Team:OUC-China/js/markdown.js

"use strict"; var Markdown;

if (typeof exports === "object" && typeof require === "function") // we're in a CommonJS (e.g. Node.js) module

   Markdown = exports;

else

   Markdown = {};

// The following text is included for historical reasons, but should // be taken with a pinch of salt; it's not all true anymore.

// // Wherever possible, Showdown is a straight, line-by-line port // of the Perl version of Markdown. // // This is not a normal parser design; it's basically just a // series of string substitutions. It's hard to read and // maintain this way, but keeping Showdown close to the original // design makes it easier to port new features. // // More importantly, Showdown behaves like markdown.pl in most // edge cases. So web applications can do client-side preview // in Javascript, and then build identical HTML on the server. // // This port needs the new RegExp functionality of ECMA 262, // 3rd Edition (i.e. Javascript 1.5). Most modern web browsers // should do fine. Even with the new regular expression features, // We do a lot of work to emulate Perl's regex functionality. // The tricky changes in this file mostly have the "attacklab:" // label. Major or self-explanatory changes don't. // // Smart diff tools like Araxis Merge will be able to match up // this file with markdown.pl in a useful way. A little tweaking // helps: in a copy of markdown.pl, replace "#" with "//" and // replace "$text" with "text". Be sure to ignore whitespace // and line endings. //


// // Usage: // // var text = "Markdown *rocks*."; // // var converter = new Markdown.Converter(); // var html = converter.makeHtml(text); // // alert(html); // // Note: move the sample code to the bottom of this // file before uncommenting it. //

(function () {

   function identity(x) { return x; }
   function returnFalse(x) { return false; }
   function HookCollection() { }
   HookCollection.prototype = {
       chain: function (hookname, func) {
           var original = this[hookname];
           if (!original)
               throw new Error("unknown hook " + hookname);
           if (original === identity)
               this[hookname] = func;
           else
               this[hookname] = function (text) {
                   var args = Array.prototype.slice.call(arguments, 0);
                   args[0] = original.apply(null, args);
                   return func.apply(null, args);
               };
       },
       set: function (hookname, func) {
           if (!this[hookname])
               throw new Error("unknown hook " + hookname);
           this[hookname] = func;
       },
       addNoop: function (hookname) {
           this[hookname] = identity;
       },
       addFalse: function (hookname) {
           this[hookname] = returnFalse;
       }
   };
   Markdown.HookCollection = HookCollection;
   // g_urls and g_titles allow arbitrary user-entered strings as keys. This
   // caused an exception (and hence stopped the rendering) when the user entered
   // e.g. [push] or [__proto__]. Adding a prefix to the actual key prevents this
   // (since no builtin property starts with "s_"). See
   // http://meta.stackexchange.com/questions/64655/strange-wmd-bug
   // (granted, switching from Array() to Object() alone would have left only __proto__
   // to be a problem)
   function SaveHash() { }
   SaveHash.prototype = {
       set: function (key, value) {
           this["s_" + key] = value;
       },
       get: function (key) {
           return this["s_" + key];
       }
   };
   Markdown.Converter = function (OPTIONS) {
       var pluginHooks = this.hooks = new HookCollection();
       
       // given a URL that was encountered by itself (without markup), should return the link text that's to be given to this link
       pluginHooks.addNoop("plainLinkText");
       
       // called with the orignal text as given to makeHtml. The result of this plugin hook is the actual markdown source that will be cooked
       pluginHooks.addNoop("preConversion");
       
       // called with the text once all normalizations have been completed (tabs to spaces, line endings, etc.), but before any conversions have
       pluginHooks.addNoop("postNormalization");
       
       // Called with the text before / after creating block elements like code blocks and lists. Note that this is called recursively
       // with inner content, e.g. it's called with the full text, and then only with the content of a blockquote. The inner
       // call will receive outdented text.
       pluginHooks.addNoop("preBlockGamut");
       pluginHooks.addNoop("postBlockGamut");
       
       // called with the text of a single block element before / after the span-level conversions (bold, code spans, etc.) have been made
       pluginHooks.addNoop("preSpanGamut");
       pluginHooks.addNoop("postSpanGamut");
       
       // called with the final cooked HTML code. The result of this plugin hook is the actual output of makeHtml
       pluginHooks.addNoop("postConversion");
       //
       // Private state of the converter instance:
       //
       // Global hashes, used by various utility routines
       var g_urls;
       var g_titles;
       var g_html_blocks;
       // Used to track when we're inside an ordered or unordered list
       // (see _ProcessListItems() for details):
       var g_list_level;
       
