"""Utilities for parsing source text
"""
from __future__ import annotations
import re
from typing import Match, TypeVar
from .entities import entities
[docs]def charCodeAt(src: str, pos: int) -> int | None:
"""
Returns the Unicode value of the character at the specified location.
@param - index The zero-based index of the desired character.
If there is no character at the specified index, NaN is returned.
This was added for compatibility with python
"""
try:
return ord(src[pos])
except IndexError:
return None
[docs]def charStrAt(src: str, pos: int) -> str | None:
"""
Returns the Unicode value of the character at the specified location.
@param - index The zero-based index of the desired character.
If there is no character at the specified index, NaN is returned.
This was added for compatibility with python
"""
try:
return src[pos]
except IndexError:
return None
_ItemTV = TypeVar("_ItemTV")
[docs]def arrayReplaceAt(
src: list[_ItemTV], pos: int, newElements: list[_ItemTV]
) -> list[_ItemTV]:
"""
Remove element from array and put another array at those position.
Useful for some operations with tokens
"""
return src[:pos] + newElements + src[pos + 1 :]
[docs]def isValidEntityCode(c: int) -> bool:
# broken sequence
if c >= 0xD800 and c <= 0xDFFF:
return False
# never used
if c >= 0xFDD0 and c <= 0xFDEF:
return False
if ((c & 0xFFFF) == 0xFFFF) or ((c & 0xFFFF) == 0xFFFE):
return False
# control codes
if c >= 0x00 and c <= 0x08:
return False
if c == 0x0B:
return False
if c >= 0x0E and c <= 0x1F:
return False
if c >= 0x7F and c <= 0x9F:
return False
# out of range
if c > 0x10FFFF:
return False
return True
[docs]def fromCodePoint(c: int) -> str:
"""Convert ordinal to unicode.
Note, in the original Javascript two string characters were required,
for codepoints larger than `0xFFFF`.
But Python 3 can represent any unicode codepoint in one character.
"""
return chr(c)
# UNESCAPE_MD_RE = re.compile(r'\\([!"#$%&\'()*+,\-.\/:;<=>?@[\\\]^_`{|}~])')
# ENTITY_RE_g = re.compile(r'&([a-z#][a-z0-9]{1,31})', re.IGNORECASE)
UNESCAPE_ALL_RE = re.compile(
r'\\([!"#$%&\'()*+,\-.\/:;<=>?@[\\\]^_`{|}~])' + "|" + r"&([a-z#][a-z0-9]{1,31});",
re.IGNORECASE,
)
DIGITAL_ENTITY_BASE10_RE = re.compile(r"#([0-9]{1,8})")
DIGITAL_ENTITY_BASE16_RE = re.compile(r"#x([a-f0-9]{1,8})", re.IGNORECASE)
[docs]def replaceEntityPattern(match: str, name: str) -> str:
"""Convert HTML entity patterns,
see https://spec.commonmark.org/0.30/#entity-references
"""
if name in entities:
return entities[name]
code: None | int = None
if pat := DIGITAL_ENTITY_BASE10_RE.fullmatch(name):
code = int(pat.group(1), 10)
elif pat := DIGITAL_ENTITY_BASE16_RE.fullmatch(name):
code = int(pat.group(1), 16)
if code is not None and isValidEntityCode(code):
return fromCodePoint(code)
return match
[docs]def unescapeAll(string: str) -> str:
def replacer_func(match: Match[str]) -> str:
escaped = match.group(1)
if escaped:
return escaped
entity = match.group(2)
return replaceEntityPattern(match.group(), entity)
if "\\" not in string and "&" not in string:
return string
return UNESCAPE_ALL_RE.sub(replacer_func, string)
ESCAPABLE = r"""\\!"#$%&'()*+,./:;<=>?@\[\]^`{}|_~-"""
ESCAPE_CHAR = re.compile(r"\\([" + ESCAPABLE + r"])")
[docs]def stripEscape(string: str) -> str:
"""Strip escape \\ characters"""
return ESCAPE_CHAR.sub(r"\1", string)
[docs]def escapeHtml(raw: str) -> str:
"""Replace special characters "&", "<", ">" and '"' to HTML-safe sequences."""
