/apigen/libs/Texy/texy/texy.php

<?php

/**
 * Texy! - human-readable text to HTML converter.
 *
 * @copyright  Copyright (c) 2004, 2010 David Grudl
 * @license    GNU GENERAL PUBLIC LICENSE version 2 or 3
 * @link       http://texy.info
 * @package    Texy
 */


define('TEXY_VERSION',  '2.1');


/**
 * Check PHP configuration.
 */
if (extension_loaded('mbstring')) {
	if (mb_get_info('func_overload') & 2 && substr(mb_get_info('internal_encoding'), 0, 1) === 'U') { // U??
		mb_internal_encoding('pass');
		trigger_error("Texy: mb_internal_encoding changed to 'pass'", E_USER_WARNING);
	}
}

if (ini_get('zend.ze1_compatibility_mode') % 256 ||
	preg_match('#on$|true$|yes$#iA', ini_get('zend.ze1_compatibility_mode'))) {
	throw new RuntimeException("Texy cannot run with zend.ze1_compatibility_mode enabled.");
}


// Texy! libraries
require_once dirname(__FILE__) . '/libs/RegExp.Patterns.php';
require_once dirname(__FILE__) . '/libs/TexyObject.php';
require_once dirname(__FILE__) . '/libs/TexyHtml.php';
require_once dirname(__FILE__) . '/libs/TexyModifier.php';
require_once dirname(__FILE__) . '/libs/TexyModule.php';
require_once dirname(__FILE__) . '/libs/TexyParser.php';
require_once dirname(__FILE__) . '/libs/TexyUtf.php';
require_once dirname(__FILE__) . '/libs/TexyConfigurator.php';
require_once dirname(__FILE__) . '/libs/TexyHandlerInvocation.php';
require_once dirname(__FILE__) . '/modules/TexyParagraphModule.php';
require_once dirname(__FILE__) . '/modules/TexyBlockModule.php';
require_once dirname(__FILE__) . '/modules/TexyHeadingModule.php';
require_once dirname(__FILE__) . '/modules/TexyHorizLineModule.php';
require_once dirname(__FILE__) . '/modules/TexyHtmlModule.php';
require_once dirname(__FILE__) . '/modules/TexyFigureModule.php';
require_once dirname(__FILE__) . '/modules/TexyImageModule.php';
require_once dirname(__FILE__) . '/modules/TexyLinkModule.php';
require_once dirname(__FILE__) . '/modules/TexyListModule.php';
require_once dirname(__FILE__) . '/modules/TexyLongWordsModule.php';
require_once dirname(__FILE__) . '/modules/TexyPhraseModule.php';
require_once dirname(__FILE__) . '/modules/TexyBlockQuoteModule.php';
require_once dirname(__FILE__) . '/modules/TexyScriptModule.php';
require_once dirname(__FILE__) . '/modules/TexyEmoticonModule.php';
require_once dirname(__FILE__) . '/modules/TexyTableModule.php';
require_once dirname(__FILE__) . '/modules/TexyTypographyModule.php';
require_once dirname(__FILE__) . '/modules/TexyHtmlOutputModule.php';



/**
 * Compatibility with PHP < 5.1.
 */
if (!class_exists('LogicException', FALSE)) {
	class LogicException extends Exception {}
}

if (!class_exists('InvalidArgumentException', FALSE)) {
	class InvalidArgumentException extends LogicException {}
}

if (!class_exists('RuntimeException', FALSE)) {
	class RuntimeException extends Exception {}
}

if (!class_exists('UnexpectedValueException', FALSE)) {
	class UnexpectedValueException extends RuntimeException {}
}



/**
 * Compatibility with Nette
 */
if (!class_exists('NotSupportedException', FALSE)) {
	class NotSupportedException extends LogicException {}
}

if (!class_exists('MemberAccessException', FALSE)) {
	class MemberAccessException extends LogicException {}
}

if (!class_exists('InvalidStateException', FALSE)) {
	class InvalidStateException extends RuntimeException {}
}



