<?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

{

    #

    # Philosophy

    #



    # Markdown is intended to be easy-to-read by humans - those of us who read

    # line by line, left to right, top to bottom. In order to take advantage of

    # this, Parsedown tries to read in a similar way. It breaks texts into

    # lines, it iterates through them and it looks at how they start and relate

    # to each other.



    #

    # Setters

    #



    # Enables GFM line breaks.



    function setBreaksEnabled($breaksEnabled)

    {

        $this->breaksEnabled = $breaksEnabled;



        return $this;

    }



    /**

     * For backwards compatibility before PSR-2 naming.

     *

     * @deprecated Use setBreaksEnabled instead.

     */

    function set_breaks_enabled($breaks_enabled)

    {

        return $this->setBreaksEnabled($breaks_enabled);

    }



    private $breaksEnabled = false;



    #

    # Methods

    #



    function parse($text)

    {

        # standardize line breaks

        $text = str_replace("\r\n", "\n", $text);

        $text = str_replace("\r", "\n", $text);



        # replace tabs with spaces

        $text = str_replace("\t", '    ', $text);



        # remove surrounding line breaks

        $text = trim($text, "\n");



        # split text into lines

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



        # iterate through lines to identify blocks

        $blocks = $this->findBlocks($lines);



        # iterate through blocks to build markup

        $markup = $this->compile($blocks);



        # trim line breaks

        $markup = trim($markup, "\n");



        # add .markdown div

        $markup = '<div class="markdown">'.$markup.'</div>';



        return $markup;

    }



    #

    # Private



    private function findBlocks(array $lines, $blockContext = null)

    {

        $block = null;



        $context = null;

        $contextData = null;



        foreach ($lines as $line)

        {

            $indentedLine = $line;



            $indentation = 0;



            while(isset($line[$indentation]) and $line[$indentation] === ' ')

            {

                $indentation++;

            }



            if ($indentation > 0)

            {

                $line = ltrim($line);

            }



            # ~



            switch ($context)

            {

                case null:



                    $contextData = null;



                    if ($line === '')

                    {

                        continue 2;

                    }



                    break;



                # ~~~ javascript

                # var message = 'Hello!';



                case 'fenced code':



                    if ($line === '')

                    {

                        $block['content'][0]['content'] .= "\n";



                        continue 2;

                    }



                    if (preg_match('/^[ ]*'.$contextData['marker'].'{3,}[ ]*$/', $line))

                    {

                        $context = null;

                    }

                    else

                    {

                        if ($block['content'][0]['content'])

                        {

                            $block['content'][0]['content'] .= "\n";

                        }



                        $string = htmlspecialchars($indentedLine, ENT_NOQUOTES, 'UTF-8');



                        $block['content'][0]['content'] .= $string;

                    }



                    continue 2;



                case 'markup':



                    if (stripos($line, $contextData['start']) !== false) # opening tag

                    {

                        $contextData['depth']++;

                    }



                    if (stripos($line, $contextData['end']) !== false) # closing tag

                    {

                        if ($contextData['depth'] > 0)

                        {

                            $contextData['depth']--;

                        }

                        else

                        {

                            $context = null;

                        }

                    }



                    $block['content'] .= "\n".$indentedLine;



                    continue 2;



                case 'li':



                    if ($line === '')

                    {

                        $contextData['interrupted'] = true;



                        continue 2;

                    }



                    if ($contextData['indentation'] === $indentation and preg_match('/^'.$contextData['marker'].'[ ]+(.*)/', $line, $matches))

                    {

                        if (isset($contextData['interrupted']))

                        {

                            $nestedBlock['content'] []= '';



                            unset($contextData['interrupted']);

                        }



                        unset($nestedBlock);



                        $nestedBlock = array(

                            'name' => 'li',

                            'content type' => 'lines',

                            'content' => array(

                                $matches[1],

                            ),

                        );



                        $block['content'] []= & $nestedBlock;