       OPTIONS = OPTIONS || {};
       var asciify = identity, deasciify = identity;
       if (OPTIONS.nonAsciiLetters) {
           /* In JavaScript regular expressions, \w only denotes [a-zA-Z0-9_].
            * That's why there's inconsistent handling e.g. with intra-word bolding
            * of Japanese words. That's why we do the following if OPTIONS.nonAsciiLetters
            * is true:
            *
            * Before doing bold and italics, we find every instance
            * of a unicode word character in the Markdown source that is not
            * matched by \w, and the letter "Q". We take the character's code point
            * and encode it in base 51, using the "digits"
            *
            *     A, B, ..., P, R, ..., Y, Z, a, b, ..., y, z
            *
            * delimiting it with "Q" on both sides. For example, the source
            *
            * > In Chinese, the smurfs are called 藍精靈, meaning "blue spirits".
            *
            * turns into
            *
            * > In Chinese, the smurfs are called QNIhQQMOIQQOuUQ, meaning "blue spirits".
            *
            * Since everything that is a letter in Unicode is now a letter (or
            * several letters) in ASCII, \w and \b should always do the right thing.
            *
            * After the bold/italic conversion, we decode again; since "Q" was encoded
            * alongside all non-ascii characters (as "QBfQ"), and the conversion
            * will not generate "Q", the only instances of that letter should be our
            * encoded characters. And since the conversion will not break words, the
            * "Q...Q" should all still be in one piece.
            *
            * We're using "Q" as the delimiter because it's probably one of the
            * rarest characters, and also because I can't think of any special behavior
            * that would ever be triggered by this letter (to use a silly example, if we
            * delimited with "H" on the left and "P" on the right, then "Ψ" would be
            * encoded as "HTTP", which may cause special behavior). The latter would not
            * actually be a huge issue for bold/italic, but may be if we later use it
            * in other places as well.
            * */            
           (function () {
               var lettersThatJavaScriptDoesNotKnowAndQ = /[Q\u00aa\u00b5\u00ba\u00c0-\u00d6\u00d8-\u00f6\u00f8-\u02c1\u02c6-\u02d1\u02e0-\u02e4\u02ec\u02ee\u0370-\u0374\u0376-\u0377\u037a-\u037d\u0386\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03f5\u03f7-\u0481\u048a-\u0523\u0531-\u0556\u0559\u0561-\u0587\u05d0-\u05ea\u05f0-\u05f2\u0621-\u064a\u0660-\u0669\u066e-\u066f\u0671-\u06d3\u06d5\u06e5-\u06e6\u06ee-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07c0-\u07ea\u07f4-\u07f5\u07fa\u0904-\u0939\u093d\u0950\u0958-\u0961\u0966-\u096f\u0971-\u0972\u097b-\u097f\u0985-\u098c\u098f-\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2\u09b6-\u09b9\u09bd\u09ce\u09dc-\u09dd\u09df-\u09e1\u09e6-\u09f1\u0a05-\u0a0a\u0a0f-\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32-\u0a33\u0a35-\u0a36\u0a38-\u0a39\u0a59-\u0a5c\u0a5e\u0a66-\u0a6f\u0a72-\u0a74\u0a85-\u0a8d\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2-\u0ab3\u0ab5-\u0ab9\u0abd\u0ad0\u0ae0-\u0ae1\u0ae6-\u0aef\u0b05-\u0b0c\u0b0f-\u0b10\u0b13-\u0b28\u0b2a-\u0b30\u0b32-\u0b33\u0b35-\u0b39\u0b3d\u0b5c-\u0b5d\u0b5f-\u0b61\u0b66-\u0b6f\u0b71\u0b83\u0b85-\u0b8a\u0b8e-\u0b90\u0b92-\u0b95\u0b99-\u0b9a\u0b9c\u0b9e-\u0b9f\u0ba3-\u0ba4\u0ba8-\u0baa\u0bae-\u0bb9\u0bd0\u0be6-\u0bef\u0c05-\u0c0c\u0c0e-\u0c10\u0c12-\u0c28\u0c2a-\u0c33\u0c35-\u0c39\u0c3d\u0c58-\u0c59\u0c60-\u0c61\u0c66-\u0c6f\u0c85-\u0c8c\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cbd\u0cde\u0ce0-\u0ce1\u0ce6-\u0cef\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d28\u0d2a-\u0d39\u0d3d\u0d60-\u0d61\u0d66-\u0d6f\u0d7a-\u0d7f\u0d85-\u0d96\u0d9a-\u0db1\u0db3-\u0dbb\u0dbd\u0dc0-\u0dc6\u0e01-\u0e30\u0e32-\u0e33\u0e40-\u0e46\u0e50-\u0e59\u0e81-\u0e82\u0e84\u0e87-\u0e88\u0e8a\u0e8d\u0e94-\u0e97\u0e99-\u0e9f\u0ea1-\u0ea3\u0ea5\u0ea7\u0eaa-\u0eab\u0ead-\u0eb0\u0eb2-\u0eb3\u0ebd\u0ec0-\u0ec4\u0ec6\u0ed0-\u0ed9\u0edc-\u0edd\u0f00\u0f20-\u0f29\u0f40-\u0f47\u0f49-\u0f6c\u0f88-\u0f8b\u1000-\u102a\u103f-\u1049\u1050-\u1055\u105a-\u105d\u1061\u1065-\u1066\u106e-\u1070\u1075-\u1081\u108e\u1090-\u1099\u10a0-\u10c5\u10d0-\u10fa\u10fc\u1100-\u1159\u115f-\u11a2\u11a8-\u11f9\u1200-\u1248\u124a-\u124d\u1250-\u1256\u1258\u125a-\u125d\u1260-\u1288\u128a-\u128d\u1290-\u12b0\u12b2-\u12b5\u12b8-\u12be\u12c0\u12c2-\u12c5\u12c8-\u12d6\u12d8-\u1310\u1312-\u1315\u1318-\u135a\u1380-\u138f\u13a0-\u13f4\u1401-\u166c\u166f-\u1676\u1681-\u169a\u16a0-\u16ea\u1700-\u170c\u170e-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176c\u176e-\u1770\u1780-\u17b3\u17d7\u17dc\u17e0-\u17e9\u1810-\u1819\u1820-\u1877\u1880-\u18a8\u18aa\u1900-\u191c\u1946-\u196d\u1970-\u1974\u1980-\u19a9\u19c1-\u19c7\u19d0-\u19d9\u1a00-\u1a16\u1b05-\u1b33\u1b45-\u1b4b\u1b50-\u1b59\u1b83-\u1ba0\u1bae-\u1bb9\u1c00-\u1c23\u1c40-\u1c49\u1c4d-\u1c7d\u1d00-\u1dbf\u1e00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec\u1ff2-\u1ff4\u1ff6-\u1ffc\u203f-\u2040\u2054\u2071\u207f\u2090-\u2094\u2102\u2107\u210a-\u2113\u2115\u2119-\u211d\u2124\u2126\u2128\u212a-\u212d\u212f-\u2139\u213c-\u213f\u2145-\u2149\u214e\u2183-\u2184\u2c00-\u2c2e\u2c30-\u2c5e\u2c60-\u2c6f\u2c71-\u2c7d\u2c80-\u2ce4\u2d00-\u2d25\u2d30-\u2d65\u2d6f\u2d80-\u2d96\u2da0-\u2da6\u2da8-\u2dae\u2db0-\u2db6\u2db8-\u2dbe\u2dc0-\u2dc6\u2dc8-\u2dce\u2dd0-\u2dd6\u2dd8-\u2dde\u2e2f\u3005-\u3006\u3031-\u3035\u303b-\u303c\u3041-\u3096\u309d-\u309f\u30a1-\u30fa\u30fc-\u30ff\u3105-\u312d\u3131-\u318e\u31a0-\u31b7\u31f0-\u31ff\u3400-\u4db5\u4e00-\u9fc3\ua000-\ua48c\ua500-\ua60c\ua610-\ua62b\ua640-\ua65f\ua662-\ua66e\ua67f-\ua697\ua717-\ua71f\ua722-\ua788\ua78b-\ua78c\ua7fb-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8d0-\ua8d9\ua900-\ua925\ua930-\ua946\uaa00-\uaa28\uaa40-\uaa42\uaa44-\uaa4b\uaa50-\uaa59\uac00-\ud7a3\uf900-\ufa2d\ufa30-\ufa6a\ufa70-\ufad9\ufb00-\ufb06\ufb13-\ufb17\ufb1d\ufb1f-\ufb28\ufb2a-\ufb36\ufb38-\ufb3c\ufb3e\ufb40-\ufb41\ufb43-\ufb44\ufb46-\ufbb1\ufbd3-\ufd3d\ufd50-\ufd8f\ufd92-\ufdc7\ufdf0-\ufdfb\ufe33-\ufe34\ufe4d-\ufe4f\ufe70-\ufe74\ufe76-\ufefc\uff10-\uff19\uff21-\uff3a\uff3f\uff41-\uff5a\uff66-\uffbe\uffc2-\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc]/g;
               var cp_Q = "Q".charCodeAt(0);
               var cp_A = "A".charCodeAt(0);
               var cp_Z = "Z".charCodeAt(0);
               var dist_Za = "a".charCodeAt(0) - cp_Z - 1;
               