/**
 * For Texy 1 backward compatibility.
 */
define('TEXY_ALL',  TRUE);
define('TEXY_NONE',  FALSE);
define('TEXY_CONTENT_MARKUP',  "\x17");
define('TEXY_CONTENT_REPLACED',  "\x16");
define('TEXY_CONTENT_TEXTUAL',  "\x15");
define('TEXY_CONTENT_BLOCK',  "\x14");




/**
 * Texy! - Convert plain text to XHTML format using {@link process()}.
 *
 * <code>
 *     $texy = new Texy();
 *     $html = $texy->process($text);
 * </code>
 *
 * @copyright  Copyright (c) 2004, 2010 David Grudl
 * @package    Texy
 */
class Texy extends TexyObject
{
	// configuration directives
	const ALL = TRUE;
	const NONE = FALSE;

	// Texy version
	const VERSION = TEXY_VERSION;
	const REVISION = '$WCREV$ released on $WCDATE$';

	// types of protection marks
	const CONTENT_MARKUP = "\x17";
	const CONTENT_REPLACED = "\x16";
	const CONTENT_TEXTUAL = "\x15";
	const CONTENT_BLOCK = "\x14";

	// url filters
	const FILTER_ANCHOR = 'anchor';
	const FILTER_IMAGE = 'image';

	// HTML minor-modes
	const XML = 2;

	// HTML modes
	const HTML4_TRANSITIONAL = 0;
	const HTML4_STRICT = 1;
	const HTML5 = 4;
	const XHTML1_TRANSITIONAL = 2; // Texy::HTML4_TRANSITIONAL | Texy::XML;
	const XHTML1_STRICT = 3; // Texy::HTML4_STRICT | Texy::XML;
	const XHTML5 = 6; // Texy::HTML5 | Texy::XML;

	/** @var string  input & output text encoding */
	public $encoding = 'utf-8';

	/** @var array  Texy! syntax configuration */
	public $allowed = array();

	/** @var TRUE|FALSE|array  Allowed HTML tags */
	public $allowedTags;

	/** @var TRUE|FALSE|array  Allowed classes */
	public $allowedClasses = Texy::ALL; // all classes and id are allowed

	/** @var TRUE|FALSE|array  Allowed inline CSS style */
	public $allowedStyles = Texy::ALL;  // all inline styles are allowed

	/** @var int  TAB width (for converting tabs to spaces) */
	public $tabWidth = 8;

	/** @var boolean  Do obfuscate e-mail addresses? */
	public $obfuscateEmail = TRUE;

	/** @var array  regexps to check URL schemes */
	public $urlSchemeFilters = NULL; // disable URL scheme filter

	/** @var bool  Paragraph merging mode */
	public $mergeLines = TRUE;

	/** @var array  Parsing summary */
	public $summary = array(
		'images' => array(),
		'links' => array(),
		'preload' => array(),
	);

	/** @var string  Generated stylesheet */
	public $styleSheet = '';

	/** @var array  CSS classes for align modifiers */
	public $alignClasses = array(
		'left' => NULL,
		'right' => NULL,
		'center' => NULL,
		'justify' => NULL,
		'top' => NULL,
		'middle' => NULL,
		'bottom' => NULL,
	);

	/** @var bool  remove soft hyphens (SHY)? */
	public $removeSoftHyphens = TRUE;

	/** @var mixed */
	public static $advertisingNotice = 'once';

	/** @var string */
	public $nontextParagraph = 'div';

	/** @var TexyScriptModule */
	public $scriptModule;

	/** @var TexyParagraphModule */
	public $paragraphModule;

	/** @var TexyHtmlModule */
	public $htmlModule;

	/** @var TexyImageModule */
	public $imageModule;

	/** @var TexyLinkModule */
	public $linkModule;

