Current File : //usr/lib/python3/dist-packages/markdown/inlinepatterns.py
# Python Markdown
# A Python implementation of John Gruber's Markdown.
# Documentation: https://python-markdown.github.io/
# GitHub: https://github.com/Python-Markdown/markdown/
# PyPI: https://pypi.org/project/Markdown/
# Started by Manfred Stienstra (http://www.dwerg.net/).
# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
# Currently maintained by Waylan Limberg (https://github.com/waylan),
# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
# Copyright 2004 Manfred Stienstra (the original version)
# License: BSD (see LICENSE.md for details).
"""
In version 3.0, a new, more flexible inline processor was added, [`markdown.inlinepatterns.InlineProcessor`][]. The
original inline patterns, which inherit from [`markdown.inlinepatterns.Pattern`][] or one of its children are still
supported, though users are encouraged to migrate.
The new `InlineProcessor` provides two major enhancements to `Patterns`:
1. Inline Processors no longer need to match the entire block, so regular expressions no longer need to start with
`r'^(.*?)'` and end with `r'(.*?)%'`. This runs faster. The returned [`Match`][re.Match] object will only contain
what is explicitly matched in the pattern, and extension pattern groups now start with `m.group(1)`.
2. The `handleMatch` method now takes an additional input called `data`, which is the entire block under analysis,
not just what is matched with the specified pattern. The method now returns the element *and* the indexes relative
to `data` that the return element is replacing (usually `m.start(0)` and `m.end(0)`). If the boundaries are
returned as `None`, it is assumed that the match did not take place, and nothing will be altered in `data`.
This allows handling of more complex constructs than regular expressions can handle, e.g., matching nested
brackets, and explicit control of the span "consumed" by the processor.
"""
from __future__ import annotations
from . import util
from typing import TYPE_CHECKING, Any, Collection, NamedTuple
import re
import xml.etree.ElementTree as etree
from html import entities
if TYPE_CHECKING: # pragma: no cover
from markdown import Markdown
def build_inlinepatterns(md: Markdown, **kwargs: Any) -> util.Registry[InlineProcessor]:
"""
Build the default set of inline patterns for Markdown.
The order in which processors and/or patterns are applied is very important - e.g. if we first replace
`http://.../` links with `<a>` tags and _then_ try to replace inline HTML, we would end up with a mess. So, we
apply the expressions in the following order:
* backticks and escaped characters have to be handled before everything else so that we can preempt any markdown
patterns by escaping them;
* then we handle the various types of links (auto-links must be handled before inline HTML);
* then we handle inline HTML. At this point we will simply replace all inline HTML strings with a placeholder
and add the actual HTML to a stash;
* finally we apply strong, emphasis, etc.
"""
inlinePatterns = util.Registry()
inlinePatterns.register(BacktickInlineProcessor(BACKTICK_RE), 'backtick', 190)
inlinePatterns.register(EscapeInlineProcessor(ESCAPE_RE, md), 'escape', 180)
inlinePatterns.register(ReferenceInlineProcessor(REFERENCE_RE, md), 'reference', 170)
inlinePatterns.register(LinkInlineProcessor(LINK_RE, md), 'link', 160)
inlinePatterns.register(ImageInlineProcessor(IMAGE_LINK_RE, md), 'image_link', 150)
inlinePatterns.register(
ImageReferenceInlineProcessor(IMAGE_REFERENCE_RE, md), 'image_reference', 140
)
inlinePatterns.register(
ShortReferenceInlineProcessor(REFERENCE_RE, md), 'short_reference', 130
)
inlinePatterns.register(
ShortImageReferenceInlineProcessor(IMAGE_REFERENCE_RE, md), 'short_image_ref', 125
)
inlinePatterns.register(AutolinkInlineProcessor(AUTOLINK_RE, md), 'autolink', 120)
inlinePatterns.register(AutomailInlineProcessor(AUTOMAIL_RE, md), 'automail', 110)
inlinePatterns.register(SubstituteTagInlineProcessor(LINE_BREAK_RE, 'br'), 'linebreak', 100)
inlinePatterns.register(HtmlInlineProcessor(HTML_RE, md), 'html', 90)
inlinePatterns.register(HtmlInlineProcessor(ENTITY_RE, md), 'entity', 80)
inlinePatterns.register(SimpleTextInlineProcessor(NOT_STRONG_RE), 'not_strong', 70)
inlinePatterns.register(AsteriskProcessor(r'\*'), 'em_strong', 60)
inlinePatterns.register(UnderscoreProcessor(r'_'), 'em_strong2', 50)
return inlinePatterns
# The actual regular expressions for patterns
# -----------------------------------------------------------------------------
NOIMG = r'(?<!\!)'
