:arrow_up: :hammer: Upgrade PHP Markdown library.

The current version throws deprecated warning with PHP7.1 and PHPUnit.
Upgrade the Markdown library to the current PHP Markdown Lib 1.7.0.
Used composer to manage this library.

1 files changed, 1896 insertions, 0 deletions

diff --git a/vendor/michelf/php-markdown/Michelf/Markdown.php b/vendor/michelf/php-markdown/Michelf/Markdown.php
new file mode 100644
index 000000000..c3eaf4464
--- /dev/null
+++ b/vendor/michelf/php-markdown/Michelf/Markdown.php
@@ -0,0 +1,1896 @@
+<?php
+/**
+ * Markdown  -  A text-to-HTML conversion tool for web writers
+ *
+ * @package   php-markdown
+ * @author    Michel Fortin <michel.fortin@michelf.com>
+ * @copyright 2004-2016 Michel Fortin <https://michelf.com/projects/php-markdown/>
+ * @copyright (Original Markdown) 2004-2006 John Gruber <https://daringfireball.net/projects/markdown/>
+ */
+
+namespace Michelf;
+
+/**
+ * Markdown Parser Class
+ */
+class Markdown implements MarkdownInterface {
+	/**
+	 * Define the package version
+	 * @var string
+	 */
+	const MARKDOWNLIB_VERSION = "1.7.0";
+
+	/**
+	 * Simple function interface - Initialize the parser and return the result
+	 * of its transform method. This will work fine for derived classes too.
+	 *
+	 * @api
+	 *
+	 * @param  string $text
+	 * @return string
+	 */
+	public static function defaultTransform($text) {
+		// Take parser class on which this function was called.
+		$parser_class = \get_called_class();
+
+		// Try to take parser from the static parser list
+		static $parser_list;
+		$parser =& $parser_list[$parser_class];
+
+		// Create the parser it not already set
+		if (!$parser) {
+			$parser = new $parser_class;
+		}
+
+		// Transform text using parser.
+		return $parser->transform($text);
+	}
+
+	/**
+	 * Configuration variables
+	 */
+
+	/**
+	 * Change to ">" for HTML output.
+	 * @var string
+	 */
+	public $empty_element_suffix = " />";
+
+	/**
+	 * The width of indentation of the output markup
+	 * @var int
+	 */
+	public $tab_width = 4;
+	
+	/**
+	 * Change to `true` to disallow markup or entities.
+	 * @var boolean
+	 */
+	public $no_markup   = false;
+	public $no_entities = false;
+	
+
+	/**
+	 * Change to `true` to enable line breaks on \n without two trailling spaces
+	 * @var boolean
+	 */
+	public $hard_wrap = false;
+
+	/**
+	 * Predefined URLs and titles for reference links and images.
+	 * @var array
+	 */
+	public $predef_urls   = array();
+	public $predef_titles = array();
+
+	/**
+	 * Optional filter function for URLs
+	 * @var callable
+	 */
+	public $url_filter_func = null;
+
+	/**
+	 * Optional header id="" generation callback function.
+	 * @var callable
+	 */
+	public $header_id_func = null;
+	
+	/**
+	 * Optional function for converting code block content to HTML
+	 * @var callable
+	 */
+	public $code_block_content_func = null;
+
+	/**
+	 * Optional function for converting code span content to HTML.
+	 * @var callable
+	 */
+	public $code_span_content_func = null;
+
+	/**
+	 * Class attribute to toggle "enhanced ordered list" behaviour
+	 * setting this to true will allow ordered lists to start from the index
+	 * number that is defined first.
+	 * 
+	 * For example:
+	 * 2. List item two
+	 * 3. List item three
+	 *
+	 * Becomes:
+	 * <ol start="2">
+	 * <li>List item two</li>
+	 * <li>List item three</li>
+	 * </ol>
+	 *
+	 * @var bool
+	 */
+	public $enhanced_ordered_list = false;
+
+	/**
+	 * Parser implementation
+	 */
+
+	/**
+	 * Regex to match balanced [brackets].
+	 * Needed to insert a maximum bracked depth while converting to PHP.
+	 * @var int
+	 */
+	protected $nested_brackets_depth = 6;
+	protected $nested_brackets_re;
+
+	protected $nested_url_parenthesis_depth = 4;
+	protected $nested_url_parenthesis_re;
+
+	/**
+	 * Table of hash values for escaped characters:
+	 * @var string
+	 */
+	protected $escape_chars = '\`*_{}[]()>#+-.!';
+	protected $escape_chars_re;
+
+	/**
+	 * Constructor function. Initialize appropriate member variables.
+	 * @return void
+	 */
+	public function __construct() {
+		$this->_initDetab();
+		$this->prepareItalicsAndBold();
+	
+		$this->nested_brackets_re = 
+			str_repeat('(?>[^\[\]]+|\[', $this->nested_brackets_depth).
+			str_repeat('\])*', $this->nested_brackets_depth);
+	
+		$this->nested_url_parenthesis_re = 
+			str_repeat('(?>[^()\s]+|\(', $this->nested_url_parenthesis_depth).
+			str_repeat('(?>\)))*', $this->nested_url_parenthesis_depth);
+		
+		$this->escape_chars_re = '['.preg_quote($this->escape_chars).']';
+		
+		// Sort document, block, and span gamut in ascendent priority order.
+		asort($this->document_gamut);
+		asort($this->block_gamut);
+		asort($this->span_gamut);
+	}
+
+
+	/**
+	 * Internal hashes used during transformation.
+	 * @var array
+	 */
+	protected $urls        = array();
+	protected $titles      = array();
+	protected $html_hashes = array();
+	
+	/**
+	 * Status flag to avoid invalid nesting.
+	 * @var boolean
+	 */
+	protected $in_anchor = false;
+	
+	/**
+	 * Called before the transformation process starts to setup parser states.
+	 * @return void
+	 */
+	protected function setup() {
+		// Clear global hashes.
+		$this->urls        = $this->predef_urls;
+		$this->titles      = $this->predef_titles;
+		$this->html_hashes = array();
+		$this->in_anchor   = false;
+	}
+	
+	/**
+	 * Called after the transformation process to clear any variable which may
+	 * be taking up memory unnecessarly.
+	 * @return void
+	 */
+	protected function teardown() {
+		$this->urls        = array();
+		$this->titles      = array();
+		$this->html_hashes = array();
+	}
+
+	/**
+	 * Main function. Performs some preprocessing on the input text and pass
+	 * it through the document gamut.
+	 *
+	 * @api
+	 *
+	 * @param  string $text
+	 * @return string
+	 */
+	public function transform($text) {
+		$this->setup();
+	
+		# Remove UTF-8 BOM and marker character in input, if present.
+		$text = preg_replace('{^\xEF\xBB\xBF|\x1A}', '', $text);
+
+		# Standardize line endings:
+		#   DOS to Unix and Mac to Unix
+		$text = preg_replace('{\r\n?}', "\n", $text);
+
+		# Make sure $text ends with a couple of newlines:
+		$text .= "\n\n";
+
+		# Convert all tabs to spaces.
+		$text = $this->detab($text);
+
+		# Turn block-level HTML blocks into hash entries
+		$text = $this->hashHTMLBlocks($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 /[ ]*\n+/ .
