<?php

#
#
# Parsedown
# http://parsedown.org
#
# (c) Emanuil Rusev
# http://erusev.com
#
# For the full license information, view the LICENSE file that was distributed
# with this source code.
#
#

class Parsedown
{
	# ~

	const version = '1.8.0-beta-7';

	# ~

	function text($text)
	{
		$Elements = $this->textElements($text);

		# convert to markup
		$markup = $this->elements($Elements);

		# trim line breaks
		$markup = trim($markup, "\n");

		return $markup;
	}

	protected function textElements($text)
	{
		# make sure no definitions are set
		$this->DefinitionData = array();

		# standardize line breaks
		$text = str_replace(array("\r\n", "\r"), "\n", $text);

		# remove surrounding line breaks
		$text = trim($text, "\n");

		# split text into lines
		$lines = explode("\n", $text);

		# iterate through lines to identify blocks
		return $this->linesElements($lines);
	}

	#
	# Setters
	#

	function setBreaksEnabled($breaksEnabled)
	{
		$this->breaksEnabled = $breaksEnabled;

		return $this;
	}

	protected $breaksEnabled;

	function setMarkupEscaped($markupEscaped)
	{
		$this->markupEscaped = $markupEscaped;

		return $this;
	}

	protected $markupEscaped;

	function setUrlsLinked($urlsLinked)
	{
		$this->urlsLinked = $urlsLinked;

		return $this;
	}

	protected $urlsLinked = true;

	function setSafeMode($safeMode)
	{
		$this->safeMode = (bool) $safeMode;

		return $this;
	}

	protected $safeMode;

	function setStrictMode($strictMode)
	{
		$this->strictMode = (bool) $strictMode;

		return $this;
	}

	protected $strictMode;

	protected $safeLinksWhitelist = array(
		'http://',
		'https://',
		'ftp://',
		'ftps://',
		'mailto:',
		'tel:',
		'data:image/png;base64,',
		'data:image/gif;base64,',
		'data:image/jpeg;base64,',
		'irc:',
		'ircs:',
		'git:',
		'ssh:',
		'news:',
		'steam:',
	);

	#
	# Lines
	#

	protected $BlockTypes = array(
		'#' => array('Header'),
		'*' => array('Rule', 'List'),
		'+' => array('List'),
		'-' => array('SetextHeader', 'Table', 'Rule', 'List'),
		'0' => array('List'),
		'1' => array('List'),
		'2' => array('List'),
		'3' => array('List'),
		'4' => array('List'),
		'5' => array('List'),
		'6' => array('List'),
		'7' => array('List'),
		'8' => array('List'),
		'9' => array('List'),
		':' => array('Table'),
		'<' => array('Comment', 'Markup'),
		'=' => array('SetextHeader'),
		'>' => array('Quote'),
		'[' => array('Reference'),
		'_' => array('Rule'),
		'`' => array('FencedCode'),
		'|' => array('Table'),
		'~' => array('FencedCode'),
	);

	# ~

	protected $unmarkedBlockTypes = array(
		'Code',
	);

	#
	# Blocks
	#

	protected function lines(array $lines)
	{
		return $this->elements($this->linesElements($lines));
	}

	protected function linesElements(array $lines)
	{
		$Elements = array();
		$CurrentBlock = null;

		foreach ($lines as $line)
		{
			if (chop($line) === '')
			{
				if (isset($CurrentBlock))
				{
					$CurrentBlock['interrupted'] = (isset($CurrentBlock['interrupted'])
						? $CurrentBlock['interrupted'] + 1 : 1
						);
				}

				continue;
			}

			while (($beforeTab = strstr($line, "\t", true)) !== false)
			{
				$shortage = 4 - mb_strlen($beforeTab, 'utf-8') % 4;

				$line = $beforeTab
				. str_repeat(' ', $shortage)
				. substr($line, strlen($beforeTab) + 1)
				;
			}

			$indent = strspn($line, ' ');

			$text = $indent > 0 ? substr($line, $indent) : $line;

			# ~

			$Line = array('body' => $line, 'indent' => $indent, 'text' => $text);

			# ~

			if (isset($CurrentBlock['continuable']))
			{
				$methodName = 'block' . $CurrentBlock['type'] . 'Continue';
				$Block = $this->$methodName($Line, $CurrentBlock);

				if (isset($Block))
				{
					$CurrentBlock = $Block;

					continue;
				}
				else
				{
					if ($this->isBlockCompletable($CurrentBlock['type']))
					{
						$methodName = 'block' . $CurrentBlock['type'] . 'Complete';
						$CurrentBlock = $this->$methodName($CurrentBlock);
					}
				}
			}

			# ~

			$marker = $text[0];

			# ~

			$blockTypes = $this->unmarkedBlockTypes;

			if (isset($this->BlockTypes[$marker]))
			{
				foreach ($this->BlockTypes[$marker] as $blockType)
				{
					$blockTypes []= $blockType;
				}
			}

			#
			# ~

			foreach ($blockTypes as $blockType)
			{
				$Block = $this->{"block$blockType"}($Line, $CurrentBlock);

				if (isset($Block))
				{
					$Block['type'] = $blockType;

					if ( ! isset($Block['identified']))
					{
						if (isset($CurrentBlock))
						{
							$Elements[] = $this->extractElement($CurrentBlock);
						}

						$Block['identified'] = true;
					}

					if ($this->isBlockContinuable($blockType))
					{
						$Block['continuable'] = true;
					}

					$CurrentBlock = $Block;

					continue 2;
				}
			}

			# ~

			if (isset($CurrentBlock) and $CurrentBlock['type'] === 'Paragraph')
			{
				$Block = $this->paragraphContinue($Line, $CurrentBlock);
			}

			if (isset($Block))
			{
				$CurrentBlock = $Block;
			}
			else
			{
				if (isset($CurrentBlock))
				{
					$Elements[] = $this->extractElement($CurrentBlock);
				}