""" Match not an image. Partial regular expression which matches if not preceded by `!`. """
BACKTICK_RE = r'(?:(?<!\\)((?:\\{2})+)(?=`+)|(?<!\\)(`+)(.+?)(?<!`)\2(?!`))'
""" Match backtick quoted string (`` `e=f()` `` or ``` ``e=f("`")`` ```). """
ESCAPE_RE = r'\\(.)'
""" Match a backslash escaped character (`\\<` or `\\*`). """
EMPHASIS_RE = r'(\*)([^\*]+)\1'
""" Match emphasis with an asterisk (`*emphasis*`). """
STRONG_RE = r'(\*{2})(.+?)\1'
""" Match strong with an asterisk (`**strong**`). """
SMART_STRONG_RE = r'(?<!\w)(_{2})(?!_)(.+?)(?<!_)\1(?!\w)'
""" Match strong with underscore while ignoring middle word underscores (`__smart__strong__`). """
SMART_EMPHASIS_RE = r'(?<!\w)(_)(?!_)(.+?)(?<!_)\1(?!\w)'
""" Match emphasis with underscore while ignoring middle word underscores (`_smart_emphasis_`). """
SMART_STRONG_EM_RE = r'(?<!\w)(\_)\1(?!\1)(.+?)(?<!\w)\1(?!\1)(.+?)\1{3}(?!\w)'
""" Match strong emphasis with underscores (`__strong _em__`). """
EM_STRONG_RE = r'(\*)\1{2}(.+?)\1(.*?)\1{2}'
""" Match emphasis strong with asterisk (`***strongem***` or `***em*strong**`). """
EM_STRONG2_RE = r'(_)\1{2}(.+?)\1(.*?)\1{2}'
""" Match emphasis strong with underscores (`___emstrong___` or `___em_strong__`). """
STRONG_EM_RE = r'(\*)\1{2}(.+?)\1{2}(.*?)\1'
""" Match strong emphasis with asterisk (`***strong**em*`). """
STRONG_EM2_RE = r'(_)\1{2}(.+?)\1{2}(.*?)\1'
""" Match strong emphasis with underscores (`___strong__em_`). """
STRONG_EM3_RE = r'(\*)\1(?!\1)([^*]+?)\1(?!\1)(.+?)\1{3}'
""" Match strong emphasis with asterisk (`**strong*em***`). """
LINK_RE = NOIMG + r'\['
""" Match start of in-line link (`[text](url)` or `[text](<url>)` or `[text](url "title")`). """
IMAGE_LINK_RE = r'\!\['
""" Match start of in-line image link (`` or ``). """
REFERENCE_RE = LINK_RE
""" Match start of reference link (`[Label][3]`). """
IMAGE_REFERENCE_RE = IMAGE_LINK_RE
""" Match start of image reference (`![alt text][2]`). """
NOT_STRONG_RE = r'((^|(?<=\s))(\*{1,3}|_{1,3})(?=\s|$))'
""" Match a stand-alone `*` or `_`. """
AUTOLINK_RE = r'<((?:[Ff]|[Hh][Tt])[Tt][Pp][Ss]?://[^<>]*)>'
""" Match an automatic link (`<http://www.example.com>`). """
AUTOMAIL_RE = r'<([^<> !]+@[^@<> ]+)>'
""" Match an automatic email link (`<me@example.com>`). """
HTML_RE = r'(<(\/?[a-zA-Z][^<>@ ]*( [^<>]*)?|!--(?:(?!<!--|-->).)*--)>)'
""" Match an HTML tag (`<...>`). """
ENTITY_RE = r'(&(?:\#[0-9]+|\#x[0-9a-fA-F]+|[a-zA-Z0-9]+);)'
""" Match an HTML entity (`&` (decimal) or `&` (hex) or `&` (named)). """
LINE_BREAK_RE = r' \n'
""" Match two spaces at end of line. """
def dequote(string: str) -> str:
"""Remove quotes from around a string."""
