From 9ddeb1b1a33513e8b80d055b8b4f2445a235beb0 Mon Sep 17 00:00:00 2001 From: saxmatt Date: Mon, 24 Jan 2005 06:30:16 +0000 Subject: [PATCH] Updating Markdown to 1.0.1 - http://mosquito.wordpress.org/view.php?id=730 git-svn-id: http://svn.automattic.com/wordpress/trunk@2128 1a063a9b-81f0-0310-95a4-ce76da25c4cd --- wp-content/plugins/markdown.php | 603 +++++++++++++++++++++++++++----- 1 file changed, 514 insertions(+), 89 deletions(-) diff --git a/wp-content/plugins/markdown.php b/wp-content/plugins/markdown.php index 56d437484..de489d7bc 100644 --- a/wp-content/plugins/markdown.php +++ b/wp-content/plugins/markdown.php @@ -6,22 +6,19 @@ # Copyright (c) 2004 John Gruber # # -# Copyright (c) 2004 Michel Fortin - Translation to PHP +# Copyright (c) 2004 Michel Fortin - PHP Port # # -# This version has been modified for inclusion in WordPress -# For the original please see Michel's site - global $MarkdownPHPVersion, $MarkdownSyntaxVersion, $md_empty_element_suffix, $md_tab_width, $md_nested_brackets_depth, $md_nested_brackets, - $md_escape_table, $md_backslash_escape_table; + $md_escape_table, $md_backslash_escape_table, + $md_list_level; - -$MarkdownPHPVersion = '1.0'; # Sat 21 Aug 2004 -$MarkdownSyntaxVersion = '1.0'; # Fri 20 Aug 2004 +$MarkdownPHPVersion = '1.0.1'; # Fri 17 Dec 2004 +$MarkdownSyntaxVersion = '1.0.1'; # Sun 12 Dec 2004 # @@ -34,9 +31,9 @@ $md_tab_width = 4; # -- WordPress Plugin Interface ----------------------------------------------- /* Plugin Name: Markdown -Plugin URI: http://codex.wordpress.org/Plugin:Markdown +Plugin URI: http://www.michelf.com/projects/php-markdown/ Description: Markdown syntax allows you to write using an easy-to-read, easy-to-write plain text format. Based on the original Perl version by John Gruber. More... -Version: 1.0 +Version: 1.0.1 Author: Michel Fortin Author URI: http://www.michelf.com/ */ @@ -51,15 +48,56 @@ if (isset($wp_version)) { add_filter('comment_text', 'Markdown', 6); } + +# -- bBlog Plugin Info -------------------------------------------------------- +function identify_modifier_markdown() { + global $MarkdownPHPVersion; + return array( + 'name' => 'markdown', + 'type' => 'modifier', + 'nicename' => 'Markdown', + 'description' => 'A text-to-HTML conversion tool for web writers', + 'authors' => 'Michel Fortin and John Gruber', + 'licence' => 'GPL', + 'version' => $MarkdownPHPVersion, + 'help' => 'Markdown syntax allows you to write using an easy-to-read, easy-to-write plain text format. Based on the original Perl version by John Gruber. More...' + ); +} + +# -- Smarty Modifier Interface ------------------------------------------------ function smarty_modifier_markdown($text) { return Markdown($text); } +# -- Textile Compatibility Mode ----------------------------------------------- +# Rename this file to "classTextile.php" and it can replace Textile anywhere. +if (strcasecmp(substr(__FILE__, -16), "classTextile.php") == 0) { + # Try to include PHP SmartyPants. Should be in the same directory. + @include_once 'smartypants.php'; + # Fake Textile class. It calls Markdown instead. + class Textile { + function TextileThis($text, $lite='', $encode='', $noimage='', $strict='') { + if ($lite == '' && $encode == '') $text = Markdown($text); + if (function_exists('SmartyPants')) $text = SmartyPants($text); + return $text; + } + } +} + + + +# +# Globals: +# + +# Regex to match balanced [brackets]. +# Needed to insert a maximum bracked depth while converting to PHP. $md_nested_brackets_depth = 6; $md_nested_brackets = str_repeat('(?