				$CurrentBlock = $this->paragraph($Line);

				$CurrentBlock['identified'] = true;
			}
		}

		# ~

		if (isset($CurrentBlock['continuable']) and $this->isBlockCompletable($CurrentBlock['type']))
		{
			$methodName = 'block' . $CurrentBlock['type'] . 'Complete';
			$CurrentBlock = $this->$methodName($CurrentBlock);
		}

		# ~

		if (isset($CurrentBlock))
		{
			$Elements[] = $this->extractElement($CurrentBlock);
		}

		# ~

		return $Elements;
	}

	protected function extractElement(array $Component)
	{
		if ( ! isset($Component['element']))
		{
			if (isset($Component['markup']))
			{
				$Component['element'] = array('rawHtml' => $Component['markup']);
			}
			elseif (isset($Component['hidden']))
			{
				$Component['element'] = array();
			}
		}

		return $Component['element'];
	}

	protected function isBlockContinuable($Type)
	{
		return method_exists($this, 'block' . $Type . 'Continue');
	}

	protected function isBlockCompletable($Type)
	{
		return method_exists($this, 'block' . $Type . 'Complete');
	}

	#
	# Code

	protected function blockCode($Line, $Block = null)
	{
		if (isset($Block) and $Block['type'] === 'Paragraph' and ! isset($Block['interrupted']))
		{
			return;
		}

		if ($Line['indent'] >= 4)
		{
			$text = substr($Line['body'], 4);

			$Block = array(
				'element' => array(
					'name' => 'pre',
					'element' => array(
						'name' => 'code',
						'text' => $text,
					),
				),
			);

			return $Block;
		}
	}

	protected function blockCodeContinue($Line, $Block)
	{
		if ($Line['indent'] >= 4)
		{
			if (isset($Block['interrupted']))
			{
				$Block['element']['element']['text'] .= str_repeat("\n", $Block['interrupted']);

				unset($Block['interrupted']);
			}

			$Block['element']['element']['text'] .= "\n";

			$text = substr($Line['body'], 4);

			$Block['element']['element']['text'] .= $text;

			return $Block;
		}
	}

	protected function blockCodeComplete($Block)
	{
		return $Block;
	}

	#
	# Comment

	protected function blockComment($Line)
	{
		if ($this->markupEscaped or $this->safeMode)
		{
			return;
		}

		if (strpos($Line['text'], '<!--') === 0)
		{
			$Block = array(
				'element' => array(
					'rawHtml' => $Line['body'],
					'autobreak' => true,
				),
			);

			if (strpos($Line['text'], '-->') !== false)
			{
				$Block['closed'] = true;
			}

			return $Block;
		}
	}

	protected function blockCommentContinue($Line, array $Block)
	{
		if (isset($Block['closed']))
		{
			return;
		}

		$Block['element']['rawHtml'] .= "\n" . $Line['body'];

		if (strpos($Line['text'], '-->') !== false)
		{
			$Block['closed'] = true;
		}

		return $Block;
	}

	#
	# Fenced Code

	protected function blockFencedCode($Line)
	{
		$marker = $Line['text'][0];

		$openerLength = strspn($Line['text'], $marker);

		if ($openerLength < 3)
		{
			return;
		}

		$infostring = trim(substr($Line['text'], $openerLength), "\t ");

		if (strpos($infostring, '`') !== false)
		{
			return;
		}

		$Element = array(
			'name' => 'code',
			'text' => '',
		);

		if ($infostring !== '')
		{
			/**
			 * https://www.w3.org/TR/2011/WD-html5-20110525/elements.html#classes
			 * Every HTML element may have a class attribute specified.
			 * The attribute, if specified, must have a value that is a set
			 * of space-separated tokens representing the various classes
			 * that the element belongs to.
			 * [...]
			 * The space characters, for the purposes of this specification,
			 * are U+0020 SPACE, U+0009 CHARACTER TABULATION (tab),
			 * U+000A LINE FEED (LF), U+000C FORM FEED (FF), and
			 * U+000D CARRIAGE RETURN (CR).
			 */
			$language = substr($infostring, 0, strcspn($infostring, " \t\n\f\r"));

			$Element['attributes'] = array('class' => "language-$language");
		}

		$Block = array(
			'char' => $marker,
			'openerLength' => $openerLength,
			'element' => array(
				'name' => 'pre',
				'element' => $Element,
			),
		);

		return $Block;
	}

	protected function blockFencedCodeContinue($Line, $Block)
	{
		if (isset($Block['complete']))
		{
			return;
		}

		if (isset($Block['interrupted']))
		{
			$Block['element']['element']['text'] .= str_repeat("\n", $Block['interrupted']);

			unset($Block['interrupted']);
		}

		if (($len = strspn($Line['text'], $Block['char'])) >= $Block['openerLength']
			and chop(substr($Line['text'], $len), ' ') === ''
			) {
				$Block['element']['element']['text'] = substr($Block['element']['element']['text'], 1);

				$Block['complete'] = true;

				return $Block;
			}

			$Block['element']['element']['text'] .= "\n" . $Line['body'];

			return $Block;
	}

	protected function blockFencedCodeComplete($Block)
	{
		return $Block;
	}

	#
	# Header

	protected function blockHeader($Line)
	{
		$level = strspn($Line['text'], '#');

		if ($level > 6)
		{
			return;
		}

		$text = trim($Line['text'], '#');

		if ($this->strictMode and isset($text[0]) and $text[0] !== ' ')
		{
			return;
		}

		$text = trim($text, ' ');