                        continue 2;

                    }



                    if (empty($contextData['interrupted']))

                    {

                        $value = $line;



                        if ($indentation > $contextData['baseline'])

                        {

                            $value = str_repeat(' ', $indentation - $contextData['baseline']) . $value;

                        }



                        $nestedBlock['content'] []= $value;



                        continue 2;

                    }



                    if ($indentation > 0)

                    {

                        $nestedBlock['content'] []= '';



                        $value = $line;



                        if ($indentation > $contextData['baseline'])

                        {

                            $value = str_repeat(' ', $indentation - $contextData['baseline']) . $value;

                        }



                        $nestedBlock['content'] []= $value;



                        unset($contextData['interrupted']);



                        continue 2;

                    }



                    $context = null;



                    break;



                case 'quote':



                    if ($line === '')

                    {

                        $contextData['interrupted'] = true;



                        continue 2;

                    }



                    if (preg_match('/^>[ ]?(.*)/', $line, $matches))

                    {

                        $block['content'] []= $matches[1];



                        continue 2;

                    }



                    if (empty($contextData['interrupted']))

                    {

                        $block['content'] []= $line;



                        continue 2;

                    }



                    $context = null;



                    break;



                case 'code':



                    if ($line === '')

                    {

                        $contextData['interrupted'] = true;



                        continue 2;

                    }



                    if ($indentation >= 4)

                    {

                        if (isset($contextData['interrupted']))

                        {

                            $block['content'][0]['content'] .= "\n";



                            unset($contextData['interrupted']);

                        }



                        $block['content'][0]['content'] .= "\n";



                        $string = htmlspecialchars($line, ENT_NOQUOTES, 'UTF-8');

                        $string = str_repeat(' ', $indentation - 4) . $string;



                        $block['content'][0]['content'] .= $string;



                        continue 2;

                    }



                    $context = null;



                    break;



                case 'table':



                    if ($line === '')

                    {

                        $context = null;



                        continue 2;

                    }



                    if (strpos($line, '|') !== false)

                    {

                        $nestedBlocks = array();



                        $substring = preg_replace('/^[|][ ]*/', '', $line);

                        $substring = preg_replace('/[|]?[ ]*$/', '', $substring);



                        $parts = explode('|', $substring);



                        foreach ($parts as $index => $part)

                        {

                            $substring = trim($part);



                            $nestedBlock = array(

                                'name' => 'td',

                                'content type' => 'line',

                                'content' => $substring,

                            );



                            if (isset($contextData['alignments'][$index]))

                            {

                                $nestedBlock['attributes'] = array(

                                    'align' => $contextData['alignments'][$index],

                                );

                            }



                            $nestedBlocks []= $nestedBlock;

                        }



                        $nestedBlock = array(

                            'name' => 'tr',

                            'content type' => 'blocks',

                            'content' => $nestedBlocks,

                        );



                        $block['content'][1]['content'] []= $nestedBlock;



                        continue 2;

                    }



                    $context = null;



                    break;



                case 'paragraph':



                    if ($line === '')

                    {

                        $block['name'] = 'p'; # dense li



                        $context = null;



                        continue 2;

                    }



                    if ($line[0] === '=' and chop($line, '=') === '')

                    {

                        $block['name'] = 'h1';



                        $context = null;



                        continue 2;

                    }



                    if ($line[0] === '-' and chop($line, '-') === '')

                    {

                        $block['name'] = 'h2';



                        $context = null;



                        continue 2;

                    }



                    if (strpos($line, '|') !== false and strpos($block['content'], '|') !== false and chop($line, ' -:|') === '')

                    {

                        $values = array();



                        $substring = trim($line, ' |');



                        $parts = explode('|', $substring);



                        foreach ($parts as $part)

                        {

                            $substring = trim($part);



                            $value = null;



                            if ($substring[0] === ':')

                            {

                                $value = 'left';

                            }



                            if (substr($substring, -1) === ':')