if ((string.startswith('"') and string.endswith('"')) or
(string.startswith("'") and string.endswith("'"))):
return string[1:-1]
else:
return string
class EmStrongItem(NamedTuple):
"""Emphasis/strong pattern item."""
pattern: re.Pattern[str]
builder: str
tags: str
# The pattern classes
# -----------------------------------------------------------------------------
class Pattern: # pragma: no cover
"""
Base class that inline patterns subclass.
Inline patterns are handled by means of `Pattern` subclasses, one per regular expression.
Each pattern object uses a single regular expression and must support the following methods:
[`getCompiledRegExp`][markdown.inlinepatterns.Pattern.getCompiledRegExp] and
[`handleMatch`][markdown.inlinepatterns.Pattern.handleMatch].
All the regular expressions used by `Pattern` subclasses must capture the whole block. For this
reason, they all start with `^(.*)` and end with `(.*)!`. When passing a regular expression on
class initialization, the `^(.*)` and `(.*)!` are added automatically and the regular expression
is pre-compiled.
It is strongly suggested that the newer style [`markdown.inlinepatterns.InlineProcessor`][] that
use a more efficient and flexible search approach be used instead. However, the older style
`Pattern` remains for backward compatibility with many existing third-party extensions.
"""
ANCESTOR_EXCLUDES: Collection[str] = tuple()
"""
A collection of elements which are undesirable ancestors. The processor will be skipped if it
would cause the content to be a descendant of one of the listed tag names.
"""
compiled_re: re.Pattern[str]
md: Markdown | None
def __init__(self, pattern: str, md: Markdown | None = None):
"""
Create an instant of an inline pattern.
Arguments:
pattern: A regular expression that matches a pattern.
md: An optional pointer to the instance of `markdown.Markdown` and is available as
`self.md` on the class instance.
"""
self.pattern = pattern
self.compiled_re = re.compile(r"^(.*?)%s(.*)$" % pattern,
re.DOTALL | re.UNICODE)
self.md = md
def getCompiledRegExp(self) -> re.Pattern:
""" Return a compiled regular expression. """
return self.compiled_re
def handleMatch(self, m: re.Match[str]) -> etree.Element | str:
"""Return a ElementTree element from the given match.
Subclasses should override this method.
Arguments:
m: A match object containing a match of the pattern.
Returns: An ElementTree Element object.
"""
pass # pragma: no cover
def type(self) -> str:
""" Return class name, to define pattern type """
return self.__class__.__name__
def unescape(self, text: str) -> str:
""" Return unescaped text given text with an inline placeholder. """
try:
stash = self.md.treeprocessors['inline'].stashed_nodes
except KeyError: # pragma: no cover
return text
def get_stash(m):
id = m.group(1)
if id in stash:
value = stash.get(id)
if isinstance(value, str):
return value
else:
# An `etree` Element - return text content only
return ''.join(value.itertext())
return util.INLINE_PLACEHOLDER_RE.sub(get_stash, text)
class InlineProcessor(Pattern):
"""
Base class that inline processors subclass.
This is the newer style inline processor that uses a more
efficient and flexible search approach.
"""
def __init__(self, pattern: str, md: Markdown | None = None):
"""
Create an instant of an inline processor.
Arguments:
pattern: A regular expression that matches a pattern.
md: An optional pointer to the instance of `markdown.Markdown` and is available as
`self.md` on the class instance.
"""
self.pattern = pattern
self.compiled_re = re.compile(pattern, re.DOTALL | re.UNICODE)
# API for Markdown to pass `safe_mode` into instance
self.safe_mode = False
self.md = md
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | str | None, int | None, int | None]:
"""Return a ElementTree element from the given match and the
start and end index of the matched text.
