Open Source Monorail

appengine/monorail/third_party/markdown.py

+#!/usr/bin/python
+import re, md5, sys, string
+
+"""markdown.py: A Markdown-styled-text to HTML converter in Python.
+
+Usage:
+  ./markdown.py textfile.markdown
+ 
+Calling:
+  import markdown
+  somehtml = markdown.markdown(sometext)
+
+For other versions of markdown, see: 
+  http://www.freewisdom.org/projects/python-markdown/
+  http://en.wikipedia.org/wiki/Markdown
+"""
+
+__version__ = '1.0.1-2' # port of 1.0.1
+__license__ = "GNU GPL 2"
+__author__ = [
+  'John Gruber <http://daringfireball.net/>',
+  'Tollef Fog Heen <tfheen@err.no>', 
+  'Aaron Swartz <me@aaronsw.com>'
+]
+
+def htmlquote(text):
+    """Encodes `text` for raw use in HTML."""
+    text = text.replace("&", "&amp;") # Must be done first!
+    text = text.replace("<", "&lt;")
+    text = text.replace(">", "&gt;")
+    text = text.replace("'", "&#39;")
+    text = text.replace('"', "&quot;")
+    return text
+
+def semirandom(seed):
+    x = 0
+    for c in md5.new(seed).digest(): x += ord(c)
+    return x / (255*16.)
+
+class _Markdown:
+    emptyelt = " />"
+    tabwidth = 4
+
+    escapechars = '\\`*_{}[]()>#+-.!'
+    escapetable = {}
+    for char in escapechars:
+        escapetable[char] = md5.new(char).hexdigest()
+    
+    r_multiline = re.compile("\n{2,}")
+    r_stripspace = re.compile(r"^[ \t]+$", re.MULTILINE)
+    def parse(self, text):
+        self.urls = {}
+        self.titles = {}
+        self.html_blocks = {}
+        self.list_level = 0
+        
+        text = text.replace("\r\n", "\n")
+        text = text.replace("\r", "\n")
+        text += "\n\n"
+        text = self._Detab(text)
+        text = self.r_stripspace.sub("", text)
+        text = self._HashHTMLBlocks(text)
+        text = self._StripLinkDefinitions(text)
+        text = self._RunBlockGamut(text)
+        text = self._UnescapeSpecialChars(text)
+        return text
+    
+    r_StripLinkDefinitions = re.compile(r"""
+    ^[ ]{0,%d}\[(.+)\]:  # id = $1
+      [ \t]*\n?[ \t]*
+    <?(\S+?)>?           # url = $2
+      [ \t]*\n?[ \t]*
+    (?:
+      (?<=\s)            # lookbehind for whitespace
+      [\"\(]             # " is backlashed so it colorizes our code right
+      (.+?)              # title = $3
+      [\"\)]
+      [ \t]*
+    )?                   # title is optional
+    (?:\n+|\Z)
+    """ % (tabwidth-1), re.MULTILINE|re.VERBOSE)
+    def _StripLinkDefinitions(self, text):
+        def replacefunc(matchobj):
+            (t1, t2, t3) = matchobj.groups()
+            #@@ case sensitivity?
+            self.urls[t1.lower()] = self._EncodeAmpsAndAngles(t2)
+            if t3 is not None:
+                self.titles[t1.lower()] = t3.replace('"', '&quot;')
+            return ""
+
+        text = self.r_StripLinkDefinitions.sub(replacefunc, text)
+        return text
+
+    blocktagsb = r"p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|math"
+    blocktagsa = blocktagsb + "|ins|del"
+    
+    r_HashHTMLBlocks1 = re.compile(r"""
+    (            # save in $1
+    ^            # start of line  (with /m)
+    <(%s)        # start tag = $2
+    \b           # word break
+    (.*\n)*?     # any number of lines, minimally matching
+    </\2>        # the matching end tag
+    [ \t]*       # trailing spaces/tabs
+    (?=\n+|$)    # followed by a newline or end of document
+    )
+    """ % blocktagsa, re.MULTILINE | re.VERBOSE)
+
+    r_HashHTMLBlocks2 = re.compile(r"""
+    (            # save in $1
+    ^            # start of line  (with /m)
+    <(%s)        # start tag = $2
+    \b           # word break
+    (.*\n)*?     # any number of lines, minimally matching
+    .*</\2>      # the matching end tag
+    [ \t]*       # trailing spaces/tabs
+    (?=\n+|\Z)   # followed by a newline or end of document
+    )
+    """ % blocktagsb, re.MULTILINE | re.VERBOSE)
+
+    r_HashHR = re.compile(r"""
+    (?:
+    (?<=\n\n)    # Starting after a blank line
+    |            # or
+    \A\n?        # the beginning of the doc
+    )
+    (            # save in $1
+    [ ]{0,%d}
+    <(hr)        # start tag = $2
+    \b           # word break
+    ([^<>])*?    # 
+    /?>          # the matching end tag
+    [ \t]*
+    (?=\n{2,}|\Z)# followed by a blank line or end of document
+    )
+    """ % (tabwidth-1), re.VERBOSE)
+    r_HashComment = re.compile(r"""
+    (?:
+    (?<=\n\n)    # Starting after a blank line
+    |            # or
+    \A\n?        # the beginning of the doc
+    )
+    (            # save in $1
+    [ ]{0,%d}
+    (?: 
+      <!
