Replaced old core parser with new BlockParser and copied old core into extension.

1 files changed, 469 insertions, 0 deletions

diff --git a/markdown_extensions/legacy.py b/markdown_extensions/legacy.py
new file mode 100644
index 0000000..1320734
--- /dev/null
+++ b/markdown_extensions/legacy.py
@@ -0,0 +1,469 @@
+"""
+Legacy Extension for Python-Markdown
+====================================
+
+Replaces the core parser with the old one.
+
+"""
+
+import markdown
+
+"""Basic and reusable regular expressions."""
+
+def wrapRe(raw_re) : return re.compile("^%s$" % raw_re, re.DOTALL)
+CORE_RE = {
+    'header':          wrapRe(r'(#{1,6})[ \t]*(.*?)[ \t]*(#*)'), # # A title
+    'reference-def':   wrapRe(r'(\ ?\ ?\ ?)\[([^\]]*)\]:\s*([^ ]*)(.*)'),
+                               # [Google]: http://www.google.com/
+    'containsline':    wrapRe(r'([-]*)$|^([=]*)'), # -----, =====, etc.
+    'ol':              wrapRe(r'[ ]{0,3}[\d]*\.\s+(.*)'), # 1. text
+    'ul':              wrapRe(r'[ ]{0,3}[*+-]\s+(.*)'), # "* text"
+    'isline1':         wrapRe(r'(\**)'), # ***
+    'isline2':         wrapRe(r'(\-*)'), # ---
+    'isline3':         wrapRe(r'(\_*)'), # ___
+    'tabbed':          wrapRe(r'((\t)|(    ))(.*)'), # an indented line
+    'quoted':          wrapRe(r'[ ]{0,2}> ?(.*)'), # a quoted block ("> ...")
+    'containsline':    re.compile(r'^([-]*)$|^([=]*)$', re.M),
+    'attr':            re.compile("\{@([^\}]*)=([^\}]*)}") # {@id=123}
+}
+
+class MarkdownParser:
+    """Parser Markdown into a ElementTree."""
+
+    def __init__(self):
+        pass
+
+    def parseDocument(self, lines):
+        """Parse a markdown string into an ElementTree."""
+        # Create a ElementTree from the lines
+        root = etree.Element("div")
+        buffer = []
+        for line in lines:
+            if line.startswith("#"):
+                self.parseChunk(root, buffer)
+                buffer = [line]
+            else:
+                buffer.append(line)
+
+        self.parseChunk(root, buffer)
+
+        return etree.ElementTree(root)
+
+    def parseChunk(self, parent_elem, lines, inList=0, looseList=0):
+        """Process a chunk of markdown-formatted text and attach the parse to
+        an ElementTree node.
+
+        Process a section of a source document, looking for high
+        level structural elements like lists, block quotes, code
+        segments, html blocks, etc.  Some those then get stripped
+        of their high level markup (e.g. get unindented) and the
+        lower-level markup is processed recursively.
+
+        Keyword arguments:
+
+        * parent_elem: The ElementTree element to which the content will be
+                       added.
+        * lines: a list of lines
+        * inList: a level
+
+        Returns: None
+
+        """
+        # Loop through lines until none left.
+        while lines:
+            # Skipping empty line
+            if not lines[0]:
+                lines = lines[1:]
+                continue
+
+            # Check if this section starts with a list, a blockquote or
+            # a code block.  If so, process them.
+            processFn = { 'ul':     self.__processUList,
+                          'ol':     self.__processOList,
+                          'quoted': self.__processQuote,
+                          'tabbed': self.__processCodeBlock}
+            for regexp in ['ul', 'ol', 'quoted', 'tabbed']:
+                m = CORE_RE[regexp].match(lines[0])
+                if m:
+                    processFn[regexp](parent_elem, lines, inList)
+                    return
+
+            # We are NOT looking at one of the high-level structures like
+            # lists or blockquotes.  So, it's just a regular paragraph
+            # (though perhaps nested inside a list or something else).  If
+            # we are NOT inside a list, we just need to look for a blank
+            # line to find the end of the block.  If we ARE inside a
+            # list, however, we need to consider that a sublist does not
+            # need to be separated by a blank line.  Rather, the following
+            # markup is legal:
+            #
+            # * The top level list item
+            #
+            #     Another paragraph of the list.  This is where we are now.
+            #     * Underneath we might have a sublist.
+            #
+
+            if inList:
+                start, lines  = self.__linesUntil(lines, (lambda line:
+                                 CORE_RE['ul'].match(line)
+                                 or CORE_RE['ol'].match(line)
+                                                  or not line.strip()))
+                self.parseChunk(parent_elem, start, inList-1,
+                                looseList=looseList)
+                inList = inList-1
+
+            else: # Ok, so it's just a simple block
+                test = lambda line: not line.strip() or line[0] == '>'
+                paragraph, lines = self.__linesUntil(lines, test)
+                if len(paragraph) and paragraph[0].startswith('#'):
+                    self.__processHeader(parent_elem, paragraph)
+                elif len(paragraph) and CORE_RE["isline3"].match(paragraph[0]):
+                    self.__processHR(parent_elem)
+                    lines = paragraph[1:] + lines
+                elif paragraph:
+                    self.__processParagraph(parent_elem, paragraph,
+                                          inList, looseList)
+
+            if lines and not lines[0].strip():
+                lines = lines[1:]  # skip the first (blank) line
+
+    def __processHR(self, parentElem):
+        hr = etree.SubElement(parentElem, "hr")
+
+    def __processHeader(self, parentElem, paragraph):
+        m = CORE_RE['header'].match(paragraph[0])
+        if m:
+            level = len(m.group(1))
+            h = etree.SubElement(parentElem, "h%d" % level)
+            h.text = m.group(2).strip()
+        else:
+            message(CRITICAL, "We've got a problem header!")