		$Block = array(
			'element' => array(
				'name' => 'h' . $level,
				'handler' => array(
					'function' => 'lineElements',
					'argument' => $text,
					'destination' => 'elements',
				)
			),
		);

		return $Block;
	}

	#
	# List

	protected function blockList($Line, $CurrentBlock = null)
	{
		list($name, $pattern) = $Line['text'][0] <= '-' ? array('ul', '[*+-]') : array('ol', '[0-9]{1,9}+[.\)]');

		if (preg_match('/^('.$pattern.'([ ]++|$))(.*+)/', $Line['text'], $matches))
		{
			$contentIndent = strlen($matches[2]);

			if ($contentIndent >= 5)
			{
				$contentIndent -= 1;
				$matches[1] = substr($matches[1], 0, -$contentIndent);
				$matches[3] = str_repeat(' ', $contentIndent) . $matches[3];
			}
			elseif ($contentIndent === 0)
			{
				$matches[1] .= ' ';
			}

			$markerWithoutWhitespace = strstr($matches[1], ' ', true);

			$Block = array(
				'indent' => $Line['indent'],
				'pattern' => $pattern,
				'data' => array(
					'type' => $name,
					'marker' => $matches[1],
					'markerType' => ($name === 'ul' ? $markerWithoutWhitespace : substr($markerWithoutWhitespace, -1)),
				),
				'element' => array(
					'name' => $name,
					'elements' => array(),
				),
			);
			$Block['data']['markerTypeRegex'] = preg_quote($Block['data']['markerType'], '/');

			if ($name === 'ol')
			{
				$listStart = ltrim(strstr($matches[1], $Block['data']['markerType'], true), '0') ?: '0';

				if ($listStart !== '1')
				{
					if (
						isset($CurrentBlock)
						and $CurrentBlock['type'] === 'Paragraph'
						and ! isset($CurrentBlock['interrupted'])
						) {
							return;
						}

						$Block['element']['attributes'] = array('start' => $listStart);
				}
			}

			$Block['li'] = array(
				'name' => 'li',
				'handler' => array(
					'function' => 'li',
					'argument' => !empty($matches[3]) ? array($matches[3]) : array(),
					'destination' => 'elements'
				)
			);

			$Block['element']['elements'] []= & $Block['li'];

			return $Block;
		}
	}

	protected function blockListContinue($Line, array $Block)
	{
		if (isset($Block['interrupted']) and empty($Block['li']['handler']['argument']))
		{
			return null;
		}

		$requiredIndent = ($Block['indent'] + strlen($Block['data']['marker']));

		if ($Line['indent'] < $requiredIndent
			and (
				(
					$Block['data']['type'] === 'ol'
					and preg_match('/^[0-9]++'.$Block['data']['markerTypeRegex'].'(?:[ ]++(.*)|$)/', $Line['text'], $matches)
					) or (
						$Block['data']['type'] === 'ul'
						and preg_match('/^'.$Block['data']['markerTypeRegex'].'(?:[ ]++(.*)|$)/', $Line['text'], $matches)
						)
				)
			) {
				if (isset($Block['interrupted']))
				{
					$Block['li']['handler']['argument'] []= '';

					$Block['loose'] = true;

					unset($Block['interrupted']);
				}

				unset($Block['li']);

				$text = isset($matches[1]) ? $matches[1] : '';

				$Block['indent'] = $Line['indent'];

				$Block['li'] = array(
					'name' => 'li',
					'handler' => array(
						'function' => 'li',
						'argument' => array($text),
						'destination' => 'elements'
					)
				);

				$Block['element']['elements'] []= & $Block['li'];

				return $Block;
			}
			elseif ($Line['indent'] < $requiredIndent and $this->blockList($Line))
			{
				return null;
			}

			if ($Line['text'][0] === '[' and $this->blockReference($Line))
			{
				return $Block;
			}

			if ($Line['indent'] >= $requiredIndent)
			{
				if (isset($Block['interrupted']))
				{
					$Block['li']['handler']['argument'] []= '';

					$Block['loose'] = true;

					unset($Block['interrupted']);
				}

				$text = substr($Line['body'], $requiredIndent);

				$Block['li']['handler']['argument'] []= $text;

				return $Block;
			}

			if ( ! isset($Block['interrupted']))
			{
				$text = preg_replace('/^[ ]{0,'.$requiredIndent.'}+/', '', $Line['body']);

				$Block['li']['handler']['argument'] []= $text;

				return $Block;
			}
	}

	protected function blockListComplete(array $Block)
	{
		if (isset($Block['loose']))
		{
			foreach ($Block['element']['elements'] as &$li)
			{
				if (end($li['handler']['argument']) !== '')
				{
					$li['handler']['argument'] []= '';
				}
			}
		}

		return $Block;
	}

	#
	# Quote

	protected function blockQuote($Line)
	{
		if (preg_match('/^>[ ]?+(.*+)/', $Line['text'], $matches))
		{
			$Block = array(
				'element' => array(
					'name' => 'blockquote',
					'handler' => array(
						'function' => 'linesElements',
						'argument' => (array) $matches[1],
						'destination' => 'elements',
					)
				),
			);

			return $Block;
		}
	}

	protected function blockQuoteContinue($Line, array $Block)
	{
		if (isset($Block['interrupted']))
		{
			return;
		}

		if ($Line['text'][0] === '>' and preg_match('/^>[ ]?+(.*+)/', $Line['text'], $matches))
		{
			$Block['element']['handler']['argument'] []= $matches[1];

			return $Block;
		}

		if ( ! isset($Block['interrupted']))
		{
			$Block['element']['handler']['argument'] []= $Line['text'];

			return $Block;
		}
	}

	#
	# Rule

	protected function blockRule($Line)
	{
		$marker = $Line['text'][0];

