types from [mobily/ts-belt](https://github.com/mobily/ts-belt).\n\n- Improve performance of `R.uniqWith`.\n\n- Wrong `R.update` if index is `-1` - [PR #593](https://github.com/selfrefactor/rambda/pull/593)\n\n- Make `R.eqProps` safe for falsy inputs - based on [this opened Ramda PR](https://github.com/ramda/ramda/pull/2943).\n\n- Incorrect benchmarks for `R.pipe/R.compose` - [Issue #608](https://github.com/selfrefactor/rambda/issues/608)\n\n- Fix `R.last/R.head` typings - [Issue #609](https://github.com/selfrefactor/rambda/issues/609) \n\n6.9.0\n\n- Fix slow `R.uniq` methods - [Issue #581](https://github.com/selfrefactor/rambda/issues/581)\n\nFixing `R.uniq` was done by improving `R.indexOf` which has performance implication to all methods importing `R.indexOf`:\n\n- R.includes\n- R.intersection\n- R.difference\n- R.excludes\n- R.symmetricDifference\n- R.union\n\n- R.without no longer support the following case - `without('0:1', ['0', '0:1']) // => ['0']`. Now it throws as the first argument should be a list, not a string. Ramda, on the other hand, returns an empty list - https://github.com/ramda/ramda/issues/3086. \n\n6.8.3\n\n- Fix TypeScript build process with `rambda/immutable` - [Issue #572](https://github.com/selfrefactor/rambda/issues/572)\n\n- Add `R.objOf` method\n\n- Add `R.mapObjIndexed` method\n\n- Publish shorter README.md version to NPM\n\n6.8.0\n\n- `R.has` use `Object.prototype.hasOwnProperty`- [Issue #572](https://github.com/selfrefactor/rambda/issues/572)\n\n- Expose `immutable.ts` typings which are Rambda typings with `readonly` statements - [Issue #565](https://github.com/selfrefactor/rambda/issues/565)\n\n- Fix `R.intersection` wrong order compared to Ramda.\n\n- `R.path` wrong return of `null` instead of `undefined` when path value is `null` - [PR #577](https://github.com/selfrefactor/rambda/pull/577)\n\n6.7.0\n\n- Remove `ts-toolbelt` types from TypeScript definitions. Most affected are the following methods, which lose one of its curried definitions:\n\n1. R.maxBy\n2. R.minBy\n3. R.pathEq\n4. R.viewOr\n5. R.when\n6. R.merge\n7. R.mergeDeepRight\n8. R.mergeLeft\n\n6.6.0\n\n- Change `R.piped` typings to mimic that of `R.pipe`. Main difference is that `R.pipe` is focused on unary functions.\n\n- Fix wrong logic when `R.without` use `R.includes` while it should use array version of `R.includes`.\n\n- Use uglify plugin for UMD bundle.\n\n- Remove `dist` folder from `.gitignore` in order to fix `Deno` broken package. [Issue #570](https://github.com/selfrefactor/rambda/issues/570)\n\n- Improve `R.fromPairs` typings - [Issue #567](https://github.com/selfrefactor/rambda/issues/567)\n\n6.5.3\n\n- Wrong logic where `R.without` use `R.includes` while it should use the array version of `R.includes`\n\nThis is Ramda bug, that Rambda also has before this release - https://github.com/ramda/ramda/issues/3086\n\n6.5.2\n\n- Wrong `R.defaultTo` typings - changes introduced in v6.5.0 are missing their TS equivalent.\n\n- Update dependencies\n\n6.5.1\n\nFix wrong versions in changelog\n\n6.5.0\n\n- `R.defaultTo` no longer accepts infinite inputs, thus it follows Ramda implementation.\n\n- `R.equals` supports equality of functions.\n\n- `R.pipe` doesn't use `R.compose`.\n\n- Close [Issue #561](https://github.com/selfrefactor/rambda/issues/561) - export several internal TS interfaces and types\n\n- Close [Issue #559](https://github.com/selfrefactor/rambda/issues/559) - improve `R.propOr` typings\n\n- Add `CHANGELOG.md` file in release files list\n\n> This is only part of the changelog. You can read the full text in [CHANGELOG.md](CHANGELOG.md) file.\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-changelog)\n\n## ❯ Additional info\n\n> Most influential contributors(in alphabetical order)\n\n- ![farwayer avatar](https://avatars.githubusercontent.com/farwayer) [@farwayer](https://github.com/farwayer) - improving performance in R.find, R.filter; give the idea how to make benchmarks more reliable;\n\n- ![thejohnfreeman avatar](https://avatars.githubusercontent.com/thejohnfreeman) [@thejohnfreeman](https://github.com/thejohnfreeman) - add R.assoc, R.chain;\n\n- ![peeja avatar](https://avatars.githubusercontent.com/peeja) [@peeja](https://github.com/peeja) - add several methods and fix mutiple issues; provides great MR documentation\n\n- ![helmuthdu avatar](https://avatars.githubusercontent.com/helmuthdu) [@helmuthdu](https://github.com/helmuthdu) - add R.clone; help improve code style;\n\n- ![jpgorman avatar](https://avatars.githubusercontent.com/jpgorman) [@jpgorman](https://github.com/jpgorman) - add