+
+    def __processParagraph(self, parentElem, paragraph, inList, looseList):
+
+        if ( parentElem.tag == 'li'
+                and not (looseList or parentElem.getchildren())):
+
+            # If this is the first paragraph inside "li", don't
+            # put <p> around it - append the paragraph bits directly
+            # onto parentElem
+            el = parentElem
+        else:
+            # Otherwise make a "p" element
+            el = etree.SubElement(parentElem, "p")
+
+        dump = []
+
+        # Searching for hr or header
+        for line in paragraph:
+            # it's hr
+            if CORE_RE["isline3"].match(line):
+                el.text = "\n".join(dump)
+                self.__processHR(el)
+                dump = []
+            # it's header
+            elif line.startswith("#"):
+                el.text = "\n".join(dump)
+                self.__processHeader(parentElem, [line])
+                dump = []
+            else:
+                dump.append(line)
+        if dump:
+            text = "\n".join(dump)
+            el.text = text
+
+    def __processUList(self, parentElem, lines, inList):
+        self.__processList(parentElem, lines, inList, listexpr='ul', tag='ul')
+
+    def __processOList(self, parentElem, lines, inList):
+        self.__processList(parentElem, lines, inList, listexpr='ol', tag='ol')
+
+    def __processList(self, parentElem, lines, inList, listexpr, tag):
+        """
+        Given a list of document lines starting with a list item,
+        finds the end of the list, breaks it up, and recursively
+        processes each list item and the remainder of the text file.
+
+        Keyword arguments:
+
+        * parentElem: A ElementTree element to which the content will be added
+        * lines: a list of lines
+        * inList: a level
+
+        Returns: None
+
+        """
+        ul = etree.SubElement(parentElem, tag) # ul might actually be '<ol>'
+
+        looseList = 0
+
+        # Make a list of list items
+        items = []
+        item = -1
+
+        i = 0  # a counter to keep track of where we are
+        for line in lines:
+            loose = 0
+            if not line.strip():
+                # If we see a blank line, this _might_ be the end of the list
+                i += 1
+                loose = 1
+
+                # Find the next non-blank line
+                for j in range(i, len(lines)):
+                    if lines[j].strip():
+                        next = lines[j]
+                        break
+                else:
+                    # There is no more text => end of the list
+                    break
+
+                # Check if the next non-blank line is still a part of the list
+
+                if ( CORE_RE[listexpr].match(next) or
+                     CORE_RE['tabbed'].match(next) ):
+                    # get rid of any white space in the line
+                    items[item].append(line.strip())
+                    looseList = loose or looseList
+                    continue
+                else:
+                    break # found end of the list
+
+            # Now we need to detect list items (at the current level)
+            # while also detabing child elements if necessary
+
+            for expr in ['ul', 'ol', 'tabbed']:
+                m = CORE_RE[expr].match(line)
+                if m:
+                    if expr in ['ul', 'ol']:  # We are looking at a new item
+                        #if m.group(1) :
+                        # Removed the check to allow for a blank line
+                        # at the beginning of the list item
+                        items.append([m.group(1)])
+                        item += 1
+                    elif expr == 'tabbed':  # This line needs to be detabbed
+                        items[item].append(m.group(4)) #after the 'tab'
+                    i += 1
+                    break
+            else:
+                items[item].append(line)  # Just regular continuation
+                i += 1 # added on 2006.02.25
+        else:
+            i += 1
+
+        # Add the ElementTree elements
+        for item in items:
+            li = etree.SubElement(ul, "li")
+            self.parseChunk(li, item, inList + 1, looseList = looseList)
+
+        # Process the remaining part of the section
+        self.parseChunk(parentElem, lines[i:], inList)
+
+    def __linesUntil(self, lines, condition):
+        """
+        A utility function to break a list of lines upon the
+        first line that satisfied a condition.  The condition
+        argument should be a predicate function.
+
+        """
+        i = -1
+        for line in lines:
+            i += 1
+            if condition(line):
+                break
+        else:
+            i += 1
+        return lines[:i], lines[i:]
+
+    def __processQuote(self, parentElem, lines, inList):
+        """
+        Given a list of document lines starting with a quote finds
+        the end of the quote, unindents it and recursively
+        processes the body of the quote and the remainder of the
+        text file.
