blob: 360988b6da7bc755bfe67cd894095765f3c15112 [file] [log] [blame]
'''
Legacy Em Extension for Python-Markdown
=======================================
This extension provides legacy behavior for _connected_words_.
Copyright 2015-2018 The Python Markdown Project
License: [BSD](https://opensource.org/licenses/bsd-license.php)
'''
from . import Extension
from ..inlinepatterns import UnderscoreProcessor, EmStrongItem, EM_STRONG2_RE, STRONG_EM2_RE
import re
# _emphasis_
EMPHASIS_RE = r'(_)([^_]+)\1'
# __strong__
STRONG_RE = r'(_{2})(.+?)\1'
# __strong_em___
STRONG_EM_RE = r'(_)\1(?!\1)([^_]+?)\1(?!\1)(.+?)\1{3}'
class LegacyUnderscoreProcessor(UnderscoreProcessor):
"""Emphasis processor for handling strong and em matches inside underscores."""
PATTERNS = [
EmStrongItem(re.compile(EM_STRONG2_RE, re.DOTALL | re.UNICODE), 'double', 'strong,em'),
EmStrongItem(re.compile(STRONG_EM2_RE, re.DOTALL | re.UNICODE), 'double', 'em,strong'),
EmStrongItem(re.compile(STRONG_EM_RE, re.DOTALL | re.UNICODE), 'double2', 'strong,em'),
EmStrongItem(re.compile(STRONG_RE, re.DOTALL | re.UNICODE), 'single', 'strong'),
EmStrongItem(re.compile(EMPHASIS_RE, re.DOTALL | re.UNICODE), 'single', 'em')
]
class LegacyEmExtension(Extension):
""" Add legacy_em extension to Markdown class."""
def extendMarkdown(self, md):
""" Modify inline patterns. """
md.inlinePatterns.register(LegacyUnderscoreProcessor(r'_'), 'em_strong2', 50)
def makeExtension(**kwargs): # pragma: no cover
""" Return an instance of the LegacyEmExtension """
return LegacyEmExtension(**kwargs)