If `start` and/or `end` are returned as `None`, it will be
assumed that the processor did not find a valid region of text.
Subclasses should override this method.
Arguments:
m: A re match object containing a match of the pattern.
data: The buffer currently under analysis.
Returns:
el: The ElementTree element, text or None.
start: The start of the region that has been matched or None.
end: The end of the region that has been matched or None.
"""
pass # pragma: no cover
class SimpleTextPattern(Pattern): # pragma: no cover
""" Return a simple text of `group(2)` of a Pattern. """
def handleMatch(self, m: re.Match[str]) -> str:
""" Return string content of `group(2)` of a matching pattern. """
return m.group(2)
class SimpleTextInlineProcessor(InlineProcessor):
""" Return a simple text of `group(1)` of a Pattern. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[str, int, int]:
""" Return string content of `group(1)` of a matching pattern. """
return m.group(1), m.start(0), m.end(0)
class EscapeInlineProcessor(InlineProcessor):
""" Return an escaped character. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[str | None, int, int]:
"""
If the character matched by `group(1)` of a pattern is in [`ESCAPED_CHARS`][markdown.Markdown.ESCAPED_CHARS]
then return the integer representing the character's Unicode code point (as returned by [`ord`][]) wrapped
in [`util.STX`][markdown.util.STX] and [`util.ETX`][markdown.util.ETX].
If the matched character is not in [`ESCAPED_CHARS`][markdown.Markdown.ESCAPED_CHARS], then return `None`.
"""
char = m.group(1)
if char in self.md.ESCAPED_CHARS:
return '{}{}{}'.format(util.STX, ord(char), util.ETX), m.start(0), m.end(0)
else:
return None, m.start(0), m.end(0)
class SimpleTagPattern(Pattern): # pragma: no cover
"""
Return element of type `tag` with a text attribute of `group(3)`
of a Pattern.
"""
def __init__(self, pattern: str, tag: str):
"""
Create an instant of an simple tag pattern.
Arguments:
pattern: A regular expression that matches a pattern.
tag: Tag of element.
"""
Pattern.__init__(self, pattern)
self.tag = tag
""" The tag of the rendered element. """
def handleMatch(self, m: re.Match[str]) -> etree.Element:
"""
Return [`Element`][xml.etree.ElementTree.Element] of type `tag` with the string in `group(3)` of a
matching pattern as the Element's text.
"""
el = etree.Element(self.tag)
el.text = m.group(3)
return el
class SimpleTagInlineProcessor(InlineProcessor):
"""
Return element of type `tag` with a text attribute of `group(2)`
of a Pattern.
"""
def __init__(self, pattern: str, tag: str):
"""
Create an instant of an simple tag processor.
Arguments:
pattern: A regular expression that matches a pattern.
tag: Tag of element.
"""
InlineProcessor.__init__(self, pattern)
self.tag = tag
""" The tag of the rendered element. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]: # pragma: no cover
"""
Return [`Element`][xml.etree.ElementTree.Element] of type `tag` with the string in `group(2)` of a
matching pattern as the Element's text.
"""
el = etree.Element(self.tag)
el.text = m.group(2)
return el, m.start(0), m.end(0)
class SubstituteTagPattern(SimpleTagPattern): # pragma: no cover
""" Return an element of type `tag` with no children. """
def handleMatch(self, m: re.Match[str]) -> etree.Element:
""" Return empty [`Element`][xml.etree.ElementTree.Element] of type `tag`. """
return etree.Element(self.tag)
class SubstituteTagInlineProcessor(SimpleTagInlineProcessor):
""" Return an element of type `tag` with no children. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:
""" Return empty [`Element`][xml.etree.ElementTree.Element] of type `tag`. """
return etree.Element(self.tag), m.start(0), m.end(0)
class BacktickInlineProcessor(InlineProcessor):
""" Return a `<code>` element containing the escaped matching text. """
def __init__(self, pattern: str):
InlineProcessor.__init__(self, pattern)
self.ESCAPED_BSLASH = '{}{}{}'.format(util.STX, ord('\\'), util.ETX)
self.tag = 'code'
""" The tag of the rendered element. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | str, int, int]:
"""
If the match contains `group(3)` of a pattern, then return a `code`
[`Element`][xml.etree.ElementTree.Element] which contains HTML escaped text (with
[`code_escape`][markdown.util.code_escape]) as an [`AtomicString`][markdown.util.AtomicString].