	/** @var TexyPhraseModule */
	public $phraseModule;

	/** @var TexyEmoticonModule */
	public $emoticonModule;

	/** @var TexyBlockModule */
	public $blockModule;

	/** @var TexyHeadingModule */
	public $headingModule;

	/** @var TexyHorizLineModule */
	public $horizLineModule;

	/** @var TexyBlockQuoteModule */
	public $blockQuoteModule;

	/** @var TexyListModule */
	public $listModule;

	/** @var TexyTableModule */
	public $tableModule;

	/** @var TexyFigureModule */
	public $figureModule;

	/** @var TexyTypographyModule */
	public $typographyModule;

	/** @var TexyLongWordsModule */
	public $longWordsModule;

	/** @var TexyHtmlOutputModule */
	public $htmlOutputModule;


	/**
	 * Registered regexps and associated handlers for inline parsing.
	 * @var array of ('handler' => callback
	 *                'pattern' => regular expression)
	 */
	private $linePatterns = array();
	private $_linePatterns;

	/**
	 * Registered regexps and associated handlers for block parsing.
	 * @var array of ('handler' => callback
	 *                'pattern' => regular expression)
	 */
	private $blockPatterns = array();
	private $_blockPatterns;

	/** @var array */
	private $postHandlers = array();

	/** @var TexyHtml  DOM structure for parsed text */
	private $DOM;

	/** @var array  Texy protect markup table */
	private $marks = array();

	/** @var array  for internal usage */
	public $_classes, $_styles;

	/** @var bool */
	private $processing;

	/** @var array of events and registered handlers */
	private $handlers = array();

	/**
	 * DTD descriptor.
	 *   $dtd[element][0] - allowed attributes (as array keys)
	 *   $dtd[element][1] - allowed content for an element (content model) (as array keys)
	 *                    - array of allowed elements (as keys)
	 *                    - FALSE - empty element
	 *                    - 0 - special case for ins & del
	 * @var array
	 */
	public $dtd;

	/** @var array */
	private static $dtdCache;

	/** @var int  HTML mode */
	private $mode;


	/** DEPRECATED */
	public static $strictDTD;
	public $cleaner;
	public $xhtml;



	public function __construct()
	{
		// load all modules
		$this->loadModules();

		// DEPRECATED
		if (self::$strictDTD !== NULL) {
			$this->setOutputMode(self::$strictDTD ? self::XHTML1_STRICT : self::XHTML1_TRANSITIONAL);
		} else {
			$this->setOutputMode(self::XHTML1_TRANSITIONAL);
		}

		// DEPRECATED
		$this->cleaner = & $this->htmlOutputModule;

		// examples of link references ;-)
		$link = new TexyLink('http://texy.info/');
		$link->modifier->title = 'The best text -> HTML converter and formatter';
		$link->label = 'Texy!';
		$this->linkModule->addReference('texy', $link);

		$link = new TexyLink('http://www.google.com/search?q=%s');
		$this->linkModule->addReference('google', $link);

		$link = new TexyLink('http://en.wikipedia.org/wiki/Special:Search?search=%s');
		$this->linkModule->addReference('wikipedia', $link);
	}



	/**
	 * Set HTML/XHTML output mode (overwrites self::$allowedTags)
	 * @param  int
	 * @return void
	 */
	public function setOutputMode($mode)
	{
		if (!in_array($mode, array(self::HTML4_TRANSITIONAL, self::HTML4_STRICT,
			self::HTML5, self::XHTML1_TRANSITIONAL, self::XHTML1_STRICT, self::XHTML5), TRUE)) {
			throw new InvalidArgumentException("Invalid mode.");
		}

		if (!isset(self::$dtdCache[$mode])) {
			require dirname(__FILE__) . '/libs/DTD.php';
			self::$dtdCache[$mode] = $dtd;
		}

		$this->mode = $mode;
		$this->dtd = self::$dtdCache[$mode];
		TexyHtml::$xhtml = (bool) ($mode & self::XML); // TODO: remove?