		if (substr_count($Line['text'], $marker) >= 3 and chop($Line['text'], " $marker") === '')
		{
			$Block = array(
				'element' => array(
					'name' => 'hr',
				),
			);

			return $Block;
		}
	}

	#
	# Setext

	protected function blockSetextHeader($Line, $Block = null)
	{
		if ( ! isset($Block) or $Block['type'] !== 'Paragraph' or isset($Block['interrupted']))
		{
			return;
		}

		if ($Line['indent'] < 4 and chop(chop($Line['text'], ' '), $Line['text'][0]) === '')
		{
			$Block['element']['name'] = $Line['text'][0] === '=' ? 'h1' : 'h2';

			return $Block;
		}
	}

	#
	# Markup

	protected function blockMarkup($Line)
	{
		if ($this->markupEscaped or $this->safeMode)
		{
			return;
		}

		if (preg_match('/^<[\/]?+(\w*)(?:[ ]*+'.$this->regexHtmlAttribute.')*+[ ]*+(\/)?>/', $Line['text'], $matches))
		{
			$element = strtolower($matches[1]);

			if (in_array($element, $this->textLevelElements))
			{
				return;
			}

			$Block = array(
				'name' => $matches[1],
				'element' => array(
					'rawHtml' => $Line['text'],
					'autobreak' => true,
				),
			);

			return $Block;
		}
	}

	protected function blockMarkupContinue($Line, array $Block)
	{
		if (isset($Block['closed']) or isset($Block['interrupted']))
		{
			return;
		}

		$Block['element']['rawHtml'] .= "\n" . $Line['body'];

		return $Block;
	}

	#
	# Reference

	protected function blockReference($Line)
	{
		if (strpos($Line['text'], ']') !== false
			and preg_match('/^\[(.+?)\]:[ ]*+<?(\S+?)>?(?:[ ]+["\'(](.+)["\')])?[ ]*+$/', $Line['text'], $matches)
			) {
				$id = strtolower($matches[1]);

				$Data = array(
					'url' => $matches[2],
					'title' => isset($matches[3]) ? $matches[3] : null,
				);

				$this->DefinitionData['Reference'][$id] = $Data;

				$Block = array(
					'element' => array(),
				);

				return $Block;
			}
	}

	#
	# Table

	protected function blockTable($Line, array $Block = null)
	{
		if ( ! isset($Block) or $Block['type'] !== 'Paragraph' or isset($Block['interrupted']))
		{
			return;
		}

		if (
			strpos($Block['element']['handler']['argument'], '|') === false
			and strpos($Line['text'], '|') === false
			and strpos($Line['text'], ':') === false
			or strpos($Block['element']['handler']['argument'], "\n") !== false
			) {
				return;
			}

			if (chop($Line['text'], ' -:|') !== '')
			{
				return;
			}

			$alignments = array();

			$divider = $Line['text'];

			$divider = trim($divider);
			$divider = trim($divider, '|');

			$dividerCells = explode('|', $divider);

			foreach ($dividerCells as $dividerCell)
			{
				$dividerCell = trim($dividerCell);

				if ($dividerCell === '')
				{
					return;
				}

				$alignment = null;

				if ($dividerCell[0] === ':')
				{
					$alignment = 'left';
				}

				if (substr($dividerCell, - 1) === ':')
				{
					$alignment = $alignment === 'left' ? 'center' : 'right';
				}

				$alignments []= $alignment;
			}

			# ~

			$HeaderElements = array();

			$header = $Block['element']['handler']['argument'];

			$header = trim($header);
			$header = trim($header, '|');

			$headerCells = explode('|', $header);

			if (count($headerCells) !== count($alignments))
			{
				return;
			}

			foreach ($headerCells as $index => $headerCell)
			{
				$headerCell = trim($headerCell);

				$HeaderElement = array(
					'name' => 'th',
					'handler' => array(
						'function' => 'lineElements',
						'argument' => $headerCell,
						'destination' => 'elements',
					)
				);

				if (isset($alignments[$index]))
				{
					$alignment = $alignments[$index];

					$HeaderElement['attributes'] = array(
						'style' => "text-align: $alignment;",
					);
				}

				$HeaderElements []= $HeaderElement;
			}

			# ~

			$Block = array(
				'alignments' => $alignments,
				'identified' => true,
				'element' => array(
					'name' => 'table',
					'elements' => array(),
				),
			);

			$Block['element']['elements'] []= array(
				'name' => 'thead',
			);

			$Block['element']['elements'] []= array(
				'name' => 'tbody',
				'elements' => array(),
			);

			$Block['element']['elements'][0]['elements'] []= array(
				'name' => 'tr',
				'elements' => $HeaderElements,
			);

			return $Block;
	}

	protected function blockTableContinue($Line, array $Block)
	{
		if (isset($Block['interrupted']))
		{
			return;
		}

		if (count($Block['alignments']) === 1 or $Line['text'][0] === '|' or strpos($Line['text'], '|'))
		{
			$Elements = array();

			$row = $Line['text'];

			$row = trim($row);
			$row = trim($row, '|');

			preg_match_all('/(?:(\\\\[|])|[^|`]|`[^`]++`|`)++/', $row, $matches);

			$cells = array_slice($matches[0], 0, count($Block['alignments']));

			foreach ($cells as $index => $cell)
			{
				$cell = trim($cell);

				$Element = array(
					'name' => 'td',
					'handler' => array(
						'function' => 'lineElements',
						'argument' => $cell,
						'destination' => 'elements',
					)
				);

				if (isset($Block['alignments'][$index]))
				{
					$Element['attributes'] = array(
						'style' => 'text-align: ' . $Block['alignments'][$index] . ';',
					);
				}