+		$text = preg_replace('/^[ ]+$/m', '', $text);
+
+		# Run document gamut methods.
+		foreach ($this->document_gamut as $method => $priority) {
+			$text = $this->$method($text);
+		}
+		
+		$this->teardown();
+
+		return $text . "\n";
+	}
+
+	/**
+	 * Define the document gamut
+	 * @var array
+	 */
+	protected $document_gamut = array(
+		// Strip link definitions, store in hashes.
+		"stripLinkDefinitions" => 20,
+		"runBasicBlockGamut"   => 30,
+	);
+
+	/**
+	 * Strips link definitions from text, stores the URLs and titles in
+	 * hash references
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function stripLinkDefinitions($text) {
+	
+		$less_than_tab = $this->tab_width - 1;
+
+		// Link defs are in the form: ^[id]: url "optional title"
+		$text = preg_replace_callback('{
+							^[ ]{0,'.$less_than_tab.'}\[(.+)\][ ]?:	# id = $1
+							  [ ]*
+							  \n?				# maybe *one* newline
+							  [ ]*
+							(?:
+							  <(.+?)>			# url = $2
+							|
+							  (\S+?)			# url = $3
+							)
+							  [ ]*
+							  \n?				# maybe one newline
+							  [ ]*
+							(?:
+								(?<=\s)			# lookbehind for whitespace
+								["(]
+								(.*?)			# title = $4
+								[")]
+								[ ]*
+							)?	# title is optional
+							(?:\n+|\Z)
+			}xm',
+			array($this, '_stripLinkDefinitions_callback'),
+			$text
+		);
+		return $text;
+	}
+
+	/**
+	 * The callback to strip link definitions
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _stripLinkDefinitions_callback($matches) {
+		$link_id = strtolower($matches[1]);
+		$url = $matches[2] == '' ? $matches[3] : $matches[2];
+		$this->urls[$link_id] = $url;
+		$this->titles[$link_id] =& $matches[4];
+		return ''; // String that will replace the block
+	}
+
+	/**
+	 * Hashify HTML blocks
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function hashHTMLBlocks($text) {
+		if ($this->no_markup) {
+			return $text;
+		}
+
+		$less_than_tab = $this->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 <p>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:
+		 *
+		 * *  List "a" is made of tags which can be both inline or block-level.
+		 *    These will be treated block-level when the start tag is alone on 
+		 *    its line, otherwise they're not matched here and will be taken as 
+		 *    inline later.
+		 * *  List "b" is made of tags which are always block-level;
+		 */
+		$block_tags_a_re = 'ins|del';
+		$block_tags_b_re = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|address|'.
+						   'script|noscript|style|form|fieldset|iframe|math|svg|'.
+						   'article|section|nav|aside|hgroup|header|footer|'.
+						   'figure';
+
+		// Regular expression for the content of a block tag.
+		$nested_tags_level = 4;
+		$attr = '
+			(?>				# optional tag attributes
+			  \s			# starts with whitespace
+			  (?>
+				[^>"/]+		# text outside quotes
+			  |
+				/+(?!>)		# slash not followed by ">"
+			  |
+				"[^"]*"		# text inside double quotes (tolerate ">")
+			  |
+				\'[^\']*\'	# text inside single quotes (tolerate ">")
+			  )*
+			)?	
+			';
+		$content =
+			str_repeat('
+				(?>
+				  [^<]+			# content without tag
+				|
+				  <\2			# nested opening tag
+					'.$attr.'	# attributes
+					(?>
+					  />
+					|
+					  >', $nested_tags_level).	// end of opening tag
+					  '.*?'.					// last level nested tag content
+			str_repeat('
+					  </\2\s*>	# closing nested tag
+					)
+				  |				
+					<(?!/\2\s*>	# other tags with a different name
+				  )
+				)*',
+				$nested_tags_level);
+		$content2 = str_replace('\2', '\3', $content);
+
+		/**
+		 * First, look for nested blocks, e.g.:
+		 * 	<div>
+		 * 		<div>
+		 * 		tags for inner block must be indented.
+		 * 		</div>
+		 * 	</div>
+		 *
+		 * 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 `<div>` and stop at the
+		 * first `</div>`.
+		 */
+		$text = preg_replace_callback('{(?>
+			(?>
+				(?<=\n)			# Starting on its own line
+				|				# or
+				\A\n?			# the at beginning of the doc
+			)
+			(						# save in $1
+
+			  # Match from `\n<tag>` to `</tag>\n`, handling nested tags 
+			  # in between.
+					
+						[ ]{0,'.$less_than_tab.'}
+						<('.$block_tags_b_re.')# start tag = $2
+						'.$attr.'>			# attributes followed by > and \n
+						'.$content.'		# content, support nesting
+						</\2>				# the matching end tag
+						[ ]*				# trailing spaces/tabs
+						(?=\n+|\Z)	# followed by a newline or end of document
+
+			| # Special version for tags of group a.
+
+						[ ]{0,'.$less_than_tab.'}
+						<('.$block_tags_a_re.')# start tag = $3
+						'.$attr.'>[ ]*\n	# attributes followed by >
+						'.$content2.'		# content, support nesting
+						</\3>				# the matching end tag
+						[ ]*				# trailing spaces/tabs
+						(?=\n+|\Z)	# followed by a newline or end of document
+					
+			| # Special case just for <hr />. It was easier to make a special 
+			  # case than to make the other regex more complicated.
+			
+						[ ]{0,'.$less_than_tab.'}
+						<(hr)				# start tag = $2
+						'.$attr.'			# attributes
+						/?>					# the matching end tag
+						[ ]*
+						(?=\n{2,}|\Z)		# followed by a blank line or end of document
+			
+			| # Special case for standalone HTML comments:
+			
+					[ ]{0,'.$less_than_tab.'}
+					(?s:
+						<!-- .*? -->
+					)
+					[ ]*
+					(?=\n{2,}|\Z)		# followed by a blank line or end of document
+			
+			| # PHP and ASP-style processor instructions (<? and <%)
+			
+					[ ]{0,'.$less_than_tab.'}
+					(?s:
+						<([?%])			# $2
+						.*?
+						\2>
+					)
+					[ ]*
+					(?=\n{2,}|\Z)		# followed by a blank line or end of document
+					
+			)
+			)}Sxmi',
+			array($this, '_hashHTMLBlocks_callback'),
+			$text
+		);
+
+		return $text;
+	}
+
+	/**
+	 * The callback for hashing HTML blocks
+	 * @param  string $matches
+	 * @return string
+	 */
+	protected function _hashHTMLBlocks_callback($matches) {
+		$text = $matches[1];
+		$key  = $this->hashBlock($text);
+		return "\n\n$key\n\n";
+	}
+	
+	/**
+	 * Called whenever a tag must be hashed when a function insert an atomic 
+	 * element in the text stream. Passing $text to through this function gives
+	 * a unique text-token which will be reverted back when calling unhash.
+	 *
+	 * The $boundary argument specify what character should be used to surround
+	 * the token. By convension, "B" is used for block elements that needs not
+	 * to be wrapped into paragraph tags at the end, ":" is used for elements
+	 * that are word separators and "X" is used in the general case.