		// accept all valid HTML tags and attributes by default
		$this->allowedTags = array();
		foreach ($this->dtd as $tag => $dtd) {
			$this->allowedTags[$tag] = self::ALL;
		}
	}



	/**
	 * Get HTML/XHTML output mode
	 * @return int
	 */
	public function getOutputMode()
	{
		return $this->mode;
	}



	/**
	 * Create array of all used modules ($this->modules).
	 * This array can be changed by overriding this method (by subclasses)
	 */
	protected function loadModules()
	{
		// line parsing
		$this->scriptModule = new TexyScriptModule($this);
		$this->htmlModule = new TexyHtmlModule($this);
		$this->imageModule = new TexyImageModule($this);
		$this->phraseModule = new TexyPhraseModule($this);
		$this->linkModule = new TexyLinkModule($this);
		$this->emoticonModule = new TexyEmoticonModule($this);

		// block parsing
		$this->paragraphModule = new TexyParagraphModule($this);
		$this->blockModule = new TexyBlockModule($this);
		$this->figureModule = new TexyFigureModule($this);
		$this->horizLineModule = new TexyHorizLineModule($this);
		$this->blockQuoteModule = new TexyBlockQuoteModule($this);
		$this->tableModule = new TexyTableModule($this);
		$this->headingModule = new TexyHeadingModule($this);
		$this->listModule = new TexyListModule($this);

		// post process
		$this->typographyModule = new TexyTypographyModule($this);
		$this->longWordsModule = new TexyLongWordsModule($this);
		$this->htmlOutputModule = new TexyHtmlOutputModule($this);
	}



	final public function registerLinePattern($handler, $pattern, $name, $againTest = NULL)
	{
		if (!is_callable($handler)) {
			$able = is_callable($handler, TRUE, $textual);
			throw new InvalidArgumentException("Handler '$textual' is not " . ($able ? 'callable.' : 'valid PHP callback.'));
		}

		if (!isset($this->allowed[$name])) $this->allowed[$name] = TRUE;

		$this->linePatterns[$name] = array(
			'handler'     => $handler,
			'pattern'     => $pattern,
			'again'       => $againTest,
		);
	}



	final public function registerBlockPattern($handler, $pattern, $name)
	{
		if (!is_callable($handler)) {
			$able = is_callable($handler, TRUE, $textual);
			throw new InvalidArgumentException("Handler '$textual' is not " . ($able ? 'callable.' : 'valid PHP callback.'));
		}

		// if (!preg_match('#(.)\^.*\$\\1[a-z]*#is', $pattern)) die("Texy: Not a block pattern $name");
		if (!isset($this->allowed[$name])) $this->allowed[$name] = TRUE;

		$this->blockPatterns[$name] = array(
			'handler'     => $handler,
			'pattern'     => $pattern  . 'm',  // force multiline
		);
	}



	final public function registerPostLine($handler, $name)
	{
		if (!is_callable($handler)) {
			$able = is_callable($handler, TRUE, $textual);
			throw new InvalidArgumentException("Handler '$textual' is not " . ($able ? 'callable.' : 'valid PHP callback.'));
		}

		if (!isset($this->allowed[$name])) $this->allowed[$name] = TRUE;

		$this->postHandlers[$name] = $handler;
	}



	/**
	 * Converts document in Texy! to (X)HTML code.
	 *
	 * @param  string   input text
	 * @param  bool     is single line?
	 * @return string   output HTML code
	 */
	public function process($text, $singleLine = FALSE)
	{
		if ($this->processing) {
			throw new InvalidStateException('Processing is in progress yet.');
		}

		// initialization
		$this->marks = array();
		$this->processing = TRUE;

