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Direktori : /lib/python3/dist-packages/markdown/extensions/ |
Current File : //lib/python3/dist-packages/markdown/extensions/codehilite.py |
# CodeHilite Extension for Python-Markdown # ======================================== # Adds code/syntax highlighting to standard Python-Markdown code blocks. # See https://Python-Markdown.github.io/extensions/code_hilite # for documentation. # Original code Copyright 2006-2008 [Waylan Limberg](http://achinghead.com/). # All changes Copyright 2008-2014 The Python Markdown Project # License: [BSD](https://opensource.org/licenses/bsd-license.php) """ Adds code/syntax highlighting to standard Python-Markdown code blocks. See the [documentation](https://Python-Markdown.github.io/extensions/code_hilite) for details. """ from __future__ import annotations from . import Extension from ..treeprocessors import Treeprocessor from ..util import parseBoolValue from typing import TYPE_CHECKING, Callable, Any if TYPE_CHECKING: # pragma: no cover import xml.etree.ElementTree as etree try: # pragma: no cover from pygments import highlight from pygments.lexers import get_lexer_by_name, guess_lexer from pygments.formatters import get_formatter_by_name from pygments.util import ClassNotFound pygments = True except ImportError: # pragma: no cover pygments = False def parse_hl_lines(expr: str) -> list[int]: """Support our syntax for emphasizing certain lines of code. `expr` should be like '1 2' to emphasize lines 1 and 2 of a code block. Returns a list of integers, the line numbers to emphasize. """ if not expr: return [] try: return list(map(int, expr.split())) except ValueError: # pragma: no cover return [] # ------------------ The Main CodeHilite Class ---------------------- class CodeHilite: """ Determine language of source code, and pass it on to the Pygments highlighter. Usage: ```python code = CodeHilite(src=some_code, lang='python') html = code.hilite() ``` Arguments: src: Source string or any object with a `.readline` attribute. Keyword arguments: lang (str): String name of Pygments lexer to use for highlighting. Default: `None`. guess_lang (bool): Auto-detect which lexer to use. Ignored if `lang` is set to a valid value. Default: `True`. use_pygments (bool): Pass code to Pygments for code highlighting. If `False`, the code is instead wrapped for highlighting by a JavaScript library. Default: `True`. pygments_formatter (str): The name of a Pygments formatter or a formatter class used for highlighting the code blocks. Default: `html`. linenums (bool): An alias to Pygments `linenos` formatter option. Default: `None`. css_class (str): An alias to Pygments `cssclass` formatter option. Default: 'codehilite'. lang_prefix (str): Prefix prepended to the language. Default: "language-". Other Options: Any other options are accepted and passed on to the lexer and formatter. Therefore, valid options include any options which are accepted by the `html` formatter or whichever lexer the code's language uses. Note that most lexers do not have any options. However, a few have very useful options, such as PHP's `startinline` option. Any invalid options are ignored without error. * **Formatter options**: <https://pygments.org/docs/formatters/#HtmlFormatter> * **Lexer Options**: <https://pygments.org/docs/lexers/> Additionally, when Pygments is enabled, the code's language is passed to the formatter as an extra option `lang_str`, whose value being `{lang_prefix}{lang}`. This option has no effect to the Pygments' builtin formatters. Advanced Usage: ```python code = CodeHilite( src = some_code, lang = 'php', startinline = True, # Lexer option. Snippet does not start with `<?php`. linenostart = 42, # Formatter option. Snippet starts on line 42. hl_lines = [45, 49, 50], # Formatter option. Highlight lines 45, 49, and 50. linenos = 'inline' # Formatter option. Avoid alignment problems. ) html = code.hilite() ``` """ def __init__(self, src: str, **options): self.src = src self.lang: str | None = options.pop('lang', None) self.guess_lang: bool = options.pop('guess_lang', True) self.use_pygments: bool = options.pop('use_pygments', True) self.lang_prefix: str = options.pop('lang_prefix', 'language-') self.pygments_formatter: str | Callable = options.pop('pygments_formatter', 'html') if 'linenos' not in options: options['linenos'] = options.pop('linenums', None) if 'cssclass' not in options: options['cssclass'] = options.pop('css_class', 'codehilite') if 'wrapcode' not in options: # Override Pygments default options['wrapcode'] = True # Disallow use of `full` option options['full'] = False self.options = options def hilite(self, shebang: bool = True) -> str: """ Pass code to the [Pygments](https://pygments.org/) highlighter with optional line numbers. The output should then be styled with CSS to your liking. No styles are applied by default - only styling hooks (i.e.: `<span class="k">`). returns : A string of html. """ self.src = self.src.strip('\n') if self.lang is None and shebang: self._parseHeader() if pygments and self.use_pygments: try: lexer = get_lexer_by_name(self.lang, **self.options) except ValueError: try: if self.guess_lang: lexer = guess_lexer(self.src, **self.options) else: lexer = get_lexer_by_name('text', **self.options) except ValueError: # pragma: no cover lexer = get_lexer_by_name('text', **self.options) if not self.lang: # Use the guessed lexer's language