+	 *
+	 * @param  string $text
+	 * @param  string $boundary
+	 * @return string
+	 */
+	protected function hashPart($text, $boundary = 'X') {
+		// Swap back any tag hash found in $text so we do not have to `unhash`
+		// multiple times at the end.
+		$text = $this->unhash($text);
+		
+		// Then hash the block.
+		static $i = 0;
+		$key = "$boundary\x1A" . ++$i . $boundary;
+		$this->html_hashes[$key] = $text;
+		return $key; // String that will replace the tag.
+	}
+
+	/**
+	 * Shortcut function for hashPart with block-level boundaries.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function hashBlock($text) {
+		return $this->hashPart($text, 'B');
+	}
+
+	/**
+	 * Define the block gamut - these are all the transformations that form
+	 * block-level tags like paragraphs, headers, and list items.
+	 * @var array
+	 */
+	protected $block_gamut = array(
+		"doHeaders"         => 10,
+		"doHorizontalRules" => 20,
+		"doLists"           => 40,
+		"doCodeBlocks"      => 50,
+		"doBlockQuotes"     => 60,
+	);
+
+	/**
+	 * Run block gamut tranformations.
+	 *
+	 * We need to escape raw HTML in Markdown source before doing anything 
+	 * else. This need to be done for each block, and not only at the 
+	 * begining in the Markdown function since hashed blocks can be part of
+	 * list items and could have been indented. Indented blocks would have 
+	 * been seen as a code block in a previous pass of hashHTMLBlocks.
+	 *
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function runBlockGamut($text) {
+		$text = $this->hashHTMLBlocks($text);
+		return $this->runBasicBlockGamut($text);
+	}
+
+	/**
+	 * Run block gamut tranformations, without hashing HTML blocks. This is 
+	 * useful when HTML blocks are known to be already hashed, like in the first
+	 * whole-document pass.
+	 *
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function runBasicBlockGamut($text) {
+	
+		foreach ($this->block_gamut as $method => $priority) {
+			$text = $this->$method($text);
+		}
+		
+		// Finally form paragraph and restore hashed blocks.
+		$text = $this->formParagraphs($text);
+
+		return $text;
+	}
+
+	/**
+	 * Convert horizontal rules
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doHorizontalRules($text) {
+		return preg_replace(
+			'{
+				^[ ]{0,3}	# Leading space
+				([-*_])		# $1: First marker
+				(?>			# Repeated marker group
+					[ ]{0,2}	# Zero, one, or two spaces.
+					\1			# Marker character
+				){2,}		# Group repeated at least twice
+				[ ]*		# Tailing spaces
+				$			# End of line.
+			}mx',
+			"\n".$this->hashBlock("<hr$this->empty_element_suffix")."\n", 
+			$text
+		);
+	}
+
+	/**
+	 * These are all the transformations that occur *within* block-level
+	 * tags like paragraphs, headers, and list items.
+	 * @var array
+	 */
+	protected $span_gamut = array(
+		// Process character escapes, code spans, and inline HTML
+		// in one shot.
+		"parseSpan"           => -30,
+		// Process anchor and image tags. Images must come first,
+		// because ![foo][f] looks like an anchor.
+		"doImages"            =>  10,
+		"doAnchors"           =>  20,
+		// Make links out of things like `<https://example.com/>`
+		// Must come after doAnchors, because you can use < and >
+		// delimiters in inline links like [this](<url>).
+		"doAutoLinks"         =>  30,
+		"encodeAmpsAndAngles" =>  40,
+		"doItalicsAndBold"    =>  50,
+		"doHardBreaks"        =>  60,
+	);
+
+	/**
+	 * Run span gamut transformations
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function runSpanGamut($text) {
+		foreach ($this->span_gamut as $method => $priority) {
+			$text = $this->$method($text);
+		}
+
+		return $text;
+	}
+
+	/**
+	 * Do hard breaks
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doHardBreaks($text) {
+		if ($this->hard_wrap) {
+			return preg_replace_callback('/ *\n/', 
+				array($this, '_doHardBreaks_callback'), $text);
+		} else {
+			return preg_replace_callback('/ {2,}\n/', 
+				array($this, '_doHardBreaks_callback'), $text);
+		}
+	}
+
+	/**
+	 * Trigger part hashing for the hard break (callback method)
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doHardBreaks_callback($matches) {
+		return $this->hashPart("<br$this->empty_element_suffix\n");
+	}
+
+	/**
+	 * Turn Markdown link shortcuts into XHTML <a> tags.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doAnchors($text) {
+		if ($this->in_anchor) {
+			return $text;
+		}
+		$this->in_anchor = true;
+		
+		// First, handle reference-style links: [link text] [id]
+		$text = preg_replace_callback('{
+			(					# wrap whole match in $1
+			  \[
+				('.$this->nested_brackets_re.')	# link text = $2
+			  \]
+
+			  [ ]?				# one optional space
+			  (?:\n[ ]*)?		# one optional newline followed by spaces
+
+			  \[
+				(.*?)		# id = $3
+			  \]
+			)
+			}xs',
+			array($this, '_doAnchors_reference_callback'), $text);
+
+		// Next, inline-style links: [link text](url "optional title")
+		$text = preg_replace_callback('{
+			(				# wrap whole match in $1
+			  \[
+				('.$this->nested_brackets_re.')	# link text = $2
+			  \]
+			  \(			# literal paren
+				[ \n]*
+				(?:
+					<(.+?)>	# href = $3
+				|
+					('.$this->nested_url_parenthesis_re.')	# href = $4
+				)
+				[ \n]*
+				(			# $5
+				  ([\'"])	# quote char = $6
+				  (.*?)		# Title = $7
+				  \6		# matching quote
+				  [ \n]*	# ignore any spaces/tabs between closing quote and )
+				)?			# title is optional
+			  \)
+			)
+			}xs',
+			array($this, '_doAnchors_inline_callback'), $text);
+
+		// Last, handle reference-style shortcuts: [link text]
+		// These must come last in case you've also got [link text][1]
+		// or [link text](/foo)
+		$text = preg_replace_callback('{
+			(					# wrap whole match in $1
+			  \[
+				([^\[\]]+)		# link text = $2; can\'t contain [ or ]
+			  \]
+			)
+			}xs',
+			array($this, '_doAnchors_reference_callback'), $text);
+
+		$this->in_anchor = false;
+		return $text;
+	}
+
+	/**
+	 * Callback method to parse referenced anchors
+	 * @param  string $matches
+	 * @return string
+	 */
+	protected function _doAnchors_reference_callback($matches) {
+		$whole_match =  $matches[1];
+		$link_text   =  $matches[2];
+		$link_id     =& $matches[3];
+
+		if ($link_id == "") {
+			// for shortcut links like [this][] or [this].