                            {

                                $value = $value === 'left' ? 'center' : 'right';

                            }



                            $values []= $value;

                        }



                        # ~



                        $nestedBlocks = array();



                        $substring = preg_replace('/^[|][ ]*/', '', $block['content']);

                        $substring = preg_replace('/[|]?[ ]*$/', '', $substring);



                        $parts = explode('|', $substring);



                        foreach ($parts as $index => $part)

                        {

                            $substring = trim($part);



                            $nestedBlock = array(

                                'name' => 'th',

                                'content type' => 'line',

                                'content' => $substring,

                            );



                            if (isset($values[$index]))

                            {

                                $value = $values[$index];



                                $nestedBlock['attributes'] = array(

                                    'align' => $value,

                                );

                            }



                            $nestedBlocks []= $nestedBlock;

                        }



                        # ~



                        $block = array(

                            'name' => 'table',

                            'content type' => 'blocks',

                            'content' => array(),

                        );



                        $block['content'] []= array(

                            'name' => 'thead',

                            'content type' => 'blocks',

                            'content' => array(),

                        );



                        $block['content'] []= array(

                            'name' => 'tbody',

                            'content type' => 'blocks',

                            'content' => array(),

                        );



                        $block['content'][0]['content'] []= array(

                            'name' => 'tr',

                            'content type' => 'blocks',

                            'content' => array(),

                        );



                        $block['content'][0]['content'][0]['content'] = $nestedBlocks;



                        # ~



                        $context = 'table';



                        $contextData = array(

                            'alignments' => $values,

                        );



                        # ~



                        continue 2;

                    }



                    break;



                default:



                    throw new Exception('Unrecognized context - '.$context);

            }



            if ($indentation >= 4)

            {

                $blocks []= $block;



                $string = htmlspecialchars($line, ENT_NOQUOTES, 'UTF-8');

                $string = str_repeat(' ', $indentation - 4) . $string;



                $block = array(

                    'name' => 'pre',

                    'content type' => 'blocks',

                    'content' => array(

                        array(

                            'name' => 'code',

                            'content type' => null,

                            'content' => $string,

                        ),

                    ),

                );



                $context = 'code';



                continue;

            }



            switch ($line[0])

            {

                case '#':



                    if (isset($line[1]))

                    {

                        $blocks []= $block;



                        $level = 1;



                        while (isset($line[$level]) and $line[$level] === '#')

                        {

                            $level++;

                        }



                        $string = trim($line, '# ');

                        $string = $this->parseLine($string);



                        $block = array(

                            'name' => 'h'.$level,

                            'content type' => 'line',

                            'content' => $string,

                        );



                        $context = null;



                        continue 2;

                    }



                    break;



                case '<':



                    $position = strpos($line, '>');



                    if ($position > 1)

                    {

                        $substring = substr($line, 1, $position - 1);



                        $substring = chop($substring);



                        if (substr($substring, -1) === '/')

                        {

                            $isClosing = true;



                            $substring = substr($substring, 0, -1);

                        }



                        $position = strpos($substring, ' ');



                        if ($position)

                        {

                            $name = substr($substring, 0, $position);

                        }

                        else

                        {

                            $name = $substring;

                        }



                        $name = strtolower($name);



                        if ($name[0] == 'h' and strpos('r123456', $name[1]) !== false) #  hr, h1, h2, ...