>[^\[\]]+|\[', $md_nested_brackets_depth). str_repeat('\])*', $md_nested_brackets_depth); +# Table of hash values for escaped characters: $md_escape_table = array( "\\" => md5("\\"), "`" => md5("`"), @@ -71,7 +109,10 @@ $md_escape_table = array( "]" => md5("]"), "(" => md5("("), ")" => md5(")"), + ">" => md5(">"), "#" => md5("#"), + "+" => md5("+"), + "-" => md5("-"), "." => md5("."), "!" => md5("!") ); @@ -82,25 +123,43 @@ foreach ($md_escape_table as $key => $char) function Markdown($text) { +# +# Main function. The order in which other subs are called here is +# essential. Link and image substitutions need to happen before +# _EscapeSpecialChars(), so that any *'s or _'s in the +# and tags get encoded. +# + # Clear the global hashes. If we don't clear these, you get conflicts + # from other articles when generating a page which contains more than + # one article (e.g. an index page that shows the N most recent + # articles): global $md_urls, $md_titles, $md_html_blocks; $md_urls = array(); $md_titles = array(); $md_html_blocks = array(); + # Standardize line endings: + # DOS to Unix and Mac to Unix $text = str_replace(array("\r\n", "\r"), "\n", $text); + # Make sure $text ends with a couple of newlines: $text .= "\n\n"; + # Convert all tabs to spaces. $text = _Detab($text); + # Strip any lines consisting only of spaces and tabs. + # This makes subsequent regexen easier to write, because we can + # match consecutive blank lines with /\n+/ instead of something + # contorted like /[ \t]*\n+/ . $text = preg_replace('/^[ \t]+$/m', '', $text); + # Turn block-level HTML blocks into hash entries $text = _HashHTMLBlocks($text); + # Strip link definitions, store in hashes. $text = _StripLinkDefinitions($text); - $text = _EscapeSpecialChars($text); - $text = _RunBlockGamut($text); $text = _UnescapeSpecialChars($text); @@ -110,8 +169,16 @@ function Markdown($text) { function _StripLinkDefinitions($text) { +# +# Strips link definitions from text, stores the URLs and titles in +# hash references. +# + global $md_tab_width; + $less_than_tab = $md_tab_width - 1; + + # Link defs are in the form: ^[id]: url "optional title" $text = preg_replace_callback('{ - ^[ \t]*\[(.+)\]: # id = $1 + ^[ ]{0,'.$less_than_tab.'}\[(.+)\]: # id = $1 [ \t]* \n? # maybe *one* newline [ \t]* @@ -120,7 +187,7 @@ function _StripLinkDefinitions($text) { \n? # maybe one newline [ \t]* (?: - # Todo: Titles are delimited by "quotes" or (parens). + (?<=\s) # lookbehind for whitespace ["(] (.+?) # title = $3 [")] @@ -137,17 +204,37 @@ function _StripLinkDefinitions_callback($matches) { $link_id = strtolower($matches[1]); $md_urls[$link_id] = _EncodeAmpsAndAngles($matches[2]); if (isset($matches[3])) - $md_titles[$link_id] = htmlentities($matches[3]); + $md_titles[$link_id] = str_replace('"', '"', $matches[3]); return ''; # String that will replace the block } function _HashHTMLBlocks($text) { + global $md_tab_width; + $less_than_tab = $md_tab_width - 1; + + # Hashify HTML blocks: + # We only want to do this for block-level HTML tags, such as headers, + # lists, and tables. That's because we still want to wrap