+			$link_id = $link_text;
+		}
+		
+		// lower-case and turn embedded newlines into spaces
+		$link_id = strtolower($link_id);
+		$link_id = preg_replace('{[ ]?\n}', ' ', $link_id);
+
+		if (isset($this->urls[$link_id])) {
+			$url = $this->urls[$link_id];
+			$url = $this->encodeURLAttribute($url);
+			
+			$result = "<a href=\"$url\"";
+			if ( isset( $this->titles[$link_id] ) ) {
+				$title = $this->titles[$link_id];
+				$title = $this->encodeAttribute($title);
+				$result .=  " title=\"$title\"";
+			}
+		
+			$link_text = $this->runSpanGamut($link_text);
+			$result .= ">$link_text</a>";
+			$result = $this->hashPart($result);
+		} else {
+			$result = $whole_match;
+		}
+		return $result;
+	}
+
+	/**
+	 * Callback method to parse inline anchors
+	 * @param  string $matches
+	 * @return string
+	 */
+	protected function _doAnchors_inline_callback($matches) {
+		$whole_match	=  $matches[1];
+		$link_text		=  $this->runSpanGamut($matches[2]);
+		$url			=  $matches[3] == '' ? $matches[4] : $matches[3];
+		$title			=& $matches[7];
+
+		// If the URL was of the form <s p a c e s> it got caught by the HTML
+		// tag parser and hashed. Need to reverse the process before using
+		// the URL.
+		$unhashed = $this->unhash($url);
+		if ($unhashed != $url)
+			$url = preg_replace('/^<(.*)>$/', '\1', $unhashed);
+
+		$url = $this->encodeURLAttribute($url);
+
+		$result = "<a href=\"$url\"";
+		if (isset($title)) {
+			$title = $this->encodeAttribute($title);
+			$result .=  " title=\"$title\"";
+		}
+		
+		$link_text = $this->runSpanGamut($link_text);
+		$result .= ">$link_text</a>";
+
+		return $this->hashPart($result);
+	}
+
+	/**
+	 * Turn Markdown image shortcuts into <img> tags.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doImages($text) {
+		// First, handle reference-style labeled images: ![alt text][id]
+		$text = preg_replace_callback('{
+			(				# wrap whole match in $1
+			  !\[
+				('.$this->nested_brackets_re.')		# alt text = $2
+			  \]
+
+			  [ ]?				# one optional space
+			  (?:\n[ ]*)?		# one optional newline followed by spaces
+
+			  \[
+				(.*?)		# id = $3
+			  \]
+
+			)
+			}xs', 
+			array($this, '_doImages_reference_callback'), $text);
+
+		// Next, handle inline images:  ![alt text](url "optional title")
+		// Don't forget: encode * and _
+		$text = preg_replace_callback('{
+			(				# wrap whole match in $1
+			  !\[
+				('.$this->nested_brackets_re.')		# alt text = $2
+			  \]
+			  \s?			# One optional whitespace character
+			  \(			# literal paren
+				[ \n]*
+				(?:
+					<(\S*)>	# src url = $3
+				|
+					('.$this->nested_url_parenthesis_re.')	# src url = $4
+				)
+				[ \n]*
+				(			# $5
+				  ([\'"])	# quote char = $6
+				  (.*?)		# title = $7
+				  \6		# matching quote
+				  [ \n]*
+				)?			# title is optional
+			  \)
+			)
+			}xs',
+			array($this, '_doImages_inline_callback'), $text);
+
+		return $text;
+	}
+
+	/**
+	 * Callback to parse references image tags
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doImages_reference_callback($matches) {
+		$whole_match = $matches[1];
+		$alt_text    = $matches[2];
+		$link_id     = strtolower($matches[3]);
+
+		if ($link_id == "") {
+			$link_id = strtolower($alt_text); // for shortcut links like ![this][].
+		}
+
+		$alt_text = $this->encodeAttribute($alt_text);
+		if (isset($this->urls[$link_id])) {
+			$url = $this->encodeURLAttribute($this->urls[$link_id]);
+			$result = "<img src=\"$url\" alt=\"$alt_text\"";
+			if (isset($this->titles[$link_id])) {
+				$title = $this->titles[$link_id];
+				$title = $this->encodeAttribute($title);
+				$result .=  " title=\"$title\"";
+			}
+			$result .= $this->empty_element_suffix;
+			$result = $this->hashPart($result);
+		} else {
+			// If there's no such link ID, leave intact:
+			$result = $whole_match;
+		}
+
+		return $result;
+	}
+
+	/**
+	 * Callback to parse inline image tags
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doImages_inline_callback($matches) {
+		$whole_match	= $matches[1];
+		$alt_text		= $matches[2];
+		$url			= $matches[3] == '' ? $matches[4] : $matches[3];
+		$title			=& $matches[7];
+
+		$alt_text = $this->encodeAttribute($alt_text);
+		$url = $this->encodeURLAttribute($url);
+		$result = "<img src=\"$url\" alt=\"$alt_text\"";
+		if (isset($title)) {
+			$title = $this->encodeAttribute($title);
+			$result .=  " title=\"$title\""; // $title already quoted
+		}
+		$result .= $this->empty_element_suffix;
+
+		return $this->hashPart($result);
+	}
+
+	/**
+	 * Parse Markdown heading elements to HTML
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doHeaders($text) {
+		/**
+		 * Setext-style headers:
+		 *	  Header 1
+		 *	  ========
+		 *  
+		 *	  Header 2
+		 *	  --------
+		 */
+		$text = preg_replace_callback('{ ^(.+?)[ ]*\n(=+|-+)[ ]*\n+ }mx',
+			array($this, '_doHeaders_callback_setext'), $text);
+
+		/**
+		 * atx-style headers:
+		 *   # Header 1
+		 *   ## Header 2
+		 *   ## Header 2 with closing hashes ##
+		 *   ...
+		 *   ###### Header 6
+		 */
+		$text = preg_replace_callback('{
+				^(\#{1,6})	# $1 = string of #\'s
+				[ ]*
+				(.+?)		# $2 = Header text
+				[ ]*
+				\#*			# optional closing #\'s (not counted)
+				\n+
+			}xm',
+			array($this, '_doHeaders_callback_atx'), $text);
+
+		return $text;
+	}
+
+	/**
+	 * Setext header parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doHeaders_callback_setext($matches) {
+		// Terrible hack to check we haven't found an empty list item.
+		if ($matches[2] == '-' && preg_match('{^-(?: |$)}', $matches[1])) {
+			return $matches[0];
+		}
+		
+		$level = $matches[2]{0} == '=' ? 1 : 2;
+
+		// ID attribute generation
+		$idAtt = $this->_generateIdFromHeaderValue($matches[1]);
+
+		$block = "<h$level$idAtt>".$this->runSpanGamut($matches[1])."</h$level>";
+		return "\n" . $this->hashBlock($block) . "\n\n";
+	}
+
+	/**
+	 * ATX header parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doHeaders_callback_atx($matches) {
+		// ID attribute generation
+		$idAtt = $this->_generateIdFromHeaderValue($matches[2]);
+
+		$level = strlen($matches[1]);
+		$block = "<h$level$idAtt>".$this->runSpanGamut($matches[2])."</h$level>";
+		return "\n" . $this->hashBlock($block) . "\n\n";
+	}
+
+	/**
+	 * If a header_id_func property is set, we can use it to automatically
+	 * generate an id attribute.
+	 *
+	 * This method returns a string in the form id="foo", or an empty string
+	 * otherwise.