		// speed-up
		if (is_array($this->allowedClasses)) $this->_classes = array_flip($this->allowedClasses);
		else $this->_classes = $this->allowedClasses;

		if (is_array($this->allowedStyles)) $this->_styles = array_flip($this->allowedStyles);
		else $this->_styles = $this->allowedStyles;

		// convert to UTF-8 (and check source encoding)
		$text = TexyUtf::toUtf($text, $this->encoding);

		if ($this->removeSoftHyphens) {
			$text = str_replace("\xC2\xAD", '', $text);
		}

		// standardize line endings and spaces
		$text = self::normalize($text);

		// replace tabs with spaces
		$this->tabWidth = max(1, (int) $this->tabWidth);
		while (strpos($text, "\t") !== FALSE) {
			$text = preg_replace_callback('#^(.*)\t#mU', array($this, 'tabCb'), $text);
		}

		// user before handler
		$this->invokeHandlers('beforeParse', array($this, & $text, $singleLine));

		// select patterns
		$this->_linePatterns = $this->linePatterns;
		$this->_blockPatterns = $this->blockPatterns;
		foreach ($this->_linePatterns as $name => $foo) {
			if (empty($this->allowed[$name])) unset($this->_linePatterns[$name]);
		}
		foreach ($this->_blockPatterns as $name => $foo) {
			if (empty($this->allowed[$name])) unset($this->_blockPatterns[$name]);
		}

		// parse Texy! document into internal DOM structure
		$this->DOM = TexyHtml::el();
		if ($singleLine) {
			$this->DOM->parseLine($this, $text);
		} else {
			$this->DOM->parseBlock($this, $text);
		}

		// user after handler
		$this->invokeHandlers('afterParse', array($this, $this->DOM, $singleLine));

		// converts internal DOM structure to final HTML code
		$html = $this->DOM->toHtml($this);

		// this notice should remain
		if (self::$advertisingNotice) {
			$html .= "\n<!-- by Texy2! -->";
			if (self::$advertisingNotice === 'once') {
				self::$advertisingNotice = FALSE;
			}
		}

		$this->processing = FALSE;

		return TexyUtf::utf2html($html, $this->encoding);
	}



	/**
	 * Converts single line in Texy! to (X)HTML code.
	 *
	 * @param  string   input text
	 * @return string   output HTML code
	 */
	public function processLine($text)
	{
		return $this->process($text, TRUE);
	}



	/**
	 * Makes only typographic corrections.
	 * @param  string   input text (in encoding defined by Texy::$encoding)
	 * @return string   output text (in UTF-8)
	 */
	public function processTypo($text)
	{
		// convert to UTF-8 (and check source encoding)
		$text = TexyUtf::toUtf($text, $this->encoding);

		// standardize line endings and spaces
		$text = self::normalize($text);

		$this->typographyModule->beforeParse($this, $text);
		$text = $this->typographyModule->postLine($text, TRUE);

		if (!empty($this->allowed['longwords'])) {
			$text = $this->longWordsModule->postLine($text);
		}

		return TexyUtf::utf2html($text, $this->encoding);
	}



	/**
	 * Converts DOM structure to pure text.
	 * @return string
	 */
	public function toText()
	{
		if (!$this->DOM) {
			throw new InvalidStateException('Call $texy->process() first.');
		}

		return TexyUtf::utfTo($this->DOM->toText($this), $this->encoding);
	}



	/**
	 * Converts internal string representation to final HTML code in UTF-8.
	 * @return string
	 */
	final public function stringToHtml($s)
	{
		// decode HTML entities to UTF-8
		$s = self::unescapeHtml($s);

		// line-postprocessing
		$blocks = explode(self::CONTENT_BLOCK, $s);
		foreach ($this->postHandlers as $name => $handler) {
			if (empty($this->allowed[$name])) continue;
			foreach ($blocks as $n => $s) {
				if ($n % 2 === 0 && $s !== '') {
					$blocks[$n] = call_user_func($handler, $s);
				}
			}
		}
		$s = implode(self::CONTENT_BLOCK, $blocks);