               asciify = function(text) {
                   return text.replace(lettersThatJavaScriptDoesNotKnowAndQ, function (m) {
                       var c = m.charCodeAt(0);
                       var s = "";
                       var v;
                       while (c > 0) {
                           v = (c % 51) + cp_A;
                           if (v >= cp_Q)
                               v++;
                           if (v > cp_Z)
                               v += dist_Za;
                           s = String.fromCharCode(v) + s;
                           c = c / 51 | 0;
                       }
                       return "Q" + s + "Q";
                   })
               };
               
               deasciify = function(text) {
                   return text.replace(/Q([A-PR-Za-z]{1,3})Q/g, function (m, s) {
                       var c = 0;
                       var v;
                       for (var i = 0; i < s.length; i++) {
                           v = s.charCodeAt(i);
                           if (v > cp_Z)
                               v -= dist_Za;
                           if (v > cp_Q)
                               v--;
                           v -= cp_A;
                           c = (c * 51) + v;
                       }
                       return String.fromCharCode(c);
                   })
               }                
           })();
       }
       
       var _DoItalicsAndBold = OPTIONS.asteriskIntraWordEmphasis ? _DoItalicsAndBold_AllowIntrawordWithAsterisk : _DoItalicsAndBoldStrict;
       this.makeHtml = function (text) {
           //
           // Main function. The order in which other subs are called here is
           // essential. Link and image substitutions need to happen before
           // _EscapeSpecialCharsWithinTagAttributes(), so that any *'s or _'s in the <a>
           // and <img> tags get encoded.
           //
           // This will only happen if makeHtml on the same converter instance is called from a plugin hook.
           // Don't do that.
           if (g_urls)
               throw new Error("Recursive call to converter.makeHtml");
       
           // Create the private state objects.
           g_urls = new SaveHash();
           g_titles = new SaveHash();
           g_html_blocks = [];
           g_list_level = 0;
           text = pluginHooks.preConversion(text);
           // attacklab: Replace ~ with ~T
           // This lets us use tilde as an escape char to avoid md5 hashes
           // The choice of character is arbitray; anything that isn't
           // magic in Markdown will work.
           text = text.replace(/~/g, "~T");
           // attacklab: Replace $ with ~D
           // RegExp interprets $ as a special character
           // when it's in a replacement string
           text = text.replace(/\$/g, "~D");
           // Standardize line endings
           text = text.replace(/\r\n/g, "\n"); // DOS to Unix
           text = text.replace(/\r/g, "\n"); // Mac to Unix
           // Make sure text begins and ends with a couple of newlines:
           text = "\n\n" + text + "\n\n";
           // Convert all tabs to spaces.
           text = _Detab(text);
           // Strip any lines consisting only of spaces and tabs.
           // This makes subsequent regexen easier to write, because we can
           // match consecutive blank lines with /\n+/ instead of something
           // contorted like /[ \t]*\n+/ .
           text = text.replace(/^[ \t]+$/mg, "");
           
           text = pluginHooks.postNormalization(text);
           // Turn block-level HTML blocks into hash entries
           text = _HashHTMLBlocks(text);
           // Strip link definitions, store in hashes.
           text = _StripLinkDefinitions(text);
           text = _RunBlockGamut(text);
           text = _UnescapeSpecialChars(text);
           // attacklab: Restore dollar signs
           text = text.replace(/~D/g, "$$");
           // attacklab: Restore tildes
           text = text.replace(/~T/g, "~");
           text = pluginHooks.postConversion(text);
           g_html_blocks = g_titles = g_urls = null;
           return text;
       };
       function _StripLinkDefinitions(text) {
           //
           // Strips link definitions from text, stores the URLs and titles in
           // hash references.
           //
           // Link defs are in the form: ^[id]: url "optional title"
           /*
           text = text.replace(/
               ^[ ]{0,3}\[([^\[\]]+)\]:  // id = $1  attacklab: g_tab_width - 1
               [ \t]*
               \n?                 // maybe *one* newline
               [ \t]*
               <?(\S+?)>?          // url = $2
               (?=\s|$)            // lookahead for whitespace instead of the lookbehind removed below
               [ \t]*
               \n?                 // maybe one newline
               [ \t]*
               (                   // (potential) title = $3
                   (\n*)           // any lines skipped = $4 attacklab: lookbehind removed
                   [ \t]+
                   ["(]
                   (.+?)           // title = $5
                   [")]
                   [ \t]*
               )?                  // title is optional
               (?:\n+|$)
           /gm, function(){...});
           */
           text = text.replace(/^[ ]{0,3}\[([^\[\]]+)\]:[ \t]*\n?[ \t]*<?(\S+?)>?(?=\s|$)[ \t]*\n?[ \t]*((\n*)["(](.+?)[")][ \t]*)?(?:\n+)/gm,
               function (wholeMatch, m1, m2, m3, m4, m5) {
                   m1 = m1.toLowerCase();
                   g_urls.set(m1, _EncodeAmpsAndAngles(m2));  // Link IDs are case-insensitive
                   if (m4) {
                       // Oops, found blank lines, so it's not a title.
                       // Put back the parenthetical statement we stole.
                       return m3;
                   } else if (m5) {
                       g_titles.set(m1, m5.replace(/"/g, """));
                   }
                   // Completely remove the definition from the text
                   return "";
               }
           );
           return text;
       }
       function _HashHTMLBlocks(text) {
           // Hashify HTML blocks:
           // We only want to do this for block-level HTML tags, such as headers,
// lists, and tables. That's because we still want to wrap