+	 * @param  string $headerValue
+	 * @return string
+	 */
+	protected function _generateIdFromHeaderValue($headerValue) {		
+		if (!is_callable($this->header_id_func)) {
+			return "";
+		}
+
+		$idValue = call_user_func($this->header_id_func, $headerValue);
+		if (!$idValue) {
+			return "";
+		}
+
+		return ' id="' . $this->encodeAttribute($idValue) . '"';
+	}
+
+	/**
+	 * Form HTML ordered (numbered) and unordered (bulleted) lists.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doLists($text) {
+		$less_than_tab = $this->tab_width - 1;
+
+		// Re-usable patterns to match list item bullets and number markers:
+		$marker_ul_re  = '[*+-]';
+		$marker_ol_re  = '\d+[\.]';
+
+		$markers_relist = array(
+			$marker_ul_re => $marker_ol_re,
+			$marker_ol_re => $marker_ul_re,
+			);
+
+		foreach ($markers_relist as $marker_re => $other_marker_re) {
+			// Re-usable pattern to match any entirel ul or ol list:
+			$whole_list_re = '
+				(								# $1 = whole list
+				  (								# $2
+					([ ]{0,'.$less_than_tab.'})	# $3 = number of spaces
+					('.$marker_re.')			# $4 = first list item marker
+					[ ]+
+				  )
+				  (?s:.+?)
+				  (								# $5
+					  \z
+					|
+					  \n{2,}
+					  (?=\S)
+					  (?!						# Negative lookahead for another list item marker
+						[ ]*
+						'.$marker_re.'[ ]+
+					  )
+					|
+					  (?=						# Lookahead for another kind of list
+					    \n
+						\3						# Must have the same indentation
+						'.$other_marker_re.'[ ]+
+					  )
+				  )
+				)
+			'; // mx
+			
+			// We use a different prefix before nested lists than top-level lists.
+			//See extended comment in _ProcessListItems().
+		
+			if ($this->list_level) {
+				$text = preg_replace_callback('{
+						^
+						'.$whole_list_re.'
+					}mx',
+					array($this, '_doLists_callback'), $text);
+			} else {
+				$text = preg_replace_callback('{
+						(?:(?<=\n)\n|\A\n?) # Must eat the newline
+						'.$whole_list_re.'
+					}mx',
+					array($this, '_doLists_callback'), $text);
+			}
+		}
+
+		return $text;
+	}
+
+	/**
+	 * List parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doLists_callback($matches) {
+		// Re-usable patterns to match list item bullets and number markers:
+		$marker_ul_re  = '[*+-]';
+		$marker_ol_re  = '\d+[\.]';
+		$marker_any_re = "(?:$marker_ul_re|$marker_ol_re)";
+		$marker_ol_start_re = '[0-9]+';
+
+		$list = $matches[1];
+		$list_type = preg_match("/$marker_ul_re/", $matches[4]) ? "ul" : "ol";
+
+		$marker_any_re = ( $list_type == "ul" ? $marker_ul_re : $marker_ol_re );
+
+		$list .= "\n";
+		$result = $this->processListItems($list, $marker_any_re);
+
+		$ol_start = 1;
+		if ($this->enhanced_ordered_list) {
+			// Get the start number for ordered list.
+			if ($list_type == 'ol') {
+				$ol_start_array = array();
+				$ol_start_check = preg_match("/$marker_ol_start_re/", $matches[4], $ol_start_array);
+				if ($ol_start_check){
+					$ol_start = $ol_start_array[0];
+				}
+			}
+		}
+
+		if ($ol_start > 1 && $list_type == 'ol'){
+			$result = $this->hashBlock("<$list_type start=\"$ol_start\">\n" . $result . "</$list_type>");
+		} else {
+			$result = $this->hashBlock("<$list_type>\n" . $result . "</$list_type>");
+		}
+		return "\n". $result ."\n\n";
+	}
+
+	/**
+	 * Nesting tracker for list levels
+	 * @var integer
+	 */
+	protected $list_level = 0;
+
+	/**
+	 * Process the contents of a single ordered or unordered list, splitting it
+	 * into individual list items.
+	 * @param  string $list_str
+	 * @param  string $marker_any_re
+	 * @return string
+	 */
+	protected function processListItems($list_str, $marker_any_re) {
+		/**
+		 * The $this->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.".
+		 */		
+		$this->list_level++;
+
+		// Trim trailing blank lines:
+		$list_str = preg_replace("/\n{2,}\\z/", "\n", $list_str);
+
+		$list_str = preg_replace_callback('{
+			(\n)?							# leading line = $1
+			(^[ ]*)							# leading whitespace = $2
+			('.$marker_any_re.'				# list marker and space = $3
+				(?:[ ]+|(?=\n))	# space only required if item is not empty
+			)
+			((?s:.*?))						# list item text   = $4
+			(?:(\n+(?=\n))|\n)				# tailing blank line = $5
+			(?= \n* (\z | \2 ('.$marker_any_re.') (?:[ ]+|(?=\n))))
+			}xm',
+			array($this, '_processListItems_callback'), $list_str);
+
+		$this->list_level--;
+		return $list_str;
+	}
+
+	/**
+	 * List item parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _processListItems_callback($matches) {
+		$item = $matches[4];
+		$leading_line =& $matches[1];
+		$leading_space =& $matches[2];
+		$marker_space = $matches[3];
+		$tailing_blank_line =& $matches[5];
+
+		if ($leading_line || $tailing_blank_line || 
+			preg_match('/\n{2,}/', $item))
+		{
+			// Replace marker with the appropriate whitespace indentation
+			$item = $leading_space . str_repeat(' ', strlen($marker_space)) . $item;
+			$item = $this->runBlockGamut($this->outdent($item)."\n");
+		} else {
+			// Recursion for sub-lists:
+			$item = $this->doLists($this->outdent($item));
+			$item = $this->formParagraphs($item, false);
+		}
+
+		return "<li>" . $item . "</li>\n";
+	}
+
+	/**
+	 * Process Markdown `<pre><code>` blocks.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doCodeBlocks($text) {
+		$text = preg_replace_callback('{
+				(?:\n\n|\A\n?)
+				(	            # $1 = the code block -- one or more lines, starting with a space/tab
+				  (?>
+					[ ]{'.$this->tab_width.'}  # Lines must start with a tab or a tab-width of spaces
+					.*\n+
+				  )+
+				)
+				((?=^[ ]{0,'.$this->tab_width.'}\S)|\Z)	# Lookahead for non-space at line-start, or end of doc
+			}xm',
+			array($this, '_doCodeBlocks_callback'), $text);
+
+		return $text;
+	}
+
+	/**
+	 * Code block parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doCodeBlocks_callback($matches) {
+		$codeblock = $matches[1];
+
+		$codeblock = $this->outdent($codeblock);
+		if ($this->code_block_content_func) {
+			$codeblock = call_user_func($this->code_block_content_func, $codeblock, "");
+		} else {
+			$codeblock = htmlspecialchars($codeblock, ENT_NOQUOTES);
+		}
+
+		# trim leading newlines and trailing newlines
+		$codeblock = preg_replace('/\A\n+|\n+\z/', '', $codeblock);
+
+		$codeblock = "<pre><code>$codeblock\n</code></pre>";
+		return "\n\n" . $this->hashBlock($codeblock) . "\n\n";
+	}
+
+	/**
+	 * Create a code span markup for $code. Called from handleSpanToken.