		// encode < > &
		$s = self::escapeHtml($s);

		// replace protected marks
		$s = $this->unProtect($s);

		// wellform and reformat HTML
		$this->invokeHandlers('postProcess', array($this, & $s));

		// unfreeze spaces
		$s = self::unfreezeSpaces($s);

		return $s;
	}



	/**
	 * Converts internal string representation to final HTML code in UTF-8.
	 * @return string
	 */
	final public function stringToText($s)
	{
		$save = $this->htmlOutputModule->lineWrap;
		$this->htmlOutputModule->lineWrap = FALSE;
		$s = $this->stringToHtml( $s );
		$this->htmlOutputModule->lineWrap = $save;

		// remove tags
		$s = preg_replace('#<(script|style)(.*)</\\1>#Uis', '', $s);
		$s = strip_tags($s);
		$s = preg_replace('#\n\s*\n\s*\n[\n\s]*\n#', "\n\n", $s);

		// entities -> chars
		$s = self::unescapeHtml($s);

		// convert nbsp to normal space and remove shy
		$s = strtr($s, array(
			"\xC2\xAD" => '',  // shy
			"\xC2\xA0" => ' ', // nbsp
		));

		return $s;
	}



	/**
	 * Add new event handler.
	 *
	 * @param  string   event name
	 * @param  callback
	 * @return void
	 */
	final public function addHandler($event, $callback)
	{
		if (!is_callable($callback)) {
			$able = is_callable($callback, TRUE, $textual);
			throw new InvalidArgumentException("Handler '$textual' is not " . ($able ? 'callable.' : 'valid PHP callback.'));
		}

		$this->handlers[$event][] = $callback;
	}



	/**
	 * Invoke registered around-handlers.
	 *
	 * @param  string   event name
	 * @param  TexyParser  actual parser object
	 * @param  array    arguments passed into handler
	 * @return mixed
	 */
	final public function invokeAroundHandlers($event, $parser, $args)
	{
		if (!isset($this->handlers[$event])) return FALSE;

		$invocation = new TexyHandlerInvocation($this->handlers[$event], $parser, $args);
		$res = $invocation->proceed();
		$invocation->free();
		return $res;
	}



	/**
	 * Invoke registered after-handlers.
	 *
	 * @param  string   event name
	 * @param  array    arguments passed into handler
	 * @return void
	 */
	final public function invokeHandlers($event, $args)
	{
		if (!isset($this->handlers[$event])) return;

		foreach ($this->handlers[$event] as $handler) {
			call_user_func_array($handler, $args);
		}
	}



	/**
	 * Translate all white spaces (\t \n \r space) to meta-spaces \x01-\x04.
	 * which are ignored by TexyHtmlOutputModule routine
	 * @param  string
	 * @return string
	 */
	final public static function freezeSpaces($s)
	{
		return strtr($s, " \t\r\n", "\x01\x02\x03\x04");
	}



	/**
	 * Reverts meta-spaces back to normal spaces.
	 * @param  string
	 * @return string
	 */
	final public static function unfreezeSpaces($s)
	{
		return strtr($s, "\x01\x02\x03\x04", " \t\r\n");
	}



	/**
	 * Removes special controls characters and normalizes line endings and spaces.
	 * @param  string
	 * @return string
	 */
	final public static function normalize($s)
	{
		// standardize line endings to unix-like
		$s = str_replace("\r\n", "\n", $s); // DOS
		$s = strtr($s, "\r", "\n"); // Mac

		// remove special chars; leave \t + \n
		$s = preg_replace('#[\x00-\x08\x0B-\x1F]+#', '', $s);

		// right trim
		$s = preg_replace("#[\t ]+$#m", '', $s);