If the match does not contain `group(3)` then return the text of `group(1)` backslash escaped.
"""
if m.group(3):
el = etree.Element(self.tag)
el.text = util.AtomicString(util.code_escape(m.group(3).strip()))
return el, m.start(0), m.end(0)
else:
return m.group(1).replace('\\\\', self.ESCAPED_BSLASH), m.start(0), m.end(0)
class DoubleTagPattern(SimpleTagPattern): # pragma: no cover
"""Return a ElementTree element nested in tag2 nested in tag1.
Useful for strong emphasis etc.
"""
def handleMatch(self, m: re.Match[str]) -> etree.Element:
"""
Return [`Element`][xml.etree.ElementTree.Element] in following format:
`<tag1><tag2>group(3)</tag2>group(4)</tag2>` where `group(4)` is optional.
"""
tag1, tag2 = self.tag.split(",")
el1 = etree.Element(tag1)
el2 = etree.SubElement(el1, tag2)
el2.text = m.group(3)
if len(m.groups()) == 5:
el2.tail = m.group(4)
return el1
class DoubleTagInlineProcessor(SimpleTagInlineProcessor):
"""Return a ElementTree element nested in tag2 nested in tag1.
Useful for strong emphasis etc.
"""
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]: # pragma: no cover
"""
Return [`Element`][xml.etree.ElementTree.Element] in following format:
`<tag1><tag2>group(2)</tag2>group(3)</tag2>` where `group(3)` is optional.
"""
tag1, tag2 = self.tag.split(",")
el1 = etree.Element(tag1)
el2 = etree.SubElement(el1, tag2)
el2.text = m.group(2)
if len(m.groups()) == 3:
el2.tail = m.group(3)
return el1, m.start(0), m.end(0)
class HtmlInlineProcessor(InlineProcessor):
""" Store raw inline html and return a placeholder. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[str, int, int]:
""" Store the text of `group(1)` of a pattern and return a placeholder string. """
rawhtml = self.backslash_unescape(self.unescape(m.group(1)))
place_holder = self.md.htmlStash.store(rawhtml)
return place_holder, m.start(0), m.end(0)
def unescape(self, text: str) -> str:
""" Return unescaped text given text with an inline placeholder. """
try:
stash = self.md.treeprocessors['inline'].stashed_nodes
except KeyError: # pragma: no cover
return text
def get_stash(m: re.Match[str]) -> str:
id = m.group(1)
value = stash.get(id)
if value is not None:
try:
return self.md.serializer(value)
except Exception:
return r'\%s' % value
return util.INLINE_PLACEHOLDER_RE.sub(get_stash, text)
def backslash_unescape(self, text: str) -> str:
""" Return text with backslash escapes undone (backslashes are restored). """
try:
RE = self.md.treeprocessors['unescape'].RE
except KeyError: # pragma: no cover
return text
def _unescape(m: re.Match[str]) -> str:
return chr(int(m.group(1)))
return RE.sub(_unescape, text)
class AsteriskProcessor(InlineProcessor):
"""Emphasis processor for handling strong and em matches inside asterisks."""
PATTERNS = [
EmStrongItem(re.compile(EM_STRONG_RE, re.DOTALL | re.UNICODE), 'double', 'strong,em'),
EmStrongItem(re.compile(STRONG_EM_RE, re.DOTALL | re.UNICODE), 'double', 'em,strong'),
EmStrongItem(re.compile(STRONG_EM3_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')
]
""" The various strong and emphasis patterns handled by this processor. """
def build_single(self, m: re.Match[str], tag: str, idx: int) -> etree.Element:
"""Return single tag."""
el1 = etree.Element(tag)
text = m.group(2)
self.parse_sub_patterns(text, el1, None, idx)
return el1
def build_double(self, m: re.Match[str], tags: str, idx: int) -> etree.Element:
"""Return double tag."""