+	 * @param  string $code
+	 * @return string
+	 */
+	protected function makeCodeSpan($code) {
+		if ($this->code_span_content_func) {
+			$code = call_user_func($this->code_span_content_func, $code);
+		} else {
+			$code = htmlspecialchars(trim($code), ENT_NOQUOTES);
+		}
+		return $this->hashPart("<code>$code</code>");
+	}
+
+	/**
+	 * Define the emphasis operators with their regex matches
+	 * @var array
+	 */
+	protected $em_relist = array(
+		''  => '(?:(?<!\*)\*(?!\*)|(?<!_)_(?!_))(?![\.,:;]?\s)',
+		'*' => '(?<![\s*])\*(?!\*)',
+		'_' => '(?<![\s_])_(?!_)',
+	);
+
+	/**
+	 * Define the strong operators with their regex matches
+	 * @var array
+	 */
+	protected $strong_relist = array(
+		''   => '(?:(?<!\*)\*\*(?!\*)|(?<!_)__(?!_))(?![\.,:;]?\s)',
+		'**' => '(?<![\s*])\*\*(?!\*)',
+		'__' => '(?<![\s_])__(?!_)',
+	);
+
+	/**
+	 * Define the emphasis + strong operators with their regex matches
+	 * @var array
+	 */
+	protected $em_strong_relist = array(
+		''    => '(?:(?<!\*)\*\*\*(?!\*)|(?<!_)___(?!_))(?![\.,:;]?\s)',
+		'***' => '(?<![\s*])\*\*\*(?!\*)',
+		'___' => '(?<![\s_])___(?!_)',
+	);
+
+	/**
+	 * Container for prepared regular expressions
+	 * @var array
+	 */
+	protected $em_strong_prepared_relist;
+	
+	/**
+	 * Prepare regular expressions for searching emphasis tokens in any
+	 * context.
+	 * @return void
+	 */
+	protected function prepareItalicsAndBold() {
+		foreach ($this->em_relist as $em => $em_re) {
+			foreach ($this->strong_relist as $strong => $strong_re) {
+				// Construct list of allowed token expressions.
+				$token_relist = array();
+				if (isset($this->em_strong_relist["$em$strong"])) {
+					$token_relist[] = $this->em_strong_relist["$em$strong"];
+				}
+				$token_relist[] = $em_re;
+				$token_relist[] = $strong_re;
+				
+				// Construct master expression from list.
+				$token_re = '{(' . implode('|', $token_relist) . ')}';
+				$this->em_strong_prepared_relist["$em$strong"] = $token_re;
+			}
+		}
+	}
+
+	/**
+	 * Convert Markdown italics (emphasis) and bold (strong) to HTML
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doItalicsAndBold($text) {
+		$token_stack = array('');
+		$text_stack = array('');
+		$em = '';
+		$strong = '';
+		$tree_char_em = false;
+		
+		while (1) {
+			// Get prepared regular expression for seraching emphasis tokens
+			// in current context.
+			$token_re = $this->em_strong_prepared_relist["$em$strong"];
+			
+			// Each loop iteration search for the next emphasis token. 
+			// Each token is then passed to handleSpanToken.
+			$parts = preg_split($token_re, $text, 2, PREG_SPLIT_DELIM_CAPTURE);
+			$text_stack[0] .= $parts[0];
+			$token =& $parts[1];
+			$text =& $parts[2];
+			
+			if (empty($token)) {
+				// Reached end of text span: empty stack without emitting.
+				// any more emphasis.
+				while ($token_stack[0]) {
+					$text_stack[1] .= array_shift($token_stack);
+					$text_stack[0] .= array_shift($text_stack);
+				}
+				break;
+			}
+			
+			$token_len = strlen($token);
+			if ($tree_char_em) {
+				// Reached closing marker while inside a three-char emphasis.
+				if ($token_len == 3) {
+					// Three-char closing marker, close em and strong.
+					array_shift($token_stack);
+					$span = array_shift($text_stack);
+					$span = $this->runSpanGamut($span);
+					$span = "<strong><em>$span</em></strong>";
+					$text_stack[0] .= $this->hashPart($span);
+					$em = '';
+					$strong = '';
+				} else {
+					// Other closing marker: close one em or strong and
+					// change current token state to match the other
+					$token_stack[0] = str_repeat($token{0}, 3-$token_len);
+					$tag = $token_len == 2 ? "strong" : "em";
+					$span = $text_stack[0];
+					$span = $this->runSpanGamut($span);
+					$span = "<$tag>$span</$tag>";
+					$text_stack[0] = $this->hashPart($span);
+					$$tag = ''; // $$tag stands for $em or $strong
+				}
+				$tree_char_em = false;
+			} else if ($token_len == 3) {
+				if ($em) {
+					// Reached closing marker for both em and strong.
+					// Closing strong marker:
+					for ($i = 0; $i < 2; ++$i) {
+						$shifted_token = array_shift($token_stack);
+						$tag = strlen($shifted_token) == 2 ? "strong" : "em";
+						$span = array_shift($text_stack);
+						$span = $this->runSpanGamut($span);
+						$span = "<$tag>$span</$tag>";
+						$text_stack[0] .= $this->hashPart($span);
+						$$tag = ''; // $$tag stands for $em or $strong
+					}
+				} else {
+					// Reached opening three-char emphasis marker. Push on token 
+					// stack; will be handled by the special condition above.