                        {

                            if ($name == 'hr')

                            {

                                $isClosing = true;

                            }

                        }

                        elseif ( ! ctype_alpha($name))

                        {

                            break;

                        }



                        if (in_array($name, self::$textLevelElements))

                        {

                            break;

                        }



                        $blocks []= $block;



                        $block = array(

                            'name' => null,

                            'content type' => null,

                            'content' => $indentedLine,

                        );



                        if (isset($isClosing))

                        {

                            unset($isClosing);



                            continue 2;

                        }



                        $context = 'markup';

                        $contextData = array(

                            'start' => '<'.$name.'>',

                            'end' => '</'.$name.'>',

                            'depth' => 0,

                        );



                        if (stripos($line, $contextData['end']) !== false)

                        {

                            $context = null;

                        }



                        continue 2;

                    }



                    break;



                case '>':



                    if (preg_match('/^>[ ]?(.*)/', $line, $matches))

                    {

                        $blocks []= $block;



                        $block = array(

                            'name' => 'blockquote',

                            'content type' => 'lines',

                            'content' => array(

                                $matches[1],

                            ),

                        );



                        $context = 'quote';

                        $contextData = array();



                        continue 2;

                    }



                    break;



                case '[':



                    $position = strpos($line, ']:');



                    if ($position)

                    {

                        $reference = array();



                        $label = substr($line, 1, $position - 1);

                        $label = strtolower($label);



                        $substring = substr($line, $position + 2);

                        $substring = trim($substring);



                        if ($substring === '')

                        {

                            break;

                        }



                        if ($substring[0] === '<')

                        {

                            $position = strpos($substring, '>');



                            if ($position === false)

                            {

                                break;

                            }



                            $reference['link'] = substr($substring, 1, $position - 1);



                            $substring = substr($substring, $position + 1);

                        }

                        else

                        {

                            $position = strpos($substring, ' ');



                            if ($position === false)

                            {

                                $reference['link'] = $substring;



                                $substring = false;

                            }

                            else

                            {

                                $reference['link'] = substr($substring, 0, $position);



                                $substring = substr($substring, $position + 1);

                            }

                        }



                        if ($substring !== false)

                        {

                            if ($substring[0] !== '"' and $substring[0] !== "'" and $substring[0] !== '(')

                            {

                                break;

                            }



                            $lastChar = substr($substring, -1);



                            if ($lastChar !== '"' and $lastChar !== "'" and $lastChar !== ')')

                            {

                                break;

                            }



                            $reference['title'] = substr($substring, 1, -1);

                        }



                        $this->referenceMap[$label] = $reference;



                        continue 2;

                    }



                    break;



                case '`':

                case '~':



                    if (preg_match('/^([`]{3,}|[~]{3,})[ ]*(\w+)?[ ]*$/', $line, $matches))

                    {

                        $blocks []= $block;



                        $block = array(

                            'name' => 'pre',

                            'content type' => 'blocks',

                            'content' => array(

                                array(

                                    'name' => 'code',

                                    'content type' => null,

                                    'content' => '',

                                ),

                            ),

                        );



                        if (isset($matches[2]))

                        {

                            $block['content'][0]['attributes'] = array(

                                'class' => 'language-'.$matches[2],

                            );

                        }



                        $context = 'fenced code';

                        $contextData = array(

                            'marker' => $matches[1][0],

                        );



                        continue 2;

                    }



                    break;



                case '-':

                case '*':

                case '_':



                    if (preg_match('/^([-*_])([ ]{0,2}\1){2,}[ ]*$/', $line))

                    {

                        $blocks []= $block;



                        $block = array(

                            'name' => 'hr',

                            'content' => null,

                        );



                        continue 2;

                    }

            }



            switch (true)

            {

                case $line[0] <= '-' and preg_match('/^([*+-][ ]+)(.*)/', $line, $matches):

                case $line[0] <= '9' and preg_match('/^([0-9]+[.][ ]+)(.*)/', $line, $matches):



                    $blocks []= $block;



                    $name = $line[0] >= '0' ? 'ol' : 'ul';



                    $block = array(

                        'name' => $name,

                        'content type' => 'blocks',

                        'content' => array(),

                    );



                    unset($nestedBlock);



                    $nestedBlock = array(

                        'name' => 'li',

                        'content type' => 'lines',

                        'content' => array(

                            $matches[2],

                        ),

                    );



                    $block['content'] []= & $nestedBlock;



                    $baseline = $indentation + strlen($matches[1]);