				$Elements []= $Element;
			}

			$Element = array(
				'name' => 'tr',
				'elements' => $Elements,
			);

			$Block['element']['elements'][1]['elements'] []= $Element;

			return $Block;
		}
	}

	#
	# ~
	#

	protected function paragraph($Line)
	{
		return array(
			'type' => 'Paragraph',
			'element' => array(
				'name' => 'p',
				'handler' => array(
					'function' => 'lineElements',
					'argument' => $Line['text'],
					'destination' => 'elements',
				),
			),
		);
	}

	protected function paragraphContinue($Line, array $Block)
	{
		if (isset($Block['interrupted']))
		{
			return;
		}

		$Block['element']['handler']['argument'] .= "\n".$Line['text'];

		return $Block;
	}

	#
	# Inline Elements
	#

	protected $InlineTypes = array(
		'!' => array('Image'),
		'&' => array('SpecialCharacter'),
		'*' => array('Emphasis'),
		':' => array('Url'),
		'<' => array('UrlTag', 'EmailTag', 'Markup'),
		'[' => array('Link'),
		'_' => array('Emphasis'),
		'`' => array('Code'),
		'~' => array('Strikethrough'),
		'\\' => array('EscapeSequence'),
	);

	# ~

	protected $inlineMarkerList = '!*_&[:<`~\\';

	#
	# ~
	#

	public function line($text, $nonNestables = array())
	{
		return $this->elements($this->lineElements($text, $nonNestables));
	}

	protected function lineElements($text, $nonNestables = array())
	{
		# standardize line breaks
		$text = str_replace(array("\r\n", "\r"), "\n", $text);

		$Elements = array();

		$nonNestables = (empty($nonNestables)
			? array()
			: array_combine($nonNestables, $nonNestables)
			);

		# $excerpt is based on the first occurrence of a marker

		while ($excerpt = strpbrk($text, $this->inlineMarkerList))
		{
			$marker = $excerpt[0];

			$markerPosition = strlen($text) - strlen($excerpt);

			$Excerpt = array('text' => $excerpt, 'context' => $text);

			foreach ($this->InlineTypes[$marker] as $inlineType)
			{
				# check to see if the current inline type is nestable in the current context

				if (isset($nonNestables[$inlineType]))
				{
					continue;
				}

				$Inline = $this->{"inline$inlineType"}($Excerpt);

				if ( ! isset($Inline))
				{
					continue;
				}

				# makes sure that the inline belongs to "our" marker

				if (isset($Inline['position']) and $Inline['position'] > $markerPosition)
				{
					continue;
				}

				# sets a default inline position

				if ( ! isset($Inline['position']))
				{
					$Inline['position'] = $markerPosition;
				}

				# cause the new element to 'inherit' our non nestables


				$Inline['element']['nonNestables'] = isset($Inline['element']['nonNestables'])
				? array_merge($Inline['element']['nonNestables'], $nonNestables)
				: $nonNestables
				;

				# the text that comes before the inline
				$unmarkedText = substr($text, 0, $Inline['position']);

				# compile the unmarked text
				$InlineText = $this->inlineText($unmarkedText);
				$Elements[] = $InlineText['element'];

				# compile the inline
				$Elements[] = $this->extractElement($Inline);

				# remove the examined text
				$text = substr($text, $Inline['position'] + $Inline['extent']);

				continue 2;
			}

			# the marker does not belong to an inline

			$unmarkedText = substr($text, 0, $markerPosition + 1);

			$InlineText = $this->inlineText($unmarkedText);
			$Elements[] = $InlineText['element'];

			$text = substr($text, $markerPosition + 1);
		}

		$InlineText = $this->inlineText($text);
		$Elements[] = $InlineText['element'];

		foreach ($Elements as &$Element)
		{
			if ( ! isset($Element['autobreak']))
			{
				$Element['autobreak'] = false;
			}
		}

		return $Elements;
	}

	#
	# ~
	#

	protected function inlineText($text)
	{
		$Inline = array(
			'extent' => strlen($text),
			'element' => array(),
		);

		$Inline['element']['elements'] = self::pregReplaceElements(
			$this->breaksEnabled ? '/[ ]*+\n/' : '/(?:[ ]*+\\\\|[ ]{2,}+)\n/',
			array(
				array('name' => 'br'),
				array('text' => "\n"),
			),
			$text
			);

		return $Inline;
	}

	protected function inlineCode($Excerpt)
	{
		$marker = $Excerpt['text'][0];

		if (preg_match('/^(['.$marker.']++)[ ]*+(.+?)[ ]*+(?<!['.$marker.'])\1(?!'.$marker.')/s', $Excerpt['text'], $matches))
		{
			$text = $matches[2];
			$text = preg_replace('/[ ]*+\n/', ' ', $text);

			return array(
				'extent' => strlen($matches[0]),
				'element' => array(
					'name' => 'code',
					'text' => $text,
				),
			);
		}
	}

	protected function inlineEmailTag($Excerpt)
	{
		$hostnameLabel = '[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?';

		$commonMarkEmail = '[a-zA-Z0-9.!#$%&\'*+\/=?^_`{|}~-]++@'
			. $hostnameLabel . '(?:\.' . $hostnameLabel . ')*';

			if (strpos($Excerpt['text'], '>') !== false
				and preg_match("/^<((mailto:)?$commonMarkEmail)>/i", $Excerpt['text'], $matches)
				){
					$url = $matches[1];

					if ( ! isset($matches[2]))
					{
						$url = "mailto:$url";
					}

					return array(
						'extent' => strlen($matches[0]),
						'element' => array(
							'name' => 'a',
							'text' => $matches[1],
							'attributes' => array(
								'href' => $url,
							),
						),
					);
			}
	}

	protected function inlineEmphasis($Excerpt)
	{
		if ( ! isset($Excerpt['text'][1]))
		{
			return;
		}