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

//
           //     tags for inner block must be indented.
//
//
           //
           // The outermost tags must start at the left margin for this to match, and
           // the inner nested divs must be indented.
           // We need to do this before the next, more liberal match, because the next
// match will start at the first `
` and stop at the first `
`.
           // attacklab: This regex can be expensive when it fails.
           /*
           text = text.replace(/
               (                       // save in $1
                   ^                   // start of line  (with /m)
                   <($block_tags_a)    // start tag = $2
                   \b                  // word break
                                       // attacklab: hack around khtml/pcre bug...
                   [^\r]*?\n           // any number of lines, minimally matching
                   </\2>               // the matching end tag
                   [ \t]*              // trailing spaces/tabs
                   (?=\n+)             // followed by a newline
               )                       // attacklab: there are sentinel newlines at end of document
           /gm,function(){...}};
           */
           text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del)\b[^\r]*?\n<\/\2>[ \t]*(?=\n+))/gm, hashMatch);
           //
           // Now match more liberally, simply from `\n<tag>` to `</tag>\n`
           //
           /*
           text = text.replace(/
               (                       // save in $1
                   ^                   // start of line  (with /m)
                   <($block_tags_b)    // start tag = $2
                   \b                  // word break
                                       // attacklab: hack around khtml/pcre bug...
                   [^\r]*?             // any number of lines, minimally matching
                   .*</\2>             // the matching end tag
                   [ \t]*              // trailing spaces/tabs
                   (?=\n+)             // followed by a newline
               )                       // attacklab: there are sentinel newlines at end of document
           /gm,function(){...}};
           */
           text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math)\b[^\r]*?.*<\/\2>[ \t]*(?=\n+)\n)/gm, hashMatch);
// Special case just for
. It was easier to make a special case than
           // to make the other regex more complicated.  
           /*
           text = text.replace(/
               \n                  // Starting after a blank line
               [ ]{0,3}
               (                   // save in $1
                   (<(hr)          // start tag = $2
                       \b          // word break
                       ([^<>])*?
                   \/?>)           // the matching end tag
                   [ \t]*
                   (?=\n{2,})      // followed by a blank line
               )
           /g,hashMatch);
           */
           text = text.replace(/\n[ ]{0,3}((<(hr)\b([^<>])*?\/?>)[ \t]*(?=\n{2,}))/g, hashMatch);
           // Special case for standalone HTML comments:
           /*
           text = text.replace(/
               \n\n                                            // Starting after a blank line
               [ ]{0,3}                                        // attacklab: g_tab_width - 1
               (                                               // save in $1
                   <!
                   (--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)   // see http://www.w3.org/TR/html-markup/syntax.html#comments and http://meta.stackexchange.com/q/95256
                   >
                   [ \t]*
                   (?=\n{2,})                                  // followed by a blank line
               )
           /g,hashMatch);
           */
           text = text.replace(/\n\n[ ]{0,3}(<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>[ \t]*(?=\n{2,}))/g, hashMatch);
           // PHP and ASP-style processor instructions (<?...?> and <%...%>)
           /*
           text = text.replace(/
               (?:
                   \n\n            // Starting after a blank line
               )
               (                   // save in $1
                   [ ]{0,3}        // attacklab: g_tab_width - 1
                   (?:
                       <([?%])     // $2
                       [^\r]*?
                       \2>
                   )
                   [ \t]*
                   (?=\n{2,})      // followed by a blank line
               )
           /g,hashMatch);
           */
           text = text.replace(/(?:\n\n)([ ]{0,3}(?:<([?%])[^\r]*?\2>)[ \t]*(?=\n{2,}))/g, hashMatch);
           return text;
       }
       function hashBlock(text) {
           text = text.replace(/(^\n+|\n+$)/g, "");
           // Replace the element text with a marker ("~KxK" where x is its key)
           return "\n\n~K" + (g_html_blocks.push(text) - 1) + "K\n\n";
       }
       function hashMatch(wholeMatch, m1) {
           return hashBlock(m1);
       }
       
       var blockGamutHookCallback = function (t) { return _RunBlockGamut(t); }
       function _RunBlockGamut(text, doNotUnhash) {
           //
           // These are all the transformations that form block-level
           // tags like paragraphs, headers, and list items.
           //
           
           text = pluginHooks.preBlockGamut(text, blockGamutHookCallback);
           
           text = _DoHeaders(text);
           // Do Horizontal Rules:
var replacement = "
\n";
           text = text.replace(/^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$/gm, replacement);
           text = text.replace(/^[ ]{0,2}([ ]?-[ ]?){3,}[ \t]*$/gm, replacement);
           text = text.replace(/^[ ]{0,2}([ ]?_[ ]?){3,}[ \t]*$/gm, replacement);
           text = _DoLists(text);
           text = _DoCodeBlocks(text);
           text = _DoBlockQuotes(text);
           
           text = pluginHooks.postBlockGamut(text, blockGamutHookCallback);
           // We already ran _HashHTMLBlocks() before, in Markdown(), but that
           // was to escape raw HTML in the original Markdown source. This time,
           // we're escaping the markup we've just created, so that we don't wrap
           // <p> tags around block-level tags.
           text = _HashHTMLBlocks(text);
           text = _FormParagraphs(text, doNotUnhash);
           return text;
       }
       function _RunSpanGamut(text) {
           //
           // These are all the transformations that occur *within* block-level
           // tags like paragraphs, headers, and list items.
           //
           text = pluginHooks.preSpanGamut(text);
           
