Revert of Check in a simple pure-python based Markdown previewer.

third_party/Python-Markdown/markdown/extensions/extra.py

-"""
-Python-Markdown Extra Extension
-===============================
-
-A compilation of various Python-Markdown extensions that imitates
-[PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/).
-
-Note that each of the individual extensions still need to be available
-on your PYTHONPATH. This extension simply wraps them all up as a
-convenience so that only one extension needs to be listed when
-initiating Markdown. See the documentation for each individual
-extension for specifics about that extension.
-
-There may be additional extensions that are distributed with
-Python-Markdown that are not included here in Extra. Those extensions
-are not part of PHP Markdown Extra, and therefore, not part of
-Python-Markdown Extra. If you really would like Extra to include
-additional extensions, we suggest creating your own clone of Extra
-under a differant name. You could also edit the `extensions` global
-variable defined below, but be aware that such changes may be lost
-when you upgrade to any future version of Python-Markdown.
-
-See <https://pythonhosted.org/Markdown/extensions/extra.html>
-for documentation.
-
-Copyright The Python Markdown Project
-
-License: [BSD](http://www.opensource.org/licenses/bsd-license.php)
-
-"""
-
-from __future__ import absolute_import
-from __future__ import unicode_literals
-from . import Extension
-from ..blockprocessors import BlockProcessor
-from .. import util
-import re
-
-extensions = [
-    'markdown.extensions.smart_strong',
-    'markdown.extensions.fenced_code',
-    'markdown.extensions.footnotes',
-    'markdown.extensions.attr_list',
-    'markdown.extensions.def_list',
-    'markdown.extensions.tables',
-    'markdown.extensions.abbr'
-]
-
-
-class ExtraExtension(Extension):
-    """ Add various extensions to Markdown class."""
-
-    def __init__(self, *args, **kwargs):
-        """ config is a dumb holder which gets passed to actual ext later. """
-        self.config = kwargs.pop('configs', {})
-        self.config.update(kwargs)
-
-    def extendMarkdown(self, md, md_globals):
-        """ Register extension instances. """
-        md.registerExtensions(extensions, self.config)
-        if not md.safeMode:
-            # Turn on processing of markdown text within raw html
-            md.preprocessors['html_block'].markdown_in_raw = True
-            md.parser.blockprocessors.add('markdown_block',
-                                          MarkdownInHtmlProcessor(md.parser),
-                                          '_begin')
-            md.parser.blockprocessors.tag_counter = -1
-            md.parser.blockprocessors.contain_span_tags = re.compile(
-                r'^(p|h[1-6]|li|dd|dt|td|th|legend|address)$', re.IGNORECASE)
-
-
-def makeExtension(*args, **kwargs):
-    return ExtraExtension(*args, **kwargs)
-
-
-class MarkdownInHtmlProcessor(BlockProcessor):
-    """Process Markdown Inside HTML Blocks."""
-    def test(self, parent, block):
-        return block == util.TAG_PLACEHOLDER % \
-            str(self.parser.blockprocessors.tag_counter + 1)
-
-    def _process_nests(self, element, block):
-        """Process the element's child elements in self.run."""
-        # Build list of indexes of each nest within the parent element.
-        nest_index = []  # a list of tuples: (left index, right index)
-        i = self.parser.blockprocessors.tag_counter + 1
-        while len(self._tag_data) > i and self._tag_data[i]['left_index']:
-            left_child_index = self._tag_data[i]['left_index']
-            right_child_index = self._tag_data[i]['right_index']
-            nest_index.append((left_child_index - 1, right_child_index))
-            i += 1
-
-        # Create each nest subelement.
-        for i, (left_index, right_index) in enumerate(nest_index[:-1]):
-            self.run(element, block[left_index:right_index],
-                     block[right_index:nest_index[i + 1][0]], True)
-        self.run(element, block[nest_index[-1][0]:nest_index[-1][1]],  # last
-                 block[nest_index[-1][1]:], True)                      # nest
-
-    def run(self, parent, blocks, tail=None, nest=False):
-        self._tag_data = self.parser.markdown.htmlStash.tag_data
-
-        self.parser.blockprocessors.tag_counter += 1
-        tag = self._tag_data[self.parser.blockprocessors.tag_counter]
-
-        # Create Element
-        markdown_value = tag['attrs'].pop('markdown')
-        element = util.etree.SubElement(parent, tag['tag'], tag['attrs'])
-
-        # Slice Off Block
-        if nest:
-            self.parser.parseBlocks(parent, tail)  # Process Tail
-            block = blocks[1:]
-        else:  # includes nests since a third level of nesting isn't supported
-            block = blocks[tag['left_index'] + 1: tag['right_index']]
-            del blocks[:tag['right_index']]
-
-        # Process Text
-        if (self.parser.blockprocessors.contain_span_tags.match(  # Span Mode
-                tag['tag']) and markdown_value != 'block') or \
-                markdown_value == 'span':
-            element.text = '\n'.join(block)
-        else:                                                     # Block Mode
-            i = self.parser.blockprocessors.tag_counter + 1
-            if len(self._tag_data) > i and self._tag_data[i]['left_index']:
-                first_subelement_index = self._tag_data[i]['left_index'] - 1
-                self.parser.parseBlocks(
-                    element, block[:first_subelement_index])
-                if not nest:
-                    block = self._process_nests(element, block)
-            else:
-                self.parser.parseBlocks(element, block)