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

third_party/Python-Markdown/markdown/blockparser.py

-from __future__ import unicode_literals
-from __future__ import absolute_import
-from . import util
-from . import odict
-
-
-class State(list):
-    """ Track the current and nested state of the parser.
-
-    This utility class is used to track the state of the BlockParser and
-    support multiple levels if nesting. It's just a simple API wrapped around
-    a list. Each time a state is set, that state is appended to the end of the
-    list. Each time a state is reset, that state is removed from the end of
-    the list.
-
-    Therefore, each time a state is set for a nested block, that state must be
-    reset when we back out of that level of nesting or the state could be
-    corrupted.
-
-    While all the methods of a list object are available, only the three
-    defined below need be used.
-
-    """
-
-    def set(self, state):
-        """ Set a new state. """
-        self.append(state)
-
-    def reset(self):
-        """ Step back one step in nested state. """
-        self.pop()
-
-    def isstate(self, state):
-        """ Test that top (current) level is of given state. """
-        if len(self):
-            return self[-1] == state
-        else:
-            return False
-
-
-class BlockParser:
-    """ Parse Markdown blocks into an ElementTree object.
-
-    A wrapper class that stitches the various BlockProcessors together,
-    looping through them and creating an ElementTree object.
-    """
-
-    def __init__(self, markdown):
-        self.blockprocessors = odict.OrderedDict()
-        self.state = State()
-        self.markdown = markdown
-
-    def parseDocument(self, lines):
-        """ Parse a markdown document into an ElementTree.
-
-        Given a list of lines, an ElementTree object (not just a parent
-        Element) is created and the root element is passed to the parser
-        as the parent. The ElementTree object is returned.
-
-        This should only be called on an entire document, not pieces.
-
-        """
-        # Create a ElementTree from the lines
-        self.root = util.etree.Element(self.markdown.doc_tag)
-        self.parseChunk(self.root, '\n'.join(lines))
-        return util.etree.ElementTree(self.root)
-
-    def parseChunk(self, parent, text):
-        """ Parse a chunk of markdown text and attach to given etree node.
-
-        While the ``text`` argument is generally assumed to contain multiple
-        blocks which will be split on blank lines, it could contain only one
-        block. Generally, this method would be called by extensions when
-        block parsing is required.
-
-        The ``parent`` etree Element passed in is altered in place.
-        Nothing is returned.
-
-        """
-        self.parseBlocks(parent, text.split('\n\n'))
-
-    def parseBlocks(self, parent, blocks):
-        """ Process blocks of markdown text and attach to given etree node.
-
-        Given a list of ``blocks``, each blockprocessor is stepped through
-        until there are no blocks left. While an extension could potentially
-        call this method directly, it's generally expected to be used
-        internally.
-
-        This is a public method as an extension may need to add/alter
-        additional BlockProcessors which call this method to recursively
-        parse a nested block.
-
-        """
-        while blocks:
-            for processor in self.blockprocessors.values():
-                if processor.test(parent, blocks[0]):
-                    if processor.run(parent, blocks) is not False:
-                        # run returns True or None
-                        break