           text = _DoCodeSpans(text);
           text = _EscapeSpecialCharsWithinTagAttributes(text);
           text = _EncodeBackslashEscapes(text);
           // Process anchor and image tags. Images must come first,
           // because ![foo][f] looks like an anchor.
           text = _DoImages(text);
           text = _DoAnchors(text);
           // Make links out of things like `<http://example.com/>`
           // Must come after _DoAnchors(), because you can use < and >
           // delimiters in inline links like [this](<url>).
           text = _DoAutoLinks(text);
           
           text = text.replace(/~P/g, "://"); // put in place to prevent autolinking; reset now
           
           text = _EncodeAmpsAndAngles(text);
           text = _DoItalicsAndBold(text);
           // Do hard breaks:
           text = text.replace(/  +\n/g, " 
\n"); text = pluginHooks.postSpanGamut(text);
           return text;
       }
       function _EscapeSpecialCharsWithinTagAttributes(text) {
           //
           // Within tags -- meaning between < and > -- encode [\ ` * _] so they
           // don't conflict with their use in Markdown for code, italics and strong.
           //
           // Build a regex to find HTML tags and comments.  See Friedl's 
           // "Mastering Regular Expressions", 2nd Ed., pp. 200-201.
           // SE: changed the comment part of the regex
           var regex = /(<[a-z\/!$]("[^"]*"|'[^']*'|[^'">])*>|<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>)/gi;
           text = text.replace(regex, function (wholeMatch) {
               var tag = wholeMatch.replace(/(.)<\/?code>(?=.)/g, "$1`");
               tag = escapeCharacters(tag, wholeMatch.charAt(1) == "!" ? "\\`*_/" : "\\`*_"); // also escape slashes in comments to prevent autolinking there -- http://meta.stackexchange.com/questions/95987
               return tag;
           });
           return text;
       }
       function _DoAnchors(text) {
           
           if (text.indexOf("[") === -1)
               return text;
           
           //
           // Turn Markdown link shortcuts into XHTML <a> tags.
           //
           //
           // First, handle reference-style links: [link text] [id]
           //
           /*
           text = text.replace(/
               (                           // wrap whole match in $1
                   \[
                   (
                       (?:
                           \^\*\]      // allow brackets nested one level
                           |
                           [^\[]           // or anything else
                       )*
                   )
                   \]
                   [ ]?                    // one optional space
                   (?:\n[ ]*)?             // one optional newline followed by spaces
                   \[
                   (.*?)                   // id = $3
                   \]
               )
               ()()()()                    // pad remaining backreferences
           /g, writeAnchorTag);
           */
           text = text.replace(/(\[((?:\^\*\]|[^\[\]])*)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeAnchorTag);
           //
           // Next, inline-style links: [link text](url "optional title")
           //
           /*
           text = text.replace(/
               (                           // wrap whole match in $1
                   \[
                   (
                       (?:
                           \^\*\]      // allow brackets nested one level
                           |
                           [^\[\]]         // or anything else
                       )*
                   )
                   \]
                   \(                      // literal paren
                   [ \t]*
                   ()                      // no id, so leave $3 empty
                   <?(                     // href = $4
                       (?:
                           \([^)]*\)       // allow one level of (correctly nested) parens (think MSDN)
                           |
                           [^()\s]
                       )*?
                   )>?                
                   [ \t]*
                   (                       // $5
                       (['"])              // quote char = $6
                       (.*?)               // Title = $7
                       \6                  // matching quote
                       [ \t]*              // ignore any spaces/tabs between closing quote and )
                   )?                      // title is optional
                   \)
               )
           /g, writeAnchorTag);
           */
           text = text.replace(/(\[((?:\^\*\]|[^\[\]])*)\]\([ \t]*()<?((?:\([^)]*\)|[^()\s])*?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeAnchorTag);
           //
           // Last, handle reference-style shortcuts: [link text]
           // These must come last in case you've also got [link test][1]
           // or [link test](/foo)
           //
           /*
           text = text.replace(/
               (                   // wrap whole match in $1
                   \[
                   ([^\[\]]+)      // link text = $2; can't contain '[' or ']'
                   \]
               )
               ()()()()()          // pad rest of backreferences
           /g, writeAnchorTag);
           */
           text = text.replace(/(\[([^\[\]]+)\])()()()()()/g, writeAnchorTag);
           return text;
       }
       function writeAnchorTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
           if (m7 == undefined) m7 = "";
           var whole_match = m1;
           var link_text = m2.replace(/:\/\//g, "~P"); // to prevent auto-linking withing the link. will be converted back after the auto-linker runs
           var link_id = m3.toLowerCase();
           var url = m4;
           var title = m7;
           if (url == "") {
               if (link_id == "") {
                   // lower-case and turn embedded newlines into spaces
                   link_id = link_text.toLowerCase().replace(/ ?\n/g, " ");
               }
               url = "#" + link_id;
               if (g_urls.get(link_id) != undefined) {
                   url = g_urls.get(link_id);
                   if (g_titles.get(link_id) != undefined) {
                       title = g_titles.get(link_id);
                   }
               }
               else {
                   if (whole_match.search(/\(\s*\)$/m) > -1) {
                       // Special case for explicit empty url
                       url = "";
                   } else {
                       return whole_match;
                   }
               }
           }
           url = attributeSafeUrl(url);
           var result = "<a href=\"" + url + "\"";
           if (title != "") {
               title = attributeEncode(title);
               title = escapeCharacters(title, "*_");
               result += " title=\"" + title + "\"";
           }
           result += ">" + link_text + "</a>";
           return result;
       }
       function _DoImages(text) {
           
           if (text.indexOf("![") === -1)
               return text;
           