		$marker = $Excerpt['text'][0];

		if ($Excerpt['text'][1] === $marker and preg_match($this->StrongRegex[$marker], $Excerpt['text'], $matches))
		{
			$emphasis = 'strong';
		}
		elseif (preg_match($this->EmRegex[$marker], $Excerpt['text'], $matches))
		{
			$emphasis = 'em';
		}
		else
		{
			return;
		}

		return array(
			'extent' => strlen($matches[0]),
			'element' => array(
				'name' => $emphasis,
				'handler' => array(
					'function' => 'lineElements',
					'argument' => $matches[1],
					'destination' => 'elements',
				)
			),
		);
	}

	protected function inlineEscapeSequence($Excerpt)
	{
		if (isset($Excerpt['text'][1]) and in_array($Excerpt['text'][1], $this->specialCharacters))
		{
			return array(
				'element' => array('rawHtml' => $Excerpt['text'][1]),
				'extent' => 2,
			);
		}
	}

	protected function inlineImage($Excerpt)
	{
		if ( ! isset($Excerpt['text'][1]) or $Excerpt['text'][1] !== '[')
		{
			return;
		}

		$Excerpt['text']= substr($Excerpt['text'], 1);

		$Link = $this->inlineLink($Excerpt);

		if ($Link === null)
		{
			return;
		}

		$Inline = array(
			'extent' => $Link['extent'] + 1,
			'element' => array(
				'name' => 'img',
				'attributes' => array(
					'src' => $Link['element']['attributes']['href'],
					'alt' => $Link['element']['handler']['argument'],
				),
				'autobreak' => true,
			),
		);

		$Inline['element']['attributes'] += $Link['element']['attributes'];

		unset($Inline['element']['attributes']['href']);

		return $Inline;
	}

	protected function inlineLink($Excerpt)
	{
		$Element = array(
			'name' => 'a',
			'handler' => array(
				'function' => 'lineElements',
				'argument' => null,
				'destination' => 'elements',
			),
			'nonNestables' => array('Url', 'Link'),
			'attributes' => array(
				'href' => null,
				'title' => null,
			),
		);

		$extent = 0;

		$remainder = $Excerpt['text'];

		if (preg_match('/\[((?:[^][]++|(?R))*+)\]/', $remainder, $matches))
		{
			$Element['handler']['argument'] = $matches[1];

			$extent += strlen($matches[0]);

			$remainder = substr($remainder, $extent);
		}
		else
		{
			return;
		}

		if (preg_match('/^[(]\s*+((?:[^ ()]++|[(][^ )]+[)])++)(?:[ ]+("[^"]*+"|\'[^\']*+\'))?\s*+[)]/', $remainder, $matches))
		{
			$Element['attributes']['href'] = $matches[1];

			if (isset($matches[2]))
			{
				$Element['attributes']['title'] = substr($matches[2], 1, - 1);
			}

			$extent += strlen($matches[0]);
		}
		else
		{
			if (preg_match('/^\s*\[(.*?)\]/', $remainder, $matches))
			{
				$definition = strlen($matches[1]) ? $matches[1] : $Element['handler']['argument'];
				$definition = strtolower($definition);

				$extent += strlen($matches[0]);
			}
			else
			{
				$definition = strtolower($Element['handler']['argument']);
			}

			if ( ! isset($this->DefinitionData['Reference'][$definition]))
			{
				return;
			}

			$Definition = $this->DefinitionData['Reference'][$definition];

			$Element['attributes']['href'] = $Definition['url'];
			$Element['attributes']['title'] = $Definition['title'];
		}

		return array(
			'extent' => $extent,
			'element' => $Element,
		);
	}

	protected function inlineMarkup($Excerpt)
	{
		if ($this->markupEscaped or $this->safeMode or strpos($Excerpt['text'], '>') === false)
		{
			return;
		}

		if ($Excerpt['text'][1] === '/' and preg_match('/^<\/\w[\w-]*+[ ]*+>/s', $Excerpt['text'], $matches))
		{
			return array(
				'element' => array('rawHtml' => $matches[0]),
				'extent' => strlen($matches[0]),
			);
		}

		if ($Excerpt['text'][1] === '!' and preg_match('/^<!---?[^>-](?:-?+[^-])*-->/s', $Excerpt['text'], $matches))
		{
			return array(
				'element' => array('rawHtml' => $matches[0]),
				'extent' => strlen($matches[0]),
			);
		}

		if ($Excerpt['text'][1] !== ' ' and preg_match('/^<\w[\w-]*+(?:[ ]*+'.$this->regexHtmlAttribute.')*+[ ]*+\/?>/s', $Excerpt['text'], $matches))
		{
			return array(
				'element' => array('rawHtml' => $matches[0]),
				'extent' => strlen($matches[0]),
			);
		}
	}

	protected function inlineSpecialCharacter($Excerpt)
	{
		if (substr($Excerpt['text'], 1, 1) !== ' ' and strpos($Excerpt['text'], ';') !== false
			and preg_match('/^&(#?+[0-9a-zA-Z]++);/', $Excerpt['text'], $matches)
			) {
				return array(
					'element' => array('rawHtml' => '&' . $matches[1] . ';'),
					'extent' => strlen($matches[0]),
				);
			}

			return;
	}

	protected function inlineStrikethrough($Excerpt)
	{
		if ( ! isset($Excerpt['text'][1]))
		{
			return;
		}

		if ($Excerpt['text'][1] === '~' and preg_match('/^~~(?=\S)(.+?)(?<=\S)~~/', $Excerpt['text'], $matches))
		{
			return array(
				'extent' => strlen($matches[0]),
				'element' => array(
					'name' => 'del',
					'handler' => array(
						'function' => 'lineElements',
						'argument' => $matches[1],
						'destination' => 'elements',
					)
				),
			);
		}
	}

	protected function inlineUrl($Excerpt)
	{
		if ($this->urlsLinked !== true or ! isset($Excerpt['text'][2]) or $Excerpt['text'][2] !== '/')
		{
			return;
		}

		if (strpos($Excerpt['context'], 'http') !== false
			and preg_match('/\bhttps?+:[\/]{2}[^\s<]+\b\/*+/ui', $Excerpt['context'], $matches, PREG_OFFSET_CAPTURE)
			) {
				$url = $matches[0][0];

