# Copyright (C) 2004-2006 Python Software Foundation
# Authors: Baxter, Wouters and Warsaw
# Contact: email-sig@python.org

"""FeedParser - An email feed parser.

The feed parser implements an interface for incrementally parsing an email
message, line by line.  This has advantages for certain applications, such as
those reading email messages off a socket.

FeedParser.feed() is the primary interface for pushing new data into the
parser.  It returns when there's nothing more it can do with the available
data.  When you have no more data to push into the parser, call .close().
This completes the parsing and returns the root message object.

The other advantage of this parser is that it will never raise a parsing
exception.  Instead, when it finds something unexpected, it adds a 'defect' to
the current message.  Defects are just instances that live on the message
object's .defects attribute.
"""

__all__ = ['FeedParser', 'BytesFeedParser']

import re

from email import errors
from email._policybase import compat32
from collections import deque
from io import StringIO

NLCRE = re.compile(r'\r\n|\r|\n')
NLCRE_bol = re.compile(r'(\r\n|\r|\n)')
NLCRE_eol = re.compile(r'(\r\n|\r|\n)\Z')
NLCRE_crack = re.compile(r'(\r\n|\r|\n)')
# RFC 2822 $3.6.8 Optional fields.  ftext is %d33-57 / %d59-126, Any character
# except controls, SP, and ":".
headerRE = re.compile(r'^(From |[\041-\071\073-\176]*:|[\t ])')
EMPTYSTRING = ''
NL = '\n'

NeedMoreData = object()