s around + # "paragraphs" that are wrapped in non-block-level tags, such as anchors, + # phrase emphasis, and spans. The list of tags we're looking for is + # hard-coded: $block_tags_a = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|'. 'script|noscript|form|fieldset|iframe|math|ins|del'; $block_tags_b = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|'. 'script|noscript|form|fieldset|iframe|math'; + # First, look for nested blocks, e.g.: + #

+ #
+ # tags for inner block must be indented. + #
+ #
+ # + # The outermost tags must start at the left margin for this to match, and + # the inner nested divs must be indented. + # We need to do this before the next, more liberal match, because the next + # match will start at the first `
` and stop at the first `
`. $text = preg_replace_callback("{ ( # save in $1 ^ # start of line (with /m) @@ -162,6 +249,9 @@ function _HashHTMLBlocks($text) { '_HashHTMLBlocks_callback', $text); + # + # Now match more liberally, simply from `\n` to `\n` + # $text = preg_replace_callback("{ ( # save in $1 ^ # start of line (with /m) @@ -176,6 +266,8 @@ function _HashHTMLBlocks($text) { '_HashHTMLBlocks_callback', $text); + # Special case just for
. It was easier to make a special case than + # to make the other regex more complicated. $text = preg_replace_callback('{ (?: (?<=\n\n) # Starting after a blank line @@ -183,17 +275,39 @@ function _HashHTMLBlocks($text) { \A\n? # the beginning of the doc ) ( # save in $1 - [ \t]* + [ ]{0,'.$less_than_tab.'} <(hr) # start tag = $2 \b # word break ([^<>])*? # /?> # the matching end tag + [ \t]* (?=\n{2,}|\Z) # followed by a blank line or end of document ) }x', '_HashHTMLBlocks_callback', $text); + # Special case for standalone HTML comments: + $text = preg_replace_callback('{ + (?: + (?<=\n\n) # Starting after a blank line + | # or + \A\n? # the beginning of the doc + ) + ( # save in $1 + [ ]{0,'.$less_than_tab.'} + (?s: + + ) + [ \t]* + (?=\n{2,}|\Z) # followed by a blank line or end of document + ) + }x', + '_HashHTMLBlocks_callback', + $text); + return $text; } function _HashHTMLBlocks_callback($matches) { @@ -206,15 +320,19 @@ function _HashHTMLBlocks_callback($matches) { function _RunBlockGamut($text) { +# +# These are all the transformations that form block-level +# tags like paragraphs, headers, and list items. +# global $md_empty_element_suffix; $text = _DoHeaders($text); # Do Horizontal Rules: $text = preg_replace( - array('/^( ?\* ?){3,}$/m', - '/^( ?- ?){3,}$/m', - '/^( ?_ ?){3,}$/m'), + array('{^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$}mx', + '{^[ ]{0,2}([ ]? -[ ]?){3,}[ \t]*$}mx', + '{^[ ]{0,2}([ ]? _[ ]?){3,}[ \t]*$}mx'), "\n` - $text = _DoAutoLinks($text); - + # We already ran _HashHTMLBlocks() before, in Markdown(), but that + # was to escape raw HTML in the original Markdown source. This time, + # we're escaping the markup we've just created, so that we don't wrap + #