+      (--.*?--\s*)+
+      >
+    )
+    [ \t]*
+    (?=\n{2,}|\Z)# followed by a blank line or end of document
+    )
+    """ % (tabwidth-1), re.VERBOSE)
+
+    def _HashHTMLBlocks(self, text):
+        def handler(m):
+            key = md5.new(m.group(1)).hexdigest()
+            self.html_blocks[key] = m.group(1)
+            return "\n\n%s\n\n" % key
+
+        text = self.r_HashHTMLBlocks1.sub(handler, text)
+        text = self.r_HashHTMLBlocks2.sub(handler, text)
+        oldtext = text
+        text = self.r_HashHR.sub(handler, text)
+        text = self.r_HashComment.sub(handler, text)
+        return text
+
+    #@@@ wrong!
+    r_hr1 = re.compile(r'^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$', re.M)
+    r_hr2 = re.compile(r'^[ ]{0,2}([ ]?-[ ]?){3,}[ \t]*$', re.M)
+    r_hr3 = re.compile(r'^[ ]{0,2}([ ]?_[ ]?){3,}[ \t]*$', re.M)
+        
+    def _RunBlockGamut(self, text):
+        text = self._DoHeaders(text)
+        for x in [self.r_hr1, self.r_hr2, self.r_hr3]:
+            text = x.sub("\n<hr%s\n" % self.emptyelt, text);
+        text = self._DoLists(text)
+        text = self._DoCodeBlocks(text)
+        text = self._DoBlockQuotes(text)
+
+        # We did this in parse()
+        # to escape the source
+        # now it's stuff _we_ made
+        # so we don't wrap it in <p>s.
+        text = self._HashHTMLBlocks(text)
+        text = self._FormParagraphs(text)
+        return text
+
+    r_NewLine = re.compile(" {2,}\n")
+    def _RunSpanGamut(self, text):
+        text = self._DoCodeSpans(text)
+        text = self._EscapeSpecialChars(text)
+        text = self._DoImages(text)
+        text = self._DoAnchors(text)
+        text = self._DoAutoLinks(text)
+        text = self._EncodeAmpsAndAngles(text)
+        text = self._DoItalicsAndBold(text)
+        text = self.r_NewLine.sub(" <br%s\n" % self.emptyelt, text)
+        return text
+
+    def _EscapeSpecialChars(self, text):
+        tokens = self._TokenizeHTML(text)
+        text = ""
+        for cur_token in tokens:
+            if cur_token[0] == "tag":
+                cur_token[1] = cur_token[1].replace('*', self.escapetable["*"])
+                cur_token[1] = cur_token[1].replace('_', self.escapetable["_"])
+                text += cur_token[1]
+            else:
+                text += self._EncodeBackslashEscapes(cur_token[1])
+        return text
+
+    r_DoAnchors1 = re.compile(
+          r""" (                 # wrap whole match in $1
+                  \[
+                    (.*?)        # link text = $2 
+                    # [for bracket nesting, see below]
+                  \]
+
+                  [ ]?           # one optional space
+                  (?:\n[ ]*)?    # one optional newline followed by spaces
+
+                  \[
+                    (.*?)        # id = $3
+                  \]
+                )
+    """, re.S|re.VERBOSE)
+    r_DoAnchors2 = re.compile(
+          r""" (                   # wrap whole match in $1
+                  \[
+                    (.*?)          # link text = $2
+                  \]
+                  \(               # literal paren
+                        [ \t]*
+                        <?(.+?)>?  # href = $3
+                        [ \t]*
+                        (          # $4
+                          ([\'\"]) # quote char = $5
+                          (.*?)    # Title = $6
+                          \5       # matching quote
+                        )?         # title is optional
+                  \)
+                )
+    """, re.S|re.VERBOSE)
+    def _DoAnchors(self, text): 
+        # We here don't do the same as the perl version, as python's regex
+        # engine gives us no way to match brackets.