				$Inline = array(
					'extent' => strlen($matches[0][0]),
					'position' => $matches[0][1],
					'element' => array(
						'name' => 'a',
						'text' => $url,
						'attributes' => array(
							'href' => $url,
						),
					),
				);

				return $Inline;
			}
	}

	protected function inlineUrlTag($Excerpt)
	{
		if (strpos($Excerpt['text'], '>') !== false and preg_match('/^<(\w++:\/{2}[^ >]++)>/i', $Excerpt['text'], $matches))
		{
			$url = $matches[1];

			return array(
				'extent' => strlen($matches[0]),
				'element' => array(
					'name' => 'a',
					'text' => $url,
					'attributes' => array(
						'href' => $url,
					),
				),
			);
		}
	}

	# ~

	protected function unmarkedText($text)
	{
		$Inline = $this->inlineText($text);
		return $this->element($Inline['element']);
	}

	#
	# Handlers
	#

	protected function handle(array $Element)
	{
		if (isset($Element['handler']))
		{
			if (!isset($Element['nonNestables']))
			{
				$Element['nonNestables'] = array();
			}

			if (is_string($Element['handler']))
			{
				$function = $Element['handler'];
				$argument = $Element['text'];
				unset($Element['text']);
				$destination = 'rawHtml';
			}
			else
			{
				$function = $Element['handler']['function'];
				$argument = $Element['handler']['argument'];
				$destination = $Element['handler']['destination'];
			}

			$Element[$destination] = $this->{$function}($argument, $Element['nonNestables']);

			if ($destination === 'handler')
			{
				$Element = $this->handle($Element);
			}

			unset($Element['handler']);
		}

		return $Element;
	}

	protected function handleElementRecursive(array $Element)
	{
		return $this->elementApplyRecursive(array($this, 'handle'), $Element);
	}

	protected function handleElementsRecursive(array $Elements)
	{
		return $this->elementsApplyRecursive(array($this, 'handle'), $Elements);
	}

	protected function elementApplyRecursive($closure, array $Element)
	{
		$Element = call_user_func($closure, $Element);

		if (isset($Element['elements']))
		{
			$Element['elements'] = $this->elementsApplyRecursive($closure, $Element['elements']);
		}
		elseif (isset($Element['element']))
		{
			$Element['element'] = $this->elementApplyRecursive($closure, $Element['element']);
		}

		return $Element;
	}

	protected function elementApplyRecursiveDepthFirst($closure, array $Element)
	{
		if (isset($Element['elements']))
		{
			$Element['elements'] = $this->elementsApplyRecursiveDepthFirst($closure, $Element['elements']);
		}
		elseif (isset($Element['element']))
		{
			$Element['element'] = $this->elementsApplyRecursiveDepthFirst($closure, $Element['element']);
		}

		$Element = call_user_func($closure, $Element);

		return $Element;
	}

	protected function elementsApplyRecursive($closure, array $Elements)
	{
		foreach ($Elements as &$Element)
		{
			$Element = $this->elementApplyRecursive($closure, $Element);
		}

		return $Elements;
	}

	protected function elementsApplyRecursiveDepthFirst($closure, array $Elements)
	{
		foreach ($Elements as &$Element)
		{
			$Element = $this->elementApplyRecursiveDepthFirst($closure, $Element);
		}

		return $Elements;
	}

	protected function element(array $Element)
	{
		if ($this->safeMode)
		{
			$Element = $this->sanitiseElement($Element);
		}

		# identity map if element has no handler
		$Element = $this->handle($Element);

		$hasName = isset($Element['name']);

		$markup = '';

		if ($hasName)
		{
			$markup .= '<' . $Element['name'];

			if (isset($Element['attributes']))
			{
				foreach ($Element['attributes'] as $name => $value)
				{
					if ($value === null)
					{
						continue;
					}

					$markup .= " $name=\"".self::escape($value).'"';
				}
			}
		}

		$permitRawHtml = false;

		if (isset($Element['text']))
		{
			$text = $Element['text'];
		}
		// very strongly consider an alternative if you're writing an
		// extension
		elseif (isset($Element['rawHtml']))
		{
			$text = $Element['rawHtml'];

			$allowRawHtmlInSafeMode = isset($Element['allowRawHtmlInSafeMode']) && $Element['allowRawHtmlInSafeMode'];
			$permitRawHtml = !$this->safeMode || $allowRawHtmlInSafeMode;
		}

		$hasContent = isset($text) || isset($Element['element']) || isset($Element['elements']);

		if ($hasContent)
		{
			$markup .= $hasName ? '>' : '';

			if (isset($Element['elements']))
			{
				$markup .= $this->elements($Element['elements']);
			}
			elseif (isset($Element['element']))
			{
				$markup .= $this->element($Element['element']);
			}
			else
			{
				if (!$permitRawHtml)
				{
					$markup .= self::escape($text, true);
				}
				else
				{
					$markup .= $text;
				}
			}

			$markup .= $hasName ? '</' . $Element['name'] . '>' : '';
		}
		elseif ($hasName)
		{
			$markup .= ' />';
		}

		return $markup;
	}

	protected function elements(array $Elements)
	{
		$markup = '';