tags around block-level tags. $text = _HashHTMLBlocks($text); $text = _FormParagraphs($text); @@ -236,20 +355,32 @@ function _RunBlockGamut($text) { function _RunSpanGamut($text) { +# +# These are all the transformations that occur *within* block-level +# tags like paragraphs, headers, and list items. +# global $md_empty_element_suffix; + $text = _DoCodeSpans($text); - # Fix unencoded ampersands and <'s: - $text = _EncodeAmpsAndAngles($text); + $text = _EscapeSpecialChars($text); # Process anchor and image tags. Images must come first, # because ![foo][f] looks like an anchor. $text = _DoImages($text); $text = _DoAnchors($text); + # Make links out of things like `` + # Must come after _DoAnchors(), because you can use < and > + # delimiters in inline links like [this](). + $text = _DoAutoLinks($text); + + # Fix unencoded ampersands and <'s: + $text = _EncodeAmpsAndAngles($text); $text = _DoItalicsAndBold($text); + # Do hard breaks: $text = preg_replace('/ {2,}\n/', " or tags. +# $tags_to_skip = "!<(/?)(?:pre|code|kbd|script|math)[\s>]!"; + foreach ($tokens as $cur_token) { if ($cur_token[0] == 'tag') { + # Within tags, encode * and _ so they don't conflict + # with their use in Markdown for italics and strong. + # We're replacing each such character with its + # corresponding MD5 checksum value; this is likely + # overkill, but it should prevent us from colliding + # with the escape values by accident. $cur_token[1] = str_replace(array('*', '_'), array($md_escape_table['*'], $md_escape_table['_']), $cur_token[1]); @@ -278,6 +418,9 @@ function _EscapeSpecialChars($text) { function _DoAnchors($text) { +# +# Turn Markdown link shortcuts into XHTML tags. +# global $md_nested_brackets; # # First, handle reference-style links: [link text] [id] @@ -298,6 +441,9 @@ function _DoAnchors($text) { }xs", '_DoAnchors_reference_callback', $text); + # + # Next, inline-style links: [link text](url "optional title") + # $text = preg_replace_callback("{ ( # wrap whole match in $1 \\[ @@ -305,7 +451,7 @@ function _DoAnchors($text) { \\] \\( # literal paren [ \\t]* - ? # href = $3 + ? # href = $3 [ \\t]* ( # $4 (['\"]) # quote char = $5 @@ -352,10 +498,10 @@ function _DoAnchors_reference_callback($matches) { } function _DoAnchors_inline_callback($matches) { global $md_escape_table; - $whole_match = $matches[1]; - $link_text = $matches[2]; - $url = $matches[3]; - $title = $matches[6]; + $whole_match = $matches[1]; + $link_text = $matches[2]; + $url = $matches[3]; + $title =& $matches[6]; # We've got to encode these to avoid conflicting with italics/bold. $url = str_replace(array('*', '_'), @@ -363,7 +509,7 @@ function _DoAnchors_inline_callback($matches) { $url); $result = " tags. +# + # + # First, handle reference-style labeled images: ![alt text][id] + # $text = preg_replace_callback('{ ( # wrap whole match in $1 !\[ @@ -456,12 +608,12 @@ function _DoImages_reference_callback($matches) { } function _DoImages_inline_callback($matches) { global $md_empty_element_suffix, $md_escape_table; - $whole_match = $matches[1]; - $alt_text = $matches[2]; - $url = $matches[3]; - $title = ''; + $whole_match = $matches[1]; + $alt_text = $matches[2]; + $url = $matches[3]; + $title = ''; if (isset($matches[6])) { - $title = $matches[6]; + $title = $matches[6]; } $alt_text = str_replace('"', '"', $alt_text); @@ -484,13 +636,27 @@ function _DoImages_inline_callback($matches) { function _DoHeaders($text) { + # Setext-style headers: + # Header 1 + # ======== + # + # Header 2 + # -------- + # $text = preg_replace( - array("/(.+)[ \t]*\n=+[ \t]*\n+/e", - "/(.+)[ \t]*\n-+[ \t]*\n+/e"), + array('{ ^(.+)[ \t]*\n=+[ \t]*\n+ }emx', + '{ ^(.+)[ \t]*\n-+[ \t]*\n+ }emx'), array("'

'._RunSpanGamut(_UnslashQuotes('\\1')).'

\n\n'", "'

'._RunSpanGamut(_UnslashQuotes('\\1')).'