tag1, tag2 = tags.split(",")
el1 = etree.Element(tag1)
el2 = etree.Element(tag2)
text = m.group(2)
self.parse_sub_patterns(text, el2, None, idx)
el1.append(el2)
if len(m.groups()) == 3:
text = m.group(3)
self.parse_sub_patterns(text, el1, el2, idx)
return el1
def build_double2(self, m: re.Match[str], tags: str, idx: int) -> etree.Element:
"""Return double tags (variant 2): `<strong>text <em>text</em></strong>`."""
tag1, tag2 = tags.split(",")
el1 = etree.Element(tag1)
el2 = etree.Element(tag2)
text = m.group(2)
self.parse_sub_patterns(text, el1, None, idx)
text = m.group(3)
el1.append(el2)
self.parse_sub_patterns(text, el2, None, idx)
return el1
def parse_sub_patterns(
self, data: str, parent: etree.Element, last: etree.Element | None, idx: int
) -> None:
"""
Parses sub patterns.
`data`: text to evaluate.
`parent`: Parent to attach text and sub elements to.
`last`: Last appended child to parent. Can also be None if parent has no children.
`idx`: Current pattern index that was used to evaluate the parent.
"""
offset = 0
pos = 0
length = len(data)
while pos < length:
# Find the start of potential emphasis or strong tokens
if self.compiled_re.match(data, pos):
matched = False
# See if the we can match an emphasis/strong pattern
for index, item in enumerate(self.PATTERNS):
# Only evaluate patterns that are after what was used on the parent
if index <= idx:
continue
m = item.pattern.match(data, pos)
if m:
# Append child nodes to parent
# Text nodes should be appended to the last
# child if present, and if not, it should
# be added as the parent's text node.
text = data[offset:m.start(0)]
if text:
if last is not None:
last.tail = text
else:
parent.text = text
el = self.build_element(m, item.builder, item.tags, index)
parent.append(el)
last = el
# Move our position past the matched hunk
offset = pos = m.end(0)
matched = True
if not matched:
# We matched nothing, move on to the next character
pos += 1
else:
# Increment position as no potential emphasis start was found.
pos += 1
# Append any leftover text as a text node.
text = data[offset:]
if text:
if last is not None:
last.tail = text
else:
parent.text = text
def build_element(self, m: re.Match[str], builder: str, tags: str, index: int) -> etree.Element:
"""Element builder."""
if builder == 'double2':
return self.build_double2(m, tags, index)
elif builder == 'double':
return self.build_double(m, tags, index)
else:
return self.build_single(m, tags, index)
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
"""Parse patterns."""
el = None
start = None
end = None
for index, item in enumerate(self.PATTERNS):
m1 = item.pattern.match(data, m.start(0))
if m1:
start = m1.start(0)
end = m1.end(0)
el = self.build_element(m1, item.builder, item.tags, index)
break
return el, start, end
class UnderscoreProcessor(AsteriskProcessor):
"""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(SMART_STRONG_EM_RE, re.DOTALL | re.UNICODE), 'double2', 'strong,em'),
EmStrongItem(re.compile(SMART_STRONG_RE, re.DOTALL | re.UNICODE), 'single', 'strong'),
EmStrongItem(re.compile(SMART_EMPHASIS_RE, re.DOTALL | re.UNICODE), 'single', 'em')
]
""" The various strong and emphasis patterns handled by this processor. """
class LinkInlineProcessor(InlineProcessor):
""" Return a link element from the given match. """
RE_LINK = re.compile(r'''\(\s*(?:(<[^<>]*>)\s*(?:('[^']*'|"[^"]*")\s*)?\))?''', re.DOTALL | re.UNICODE)
RE_TITLE_CLEAN = re.compile(r'\s')
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
""" Return an `a` [`Element`][xml.etree.ElementTree.Element] or `(None, None, None)`. """
text, index, handled = self.getText(data, m.end(0))
if not handled:
return None, None, None
href, title, index, handled = self.getLink(data, index)
if not handled:
return None, None, None
el = etree.Element("a")
el.text = text
el.set("href", href)
if title is not None:
el.set("title", title)
return el, m.start(0), index
def getLink(self, data: str, index: int) -> tuple[str, str | None, int, bool]:
"""Parse data between `()` of `[Text]()` allowing recursive `()`. """
href = ''
title: str | None = None
handled = False
m = self.RE_LINK.match(data, pos=index)
if m and m.group(1):
# Matches [Text](<link> "title")
href = m.group(1)[1:-1].strip()
if m.group(2):
title = m.group(2)[1:-1]
index = m.end(0)
handled = True
elif m:
# Track bracket nesting and index in string
bracket_count = 1
backtrack_count = 1
start_index = m.end()