R.zip, R.reject, R.without, R.addIndex;\n\n- ![ku8ar avatar](https://avatars.githubusercontent.com/ku8ar) [@ku8ar](https://github.com/ku8ar) - add R.slice, R.propOr, R.identical, R.propIs and several math related methods; introduce the idea to display missing Ramda methods;\n\n- ![romgrk avatar](https://avatars.githubusercontent.com/romgrk) [@romgrk](https://github.com/romgrk) - add R.groupBy, R.indexBy, R.findLast, R.findLastIndex;\n\n- ![squidfunk avatar](https://avatars.githubusercontent.com/squidfunk) [@squidfunk](https://github.com/squidfunk) - add R.assocPath, R.symmetricDifference, R.difference, R.intersperse;\n\n- ![synthet1c avatar](https://avatars.githubusercontent.com/synthet1c) [@synthet1c](https://github.com/synthet1c) - add all lenses methods; add R.applySpec, R.converge;\n\n- ![vlad-zhukov avatar](https://avatars.githubusercontent.com/vlad-zhukov) [@vlad-zhukov](https://github.com/vlad-zhukov) - help with configuring Rollup, Babel; change export file to use ES module exports;\n\n> Rambda references\n\n- [Interview with Dejan Totef at SurviveJS blog](https://survivejs.com/blog/rambda-interview/)\n\n- [Awesome functional Javascript programming libraries](https://github.com/stoeffel/awesome-fp-js#libraries)\n\n- [Overview of Rambda pros/cons](https://mobily.github.io/ts-belt/docs/#rambda-%EF%B8%8F)\n\n> Links to Rambda\n\n- [awesome-fp-js](https://github.com/stoeffel/awesome-fp-js)\n\n- [Web Tools Weekly #280](https://mailchi.mp/webtoolsweekly/web-tools-280)\n\n- [awesome-docsify](https://github.com/docsifyjs/awesome-docsify)\n\n> Deprecated from `Used by` section\n\n- [SAP's Cloud SDK](https://github.com/SAP/cloud-sdk) - This repo doesn't uses `Rambda` since *October/2020* [commit that removes Rambda](https://github.com/SAP/cloud-sdk/commit/b29b4f915c4e4e9c2441e7b6b67cf83dac1fdac3)\n\n[![---------------](https://raw.githubusercontent.com/selfrefactor/rambda/master/files/separator.png)](#-additional-info)\n\n## My other libraries\n\n<table>\n    <tbody>\n        <tr valign=\"top\">\n            <td width=\"20%\" align=\"center\">\n                <h4>Niketa theme</h4>\n                <a href=\"https://marketplace.visualstudio.com/items?itemName=selfrefactor.Niketa-theme\">Collection of 9 light VSCode themes</a>\n            </td>\n            <td width=\"20%\" align=\"center\">\n                <h4>Niketa dark theme</h4>\n                <a href=\"https://marketplace.visualstudio.com/items?itemName=selfrefactor.niketa-dark-theme\">Collection of 9 dark VSCode themes</a>\n            </td>\n            <td width=\"20%\" align=\"center\">\n                <h4>String-fn</h4>\n                <a href=\"https://github.com/selfrefactor/services/tree/master/packages/string-fn\">String utility library</a>\n            </td>\n            <td width=\"20%\" align=\"center\">\n                <h4>Useful Javascript libraries</h4>\n                <a href=\"https://github.com/selfrefactor/useful-javascript-libraries\">Large collection of JavaScript,TypeScript and Angular related repos links</a>\n            </td>\n            <td width=\"20%\" align=\"center\">\n                <h4>Run-fn</h4>\n                <a href=\"https://github.com/selfrefactor/services/tree/master/packages/run-fn\">CLI commands for lint JS/TS files, commit git changes and upgrade of dependencies</a>\n            </td>\n        </tr>\n    </tbody>\n</table>\n\n## Stargazers over time\n\n[![Stargazers over time](https://starchart.cc/selfrefactor/rambda.svg)](https://starchart.cc/selfrefactor/rambda)",
    "licenseText": "MIT License\n\nCopyright (c) 2017 Dejan Toteff\n\nPermission is hereby granted, free of charge, to any person obtaining a copy\nof this software and associated documentation files (the \"Software\"), to deal\nin the Software without restriction, including without limitation the rights\nto use, copy, modify, merge, publish, distribute, sublicense, and/or sell\ncopies of the Software, and to permit persons to whom the Software is\nfurnished to do so, subject to the following conditions:\n\nThe above copyright notice and this permission notice shall be included in all\ncopies or substantial portions of the Software.\n\nTHE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\nIMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\nFITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\nAUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\nLIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\nOUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\nSOFTWARE.\n"
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}