\n\n'"), $text); + # atx-style headers: + # # Header 1 + # ## Header 2 + # ## Header 2 with closing hashes ## + # ... + # ###### Header 6 + # $text = preg_replace("{ ^(\\#{1,6}) # $1 = string of #'s [ \\t]* @@ -510,7 +676,7 @@ function _DoLists($text) { # # Form HTML ordered (numbered) and unordered (bulleted) lists. # - global $md_tab_width; + global $md_tab_width, $md_list_level; $less_than_tab = $md_tab_width - 1; # Re-usable patterns to match list item bullets and number markers: @@ -518,27 +684,45 @@ function _DoLists($text) { $marker_ol = '\d+[.]'; $marker_any = "(?:$marker_ul|$marker_ol)"; - $text = preg_replace_callback("{ - ( # $1 - ( # $2 - ^[ ]{0,$less_than_tab} - ($marker_any) # $3 - first list item marker - [ \\t]+ + # Re-usable pattern to match any entirel ul or ol list: + $whole_list = ' + ( # $1 = whole list + ( # $2 + [ ]{0,'.$less_than_tab.'} + ('.$marker_any.') # $3 = first list item marker + [ \t]+ + ) + (?s:.+?) + ( # $4 + \z + | + \n{2,} + (?=\S) + (?! # Negative lookahead for another list item marker + [ \t]* + '.$marker_any.'[ \t]+ ) - (?s:.+?) - ( # $4 - \\z - | - \\n{2,} - (?=\\S) - (?! # Negative lookahead for another list item marker - [ \\t]* - {$marker_any}[ \\t]+ - ) - ) - ) - }xm", - '_DoLists_callback', $text); + ) + ) + '; // mx + + # We use a different prefix before nested lists than top-level lists. + # See extended comment in _ProcessListItems(). + + if ($md_list_level) { + $text = preg_replace_callback('{ + ^ + '.$whole_list.' + }mx', + '_DoLists_callback', $text); + } + else { + $text = preg_replace_callback('{ + (?:(?<=\n\n)|\A\n?) + '.$whole_list.' + }mx', + '_DoLists_callback', $text); + } return $text; } @@ -549,17 +733,46 @@ function _DoLists_callback($matches) { $marker_any = "(?:$marker_ul|$marker_ol)"; $list = $matches[1]; - $list_type = preg_match('/[*+-]/', $matches[3]) ? "ul" : "ol"; + $list_type = preg_match("/$marker_ul/", $matches[3]) ? "ul" : "ol"; # Turn double returns into triple returns, so that we can make a # paragraph for the last item in a list, if necessary: $list = preg_replace("/\n{2,}/", "\n\n\n", $list); $result = _ProcessListItems($list, $marker_any); - $result = "<$list_type>\n" . $result . "\n\n"; + $result = "<$list_type>\n" . $result . "\n"; return $result; } function _ProcessListItems($list_str, $marker_any) { +# +# Process the contents of a single ordered or unordered list, splitting it +# into individual list items. +# + global $md_list_level; + + # The $md_list_level global keeps track of when we're inside a list. + # Each time we enter a list, we increment it; when we leave a list, + # we decrement. If it's zero, we're not in a list anymore. + # + # We do this because when we're not inside a list, we want to treat + # something like this: + # + # I recommend upgrading to version + # 8. Oops, now this line is treated + # as a sub-list. + # + # As a single paragraph, despite the fact that the second line starts + # with a digit-period-space sequence. + # + # Whereas when we're inside a list (or sub-list), that line will be + # treated as the start of a sub-list. What a kludge, huh? This is + # an aspect of Markdown's syntax that's hard to parse perfectly + # without resorting to mind-reading. Perhaps the solution is to + # change the syntax rules such that sub-lists must start with a + # starting cardinal number; e.g. "1." or "a.". + + $md_list_level++; + # trim trailing blank lines: $list_str = preg_replace("/\n{2,}\\z/", "\n", $list_str); @@ -573,16 +786,16 @@ function _ProcessListItems($list_str, $marker_any) { }xm', '_ProcessListItems_callback', $list_str); + $md_list_level--; return $list_str; } function _ProcessListItems_callback($matches) { $item = $matches[4]; - $leading_line = $matches[1]; - $leading_space = $matches[2]; + $leading_line =& $matches[1]; + $leading_space =& $matches[2]; if ($leading_line || preg_match('/\n{2,}/', $item)) { $item = _RunBlockGamut(_Outdent($item)); - #$item =~ s/\n+/\n/g; } else { # Recursion for sub-lists: @@ -596,6 +809,9 @@ function _ProcessListItems_callback($matches) { function _DoCodeBlocks($text) { +# +# Process Markdown `
` blocks.
+#
 	global $md_tab_width;
 	$text = preg_replace_callback("{
 			(?:\\n\\n|\\A)
@@ -615,7 +831,7 @@ function _DoCodeBlocks_callback($matches) {
 	$codeblock = $matches[1];
 