instead self.lang = lexer.aliases[0] lang_str = f'{self.lang_prefix}{self.lang}' if isinstance(self.pygments_formatter, str): try: formatter = get_formatter_by_name(self.pygments_formatter, **self.options) except ClassNotFound: formatter = get_formatter_by_name('html', **self.options) else: formatter = self.pygments_formatter(lang_str=lang_str, **self.options) return highlight(self.src, lexer, formatter) else: # just escape and build markup usable by JavaScript highlighting libraries txt = self.src.replace('&', '&') txt = txt.replace('<', '<') txt = txt.replace('>', '>') txt = txt.replace('"', '"') classes = [] if self.lang: classes.append('{}{}'.format(self.lang_prefix, self.lang)) if self.options['linenos']: classes.append('linenums') class_str = '' if classes: class_str = ' class="{}"'.format(' '.join(classes)) return '<pre class="{}"><code{}>{}\n</code></pre>\n'.format( self.options['cssclass'], class_str, txt ) def _parseHeader(self) -> None: """ Determines language of a code block from shebang line and whether the said line should be removed or left in place. If the shebang line contains a path (even a single /) then it is assumed to be a real shebang line and left alone. However, if no path is given (e.i.: `#!python` or `:::python`) then it is assumed to be a mock shebang for language identification of a code fragment and removed from the code block prior to processing for code highlighting. When a mock shebang (e.i: `#!python`) is found, line numbering is turned on. When colons are found in place of a shebang (e.i.: `:::python`), line numbering is left in the current state - off by default. Also parses optional list of highlight lines, like: :::python hl_lines="1 3" """ import re # split text into lines lines = self.src.split("\n") # pull first line to examine fl = lines.pop(0) c = re.compile(r''' (?:(?:^::+)|(?P<shebang>^[#]!)) # Shebang or 2 or more colons (?P<path>(?:/\w+)*[/ ])? # Zero or 1 path (?P<lang>[\w#.+-]*) # The language \s* # Arbitrary whitespace # Optional highlight lines, single- or double-quote-delimited (hl_lines=(?P<quot>"|')(?P<hl_lines>.*?)(?P=quot))? ''', re.VERBOSE) # search first line for shebang m = c.search(fl) if m: # we have a match try: self.lang = m.group('lang').lower() except IndexError: # pragma: no cover self.lang = None if m.group('path'): # path exists - restore first line lines.insert(0, fl) if self.options['linenos'] is None and m.group('shebang'): # Overridable and Shebang exists - use line numbers self.options['linenos'] = True self.options['hl_lines'] = parse_hl_lines(m.group('hl_lines')) else: # No match lines.insert(0, fl) self.src = "\n".join(lines).strip("\n") # ------------------ The Markdown Extension ------------------------------- class HiliteTreeprocessor(Treeprocessor): """ Highlight source code in code blocks. """ config: dict[str, Any] def code_unescape(self, text: str) -> str: """Unescape code.""" text = text.replace("<", "<") text = text.replace(">", ">") # Escaped '&' should be replaced at the end to avoid # conflicting with < and >. text = text.replace("&", "&") return text def run(self, root: etree.Element) -> None: """ Find code blocks and store in `htmlStash`. """ blocks = root.iter('pre') for block in blocks: if len(block) == 1 and block[0].tag == 'code': local_config = self.config.copy() text = block[0].text if text is None: continue code = CodeHilite( self.code_unescape(text), tab_length=self.md.tab_length, style=local_config.pop('pygments_style', 'default'), **local_config ) placeholder = self.md.htmlStash.store(code.hilite()) # Clear code block in `etree` instance block.clear() # Change to `p` element which will later # be removed when inserting raw html block.tag = 'p' block.text = placeholder class CodeHiliteExtension(Extension): """ Add source code highlighting to markdown code blocks. """ def __init__(self, **kwargs): # define default configs self.config = { 'linenums': [ None, "Use lines numbers. True|table|inline=yes, False=no, None=auto. Default: `None`." ], 'guess_lang': [ True, "Automatic language detection - Default: `True`." ], 'css_class': [ "codehilite", "Set class name for wrapper <div> - Default: `codehilite`." ], 'pygments_style': [ 'default', 'Pygments HTML Formatter Style (Colorscheme). Default: `default`.' ], 'noclasses': [ False, 'Use inline styles instead of CSS classes - Default `False`.' ], 'use_pygments': [ True, 'Highlight code blocks with pygments. Disable if using a JavaScript library. Default: `True`.' ], 'lang_prefix': [ 'language-', 'Prefix prepended to the language when `use_pygments` is false. Default: `language-`.' ], 'pygments_formatter': [ 'html', 'Use a specific formatter for Pygments highlighting. Default: `html`.' ], } """ Default configuration options. """ for key, value in kwargs.items(): if key in self.config: self.setConfig(key, value) else: # manually set unknown keywords. if isinstance(value, str): try: # Attempt to parse `str` as a boolean value value = parseBoolValue(value, preserve_none=True) except ValueError: pass # Assume it's not a boolean value. Use as-is. self.config[key] = [value, ''] def extendMarkdown(self, md): """ Add `HilitePostprocessor` to Markdown instance. """ hiliter = HiliteTreeprocessor(md) hiliter.config = self.getConfigs() md.treeprocessors.register(hiliter, 'hilite', 30) md.registerExtension(self) def makeExtension(**kwargs): # pragma: no cover return CodeHiliteExtension(**kwargs)