# like html.escape, but without escaping single quotes
raw = raw.replace("&", "&") # Must be done first!
raw = raw.replace("<", "<")
raw = raw.replace(">", ">")
raw = raw.replace('"', """)
return raw
# //////////////////////////////////////////////////////////////////////////////
REGEXP_ESCAPE_RE = re.compile(r"[.?*+^$[\]\\(){}|-]")
[docs]def escapeRE(string: str) -> str:
string = REGEXP_ESCAPE_RE.sub("\\$&", string)
return string
# //////////////////////////////////////////////////////////////////////////////
[docs]def isSpace(code: int | None) -> bool:
"""Check if character code is a whitespace."""
return code in (0x09, 0x20)
[docs]def isStrSpace(ch: str | None) -> bool:
"""Check if character is a whitespace."""
return ch in ("\t", " ")
MD_WHITESPACE = {
0x09, # \t
0x0A, # \n
0x0B, # \v
0x0C, # \f
0x0D, # \r
0x20, # space
0xA0,
0x1680,
0x202F,
0x205F,
0x3000,
}
[docs]def isWhiteSpace(code: int) -> bool:
r"""Zs (unicode class) || [\t\f\v\r\n]"""
if code >= 0x2000 and code <= 0x200A:
return True
return code in MD_WHITESPACE
# //////////////////////////////////////////////////////////////////////////////
UNICODE_PUNCT_RE = re.compile(
r"[!-#%-\*,-\/:;\?@\[-\]_\{\}\xA1\xA7\xAB\xB6\xB7\xBB\xBF\u037E\u0387\u055A-\u055F\u0589\u058A\u05BE\u05C0\u05C3\u05C6\u05F3\u05F4\u0609\u060A\u060C\u060D\u061B\u061E\u061F\u066A-\u066D\u06D4\u0700-\u070D\u07F7-\u07F9\u0830-\u083E\u085E\u0964\u0965\u0970\u09FD\u0A76\u0AF0\u0C84\u0DF4\u0E4F\u0E5A\u0E5B\u0F04-\u0F12\u0F14\u0F3A-\u0F3D\u0F85\u0FD0-\u0FD4\u0FD9\u0FDA\u104A-\u104F\u10FB\u1360-\u1368\u1400\u166D\u166E\u169B\u169C\u16EB-\u16ED\u1735\u1736\u17D4-\u17D6\u17D8-\u17DA\u1800-\u180A\u1944\u1945\u1A1E\u1A1F\u1AA0-\u1AA6\u1AA8-\u1AAD\u1B5A-\u1B60\u1BFC-\u1BFF\u1C3B-\u1C3F\u1C7E\u1C7F\u1CC0-\u1CC7\u1CD3\u2010-\u2027\u2030-\u2043\u2045-\u2051\u2053-\u205E\u207D\u207E\u208D\u208E\u2308-\u230B\u2329\u232A\u2768-\u2775\u27C5\u27C6\u27E6-\u27EF\u2983-\u2998\u29D8-\u29DB\u29FC\u29FD\u2CF9-\u2CFC\u2CFE\u2CFF\u2D70\u2E00-\u2E2E\u2E30-\u2E4E\u3001-\u3003\u3008-\u3011\u3014-\u301F\u3030\u303D\u30A0\u30FB\uA4FE\uA4FF\uA60D-\uA60F\uA673\uA67E\uA6F2-\uA6F7\uA874-\uA877\uA8CE\uA8CF\uA8F8-\uA8FA\uA8FC\uA92E\uA92F\uA95F\uA9C1-\uA9CD\uA9DE\uA9DF\uAA5C-\uAA5F\uAADE\uAADF\uAAF0\uAAF1\uABEB\uFD3E\uFD3F\uFE10-\uFE19\uFE30-\uFE52\uFE54-\uFE61\uFE63\uFE68\uFE6A\uFE6B\uFF01-\uFF03\uFF05-\uFF0A\uFF0C-\uFF0F\uFF1A\uFF1B\uFF1F\uFF20\uFF3B-\uFF3D\uFF3F\uFF5B\uFF5D\uFF5F-\uFF65]|\uD800[\uDD00-\uDD02\uDF9F\uDFD0]|\uD801\uDD6F|\uD802[\uDC57\uDD1F\uDD3F\uDE50-\uDE58\uDE7F\uDEF0-\uDEF6\uDF39-\uDF3F\uDF99-\uDF9C]|\uD803[\uDF55-\uDF59]|\uD804[\uDC47-\uDC4D\uDCBB\uDCBC\uDCBE-\uDCC1\uDD40-\uDD43\uDD74\uDD75\uDDC5-\uDDC8\uDDCD\uDDDB\uDDDD-\uDDDF\uDE38-\uDE3D\uDEA9]|\uD805[\uDC4B-\uDC4F\uDC5B\uDC5D\uDCC6\uDDC1-\uDDD7\uDE41-\uDE43\uDE60-\uDE6C\uDF3C-\uDF3E]|\uD806[\uDC3B\uDE3F-\uDE46\uDE9A-\uDE9C\uDE9E-\uDEA2]|\uD807[\uDC41-\uDC45\uDC70\uDC71\uDEF7\uDEF8]|\uD809[\uDC70-\uDC74]|\uD81A[\uDE6E\uDE6F\uDEF5\uDF37-\uDF3B\uDF44]|\uD81B[\uDE97-\uDE9A]|\uD82F\uDC9F|\uD836[\uDE87-\uDE8B]|\uD83A[\uDD5E\uDD5F]"
)
# Currently without astral characters support.
[docs]def isPunctChar(ch: str) -> bool:
"""Check if character is a punctuation character."""