 	$codeblock = _EncodeCode(_Outdent($codeblock));
-	$codeblock = _Detab($codeblock);
+//	$codeblock = _Detab($codeblock);
 	# trim leading newlines and trailing whitespace
 	$codeblock = preg_replace(array('/\A\n+/', '/\s+\z/'), '', $codeblock);
 
@@ -626,6 +842,30 @@ function _DoCodeBlocks_callback($matches) {
 
 
 function _DoCodeSpans($text) {
+#
+# 	*	Backtick quotes are used for  spans.
+#
+# 	*	You can use multiple backticks as the delimiters if you want to
+# 		include literal backticks in the code span. So, this input:
+#
+#		  Just type ``foo `bar` baz`` at the prompt.
+#
+#	  	Will translate to:
+#
+#		  
Just type foo `bar` baz at the prompt.

+#
+#		There's no arbitrary limit to the number of backticks you
+#		can use as delimters. If you need three consecutive backticks
+#		in your code, use four for delimiters, etc.
+#
+#	*	You can use spaces to get literal backticks at the edges:
+#
+#		  ... type `` `bar` `` ...
+#
+#	  	Turns to:
+#
+#		  ... type `bar` ...
+#
 	$text = preg_replace_callback("@
 			(`+)		# $1 = Opening run of `
 			(.+?)		# $2 = The code block
@@ -647,13 +887,22 @@ function _DoCodeSpans_callback($matches) {
 
 
 function _EncodeCode($_) {
+#
+# Encode/escape certain characters inside Markdown code runs.
+# The point is that in code, these characters are literals,
+# and lose their special Markdown meanings.
+#
 	global $md_escape_table;
 
+	# Encode all ampersands; HTML entities are not
+	# entities within a Markdown code span.
 	$_ = str_replace('&', '&', $_);
 
+	# Do the angle bracket song and dance:
 	$_ = str_replace(array('<',    '>'), 
 					 array('<', '>'), $_);
 
+	# Now, escape characters that are magic in Markdown:
 	$_ = str_replace(array_keys($md_escape_table), 
 					 array_values($md_escape_table), $_);
 
@@ -663,7 +912,7 @@ function _EncodeCode($_) {
 
 function _DoItalicsAndBold($text) {
 	#  must go first:
-	$text = preg_replace('{ (\*\*|__) (?=\S) (.+?) (?<=\S) \1 }sx',
+	$text = preg_replace('{ (\*\*|__) (?=\S) (.+?[*_]*) (?<=\S) \1 }sx',
 		'\2', $text);
 	# Then :
 	$text = preg_replace('{ (\*|_) (?=\S) (.+?) (?<=\S) \1 }sx',
@@ -709,14 +958,20 @@ function _DoBlockQuotes_callback2($matches) {
 
 
 function _FormParagraphs($text) {
+#
+#	Params:
+#		$text - string to process with html 
 tags
+#
 	global $md_html_blocks;
 
 	# Strip leading and trailing lines:
 	$text = preg_replace(array('/\A\n+/', '/\n+\z/'), '', $text);
 
 	$grafs = preg_split('/\n{2,}/', $text, -1, PREG_SPLIT_NO_EMPTY);
-	$count = count($grafs);
 
+	#
+	# Wrap 
 tags.
+	#
 	foreach ($grafs as $key => $value) {
 		if (!isset( $md_html_blocks[$value] )) {
 			$value = _RunSpanGamut($value);
@@ -726,6 +981,9 @@ function _FormParagraphs($text) {
 		}
 	}
 
+	#
+	# Unhashify HTML blocks
+	#
 	foreach ($grafs as $key => $value) {
 		if (isset( $md_html_blocks[$value] )) {
 			$grafs[$key] = $md_html_blocks[$value];
@@ -737,6 +995,10 @@ function _FormParagraphs($text) {
 
 
 function _EncodeAmpsAndAngles($text) {
+# Smart processing for ampersands and angle brackets that need to be encoded.
+
+	# Ampersand-encoding based entirely on Nat Irons's Amputator MT plugin:
+	#   http://bumppo.net/projects/amputator/
 	$text = preg_replace('/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/', 
 						 '&', $text);;
 