           //
           // Turn Markdown image shortcuts into <img> tags.
           //
           //
           // First, handle reference-style labeled images: ![alt text][id]
           //
           /*
           text = text.replace(/
               (                   // wrap whole match in $1
                   !\[
                   (.*?)           // alt text = $2
                   \]
                   [ ]?            // one optional space
                   (?:\n[ ]*)?     // one optional newline followed by spaces
                   \[
                   (.*?)           // id = $3
                   \]
               )
               ()()()()            // pad rest of backreferences
           /g, writeImageTag);
           */
           text = text.replace(/(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeImageTag);
           //
           // Next, handle inline images:  ![alt text](url "optional title")
           // Don't forget: encode * and _
           /*
           text = text.replace(/
               (                   // wrap whole match in $1
                   !\[
                   (.*?)           // alt text = $2
                   \]
                   \s?             // One optional whitespace character
                   \(              // literal paren
                   [ \t]*
                   ()              // no id, so leave $3 empty
                   <?(\S+?)>?      // src url = $4
                   [ \t]*
                   (               // $5
                       (['"])      // quote char = $6
                       (.*?)       // title = $7
                       \6          // matching quote
                       [ \t]*
                   )?              // title is optional
                   \)
               )
           /g, writeImageTag);
           */
           text = text.replace(/(!\[(.*?)\]\s?\([ \t]*()<?(\S+?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeImageTag);
           return text;
       }
       
       function attributeEncode(text) {
           // unconditionally replace angle brackets here -- what ends up in an attribute (e.g. alt or title)
           // never makes sense to have verbatim HTML in it (and the sanitizer would totally break it)
           return text.replace(/>/g, ">").replace(/</g, "<").replace(/"/g, """).replace(/'/g, "'");
       }
       function writeImageTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
           var whole_match = m1;
           var alt_text = m2;
           var link_id = m3.toLowerCase();
           var url = m4;
           var title = m7;
           if (!title) title = "";
           if (url == "") {
               if (link_id == "") {
                   // lower-case and turn embedded newlines into spaces
                   link_id = alt_text.toLowerCase().replace(/ ?\n/g, " ");
               }
               url = "#" + link_id;
               if (g_urls.get(link_id) != undefined) {
                   url = g_urls.get(link_id);
                   if (g_titles.get(link_id) != undefined) {
                       title = g_titles.get(link_id);
                   }
               }
               else {
                   return whole_match;
               }
           }
           
           alt_text = escapeCharacters(attributeEncode(alt_text), "*_[]()");
           url = escapeCharacters(url, "*_");
           var result = "<img src=\"" + url + "\" alt=\"" + alt_text + "\"";
           // attacklab: Markdown.pl adds empty title attributes to images.
           // Replicate this bug.
           //if (title != "") {
           title = attributeEncode(title);
           title = escapeCharacters(title, "*_");
           result += " title=\"" + title + "\"";
           //}
           result += " />";
           return result;
       }
       function _DoHeaders(text) {
           // Setext-style headers:
           //  Header 1
           //  ========
           //  
           //  Header 2
           //  --------
           //
           text = text.replace(/^(.+)[ \t]*\n=+[ \t]*\n+/gm,
function (wholeMatch, m1) { return "

" + _RunSpanGamut(m1) + "

\n\n"; }
           );
           text = text.replace(/^(.+)[ \t]*\n-+[ \t]*\n+/gm,
function (matchFound, m1) { return "

" + _RunSpanGamut(m1) + "