		// trailing spaces
		$s = trim($s, "\n");

		return $s;
	}



	/**
	 * Converts to web safe characters [a-z0-9-] text.
	 * @param  string
	 * @param  string
	 * @return string
	 */
	final public static function webalize($s, $charlist = NULL)
	{
		$s = TexyUtf::utf2ascii($s);
		$s = strtolower($s);
		$s = preg_replace('#[^a-z0-9'.preg_quote($charlist, '#').']+#', '-', $s);
		$s = trim($s, '-');
		return $s;
	}



	/**
	 * Texy! version of htmlSpecialChars (much faster than htmlSpecialChars!).
	 * note: &quot; is not encoded!
	 * @param  string
	 * @return string
	 */
	final public static function escapeHtml($s)
	{
		return str_replace(array('&', '<', '>'), array('&amp;', '&lt;', '&gt;'), $s);
	}



	/**
	 * Texy! version of html_entity_decode (always UTF-8, much faster than original!).
	 * @param  string
	 * @return string
	 */
	final public static function unescapeHtml($s)
	{
		if (strpos($s, '&') === FALSE) return $s;
		return html_entity_decode($s, ENT_QUOTES, 'UTF-8');
	}



	/**
	 * Outdents text block.
	 * @param  string
	 * @return string
	 */
	final public static function outdent($s)
	{
		$s = trim($s, "\n");
		$spaces = strspn($s, ' ');
		if ($spaces) return preg_replace("#^ {1,$spaces}#m", '', $s);
		return $s;
	}



	/**
	 * Generate unique mark - useful for freezing (folding) some substrings.
	 * @param  string   any string to froze
	 * @param  int      Texy::CONTENT_* constant
	 * @return string  internal mark
	 */
	final public function protect($child, $contentType)
	{
		if ($child==='') return '';

		$key = $contentType
			. strtr(base_convert(count($this->marks), 10, 8), '01234567', "\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F")
			. $contentType;

		$this->marks[$key] = $child;

		return $key;
	}



	final public function unProtect($html)
	{
		return strtr($html, $this->marks);
	}



	/**
	 * Filters bad URLs.
	 * @param  string   user URL
	 * @param  string   type: a-anchor, i-image, c-cite
	 * @return bool
	 */
	final public function checkURL($URL, $type)
	{
		// absolute URL with scheme? check scheme!
		if (!empty($this->urlSchemeFilters[$type])
			&& preg_match('#'.TEXY_URLSCHEME.'#A', $URL)
			&& !preg_match($this->urlSchemeFilters[$type], $URL))
			return FALSE;

		return TRUE;
	}



	/**
	 * Is given URL relative?
	 * @param  string  URL
	 * @return bool
	 */
	final public static function isRelative($URL)
	{
		// check for scheme, or absolute path, or absolute URL
		return !preg_match('#'.TEXY_URLSCHEME.'|[\#/?]#A', $URL);
	}



	/**
	 * Prepends root to URL, if possible.
	 * @param  string  URL
	 * @param  string  root
	 * @return string
	 */
	final public static function prependRoot($URL, $root)
	{
		if ($root == NULL || !self::isRelative($URL)) return $URL;
		return rtrim($root, '/\\') . '/' . $URL;
	}



	final public function getLinePatterns()
	{
		return $this->_linePatterns;
	}



	final public function getBlockPatterns()
	{
		return $this->_blockPatterns;
	}



	final public function getDOM()
	{
		return $this->DOM;
	}



	private function tabCb($m)
	{
		return $m[1] . str_repeat(' ', $this->tabWidth - strlen($m[1]) % $this->tabWidth);
	}



	/**
	 * PHP garbage collector helper.
	 */
	final public function free()
	{
		if (version_compare(PHP_VERSION , '5.3', '<')) {
			foreach (array_keys(get_object_vars($this)) as $key) {
				$this->$key = NULL;
			}
		}
	}



	final public function __clone()
	{
		throw new NotSupportedException('Clone is not supported.');
	}

}