@@ -748,6 +1010,11 @@ function _EncodeAmpsAndAngles($text) {
 
 
 function _EncodeBackslashEscapes($text) {
+#
+#	Parameter:  String.
+#	Returns:    The string, with after processing the following backslash
+#				escape sequences.
+#
 	global $md_escape_table, $md_backslash_escape_table;
 	# Must process escaped backslashes first.
 	return str_replace(array_keys($md_backslash_escape_table),
@@ -762,6 +1029,7 @@ function _DoAutoLinks($text) {
 	# Email addresses: 
 	$text = preg_replace('{
 		<
+        (?:mailto:)?
 		(
 			[-.\w]+
 			\@
@@ -777,6 +1045,20 @@ function _DoAutoLinks($text) {
 
 
 function _EncodeEmailAddress($addr) {
+#
+#	Input: an email address, e.g. "foo@example.com"
+#
+#	Output: the email address as a mailto link, with each character
+#		of the address encoded as either a decimal or hex entity, in
+#		the hopes of foiling most address harvesting spam bots. E.g.:
+#
+#	  foo
+#		@example.com
+#
+#	Based by a filter by Matthew Wickline, posted to the BBEdit-Talk
+#	mailing list: 
+#
 	$addr = "mailto:" . $addr;
 	$length = strlen($addr);
 
@@ -802,56 +1084,199 @@ function _EncodeEmailAddress_callback($matches) {
 
 
 function _UnescapeSpecialChars($text) {
+#
+# Swap back in all the special characters we've hidden.
+#
 	global $md_escape_table;
 	return str_replace(array_values($md_escape_table), 
 					   array_keys($md_escape_table), $text);
 }
 
 
-if (!function_exists('_TokenizeHTML')) {
-	function _TokenizeHTML($str) {
-		$index = 0;
-		$tokens = array();
+# _TokenizeHTML is shared between PHP Markdown and PHP SmartyPants.
+# We only define it if it is not already defined.
+if (!function_exists('_TokenizeHTML')) :
+function _TokenizeHTML($str) {
+#
+#   Parameter:  String containing HTML markup.
+#   Returns:    An array of the tokens comprising the input
+#               string. Each token is either a tag (possibly with nested,
+#               tags contained therein, such as , or a
+#               run of text between tags. Each element of the array is a
+#               two-element array; the first is either 'tag' or 'text';
+#               the second is the actual value.
+#
+#
+#   Regular expression derived from the _tokenize() subroutine in 
+#   Brad Choate's MTRegex plugin.
+#   
+#
+	$index = 0;
+	$tokens = array();
 
-		$depth = 6;
-		$nested_tags = str_repeat('(?:<[a-z\/!$](?:[^<>]|',$depth)
-					   .str_repeat(')*>)', $depth);
-		$match = "(?s:)|".  # comment
-				 "(?s:<\?.*?\?>)|".         # processing instruction
-				 "$nested_tags";            # nested tags
+	$match = '(?s:)|'.	# comment
+			 '(?s:<\?.*?\?>)|'.				# processing instruction
+			 '(?:[^"\'>]+|"[^"]*"|\'[^\']*\')*>)'; # regular tags
 
-		$parts = preg_split("/($match)/", $str, -1, PREG_SPLIT_DELIM_CAPTURE);
+	$parts = preg_split("{($match)}", $str, -1, PREG_SPLIT_DELIM_CAPTURE);
 
-		foreach ($parts as $part) {
-			if (++$index % 2 && $part != '') 
-				array_push($tokens, array('text', $part));
-			else
-				array_push($tokens, array('tag', $part));
-		}
-
-		return $tokens;
+	foreach ($parts as $part) {
+		if (++$index % 2 && $part != '') 
+			array_push($tokens, array('text', $part));
+		else
+			array_push($tokens, array('tag', $part));
 	}
+
+	return $tokens;
 }
+endif;
 
 
 function _Outdent($text) {
+#
+# Remove one level of line-leading tabs or spaces
+#
 	global $md_tab_width;
 	return preg_replace("/^(\\t|[ ]{1,$md_tab_width})/m", "", $text);
 }
 