\n\n"; }
           );
           // atx-style headers:
           //  # Header 1
           //  ## Header 2
           //  ## Header 2 with closing hashes ##
           //  ...
           //  ###### Header 6
           //
           /*
           text = text.replace(/
               ^(\#{1,6})      // $1 = string of #'s
               [ \t]*
               (.+?)           // $2 = Header text
               [ \t]*
               \#*             // optional closing #'s (not counted)
               \n+
           /gm, function() {...});
           */
           text = text.replace(/^(\#{1,6})[ \t]*(.+?)[ \t]*\#*\n+/gm,
               function (wholeMatch, m1, m2) {
                   var h_level = m1.length;
                   return "<h" + h_level + ">" + _RunSpanGamut(m2) + "</h" + h_level + ">\n\n";
               }
           );
           return text;
       }
       function _DoLists(text, isInsideParagraphlessListItem) {
           //
           // Form HTML ordered (numbered) and unordered (bulleted) lists.
           //
           // attacklab: add sentinel to hack around khtml/safari bug:
           // http://bugs.webkit.org/show_bug.cgi?id=11231
           text += "~0";
           // Re-usable pattern to match any entirel ul or ol list:
           /*
           var whole_list = /
               (                                   // $1 = whole list
                   (                               // $2
                       [ ]{0,3}                    // attacklab: g_tab_width - 1
                       ([*+-]|\d+[.])              // $3 = first list item marker
                       [ \t]+
                   )
                   [^\r]+?
                   (                               // $4
                       ~0                          // sentinel for workaround; should be $
                       |
                       \n{2,}
                       (?=\S)
                       (?!                         // Negative lookahead for another list item marker
                           [ \t]*
                           (?:[*+-]|\d+[.])[ \t]+
                       )
                   )
               )
           /g
           */
           var whole_list = /^(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/gm;
           if (g_list_level) {
               text = text.replace(whole_list, function (wholeMatch, m1, m2) {
                   var list = m1;
                   var list_type = (m2.search(/[*+-]/g) > -1) ? "ul" : "ol";
                   var first_number;
                   if (list_type === "ol")
                       first_number = parseInt(m2, 10)
                   var result = _ProcessListItems(list, list_type, isInsideParagraphlessListItem);
                   // Trim any trailing whitespace, to put the closing `</$list_type>`
                   // up on the preceding line, to get it past the current stupid
                   // HTML block parser. This is a hack to work around the terrible
                   // hack that is the HTML block parser.
                   result = result.replace(/\s+$/, "");
                   var opening = "<" + list_type;
                   if (first_number && first_number !== 1)
                       opening += " start=\"" + first_number + "\"";
                   result = opening + ">" + result + "</" + list_type + ">\n";
                   return result;
               });
           } else {
               whole_list = /(\n\n|^\n?)(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/g;
               text = text.replace(whole_list, function (wholeMatch, m1, m2, m3) {
                   var runup = m1;
                   var list = m2;
                   var list_type = (m3.search(/[*+-]/g) > -1) ? "ul" : "ol";
                   var first_number;
                   if (list_type === "ol")
                       first_number = parseInt(m3, 10)
                   var result = _ProcessListItems(list, list_type);
                   var opening = "<" + list_type;
                   if (first_number && first_number !== 1)
                       opening += " start=\"" + first_number + "\"";
                   result = runup + opening + ">\n" + result + "</" + list_type + ">\n";
                   return result;
               });
           }
           // attacklab: strip sentinel
           text = text.replace(/~0/, "");
           return text;
       }
       var _listItemMarkers = { ol: "\\d+[.]", ul: "[*+-]" };
       function _ProcessListItems(list_str, list_type, isInsideParagraphlessListItem) {
           //
           //  Process the contents of a single ordered or unordered list, splitting it
           //  into individual list items.
           //
           //  list_type is either "ul" or "ol".
           // The $g_list_level global keeps track of when we're inside a list.
           // Each time we enter a list, we increment it; when we leave a list,
           // we decrement. If it's zero, we're not in a list anymore.
           //
           // We do this because when we're not inside a list, we want to treat
           // something like this:
           //
           //    I recommend upgrading to version
           //    8. Oops, now this line is treated
           //    as a sub-list.
           //
           // As a single paragraph, despite the fact that the second line starts
           // with a digit-period-space sequence.
           //
           // Whereas when we're inside a list (or sub-list), that line will be
           // treated as the start of a sub-list. What a kludge, huh? This is
           // an aspect of Markdown's syntax that's hard to parse perfectly
           // without resorting to mind-reading. Perhaps the solution is to
           // change the syntax rules such that sub-lists must start with a
           // starting cardinal number; e.g. "1." or "a.".
           g_list_level++;
           // trim trailing blank lines:
           list_str = list_str.replace(/\n{2,}$/, "\n");
           // attacklab: add sentinel to emulate \z
           list_str += "~0";
           // In the original attacklab showdown, list_type was not given to this function, and anything
// that matched /[*+-]|\d+[.]/ would just create the next
  • , causing this mismatch: // // Markdown rendered by WMD rendered by MarkdownSharp // ------------------------------------------------------------------ // 1. first 1. first 1. first // 2. second 2. second 2. second // - third 3. third * third // // We changed this to behave identical to MarkdownSharp. This is the constructed RegEx, // with {MARKER} being one of \d+[.] or [*+-], depending on list_type: /* list_str = list_str.replace(/ (^[ \t]*) // leading whitespace = $1 ({MARKER}) [ \t]+ // list marker = $2 ([^\r]+? // list item text = $3 (\n+) ) (?= (~0 | \2 ({MARKER}) [ \t]+) ) /gm, function(){...}); */ var marker = _listItemMarkers[list_type]; var re = new RegExp("(^[ \\t]*)(" + marker + ")[ \\t]+([^\\r]+?(\\n+))(?=(~0|\\1(" + marker + ")[ \\t]+))", "gm"); var last_item_had_a_double_newline = false; list_str = list_str.replace(re, function (wholeMatch, m1, m2, m3) { var item = m3; var leading_space = m1; var ends_with_double_newline = /\n\n$/.test(item); var contains_double_newline = ends_with_double_newline || item.search(/\n{2,}/) > -1; if (contains_double_newline || last_item_had_a_double_newline) { item = _RunBlockGamut(_Outdent(item), /* doNotUnhash = */true); } else { // Recursion for sub-lists: item = _DoLists(_Outdent(item), /* isInsideParagraphlessListItem= */ true); item = item.replace(/\n$/, ""); // chomp(item) if (!isInsideParagraphlessListItem) // only the outer-most item should run this, otherwise it's run multiple times for the inner ones item = _RunSpanGamut(item); } last_item_had_a_double_newline = ends_with_double_newline; return "
  • " + item + "
  • \n";
                   }
               );
    
               // attacklab: strip sentinel
               list_str = list_str.replace(/~0/g, "");
    
               g_list_level--;
               return list_str;
           }
    
           function _DoCodeBlocks(text) {
               //
    
    // Process Markdown `
    <code>` blocks.
                //  
    
                /*
                text = text.replace(/
                    (?:\n\n|^)
                    (                               // $1 = the code block -- one or more lines, starting with a space/tab
                        (?:
                            (?:[ ]{4}|\t)           // Lines must start with a tab or a tab-width of spaces - attacklab: g_tab_width
                            .*\n+
                        )+
                    )
                    (\n*[ ]{0,3}[^ \t\n]|(?=~0))    // attacklab: g_tab_width
                /g ,function(){...});
                */
    
                // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
                text += "~0";
    
                text = text.replace(/(?:\n\n|^\n?)((?:(?:[ ]{4}|\t).*\n+)+)(\n*[ ]{0,3}[^ \t\n]|(?=~0))/g,
                    function (wholeMatch, m1, m2) {
                        var codeblock = m1;
                        var nextChar = m2;
    
                        codeblock = _EncodeCode(_Outdent(codeblock));
                        codeblock = _Detab(codeblock);
                        codeblock = codeblock.replace(/^\n+/g, ""); // trim leading newlines
                        codeblock = codeblock.replace(/\n+$/g, ""); // trim trailing whitespace
    
                        codeblock = "<pre><code>" + codeblock + "\n</code>
    ";
                       return "\n\n" + codeblock + "\n\n" + nextChar;
                   }
               );
    
               // attacklab: strip sentinel
               text = text.replace(/~0/, "");
    
               return text;
           }
    
           function _DoCodeSpans(text) {
               //
               // * Backtick quotes are used for  spans.
               // 
               // * You can use multiple backticks as the delimiters if you want to
               //   include literal backticks in the code span. So, this input:
               //     
               //      Just type ``foo `bar` baz`` at the prompt.
               //     
               //   Will translate to:
               //     
    
    // <p>Just type foo `bar` baz at the prompt.