+					$em = $token{0};
+					$strong = "$em$em";
+					array_unshift($token_stack, $token);
+					array_unshift($text_stack, '');
+					$tree_char_em = true;
+				}
+			} else if ($token_len == 2) {
+				if ($strong) {
+					// Unwind any dangling emphasis marker:
+					if (strlen($token_stack[0]) == 1) {
+						$text_stack[1] .= array_shift($token_stack);
+						$text_stack[0] .= array_shift($text_stack);
+					}
+					// Closing strong marker:
+					array_shift($token_stack);
+					$span = array_shift($text_stack);
+					$span = $this->runSpanGamut($span);
+					$span = "<strong>$span</strong>";
+					$text_stack[0] .= $this->hashPart($span);
+					$strong = '';
+				} else {
+					array_unshift($token_stack, $token);
+					array_unshift($text_stack, '');
+					$strong = $token;
+				}
+			} else {
+				// Here $token_len == 1
+				if ($em) {
+					if (strlen($token_stack[0]) == 1) {
+						// Closing emphasis marker:
+						array_shift($token_stack);
+						$span = array_shift($text_stack);
+						$span = $this->runSpanGamut($span);
+						$span = "<em>$span</em>";
+						$text_stack[0] .= $this->hashPart($span);
+						$em = '';
+					} else {
+						$text_stack[0] .= $token;
+					}
+				} else {
+					array_unshift($token_stack, $token);
+					array_unshift($text_stack, '');
+					$em = $token;
+				}
+			}
+		}
+		return $text_stack[0];
+	}
+
+	/**
+	 * Parse Markdown blockquotes to HTML
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doBlockQuotes($text) {
+		$text = preg_replace_callback('/
+			  (								# Wrap whole match in $1
+				(?>
+				  ^[ ]*>[ ]?			# ">" at the start of a line
+					.+\n					# rest of the first line
+				  (.+\n)*					# subsequent consecutive lines
+				  \n*						# blanks
+				)+
+			  )
+			/xm',
+			array($this, '_doBlockQuotes_callback'), $text);
+
+		return $text;
+	}
+
+	/**
+	 * Blockquote parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doBlockQuotes_callback($matches) {
+		$bq = $matches[1];
+		// trim one level of quoting - trim whitespace-only lines
+		$bq = preg_replace('/^[ ]*>[ ]?|^[ ]+$/m', '', $bq);
+		$bq = $this->runBlockGamut($bq); // recurse
+
+		$bq = preg_replace('/^/m', "  ", $bq);
+		// These leading spaces cause problem with <pre> content, 
+		// so we need to fix that:
+		$bq = preg_replace_callback('{(\s*<pre>.+?</pre>)}sx', 
+			array($this, '_doBlockQuotes_callback2'), $bq);
+
+		return "\n" . $this->hashBlock("<blockquote>\n$bq\n</blockquote>") . "\n\n";
+	}
+
+	/**
+	 * Blockquote parsing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doBlockQuotes_callback2($matches) {
+		$pre = $matches[1];
+		$pre = preg_replace('/^  /m', '', $pre);
+		return $pre;
+	}
+
+	/**
+	 * Parse paragraphs
+	 *
+	 * @param  string $text String to process in paragraphs
+	 * @param  boolean $wrap_in_p Whether paragraphs should be wrapped in <p> tags
+	 * @return string
+	 */
+	protected function formParagraphs($text, $wrap_in_p = true) {
+		// Strip leading and trailing lines:
+		$text = preg_replace('/\A\n+|\n+\z/', '', $text);
+
+		$grafs = preg_split('/\n{2,}/', $text, -1, PREG_SPLIT_NO_EMPTY);
+
+		// Wrap <p> tags and unhashify HTML blocks
+		foreach ($grafs as $key => $value) {
+			if (!preg_match('/^B\x1A[0-9]+B$/', $value)) {
+				// Is a paragraph.
+				$value = $this->runSpanGamut($value);
+				if ($wrap_in_p) {
+					$value = preg_replace('/^([ ]*)/', "<p>", $value);
+					$value .= "</p>";
+				}
+				$grafs[$key] = $this->unhash($value);
+			} else {
+				// Is a block.
+				// Modify elements of @grafs in-place...
+				$graf = $value;
+				$block = $this->html_hashes[$graf];
+				$graf = $block;
+//				if (preg_match('{
+//					\A
+//					(							# $1 = <div> tag
+//					  <div  \s+
+//					  [^>]*
+//					  \b
+//					  markdown\s*=\s*  ([\'"])	#	$2 = attr quote char
+//					  1
+//					  \2
+//					  [^>]*
+//					  >
+//					)
+//					(							# $3 = contents
+//					.*
+//					)
+//					(</div>)					# $4 = closing tag
+//					\z
+//					}xs', $block, $matches))
+//				{
+//					list(, $div_open, , $div_content, $div_close) = $matches;
+//
+//					// We can't call Markdown(), because that resets the hash;
+//					// that initialization code should be pulled into its own sub, though.
+//					$div_content = $this->hashHTMLBlocks($div_content);
+//					
+//					// Run document gamut methods on the content.
+//					foreach ($this->document_gamut as $method => $priority) {
+//						$div_content = $this->$method($div_content);
+//					}
+//
+//					$div_open = preg_replace(
+//						'{\smarkdown\s*=\s*([\'"]).+?\1}', '', $div_open);
+//
+//					$graf = $div_open . "\n" . $div_content . "\n" . $div_close;
+//				}
+				$grafs[$key] = $graf;
+			}
+		}
+
+		return implode("\n\n", $grafs);
+	}
+
+	/**
+	 * Encode text for a double-quoted HTML attribute. This function
+	 * is *not* suitable for attributes enclosed in single quotes.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function encodeAttribute($text) {
+		$text = $this->encodeAmpsAndAngles($text);
+		$text = str_replace('"', '&quot;', $text);
+		return $text;
+	}
+
+	/**
+	 * Encode text for a double-quoted HTML attribute containing a URL,
+	 * applying the URL filter if set. Also generates the textual
+	 * representation for the URL (removing mailto: or tel:) storing it in $text.
+	 * This function is *not* suitable for attributes enclosed in single quotes.
+	 *
+	 * @param  string $url
+	 * @param  string &$text Passed by reference
+	 * @return string        URL
+	 */
+	protected function encodeURLAttribute($url, &$text = null) {
+		if ($this->url_filter_func) {
+			$url = call_user_func($this->url_filter_func, $url);
+		}
+
+		if (preg_match('{^mailto:}i', $url)) {
+			$url = $this->encodeEntityObfuscatedAttribute($url, $text, 7);
+		} else if (preg_match('{^tel:}i', $url)) {
+			$url = $this->encodeAttribute($url);
+			$text = substr($url, 4);
+		} else {
+			$url = $this->encodeAttribute($url);
+			$text = $url;
+		}
+
+		return $url;
+	}
+	
+	/**
+	 * Smart processing for ampersands and angle brackets that need to 
+	 * be encoded. Valid character entities are left alone unless the
+	 * no-entities mode is set.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function encodeAmpsAndAngles($text) {
+		if ($this->no_entities) {
+			$text = str_replace('&', '&amp;', $text);
+		} else {
+			// 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+);)/', 
+								'&amp;', $text);
+		}
+		// Encode remaining <'s
+		$text = str_replace('<', '&lt;', $text);
+
+		return $text;
+	}
+
+	/**
+	 * Parse Markdown automatic links to anchor HTML tags
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function doAutoLinks($text) {
+		$text = preg_replace_callback('{<((https?|ftp|dict|tel):[^\'">\s]+)>}i',
+			array($this, '_doAutoLinks_url_callback'), $text);
+
+		// Email addresses: <address@domain.foo>
+		$text = preg_replace_callback('{
+			<
+			(?:mailto:)?
+			(
+				(?:
+					[-!#$%&\'*+/=?^_`.{|}~\w\x80-\xFF]+
+				|
+					".*?"
+				)
+				\@
+				(?:
+					[-a-z0-9\x80-\xFF]+(\.[-a-z0-9\x80-\xFF]+)*\.[a-z]+
+				|
+					\[[\d.a-fA-F:]+\]	# IPv4 & IPv6
+				)
+			)
+			>
+			}xi',
+			array($this, '_doAutoLinks_email_callback'), $text);
+
+		return $text;
+	}
+
+	/**
+	 * Parse URL callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doAutoLinks_url_callback($matches) {
+		$url = $this->encodeURLAttribute($matches[1], $text);
+		$link = "<a href=\"$url\">$text</a>";
+		return $this->hashPart($link);
+	}
+
+	/**
+	 * Parse email address callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _doAutoLinks_email_callback($matches) {
+		$addr = $matches[1];
+		$url = $this->encodeURLAttribute("mailto:$addr", $text);
+		$link = "<a href=\"$url\">$text</a>";
+		return $this->hashPart($link);
+	}
+
+	/**
+	 * Input: some text to obfuscate, e.g. "mailto:foo@example.com"
+	 *
+	 * Output: the same text but with most characters encoded as either a
+	 *         decimal or hex entity, in the hopes of foiling most address
+	 *         harvesting spam bots. E.g.:
+	 *
+	 *        &#109;&#x61;&#105;&#x6c;&#116;&#x6f;&#58;&#x66;o&#111;
+	 *        &#x40;&#101;&#x78;&#97;&#x6d;&#112;&#x6c;&#101;&#46;&#x63;&#111;
+	 *        &#x6d;
+	 *
+	 * Note: the additional output $tail is assigned the same value as the
+	 * ouput, minus the number of characters specified by $head_length.