 
 function _Detab($text) {
+#
+# Replace tabs with the appropriate amount of space.
+#
 	global $md_tab_width;
-	$text = preg_replace(
-		"/(.*?)\t/e",
-		"'\\1'.str_repeat(' ', $md_tab_width - strlen('\\1') % $md_tab_width)",
-		$text);
+
+	# For each line we separate the line in blocks delemited by
+	# tab characters. Then we reconstruct the line adding the appropriate
+	# number of space charcters.
+	
+	$lines = explode("\n", $text);
+	$text = "";
+	
+	foreach ($lines as $line) {
+		# Split in blocks.
+		$blocks = explode("\t", $line);
+		# Add each blocks to the line.
+		$line = $blocks[0];
+		unset($blocks[0]); # Do not add first block twice.
+		foreach ($blocks as $block) {
+			# Calculate amount of space, insert spaces, insert block.
+			$amount = $md_tab_width - strlen($line) % $md_tab_width;
+			$line .= str_repeat(" ", $amount) . $block;
+		}
+		$text .= "$line\n";
+	}
 	return $text;
 }
 
 
 function _UnslashQuotes($text) {
+#
+#	This function is useful to remove automaticaly slashed double quotes
+#	when using preg_replace and evaluating an expression.
+#	Parameter:  String.
+#	Returns:    The string with any slash-double-quote (\") sequence replaced
+#				by a single double quote.
+#
 	return str_replace('\"', '"', $text);
 }
 
+
+/*
+
+PHP Markdown
+============
+
+Description
+-----------
+
+This is a PHP translation of the original Markdown formatter written in
+Perl by John Gruber.
+
+Markdown is a text-to-HTML filter; it translates an easy-to-read /
+easy-to-write structured text format into HTML. Markdown's text format
+is most similar to that of plain text email, and supports features such
+as headers, *emphasis*, code blocks, blockquotes, and links.
+
+Markdown's syntax is designed not as a generic markup language, but
+specifically to serve as a front-end to (X)HTML. You can use span-level
+HTML tags anywhere in a Markdown document, and you can use block level
+HTML tags (like 
 and  as well).
+
+For more information about Markdown's syntax, see:
+
+
+
+
+Bugs
+----
+
+To file bug reports please send email to:
+
+
+
+Please include with your report: (1) the example input; (2) the output you
+expected; (3) the output Markdown actually produced.
+
+
+Version History
+--------------- 
+
+See the readme file for detailed release notes for this version.
+
+1.0.1 - 17 Dec 2004
+
+1.0 - 21 Aug 2004
+
+
+Author & Contributors
+---------------------
+
+Original Perl version by John Gruber  
+
+
+PHP port and other contributions by Michel Fortin  
+
+
+
+Copyright and License
+---------------------
+
+Copyright (c) 2004 Michel Fortin  
+  
+All rights reserved.
+
+Copyright (c) 2003-2004 John Gruber   
+   
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+*	Redistributions of source code must retain the above copyright notice,
+	this list of conditions and the following disclaimer.
+
+*	Redistributions in binary form must reproduce the above copyright
+	notice, this list of conditions and the following disclaimer in the
+	documentation and/or other materials provided with the distribution.
+
+*	Neither the name "Markdown" nor the names of its contributors may
+	be used to endorse or promote products derived from this software
+	without specific prior written permission.
+
+This software is provided by the copyright holders and contributors "as
+is" and any express or implied warranties, including, but not limited
+to, the implied warranties of merchantability and fitness for a
+particular purpose are disclaimed. In no event shall the copyright owner
+or contributors be liable for any direct, indirect, incidental, special,
+exemplary, or consequential damages (including, but not limited to,
+procurement of substitute goods or services; loss of use, data, or
+profits; or business interruption) however caused and on any theory of
+liability, whether in contract, strict liability, or tort (including
+negligence or otherwise) arising in any way out of the use of this
+software, even if advised of the possibility of such damage.
+
+*/
 ?>
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