+
+        def handler1(m):
+            whole_match = m.group(1)
+            link_text = m.group(2)
+            link_id = m.group(3).lower()
+            if not link_id: link_id = link_text.lower()
+            title = self.titles.get(link_id, None)
+                
+
+            if self.urls.has_key(link_id):
+                url = self.urls[link_id]
+                url = url.replace("*", self.escapetable["*"])
+                url = url.replace("_", self.escapetable["_"])
+                res = '<a href="%s"' % htmlquote(url)
+
+                if title:
+                    title = title.replace("*", self.escapetable["*"])
+                    title = title.replace("_", self.escapetable["_"])
+                    res += ' title="%s"' % htmlquote(title)
+                res += ">%s</a>" % htmlquote(link_text)
+            else:
+                res = whole_match
+            return res
+
+        def handler2(m):
+            whole_match = m.group(1)
+            link_text = m.group(2)
+            url = m.group(3)
+            title = m.group(6)
+
+            url = url.replace("*", self.escapetable["*"])
+            url = url.replace("_", self.escapetable["_"])
+            res = '''<a href="%s"''' % htmlquote(url)
+            
+            if title:
+                title = title.replace('"', '&quot;')
+                title = title.replace("*", self.escapetable["*"])
+                title = title.replace("_", self.escapetable["_"])
+                res += ' title="%s"' % htmlquote(title)
+            res += ">%s</a>" % htmlquote(link_text)
+            return res
+
+        text = self.r_DoAnchors1.sub(handler1, text)
+        text = self.r_DoAnchors2.sub(handler2, text)
+        return text
+
+    r_DoImages1 = re.compile(
+           r""" (                       # wrap whole match in $1
+                  !\[
+                    (.*?)               # alt text = $2
+                  \]
+
+                  [ ]?                  # one optional space
+                  (?:\n[ ]*)?           # one optional newline followed by spaces
+
+                  \[
+                    (.*?)               # id = $3
+                  \]
+
+                )
+    """, re.VERBOSE|re.S)
+
+    r_DoImages2 = re.compile(
+          r""" (                        # wrap whole match in $1
+                  !\[
+                    (.*?)               # alt text = $2
+                  \]
+                  \(                    # literal paren
+                        [ \t]*
+                        <?(\S+?)>?      # src url = $3
+                        [ \t]*
+                        (               # $4
+                        ([\'\"])        # quote char = $5
+                          (.*?)         # title = $6
+                          \5            # matching quote
+                          [ \t]*
+                        )?              # title is optional
+                  \)
+                )
+    """, re.VERBOSE|re.S)
+
+    def _DoImages(self, text):
+        def handler1(m):
+            whole_match = m.group(1)
+            alt_text = m.group(2)
+            link_id = m.group(3).lower()
+
+            if not link_id:
+                link_id = alt_text.lower()
+
+            alt_text = alt_text.replace('"', "&quot;")
+            if self.urls.has_key(link_id):
+                url = self.urls[link_id]
+                url = url.replace("*", self.escapetable["*"])
+                url = url.replace("_", self.escapetable["_"])
+                res = '''<img src="%s" alt="%s"''' % (htmlquote(url), htmlquote(alt_text))
+                if self.titles.has_key(link_id):
+                    title = self.titles[link_id]
+                    title = title.replace("*", self.escapetable["*"])
+                    title = title.replace("_", self.escapetable["_"])