return UNICODE_PUNCT_RE.search(ch) is not None
MD_ASCII_PUNCT = {
0x21, # /* ! */
0x22, # /* " */
0x23, # /* # */
0x24, # /* $ */
0x25, # /* % */
0x26, # /* & */
0x27, # /* ' */
0x28, # /* ( */
0x29, # /* ) */
0x2A, # /* * */
0x2B, # /* + */
0x2C, # /* , */
0x2D, # /* - */
0x2E, # /* . */
0x2F, # /* / */
0x3A, # /* : */
0x3B, # /* ; */
0x3C, # /* < */
0x3D, # /* = */
0x3E, # /* > */
0x3F, # /* ? */
0x40, # /* @ */
0x5B, # /* [ */
0x5C, # /* \ */
0x5D, # /* ] */
0x5E, # /* ^ */
0x5F, # /* _ */
0x60, # /* ` */
0x7B, # /* { */
0x7C, # /* | */
0x7D, # /* } */
0x7E, # /* ~ */
}
[docs]def isMdAsciiPunct(ch: int) -> bool:
"""Markdown ASCII punctuation characters.
::
!, ", #, $, %, &, ', (, ), *, +, ,, -, ., /, :, ;, <, =, >, ?, @, [, \\, ], ^, _, `, {, |, }, or ~
See http://spec.commonmark.org/0.15/#ascii-punctuation-character
Don't confuse with unicode punctuation !!! It lacks some chars in ascii range.
"""
return ch in MD_ASCII_PUNCT
[docs]def normalizeReference(string: str) -> str:
"""Helper to unify [reference labels]."""
# Trim and collapse whitespace
#
string = re.sub(r"\s+", " ", string.strip())
# In node v10 'ẞ'.toLowerCase() === 'Ṿ', which is presumed to be a bug
# fixed in v12 (couldn't find any details).
#
# So treat this one as a special case
# (remove this when node v10 is no longer supported).
#
# if ('ẞ'.toLowerCase() === 'Ṿ') {
# str = str.replace(/ẞ/g, 'ß')
# }
# .toLowerCase().toUpperCase() should get rid of all differences
# between letter variants.
#
# Simple .toLowerCase() doesn't normalize 125 code points correctly,
# and .toUpperCase doesn't normalize 6 of them (list of exceptions:
# İ, ϴ, ẞ, Ω, K, Å - those are already uppercased, but have differently
# uppercased versions).
#
# Here's an example showing how it happens. Lets take greek letter omega:
# uppercase U+0398 (Θ), U+03f4 (ϴ) and lowercase U+03b8 (θ), U+03d1 (ϑ)
#
# Unicode entries:
# 0398;GREEK CAPITAL LETTER THETA;Lu;0;L;;;;;N;;;;03B8
# 03B8;GREEK SMALL LETTER THETA;Ll;0;L;;;;;N;;;0398;;0398
# 03D1;GREEK THETA SYMBOL;Ll;0;L;<compat> 03B8;;;;N;GREEK SMALL LETTER SCRIPT THETA;;0398;;0398
# 03F4;GREEK CAPITAL THETA SYMBOL;Lu;0;L;<compat> 0398;;;;N;;;;03B8
#
# Case-insensitive comparison should treat all of them as equivalent.
#
# But .toLowerCase() doesn't change ϑ (it's already lowercase),
# and .toUpperCase() doesn't change ϴ (already uppercase).
#
# Applying first lower then upper case normalizes any character:
# '\u0398\u03f4\u03b8\u03d1'.toLowerCase().toUpperCase() === '\u0398\u0398\u0398\u0398'
#
# Note: this is equivalent to unicode case folding; unicode normalization
# is a different step that is not required here.
#
# Final result should be uppercased, because it's later stored in an object
# (this avoid a conflict with Object.prototype members,
# most notably, `__proto__`)
#
return string.lower().upper()
LINK_OPEN_RE = re.compile(r"^<a[>\s]", flags=re.IGNORECASE)
LINK_CLOSE_RE = re.compile(r"^</a\s*>", flags=re.IGNORECASE)
[docs]def isLinkOpen(string: str) -> bool:
return bool(LINK_OPEN_RE.search(string))
[docs]def isLinkClose(string: str) -> bool:
return bool(LINK_CLOSE_RE.search(string))