                    $marker = $line[0] >= '0' ? '[0-9]+[.]' : '[*+-]';



                    $context = 'li';

                    $contextData = array(

                        'indentation' => $indentation,

                        'baseline' => $baseline,

                        'marker' => $marker,

                        'lines' => array(

                            $matches[2],

                        ),

                    );



                    continue 2;

            }



            if ($context === 'paragraph')

            {

                $block['content'] .= "\n".$line;



                continue;

            }

            else

            {

                $blocks []= $block;



                $block = array(

                    'name' => 'p',

                    'content type' => 'line',

                    'content' => $line,

                );



                if ($blockContext === 'li' and empty($blocks[1]))

                {

                    $block['name'] = null;

                }



                $context = 'paragraph';

            }

        }



        if ($blockContext === 'li' and $block['name'] === null)

        {

            return $block['content'];

        }



        $blocks []= $block;



        unset($blocks[0]);



        return $blocks;

    }



    private function compile(array $blocks)

    {

        $markup = '';



        foreach ($blocks as $block)

        {

            $markup .= "\n";



            if (isset($block['name']))

            {

                $markup .= '<'.$block['name'];



                if (isset($block['attributes']))

                {

                    foreach ($block['attributes'] as $name => $value)

                    {

                        $markup .= ' '.$name.'="'.$value.'"';

                    }

                }



                if ($block['content'] === null)

                {

                    $markup .= ' />';



                    continue;

                }

                else

                {

                    $markup .= '>';

                }

            }



            switch ($block['content type'])

            {

                case null:



                    $markup .= $block['content'];



                    break;



                case 'line':



                    $markup .= $this->parseLine($block['content']);



                    break;



                case 'lines':



                    $result = $this->findBlocks($block['content'], $block['name']);



                    if (is_string($result)) # dense li

                    {

                        $markup .= $this->parseLine($result);



                        break;

                    }



                    $markup .= $this->compile($result);



                    break;



                case 'blocks':



                    $markup .= $this->compile($block['content']);



                    break;

            }



            if (isset($block['name']))

            {

                $markup .= '</'.$block['name'].'>';

            }

        }



        $markup .= "\n";



        return $markup;

    }



    private function parseLine($text, $markers = array("  \n", '![', '&', '*', '<', '[', '\\', '_', '`', 'http', '~~'))

    {

        if (isset($text[1]) === false or $markers === array())

        {

            return $text;

        }



        # ~



        $markup = '';



        while ($markers)

        {

            $closestMarker = null;

            $closestMarkerIndex = 0;

            $closestMarkerPosition = null;



            foreach ($markers as $index => $marker)

            {

                $markerPosition = strpos($text, $marker);



                if ($markerPosition === false)

                {

                    unset($markers[$index]);



                    continue;

                }



                if ($closestMarker === null or $markerPosition < $closestMarkerPosition)

                {

                    $closestMarker = $marker;

                    $closestMarkerIndex = $index;

                    $closestMarkerPosition = $markerPosition;

                }

            }



            # ~



            if ($closestMarker === null or isset($text[$closestMarkerPosition + 1]) === false)

            {

                $markup .= $text;



                break;

            }

            else

            {

                $markup .= substr($text, 0, $closestMarkerPosition);

            }



            $text = substr($text, $closestMarkerPosition);



            # ~



            unset($markers[$closestMarkerIndex]);



            # ~



            switch ($closestMarker)

            {

                case "  \n":



                    $markup .= '<br />'."\n";



                    $offset = 3;



                    break;



                case '![':

                case '[':



                    if (strpos($text, ']') and preg_match('/\[((?:[^][]|(?R))*)\]/', $text, $matches))

                    {

                        $element = array(

                            '!' => $text[0] === '!',

                            'text' => $matches[1],

                        );



                        $offset = strlen($matches[0]);



                        if ($element['!'])

