137 lines
5.0 KiB
Python
137 lines
5.0 KiB
Python
#!/usr/bin/env python3
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# :Copyright: © 2020 Günter Milde.
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# :License: Released under the terms of the `2-Clause BSD license`_, in short:
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#
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# Copying and distribution of this file, with or without modification,
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# are permitted in any medium without royalty provided the copyright
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# notice and this notice are preserved.
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# This file is offered as-is, without any warranty.
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#
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# .. _2-Clause BSD license: https://opensource.org/licenses/BSD-2-Clause
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#
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# Revision: $Revision: 9043 $
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# Date: $Date: 2022-03-11 13:09:16 +0100 (Fr, 11. Mär 2022) $
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"""
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A parser for CommonMark Markdown text using `recommonmark`__.
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__ https://pypi.org/project/recommonmark/
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.. important:: This module is provisional
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* The "recommonmark" package is unmaintained and deprecated.
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This wrapper module will be removed in a future Docutils version.
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* The API is not settled and may change with any minor Docutils version.
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"""
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from docutils import nodes, Component
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try:
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from recommonmark.parser import CommonMarkParser
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except ImportError as err:
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raise ImportError(f'{err}.\n'
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'Parsing "recommonmark" Markdown flavour requires the '
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'package https://pypi.org/project/recommonmark which '
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'in turn depends on https://pypi.org/project/sphinx.')
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try:
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from sphinx import addnodes
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# already cached in `sys.modules` if recommonmark >= 0.5.0
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except ImportError:
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# stub to prevent errors with recommonmark < 0.5.0
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class addnodes:
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pending_xref = nodes.pending
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# auxiliary function for `document.findall()`
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def is_literal(node):
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return isinstance(node, (nodes.literal, nodes.literal_block))
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class Parser(CommonMarkParser):
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"""MarkDown parser based on recommonmark.
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This parser is provisional:
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the API is not settled and may change with any minor Docutils version.
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"""
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supported = ('recommonmark', 'commonmark', 'markdown', 'md')
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"""Formats this parser supports."""
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config_section = 'recommonmark parser'
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config_section_dependencies = ('parsers',)
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def get_transforms(self):
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return Component.get_transforms(self) # + [AutoStructify]
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def parse(self, inputstring, document):
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"""Use the upstream parser and clean up afterwards.
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"""
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# check for exorbitantly long lines
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for i, line in enumerate(inputstring.split('\n')):
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if len(line) > document.settings.line_length_limit:
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error = document.reporter.error(
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'Line %d exceeds the line-length-limit.'%(i+1))
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document.append(error)
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return
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# pass to upstream parser
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try:
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CommonMarkParser.parse(self, inputstring, document)
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except Exception as err:
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if document.settings.traceback:
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raise err
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error = document.reporter.error('Parsing with "recommonmark" '
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'returned the error:\n%s'%err)
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document.append(error)
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# Post-Processing
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# ---------------
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# merge adjoining Text nodes:
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for node in document.findall(nodes.TextElement):
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children = node.children
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i = 0
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while i+1 < len(children):
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if (isinstance(children[i], nodes.Text)
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and isinstance(children[i+1], nodes.Text)):
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children[i] = nodes.Text(children[i]+children.pop(i+1))
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children[i].parent = node
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else:
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i += 1
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# add "code" class argument to literal elements (inline and block)
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for node in document.findall(is_literal):
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if 'code' not in node['classes']:
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node['classes'].append('code')
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# move "language" argument to classes
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for node in document.findall(nodes.literal_block):
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if 'language' in node.attributes:
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node['classes'].append(node['language'])
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del node['language']
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# replace raw nodes if raw is not allowed
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if not document.settings.raw_enabled:
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for node in document.findall(nodes.raw):
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warning = document.reporter.warning('Raw content disabled.')
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node.parent.replace(node, warning)
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# drop pending_xref (Sphinx cross reference extension)
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for node in document.findall(addnodes.pending_xref):
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reference = node.children[0]
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if 'name' not in reference:
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reference['name'] = nodes.fully_normalize_name(
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reference.astext())
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node.parent.replace(node, reference)
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def visit_document(self, node):
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"""Dummy function to prevent spurious warnings.
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cf. https://github.com/readthedocs/recommonmark/issues/177
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"""
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pass
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# Overwrite parent method with version that
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# doesn't pass deprecated `rawsource` argument to nodes.Text:
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def visit_text(self, mdnode):
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self.current_node.append(nodes.Text(mdnode.literal))
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