+                    res += ' title="%s"' % htmlquote(title)
+                res += self.emptyelt
+            else:
+                res = whole_match
+            return res
+
+        def handler2(m):
+            whole_match = m.group(1)
+            alt_text = m.group(2)
+            url = m.group(3)
+            title = m.group(6) or ''
+            
+            alt_text = alt_text.replace('"', "&quot;")
+            title = title.replace('"', "&quot;")
+            url = url.replace("*", self.escapetable["*"])
+            url = url.replace("_", self.escapetable["_"])
+            res = '<img src="%s" alt="%s"' % (htmlquote(url), htmlquote(alt_text))
+            if title is not None:
+                title = title.replace("*", self.escapetable["*"])
+                title = title.replace("_", self.escapetable["_"])
+                res += ' title="%s"' % htmlquote(title)
+            res += self.emptyelt
+            return res
+
+        text = self.r_DoImages1.sub(handler1, text)
+        text = self.r_DoImages2.sub(handler2, text)
+        return text
+    
+    r_DoHeaders = re.compile(r"^(\#{1,6})[ \t]*(.+?)[ \t]*\#*\n+", re.VERBOSE|re.M)
+    def _DoHeaders(self, text):
+        def findheader(text, c, n):
+            textl = text.split('\n')
+            for i in xrange(len(textl)):
+                if i >= len(textl): continue
+                count = textl[i].strip().count(c)
+                if count > 0 and count == len(textl[i].strip()) and textl[i+1].strip() == '' and textl[i-1].strip() != '':
+                    textl = textl[:i] + textl[i+1:]
+                    textl[i-1] = '<h'+n+'>'+self._RunSpanGamut(textl[i-1])+'</h'+n+'>'
+                    textl = textl[:i] + textl[i+1:]
+            text = '\n'.join(textl)
+            return text
+        
+        def handler(m):
+            level = len(m.group(1))
+            header = self._RunSpanGamut(m.group(2))
+            return "<h%s>%s</h%s>\n\n" % (level, header, level)
+
+        text = findheader(text, '=', '1')
+        text = findheader(text, '-', '2')
+        text = self.r_DoHeaders.sub(handler, text)
+        return text
+    
+    rt_l = r"""
+    (
+      (
+        [ ]{0,%d}
+        ([*+-]|\d+[.])
+        [ \t]+
+      )
+      (?:.+?)
+      (
+        \Z
+      |
+        \n{2,}
+        (?=\S)
+        (?![ \t]* ([*+-]|\d+[.])[ \t]+)
+      )
+    )
+    """ % (tabwidth - 1)
+    r_DoLists = re.compile('^'+rt_l, re.M | re.VERBOSE | re.S)
+    r_DoListsTop = re.compile(
+      r'(?:\A\n?|(?<=\n\n))'+rt_l, re.M | re.VERBOSE | re.S)
+    
+    def _DoLists(self, text):
+        def handler(m):
+            list_type = "ol"
+            if m.group(3) in [ "*", "-", "+" ]:
+                list_type = "ul"
+            listn = m.group(1)
+            listn = self.r_multiline.sub("\n\n\n", listn)
+            res = self._ProcessListItems(listn)
+            res = "<%s>\n%s</%s>\n" % (list_type, res, list_type)
+            return res
+            
+        if self.list_level:
+            text = self.r_DoLists.sub(handler, text)
+        else:
+            text = self.r_DoListsTop.sub(handler, text)
+        return text
+
+    r_multiend = re.compile(r"\n{2,}\Z")
+    r_ProcessListItems = re.compile(r"""
+    (\n)?                            # leading line = $1
+    (^[ \t]*)                        # leading whitespace = $2
+    ([*+-]|\d+[.]) [ \t]+            # list marker = $3
+    ((?:.+?)                         # list item text = $4
+    (\n{1,2}))
+    (?= \n* (\Z | \2 ([*+-]|\d+[.]) [ \t]+))
+    """, re.VERBOSE | re.M | re.S)
+
+    def _ProcessListItems(self, text):
+        self.list_level += 1
+        text = self.r_multiend.sub("\n", text)
+        
+        def handler(m):
+            item = m.group(4)
+            leading_line = m.group(1)
+            leading_space = m.group(2)