index = start_index
last_bracket = -1
# Primary (first found) quote tracking.
quote: str | None = None
start_quote = -1
exit_quote = -1
ignore_matches = False
# Secondary (second found) quote tracking.
alt_quote = None
start_alt_quote = -1
exit_alt_quote = -1
# Track last character
last = ''
for pos in range(index, len(data)):
c = data[pos]
if c == '(':
# Count nested (
# Don't increment the bracket count if we are sure we're in a title.
if not ignore_matches:
bracket_count += 1
elif backtrack_count > 0:
backtrack_count -= 1
elif c == ')':
# Match nested ) to (
# Don't decrement if we are sure we are in a title that is unclosed.
if ((exit_quote != -1 and quote == last) or (exit_alt_quote != -1 and alt_quote == last)):
bracket_count = 0
elif not ignore_matches:
bracket_count -= 1
elif backtrack_count > 0:
backtrack_count -= 1
# We've found our backup end location if the title doesn't resolve.
if backtrack_count == 0:
last_bracket = index + 1
elif c in ("'", '"'):
# Quote has started
if not quote:
# We'll assume we are now in a title.
# Brackets are quoted, so no need to match them (except for the final one).
ignore_matches = True
backtrack_count = bracket_count
bracket_count = 1
start_quote = index + 1
quote = c
# Secondary quote (in case the first doesn't resolve): [text](link'"title")
elif c != quote and not alt_quote:
start_alt_quote = index + 1
alt_quote = c
# Update primary quote match
elif c == quote:
exit_quote = index + 1
# Update secondary quote match
elif alt_quote and c == alt_quote:
exit_alt_quote = index + 1
index += 1
# Link is closed, so let's break out of the loop
if bracket_count == 0:
# Get the title if we closed a title string right before link closed
if exit_quote >= 0 and quote == last:
href = data[start_index:start_quote - 1]
title = ''.join(data[start_quote:exit_quote - 1])
elif exit_alt_quote >= 0 and alt_quote == last:
href = data[start_index:start_alt_quote - 1]
title = ''.join(data[start_alt_quote:exit_alt_quote - 1])
else:
href = data[start_index:index - 1]
break
if c != ' ':
last = c
# We have a scenario: `[test](link"notitle)`
# When we enter a string, we stop tracking bracket resolution in the main counter,
# but we do keep a backup counter up until we discover where we might resolve all brackets
# if the title string fails to resolve.
if bracket_count != 0 and backtrack_count == 0:
href = data[start_index:last_bracket - 1]
index = last_bracket
bracket_count = 0
handled = bracket_count == 0
if title is not None:
title = self.RE_TITLE_CLEAN.sub(' ', dequote(self.unescape(title.strip())))
href = self.unescape(href).strip()
return href, title, index, handled
def getText(self, data: str, index: int) -> tuple[str, int, bool]:
"""Parse the content between `[]` of the start of an image or link
resolving nested square brackets.
"""
bracket_count = 1
text = []
for pos in range(index, len(data)):
c = data[pos]
if c == ']':
bracket_count -= 1
elif c == '[':
bracket_count += 1
index += 1
if bracket_count == 0:
break
text.append(c)
return ''.join(text), index, bracket_count == 0
class ImageInlineProcessor(LinkInlineProcessor):
""" Return a `img` element from the given match. """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
""" Return an `img` [`Element`][xml.etree.ElementTree.Element] or `(None, None, None)`. """
text, index, handled = self.getText(data, m.end(0))
if not handled:
return None, None, None
src, title, index, handled = self.getLink(data, index)
if not handled:
return None, None, None
el = etree.Element("img")
el.set("src", src)
if title is not None:
el.set("title", title)
el.set('alt', self.unescape(text))
return el, m.start(0), index
class ReferenceInlineProcessor(LinkInlineProcessor):
""" Match to a stored reference and return link element. """
NEWLINE_CLEANUP_RE = re.compile(r'\s+', re.MULTILINE)
RE_LINK = re.compile(r'\s?\[([^\]]*)\]', re.DOTALL | re.UNICODE)
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
"""
Return [`Element`][xml.etree.ElementTree.Element] returned by `makeTag` method or `(None, None, None)`.