                        {

                            $offset++;

                        }



                        $remainingText = substr($text, $offset);



                        if ($remainingText[0] === '(' and preg_match('/\([ ]*(.*?)(?:[ ]+[\'"](.+?)[\'"])?[ ]*\)/', $remainingText, $matches))

                        {

                            $element['link'] = $matches[1];



                            if (isset($matches[2]))

                            {

                                $element['title'] = $matches[2];

                            }



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

                        }

                        elseif ($this->referenceMap)

                        {

                            $reference = $element['text'];



                            if (preg_match('/^\s*\[(.*?)\]/', $remainingText, $matches))

                            {

                                $reference = $matches[1] === '' ? $element['text'] : $matches[1];



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

                            }



                            $reference = strtolower($reference);



                            if (isset($this->referenceMap[$reference]))

                            {

                                $element['link'] = $this->referenceMap[$reference]['link'];



                                if (isset($this->referenceMap[$reference]['title']))

                                {

                                    $element['title'] = $this->referenceMap[$reference]['title'];

                                }

                            }

                            else

                            {

                                unset($element);

                            }

                        }

                        else

                        {

                            unset($element);

                        }

                    }



                    if (isset($element))

                    {

                        $element['link'] = str_replace('&', '&amp;', $element['link']);

                        $element['link'] = str_replace('<', '&lt;', $element['link']);



                        if ($element['!'])

                        {

                            $markup .= '<img alt="'.$element['text'].'" src="'.$element['link'].'"';



                            if (isset($element['title']))

                            {

                                $markup .= ' title="'.$element['title'].'"';

                            }



                            $markup .= ' />';

                        }

                        else

                        {

                            $element['text'] = $this->parseLine($element['text'], $markers);



                            $markup .= '<a href="'.$element['link'].'"';



                            if (isset($element['title']))

                            {

                                $markup .= ' title="'.$element['title'].'"';

                            }



                            $markup .= '>'.$element['text'].'</a>';

                        }



                        unset($element);

                    }

                    else

                    {

                        $markup .= $closestMarker;



                        $offset = $closestMarker === '![' ? 2 : 1;

                    }



                    break;



                case '&':



                    if (preg_match('/^&#?\w+;/', $text, $matches))

                    {

                        $markup .= $matches[0];



                        $offset = strlen($matches[0]);

                    }

                    else

                    {

                        $markup .= '&amp;';



                        $offset = 1;

                    }



                    break;



                case '*':

                case '_':



                    if ($text[1] === $closestMarker and preg_match(self::$strongRegex[$closestMarker], $text, $matches))

                    {

                        $markers[$closestMarkerIndex] = $closestMarker;

                        $matches[1] = $this->parseLine($matches[1], $markers);



                        $markup .= '<strong>'.$matches[1].'</strong>';

                    }

                    elseif (preg_match(self::$emRegex[$closestMarker], $text, $matches))

                    {

                        $markers[$closestMarkerIndex] = $closestMarker;

                        $matches[1] = $this->parseLine($matches[1], $markers);



                        $markup .= '<em>'.$matches[1].'</em>';

                    }



                    if (isset($matches) and $matches)

                    {

                        $offset = strlen($matches[0]);

                    }

                    else

                    {

                        $markup .= $closestMarker;



                        $offset = 1;

                    }



                    break;



                case '<':



                    if (strpos($text, '>') !== false)

                    {

                        if ($text[1] === 'h' and preg_match('/^<(https?:[\/]{2}[^\s]+?)>/i', $text, $matches))

                        {

                            $elementUrl = $matches[1];

                            $elementUrl = str_replace('&', '&amp;', $elementUrl);

                            $elementUrl = str_replace('<', '&lt;', $elementUrl);



                            $markup .= '<a href="'.$elementUrl.'">'.$elementUrl.'</a>';



                            $offset = strlen($matches[0]);

                        }

                        elseif (strpos($text, '@') > 1 and preg_match('/<(\S+?@\S+?)>/', $text, $matches))