+
+            if leading_line or self.r_multiline.search(item):
+                item = self._RunBlockGamut(self._Outdent(item))
+            else:
+                item = self._DoLists(self._Outdent(item))
+                if item[-1] == "\n": item = item[:-1] # chomp
+                item = self._RunSpanGamut(item)
+            return "<li>%s</li>\n" % item
+
+        text = self.r_ProcessListItems.sub(handler, text)
+        self.list_level -= 1
+        return text
+    
+    r_DoCodeBlocks = re.compile(r"""
+    (?:\n\n|\A)
+    (                 # $1 = the code block
+    (?:
+    (?:[ ]{%d} | \t)  # Lines must start with a tab or equiv
+    .*\n+
+    )+
+    )
+    ((?=^[ ]{0,%d}\S)|\Z) # Lookahead for non-space/end of doc
+    """ % (tabwidth, tabwidth), re.M | re.VERBOSE)
+    def _DoCodeBlocks(self, text):
+        def handler(m):
+            codeblock = m.group(1)
+            codeblock = self._EncodeCode(self._Outdent(codeblock))
+            codeblock = self._Detab(codeblock)
+            codeblock = codeblock.lstrip("\n")
+            codeblock = codeblock.rstrip()
+            res = "\n\n<pre><code>%s\n</code></pre>\n\n" % codeblock
+            return res
+
+        text = self.r_DoCodeBlocks.sub(handler, text)
+        return text
+    r_DoCodeSpans = re.compile(r"""
+    (`+)            # $1 = Opening run of `
+    (.+?)           # $2 = The code block
+    (?<!`)
+    \1              # Matching closer
+    (?!`)
+    """, re.I|re.VERBOSE)
+    def _DoCodeSpans(self, text):
+        def handler(m):
+            c = m.group(2)
+            c = c.strip()
+            c = self._EncodeCode(c)
+            return "<code>%s</code>" % c
+
+        text = self.r_DoCodeSpans.sub(handler, text)
+        return text
+    
+    def _EncodeCode(self, text):
+        text = text.replace("&","&amp;")
+        text = text.replace("<","&lt;")
+        text = text.replace(">","&gt;")
+        for c in "*_{}[]\\":
+            text = text.replace(c, self.escapetable[c])
+        return text
+
+    
+    r_DoBold = re.compile(r"(\*\*|__) (?=\S) (.+?[*_]*) (?<=\S) \1", re.VERBOSE | re.S)
+    r_DoItalics = re.compile(r"(\*|_) (?=\S) (.+?) (?<=\S) \1", re.VERBOSE | re.S)
+    def _DoItalicsAndBold(self, text):
+        text = self.r_DoBold.sub(r"<strong>\2</strong>", text)
+        text = self.r_DoItalics.sub(r"<em>\2</em>", text)
+        return text
+    
+    r_start = re.compile(r"^", re.M)
+    r_DoBlockQuotes1 = re.compile(r"^[ \t]*>[ \t]?", re.M)
+    r_DoBlockQuotes2 = re.compile(r"^[ \t]+$", re.M)
+    r_DoBlockQuotes3 = re.compile(r"""
+    (                       # Wrap whole match in $1
+     (
+       ^[ \t]*>[ \t]?       # '>' at the start of a line
+       .+\n                 # rest of the first line
+       (.+\n)*              # subsequent consecutive lines
+       \n*                  # blanks
+      )+
+    )""", re.M | re.VERBOSE)
+    r_protectpre = re.compile(r'(\s*<pre>.+?</pre>)', re.S)
+    r_propre = re.compile(r'^  ', re.M)
+
+    def _DoBlockQuotes(self, text):
+        def prehandler(m):
+            return self.r_propre.sub('', m.group(1))
+                
+        def handler(m):
+            bq = m.group(1)
+            bq = self.r_DoBlockQuotes1.sub("", bq)
+            bq = self.r_DoBlockQuotes2.sub("", bq)
+            bq = self._RunBlockGamut(bq)
+            bq = self.r_start.sub("  ", bq)
+            bq = self.r_protectpre.sub(prehandler, bq)
+            return "<blockquote>\n%s\n</blockquote>\n\n" % bq
+            
+        text = self.r_DoBlockQuotes3.sub(handler, text)
+        return text
+
+    r_tabbed = re.compile(r"^([ \t]*)")
+    def _FormParagraphs(self, text):
+        text = text.strip("\n")
+        grafs = self.r_multiline.split(text)
+
+        for g in xrange(len(grafs)):
+            t = grafs[g].strip() #@@?
