[](https://app.circleci.com/pipelines/github/leodido/go-urn) [](https://codecov.io/gh/leodido/go-urn) [](https://godoc.org/github.com/leodido/go-urn)
**A parser for URNs**.
> As seen on [RFC 2141](https://tools.ietf.org/html/rfc2141#ref-1).
[API documentation](https://godoc.org/github.com/leodido/go-urn).
Starting with version 1.3 this library also supports [RFC 7643 SCIM URNs](https://datatracker.ietf.org/doc/html/rfc7643#section-10).
## Installation
```
go get github.com/leodido/go-urn
```
## Features
1. RFC 2141 URNs parsing (default)
2. RFC 7643 SCIM URNs parsing
3. Fallback mode: first try to parse the input as a RFC 7643 SCIM URN, then fallback to RFC 2141 URN generic format.
4. Normalization as per RFC 2141
4. Lexical equivalence as per RFC 2141
5. Precise, fine-grained errors
## Performances
This implementation results to be really fast.
Usually below ½ microsecond on my machine[1](#mymachine).
Notice it also performs, while parsing:
1. fine-grained and informative erroring
2. specific-string normalization
```
Parse/ok/00/urn:a:b______________________________________/-10 71113568 84.88 ns/op 211 B/op 3 allocs/op
Parse/ok/01/URN:foo:a123,456_____________________________/-10 49303754 126.1 ns/op 232 B/op 6 allocs/op
Parse/ok/02/urn:foo:a123%2c456___________________________/-10 46723497 122.1 ns/op 240 B/op 6 allocs/op
Parse/ok/03/urn:ietf:params:scim:schemas:core:2.0:User___/-10 34231863 175.1 ns/op 312 B/op 6 allocs/op
Parse/ok/04/urn:ietf:params:scim:schemas:extension:enterp/-10 25406808 233.6 ns/op 344 B/op 6 allocs/op
Parse/ok/05/urn:ietf:params:scim:schemas:extension:enterp/-10 22353264 265.6 ns/op 376 B/op 6 allocs/op
Parse/ok/06/urn:burnout:nss______________________________/-10 52932087 112.9 ns/op 224 B/op 6 allocs/op
Parse/ok/07/urn:abcdefghilmnopqrstuvzabcdefghilm:x_______/-10 45005554 134.3 ns/op 243 B/op 4 allocs/op
Parse/ok/08/urn:urnurnurn:urn____________________________/-10 46788519 124.7 ns/op 229 B/op 6 allocs/op
Parse/ok/09/urn:ciao:@!=%2c(xyz)+a,b.*@g=$_'_____________/-10 39037539 153.8 ns/op 264 B/op 6 allocs/op
Parse/ok/10/URN:x:abc%1dz%2f%3az_________________________/-10 45692990 121.4 ns/op 243 B/op 5 allocs/op
Parse/no/11/URN:-xxx:x___________________________________/-10 26935477 221.1 ns/op 355 B/op 5 allocs/op
Parse/no/12/urn::colon:nss_______________________________/-10 25088925 232.4 ns/op 355 B/op 5 allocs/op
Parse/no/13/urn:abcdefghilmnopqrstuvzabcdefghilmn:specifi/-10 21206989 295.1 ns/op 355 B/op 5 allocs/op
Parse/no/14/URN:a!?:x____________________________________/-10 26705482 223.5 ns/op 355 B/op 5 allocs/op
Parse/no/15/urn:urn:NSS__________________________________/-10 31609467 202.1 ns/op 307 B/op 5 allocs/op
Parse/no/16/urn:white_space:NSS__________________________/-10 26144792 232.2 ns/op 355 B/op 5 allocs/op
Parse/no/17/urn:concat:no_spaces_________________________/-10 23717426 251.1 ns/op 346 B/op 6 allocs/op
Parse/no/18/urn:a:/______________________________________/-10 27442077 221.9 ns/op 339 B/op 5 allocs/op
Parse/no/19/urn:UrN:NSS__________________________________/-10 32096002 187.4 ns/op 307 B/op 5 allocs/op
```
* [1]: Apple M1 Pro
## Example
For more examples take a look at the [examples file](examples_test.go).
```go
package main
import (
"fmt"
"github.com/leodido/go-urn"
)
func main() {
var uid = "URN:foo:a123,456"
// Parse the input string as a RFC 2141 URN only
u, e := urn.NewMachine().Parse(uid)
if e != nil {
fmt.Errorf(err)
return
}
fmt.Println(u.ID)
fmt.Println(u.SS)
// Output:
// foo
// a123,456
}
```
```go
package main
import (
"fmt"
"github.com/leodido/go-urn"
)
func main() {
var uid = "URN:foo:a123,456"
// Parse the input string as a RFC 2141 URN only
u, ok := urn.Parse([]byte(uid))
if !ok {
panic("error parsing urn")
}
fmt.Println(u.ID)
fmt.Println(u.SS)
// Output:
// foo
// a123,456
}
```
```go
package main
import (
"fmt"
"github.com/leodido/go-urn"
)
func main() {
input := "urn:ietf:params:scim:api:messages:2.0:ListResponse"
// Parsing the input string as a RFC 7643 SCIM URN
u, ok := urn.Parse([]byte(input), urn.WithParsingMode(urn.RFC7643Only))
if !ok {
panic("error parsing urn")
}
fmt.Println(u.IsSCIM())
scim := u.SCIM()
fmt.Println(scim.Type.String())
fmt.Println(scim.Name)
fmt.Println(scim.Other)
// Output:
// true
// api
// messages
// 2.0:ListResponse
}
```