"""
text, index, handled = self.getText(data, m.end(0))
if not handled:
return None, None, None
id, end, handled = self.evalId(data, index, text)
if not handled:
return None, None, None
# Clean up line breaks in id
id = self.NEWLINE_CLEANUP_RE.sub(' ', id)
if id not in self.md.references: # ignore undefined refs
return None, m.start(0), end
href, title = self.md.references[id]
return self.makeTag(href, title, text), m.start(0), end
def evalId(self, data: str, index: int, text: str) -> tuple[str | None, int, bool]:
"""
Evaluate the id portion of `[ref][id]`.
If `[ref][]` use `[ref]`.
"""
m = self.RE_LINK.match(data, pos=index)
if not m:
return None, index, False
else:
id = m.group(1).lower()
end = m.end(0)
if not id:
id = text.lower()
return id, end, True
def makeTag(self, href: str, title: str, text: str) -> etree.Element:
""" Return an `a` [`Element`][xml.etree.ElementTree.Element]. """
el = etree.Element('a')
el.set('href', href)
if title:
el.set('title', title)
el.text = text
return el
class ShortReferenceInlineProcessor(ReferenceInlineProcessor):
"""Short form of reference: `[google]`. """
def evalId(self, data: str, index: int, text: str) -> tuple[str, int, bool]:
"""Evaluate the id of `[ref]`. """
return text.lower(), index, True
class ImageReferenceInlineProcessor(ReferenceInlineProcessor):
""" Match to a stored reference and return `img` element. """
def makeTag(self, href: str, title: str, text: str) -> etree.Element:
""" Return an `img` [`Element`][xml.etree.ElementTree.Element]. """
el = etree.Element("img")
el.set("src", href)
if title:
el.set("title", title)
el.set("alt", self.unescape(text))
return el
class ShortImageReferenceInlineProcessor(ImageReferenceInlineProcessor):
""" Short form of image reference: `![ref]`. """
def evalId(self, data: str, index: int, text: str) -> tuple[str, int, bool]:
"""Evaluate the id of `[ref]`. """
return text.lower(), index, True
class AutolinkInlineProcessor(InlineProcessor):
""" Return a link Element given an auto-link (`<http://example/com>`). """
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:
""" Return an `a` [`Element`][xml.etree.ElementTree.Element] of `group(1)`. """
el = etree.Element("a")
el.set('href', self.unescape(m.group(1)))
el.text = util.AtomicString(m.group(1))
return el, m.start(0), m.end(0)
class AutomailInlineProcessor(InlineProcessor):
"""
Return a `mailto` link Element given an auto-mail link (`<foo@example.com>`).
"""
def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:
""" Return an [`Element`][xml.etree.ElementTree.Element] containing a `mailto` link of `group(1)`. """
el = etree.Element('a')
email = self.unescape(m.group(1))
if email.startswith("mailto:"):
email = email[len("mailto:"):]
def codepoint2name(code: int) -> str:
"""Return entity definition by code, or the code if not defined."""
entity = entities.codepoint2name.get(code)
if entity:
return "{}{};".format(util.AMP_SUBSTITUTE, entity)
else:
return "%s#%d;" % (util.AMP_SUBSTITUTE, code)
letters = [codepoint2name(ord(letter)) for letter in email]
el.text = util.AtomicString(''.join(letters))
mailto = "mailto:" + email
mailto = "".join([util.AMP_SUBSTITUTE + '#%d;' %
ord(letter) for letter in mailto])
el.set('href', mailto)
return el, m.start(0), m.end(0)
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