		$autoBreak = true;

		foreach ($Elements as $Element)
		{
			if (empty($Element))
			{
				continue;
			}

			$autoBreakNext = (isset($Element['autobreak'])
				? $Element['autobreak'] : isset($Element['name'])
				);
			// (autobreak === false) covers both sides of an element
			$autoBreak = !$autoBreak ? $autoBreak : $autoBreakNext;

			$markup .= ($autoBreak ? "\n" : '') . $this->element($Element);
			$autoBreak = $autoBreakNext;
		}

		$markup .= $autoBreak ? "\n" : '';

		return $markup;
	}

	# ~

	protected function li($lines)
	{
		$Elements = $this->linesElements($lines);

		if ( ! in_array('', $lines)
			and isset($Elements[0]) and isset($Elements[0]['name'])
			and $Elements[0]['name'] === 'p'
			) {
				unset($Elements[0]['name']);
			}

			return $Elements;
	}

	#
	# AST Convenience
	#

	/**
	 * Replace occurrences $regexp with $Elements in $text. Return an array of
	 * elements representing the replacement.
	 */
	protected static function pregReplaceElements($regexp, $Elements, $text)
	{
		$newElements = array();

		while (preg_match($regexp, $text, $matches, PREG_OFFSET_CAPTURE))
		{
			$offset = $matches[0][1];
			$before = substr($text, 0, $offset);
			$after = substr($text, $offset + strlen($matches[0][0]));

			$newElements[] = array('text' => $before);

			foreach ($Elements as $Element)
			{
				$newElements[] = $Element;
			}

			$text = $after;
		}

		$newElements[] = array('text' => $text);

		return $newElements;
	}

	#
	# Deprecated Methods
	#

	function parse($text)
	{
		$markup = $this->text($text);

		return $markup;
	}

	protected function sanitiseElement(array $Element)
	{
		static $goodAttribute = '/^[a-zA-Z0-9][a-zA-Z0-9-_]*+$/';
		static $safeUrlNameToAtt  = array(
			'a'   => 'href',
			'img' => 'src',
		);

		if ( ! isset($Element['name']))
		{
			unset($Element['attributes']);
			return $Element;
		}

		if (isset($safeUrlNameToAtt[$Element['name']]))
		{
			$Element = $this->filterUnsafeUrlInAttribute($Element, $safeUrlNameToAtt[$Element['name']]);
		}

		if ( ! empty($Element['attributes']))
		{
			foreach ($Element['attributes'] as $att => $val)
			{
				# filter out badly parsed attribute
				if ( ! preg_match($goodAttribute, $att))
				{
					unset($Element['attributes'][$att]);
				}
				# dump onevent attribute
				elseif (self::striAtStart($att, 'on'))
				{
					unset($Element['attributes'][$att]);
				}
			}
		}

		return $Element;
	}

	protected function filterUnsafeUrlInAttribute(array $Element, $attribute)
	{
		foreach ($this->safeLinksWhitelist as $scheme)
		{
			if (self::striAtStart($Element['attributes'][$attribute], $scheme))
			{
				return $Element;
			}
		}

		$Element['attributes'][$attribute] = str_replace(':', '%3A', $Element['attributes'][$attribute]);

		return $Element;
	}

	#
	# Static Methods
	#

	protected static function escape($text, $allowQuotes = false)
	{
		return htmlspecialchars($text, $allowQuotes ? ENT_NOQUOTES : ENT_QUOTES, 'UTF-8');
	}

	protected static function striAtStart($string, $needle)
	{
		$len = strlen($needle);

		if ($len > strlen($string))
		{
			return false;
		}
		else
		{
			return strtolower(substr($string, 0, $len)) === strtolower($needle);
		}
	}

	static function instance($name = 'default')
	{
		if (isset(self::$instances[$name]))
		{
			return self::$instances[$name];
		}

		$instance = new static();

		self::$instances[$name] = $instance;

		return $instance;
	}

	private static $instances = array();

	#
	# Fields
	#

	protected $DefinitionData;

	#
	# Read-Only

	protected $specialCharacters = array(
		'\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '>', '#', '+', '-', '.', '!', '|', '~'
	);

	protected $StrongRegex = array(
		'*' => '/^[*]{2}((?:\\\\\*|[^*]|[*][^*]*+[*])+?)[*]{2}(?![*])/s',
		'_' => '/^__((?:\\\\_|[^_]|_[^_]+_|_[^_]+_[^_]+_)+?)__(?!_)/us',
	);

	protected $EmRegex = array(
		'*' => '/^[*]((?:\\\\\*|[^*]|[*][*][^*]+?[*][*])+?)[*](?![*])/s',
		'_' => '/^_((?:\\\\_|[^_]|__[^_]*__)+?)_(?!_)\b/us',
	);

	protected $regexHtmlAttribute = '[a-zA-Z_:][\w:.-]*+(?:\s*+=\s*+(?:[^"\'=<>`\s]+|"[^"]*+"|\'[^\']*+\'))?+';

	protected $voidElements = array(
		'area', 'base', 'br', 'col', 'command', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source',
	);

	protected $textLevelElements = array(
		'a', 'br', 'bdo', 'abbr', 'blink', 'nextid', 'acronym', 'basefont',
		'b', 'em', 'big', 'cite', 'small', 'spacer', 'listing',
		'i', 'rp', 'del', 'code',          'strike', 'marquee',
		'q', 'rt', 'ins', 'font',          'strong',
		's', 'tt', 'kbd', 'mark',
		'u', 'xm', 'sub', 'nobr',
		'sup', 'ruby',
		'var', 'span',
		'wbr', 'time',
	);
}