+            if not self.html_blocks.has_key(t):
+                t = self._RunSpanGamut(t)
+                t = self.r_tabbed.sub(r"<p>", t)
+                t += "</p>"
+                grafs[g] = t
+
+        for g in xrange(len(grafs)):
+            t = grafs[g].strip()
+            if self.html_blocks.has_key(t):
+                grafs[g] = self.html_blocks[t]
+        
+        return "\n\n".join(grafs)
+
+    r_EncodeAmps = re.compile(r"&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)")
+    r_EncodeAngles = re.compile(r"<(?![a-z/?\$!])")
+    def _EncodeAmpsAndAngles(self, text):
+        text = self.r_EncodeAmps.sub("&amp;", text)
+        text = self.r_EncodeAngles.sub("&lt;", text)
+        return text
+
+    def _EncodeBackslashEscapes(self, text):
+        for char in self.escapechars:
+            text = text.replace("\\" + char, self.escapetable[char])
+        return text
+    
+    r_link = re.compile(r"<((https?|ftp):[^\'\">\s]+)>", re.I)
+    r_email = re.compile(r"""
+      <
+      (?:mailto:)?
+      (
+         [-.\w]+
+         \@
+         [-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
+      )
+      >""", re.VERBOSE|re.I)
+    def _DoAutoLinks(self, text):
+        text = self.r_link.sub(r'<a href="\1">\1</a>', text)
+
+        def handler(m):
+            l = m.group(1)
+            return self._EncodeEmailAddress(self._UnescapeSpecialChars(l))
+    
+        text = self.r_email.sub(handler, text)
+        return text
+    
+    r_EncodeEmailAddress = re.compile(r">.+?:")
+    def _EncodeEmailAddress(self, text):
+        encode = [
+            lambda x: "&#%s;" % ord(x),
+            lambda x: "&#x%X;" % ord(x),
+            lambda x: x
+        ]
+
+        text = "mailto:" + text
+        addr = ""
+        for c in text:
+            if c == ':': addr += c; continue
+            
+            r = semirandom(addr)
+            if r < 0.45:
+                addr += encode[1](c)
+            elif r > 0.9 and c != '@':
+                addr += encode[2](c)
+            else:
+                addr += encode[0](c)
+
+        text = '<a href="%s">%s</a>' % (addr, addr)
+        text = self.r_EncodeEmailAddress.sub('>', text)
+        return text
+
+    def _UnescapeSpecialChars(self, text):
+        for key in self.escapetable.keys():
+            text = text.replace(self.escapetable[key], key)
+        return text
+    
+    tokenize_depth = 6
+    tokenize_nested_tags = '|'.join([r'(?:<[a-z/!$](?:[^<>]'] * tokenize_depth) + (')*>)' * tokenize_depth)
+    r_TokenizeHTML = re.compile(
+      r"""(?: <! ( -- .*? -- \s* )+ > ) |  # comment
+          (?: <\? .*? \?> ) |              # processing instruction
+          %s                               # nested tags
+    """ % tokenize_nested_tags, re.I|re.VERBOSE)
+    def _TokenizeHTML(self, text):
+        pos = 0
+        tokens = []
+        matchobj = self.r_TokenizeHTML.search(text, pos)
+        while matchobj:
+            whole_tag = matchobj.string[matchobj.start():matchobj.end()]
+            sec_start = matchobj.end()
+            tag_start = sec_start - len(whole_tag)
+            if pos < tag_start:
+                tokens.append(["text", matchobj.string[pos:tag_start]])
+
+            tokens.append(["tag", whole_tag])
+            pos = sec_start
+            matchobj = self.r_TokenizeHTML.search(text, pos)
+
+        if pos < len(text):
+            tokens.append(["text", text[pos:]])
+        return tokens
+
+    r_Outdent = re.compile(r"""^(\t|[ ]{1,%d})""" % tabwidth, re.M)
+    def _Outdent(self, text):
+        text = self.r_Outdent.sub("", text)
+        return text    
+
+    def _Detab(self, text): return text.expandtabs(self.tabwidth)
+
+def Markdown(*args, **kw): return _Markdown().parse(*args, **kw)
+markdown = Markdown
+
+if __name__ == '__main__':
+    if len(sys.argv) > 1:
+        print Markdown(open(sys.argv[1]).read())
+    else:
+        print Markdown(sys.stdin.read())