+
+        Keyword arguments:
+
+        * parentElem: ElementTree element to which the content will be added
+        * lines: a list of lines
+        * inList: a level
+
+        Returns: None
+
+        """
+        dequoted = []
+        i = 0
+        blank_line = False # allow one blank line between paragraphs
+        for line in lines:
+            m = CORE_RE['quoted'].match(line)
+            if m:
+                dequoted.append(m.group(1))
+                i += 1
+                blank_line = False
+            elif not blank_line and line.strip() != '':
+                dequoted.append(line)
+                i += 1
+            elif not blank_line and line.strip() == '':
+                dequoted.append(line)
+                i += 1
+                blank_line = True
+            else:
+                break
+
+        blockquote = etree.SubElement(parentElem, "blockquote")
+
+        self.parseChunk(blockquote, dequoted, inList)
+        self.parseChunk(parentElem, lines[i:], inList)
+
+    def __processCodeBlock(self, parentElem, lines, inList):
+        """
+        Given a list of document lines starting with a code block
+        finds the end of the block, puts it into the ElementTree verbatim
+        wrapped in ("<pre><code>") and recursively processes the
+        the remainder of the text file.
+
+        Keyword arguments:
+
+        * parentElem: ElementTree element to which the content will be added
+        * lines: a list of lines
+        * inList: a level
+
+        Returns: None
+
+        """
+        detabbed, theRest = self.detectTabbed(lines)
+        pre = etree.SubElement(parentElem, "pre")
+        code = etree.SubElement(pre, "code")
+        text = "\n".join(detabbed).rstrip()+"\n"
+        code.text = AtomicString(text)
+        self.parseChunk(parentElem, theRest, inList)
+
+    def detectTabbed(self, lines):
+        """ Find indented text and remove indent before further proccesing.
+
+        Keyword arguments:
+
+        * lines: an array of strings
+        * fn: a function that returns a substring of a string
+           if the string matches the necessary criteria
+
+        Returns: a list of post processes items and the unused
+        remainder of the original list
+
+        """
+        items = []
+        item = -1
+        i = 0 # to keep track of where we are
+
+        def detab(line):
+            match = CORE_RE['tabbed'].match(line)
+            if match:
+               return match.group(4)
+
+        for line in lines:
+            if line.strip(): # Non-blank line
+                line = detab(line)
+                if line:
+                    items.append(line)
+                    i += 1
+                    continue
+                else:
+                    return items, lines[i:]
+
+            else: # Blank line: _maybe_ we are done.
+                i += 1 # advance
+
+                # Find the next non-blank line
+                for j in range(i, len(lines)):
+                    if lines[j].strip():
+                        next_line = lines[j]; break
+                else:
+                    break # There is no more text; we are done.
+
+                # Check if the next non-blank line is tabbed
+                if detab(next_line): # Yes, more work to do.
+                    items.append("")
+                    continue
+                else:
+                    break # No, we are done.
+        else:
+            i += 1
+
+        return items, lines[i:]
+
+class HeaderPreprocessor(Preprocessor):
+
+    """Replace underlined headers with hashed headers.
+
+    (To avoid the need for lookahead later.)
+
+    """
+
+    def run (self, lines):
+        i = -1
+        while i+1 < len(lines):
+            i = i+1
+            if not lines[i].strip():
+                continue
+
+            if lines[i].startswith("#"):
+                lines.insert(i+1, "\n")
+
+            if (i+1 <= len(lines)
+                  and lines[i+1]
+                  and lines[i+1][0] in ['-', '=']):
+
+                underline = lines[i+1].strip()
+
+                if underline == "="*len(underline):
+                    lines[i] = "# " + lines[i].strip()
+                    lines[i+1] = ""
+                elif underline == "-"*len(underline):
+                    lines[i] = "## " + lines[i].strip()
+                    lines[i+1] = ""
+
+        return lines
+
+
+class LinePreprocessor(Preprocessor):
+    """Convert HR lines to "___" format."""
+    blockquote_re = re.compile(r'^(> )+')
+
+    def run (self, lines):
+        for i in range(len(lines)):
+            prefix = ''
+            m = self.blockquote_re.search(lines[i])
+            if m:
+                prefix = m.group(0)
+            if self._isLine(lines[i][len(prefix):]):
+                lines[i] = prefix + "___"
+        return lines
+
+    def _isLine(self, block):
+        """Determine if a block should be replaced with an <HR>"""
+        if block.startswith("    "):
+            return False  # a code block
+        text = "".join([x for x in block if not x.isspace()])
+        if len(text) <= 2:
+            return False
+        for pattern in ['isline1', 'isline2', 'isline3']:
+            m = CORE_RE[pattern].match(text)
+            if (m and m.group(1)):
+                return True
+        else:
+            return False
+
+
+class LegacyExtension(markdown.Extension):
+    """ Replace Markdown's core parser. """
+
+    def extendMarkdown(self, md, md_globals):
+        """ Set the core parser to an instance of MarkdownParser. """
+        md.parser = MarkdownParser()
+        md.preprocessors.add ("header", HeaderPreprocessor(self), "<reference")
+        md.preprocessors.add("line",  LinePreprocessor(self), "<reference")
+ 
+
+def makeExtension(configs={}):
+    return LegacyExtension(configs=configs)
+