                        {

                            $markup .= '<a href="mailto:'.$matches[1].'">'.$matches[1].'</a>';



                            $offset = strlen($matches[0]);

                        }

                        elseif (preg_match('/^<\/?\w.*?>/', $text, $matches))

                        {

                            $markup .= $matches[0];



                            $offset = strlen($matches[0]);

                        }

                        else

                        {

                            $markup .= '&lt;';



                            $offset = 1;

                        }

                    }

                    else

                    {

                        $markup .= '&lt;';



                        $offset = 1;

                    }



                    break;



                case '\\':



                    if (in_array($text[1], self::$specialCharacters))

                    {

                        $markup .= $text[1];



                        $offset = 2;

                    }

                    else

                    {

                        $markup .= '\\';



                        $offset = 1;

                    }



                    break;



                case '`':



                    if (preg_match('/^(`+)[ ]*(.+?)[ ]*(?<!`)\1(?!`)/', $text, $matches))

                    {

                        $elementText = $matches[2];

                        $elementText = htmlspecialchars($elementText, ENT_NOQUOTES, 'UTF-8');



                        $markup .= '<code>'.$elementText.'</code>';



                        $offset = strlen($matches[0]);

                    }

                    else

                    {

                        $markup .= '`';



                        $offset = 1;

                    }



                    break;



                case 'http':



                    if (preg_match('/^https?:[\/]{2}[^\s]+\b\/*/ui', $text, $matches))

                    {

                        $elementUrl = $matches[0];

                        $elementUrl = str_replace('&', '&amp;', $elementUrl);

                        $elementUrl = str_replace('<', '&lt;', $elementUrl);



                        $markup .= '<a href="'.$elementUrl.'">'.$elementUrl.'</a>';



                        $offset = strlen($matches[0]);

                    }

                    else

                    {

                        $markup .= 'http';



                        $offset = 4;

                    }



                    break;



                case '~~':



                    if (preg_match('/^~~(?=\S)(.+?)(?<=\S)~~/', $text, $matches))

                    {

                        $matches[1] = $this->parseLine($matches[1], $markers);



                        $markup .= '<del>'.$matches[1].'</del>';



                        $offset = strlen($matches[0]);

                    }

                    else

                    {

                        $markup .= '~~';



                        $offset = 2;

                    }



                    break;

            }



            if (isset($offset))

            {

                $text = substr($text, $offset);

            }



            $markers[$closestMarkerIndex] = $closestMarker;

        }



        return $markup;

    }



    #

    # Static



    static function instance($name = 'default')

    {

        if (isset(self::$instances[$name]))

        {

            return self::$instances[$name];

        }



        $instance = new Parsedown();



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



        return $instance;

    }



    private static $instances = array();



    #

    # Fields

    #



    private $referenceMap = array();



    #

    # Read-only



    private static $strongRegex = array(

        '*' => '/^[*]{2}((?:[^*]|[*][^*]*[*])+?)[*]{2}(?![*])/s',

        '_' => '/^__((?:[^_]|_[^_]*_)+?)__(?!_)/us',

    );



    private static $emRegex = array(

        '*' => '/^[*]((?:[^*]|[*][*][^*]+?[*][*])+?)[*](?![*])/s',

        '_' => '/^_((?:[^_]|__[^_]*__)+?)_(?!_)\b/us',

    );



    private static $specialCharacters = array(

        '\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '>', '#', '+', '-', '.', '!',

    );



    private static $textLevelElements = array(

        'a', 'br', 'bdo', 'abbr', 'blink', 'nextid', 'acronym', 'basefont',

        'b', 'em', 'big', 'cite', 'small', 'spacer', 'listing',

        'i', 'rp', 'sub', 'code',          'strike', 'marquee',

        'q', 'rt', 'sup', 'font',          'strong',

        's', 'tt', 'var', 'mark',

        'u', 'xm', 'wbr', 'nobr',

                          'ruby',

                          'span',

                          'time',

    );

}