+	 *
+	 * Based by a filter by Matthew Wickline, posted to BBEdit-Talk.
+	 * With some optimizations by Milian Wolff. Forced encoding of HTML
+	 * attribute special characters by Allan Odgaard.
+	 *
+	 * @param  string  $text
+	 * @param  string  &$tail
+	 * @param  integer $head_length
+	 * @return string
+	 */
+	protected function encodeEntityObfuscatedAttribute($text, &$tail = null, $head_length = 0) {
+		if ($text == "") {
+			return $tail = "";
+		}
+
+		$chars = preg_split('/(?<!^)(?!$)/', $text);
+		$seed = (int)abs(crc32($text) / strlen($text)); // Deterministic seed.
+
+		foreach ($chars as $key => $char) {
+			$ord = ord($char);
+			// Ignore non-ascii chars.
+			if ($ord < 128) {
+				$r = ($seed * (1 + $key)) % 100; // Pseudo-random function.
+				// roughly 10% raw, 45% hex, 45% dec
+				// '@' *must* be encoded. I insist.
+				// '"' and '>' have to be encoded inside the attribute
+				if ($r > 90 && strpos('@"&>', $char) === false) {
+					/* do nothing */
+				} else if ($r < 45) {
+					$chars[$key] = '&#x'.dechex($ord).';';
+				} else {
+					$chars[$key] = '&#'.$ord.';';
+				}
+			}
+		}
+
+		$text = implode('', $chars);
+		$tail = $head_length ? implode('', array_slice($chars, $head_length)) : $text;
+
+		return $text;
+	}
+
+	/**
+	 * Take the string $str and parse it into tokens, hashing embeded HTML,
+	 * escaped characters and handling code spans.
+	 * @param  string $str
+	 * @return string
+	 */
+	protected function parseSpan($str) {
+		$output = '';
+		
+		$span_re = '{
+				(
+					\\\\'.$this->escape_chars_re.'
+				|
+					(?<![`\\\\])
+					`+						# code span marker
+			'.( $this->no_markup ? '' : '
+				|
+					<!--    .*?     -->		# comment
+				|
+					<\?.*?\?> | <%.*?%>		# processing instruction
+				|
+					<[!$]?[-a-zA-Z0-9:_]+	# regular tags
+					(?>
+						\s
+						(?>[^"\'>]+|"[^"]*"|\'[^\']*\')*
+					)?
+					>
+				|
+					<[-a-zA-Z0-9:_]+\s*/> # xml-style empty tag
+				|
+					</[-a-zA-Z0-9:_]+\s*> # closing tag
+			').'
+				)
+				}xs';
+
+		while (1) {
+			// Each loop iteration seach for either the next tag, the next 
+			// openning code span marker, or the next escaped character. 
+			// Each token is then passed to handleSpanToken.
+			$parts = preg_split($span_re, $str, 2, PREG_SPLIT_DELIM_CAPTURE);
+			
+			// Create token from text preceding tag.
+			if ($parts[0] != "") {
+				$output .= $parts[0];
+			}
+			
+			// Check if we reach the end.
+			if (isset($parts[1])) {
+				$output .= $this->handleSpanToken($parts[1], $parts[2]);
+				$str = $parts[2];
+			} else {
+				break;
+			}
+		}
+		
+		return $output;
+	}
+
+	/**
+	 * Handle $token provided by parseSpan by determining its nature and
+	 * returning the corresponding value that should replace it.
+	 * @param  string $token
+	 * @param  string &$str
+	 * @return string
+	 */
+	protected function handleSpanToken($token, &$str) {
+		switch ($token{0}) {
+			case "\\":
+				return $this->hashPart("&#". ord($token{1}). ";");
+			case "`":
+				// Search for end marker in remaining text.
+				if (preg_match('/^(.*?[^`])'.preg_quote($token).'(?!`)(.*)$/sm', 
+					$str, $matches))
+				{
+					$str = $matches[2];
+					$codespan = $this->makeCodeSpan($matches[1]);
+					return $this->hashPart($codespan);
+				}
+				return $token; // Return as text since no ending marker found.
+			default:
+				return $this->hashPart($token);
+		}
+	}
+
+	/**
+	 * Remove one level of line-leading tabs or spaces
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function outdent($text) {
+		return preg_replace('/^(\t|[ ]{1,' . $this->tab_width . '})/m', '', $text);
+	}
+
+
+	/**
+	 * String length function for detab. `_initDetab` will create a function to
+	 * handle UTF-8 if the default function does not exist.
+	 * @var string
+	 */
+	protected $utf8_strlen = 'mb_strlen';
+
+	/**
+	 * Replace tabs with the appropriate amount of spaces.
+	 *
+	 * For each line we separate the line in blocks delemited by tab characters.
+	 * Then we reconstruct every line by adding the  appropriate number of space
+	 * between each blocks.
+	 * 
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function detab($text) {	
+		$text = preg_replace_callback('/^.*\t.*$/m',
+			array($this, '_detab_callback'), $text);
+
+		return $text;
+	}
+
+	/**
+	 * Replace tabs callback
+	 * @param  string $matches
+	 * @return string
+	 */
+	protected function _detab_callback($matches) {
+		$line = $matches[0];
+		$strlen = $this->utf8_strlen; // strlen function for UTF-8.
+		
+		// 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 = $this->tab_width - 
+				$strlen($line, 'UTF-8') % $this->tab_width;
+			$line .= str_repeat(" ", $amount) . $block;
+		}
+		return $line;
+	}
+
+	/**
+	 * Check for the availability of the function in the `utf8_strlen` property
+	 * (initially `mb_strlen`). If the function is not available, create a 
+	 * function that will loosely count the number of UTF-8 characters with a
+	 * regular expression.
+	 * @return void
+	 */
+	protected function _initDetab() {
+	
+		if (function_exists($this->utf8_strlen)) {
+			return;
+		}
+
+		$this->utf8_strlen = create_function('$text', 'return preg_match_all(
+			"/[\\\\x00-\\\\xBF]|[\\\\xC0-\\\\xFF][\\\\x80-\\\\xBF]*/", 
+			$text, $m);');
+	}
+
+	/**
+	 * Swap back in all the tags hashed by _HashHTMLBlocks.
+	 * @param  string $text
+	 * @return string
+	 */
+	protected function unhash($text) {
+		return preg_replace_callback('/(.)\x1A[0-9]+\1/', 
+			array($this, '_unhash_callback'), $text);
+	}
+
+	/**
+	 * Unhashing callback
+	 * @param  array $matches
+	 * @return string
+	 */
+	protected function _unhash_callback($matches) {
+		return $this->html_hashes[$matches[0]];
+	}
+}