               //     
               //   There's no arbitrary limit to the number of backticks you
               //   can use as delimters. If you need three consecutive backticks
               //   in your code, use four for delimiters, etc.
               //
               // * You can use spaces to get literal backticks at the edges:
               //     
               //      ... type `` `bar` `` ...
               //     
               //   Turns to:
               //     
               //      ... type `bar` ...
               //
    
               /*
               text = text.replace(/
                   (^|[^\\`])      // Character before opening ` can't be a backslash or backtick
                   (`+)            // $2 = Opening run of `
                   (?!`)           // and no more backticks -- match the full run
                   (               // $3 = The code block
                       [^\r]*?
                       [^`]        // attacklab: work around lack of lookbehind
                   )
                   \2              // Matching closer
                   (?!`)
               /gm, function(){...});
               */
    
               text = text.replace(/(^|[^\\`])(`+)(?!`)([^\r]*?[^`])\2(?!`)/gm,
                   function (wholeMatch, m1, m2, m3, m4) {
                       var c = m3;
                       c = c.replace(/^([ \t]*)/g, ""); // leading whitespace
                       c = c.replace(/[ \t]*$/g, ""); // trailing whitespace
                       c = _EncodeCode(c);
                       c = c.replace(/:\/\//g, "~P"); // to prevent auto-linking. Not necessary in code *blocks*, but in code spans. Will be converted back after the auto-linker runs.
                       return m1 + "" + c + "";
                   }
               );
    
               return text;
           }
    
           function _EncodeCode(text) {
               //
               // Encode/escape certain characters inside Markdown code runs.
               // The point is that in code, these characters are literals,
               // and lose their special Markdown meanings.
               //
               // Encode all ampersands; HTML entities are not
               // entities within a Markdown code span.
               text = text.replace(/&/g, "&");
    
               // Do the angle bracket song and dance:
               text = text.replace(/</g, "<");
               text = text.replace(/>/g, ">");
    
               // Now, escape characters that are magic in Markdown:
               text = escapeCharacters(text, "\*_{}[]\\", false);
    
               // jj the line above breaks this:
               //---
    
               //* Item
    
               //   1. Subitem
    
               //            special char: *
               //---
    
               return text;
           }
    
           function _DoItalicsAndBoldStrict(text) {
    
               if (text.indexOf("*") === -1 && text.indexOf("_") === - 1)
                   return text;
               
               text = asciify(text);
           
               //  must go first:
               
               // (^|[\W_])           Start with a non-letter or beginning of string. Store in \1.
               // (?:(?!\1)|(?=^))    Either the next character is *not* the same as the previous,
               //                     or we started at the end of the string (in which case the previous
               //                     group had zero width, so we're still there). Because the next
               //                     character is the marker, this means that if there are e.g. multiple
               //                     underscores in a row, we can only match the left-most ones (which
               //                     prevents foo___bar__ from getting bolded)
               // (\*|_)              The marker character itself, asterisk or underscore. Store in \2.
               // \2                  The marker again, since bold needs two.
               // (?=\S)              The first bolded character cannot be a space.
               // ([^\r]*?\S)         The actual bolded string. At least one character, and it cannot *end*
               //                     with a space either. Note that like in many other places, [^\r] is
               //                     just a workaround for JS' lack of single-line regexes; it's equivalent
               //                     to a . in an /s regex, because the string cannot contain any \r (they
               //                     are removed in the normalizing step).
               // \2\2                The marker character, twice -- end of bold.
               // (?!\2)              Not followed by another marker character (ensuring that we match the
               //                     rightmost two in a longer row)...
               // (?=[\W_]|$)         ...but by any other non-word character or the end of string.
               text = text.replace(/(^|[\W_])(?:(?!\1)|(?=^))(\*|_)\2(?=\S)([^\r]*?\S)\2\2(?!\2)(?=[\W_]|$)/g,
               "$1$3");
    
               // This is almost identical to the  regex, except 1) there's obviously just one marker
               // character, and 2) the italicized string cannot contain the marker character.
               text = text.replace(/(^|[\W_])(?:(?!\1)|(?=^))(\*|_)(?=\S)((?:(?!\2)[^\r])*?\S)\2(?!\2)(?=[\W_]|$)/g,
               "$1$3");
    
               return deasciify(text);
           }
    
           function _DoItalicsAndBold_AllowIntrawordWithAsterisk(text) {
               
               if (text.indexOf("*") === -1 && text.indexOf("_") === - 1)
                   return text;
               
               text = asciify(text);
           
               //  must go first:
               // (?=[^\r][*_]|[*_])               Optimization only, to find potentially relevant text portions faster. Minimally slower in Chrome, but much faster in IE.
               // (                                Store in \1. This is the last character before the delimiter
               //     ^                            Either we're at the start of the string (i.e. there is no last character)...
               //     |                            ... or we allow one of the following:
               //     (?=                          (lookahead; we're not capturing this, just listing legal possibilities)
               //         \W__                     If the delimiter is __, then this last character must be non-word non-underscore (extra-word emphasis only)
               //         |
               //         (?!\*)[\W_]\*\*          If the delimiter is **, then this last character can be non-word non-asterisk (extra-word emphasis)...
               //         |
               //         \w\*\*\w                 ...or it can be word/underscore, but only if the first bolded character is such a character as well (intra-word emphasis)
               //     )
               //     [^\r]                        actually capture the character (can't use `.` since it could be \n)
               // )
               // (\*\*|__)                        Store in \2: the actual delimiter
               // (?!\2)                           not followed by the delimiter again (at most one more asterisk/underscore is allowed)
               // (?=\S)                           the first bolded character can't be a space
               // (                                Store in \3: the bolded string
               //                                  
               //     (?:|                         Look at all bolded characters except for the last one. Either that's empty, meaning only a single character was bolded...
               //       [^\r]*?                    ... otherwise take arbitrary characters, minimally matching; that's all bolded characters except for the last *two*
               //       (?!\2)                       the last two characters cannot be the delimiter itself (because that would mean four underscores/asterisks in a row)
               //       [^\r]                        capture the next-to-last bolded character
               //     )
               //     (?=                          lookahead at the very last bolded char and what comes after
               //         \S_                      for underscore-bolding, it can be any non-space
               //         |
               //         \w                       for asterisk-bolding (otherwise the previous alternative would've matched, since \w implies \S), either the last char is word/underscore...
               //         |
               //         \S\*\*(?:[\W_]|$)        ... or it's any other non-space, but in that case the character *after* the delimiter may not be a word character
               //     )
               //     .                            actually capture the last character (can use `.` this time because the lookahead ensures \S in all cases)
               // )
               // (?=                              lookahead; list the legal possibilities for the closing delimiter and its following character
               //     __(?:\W|$)                   for underscore-bolding, the following character (if any) must be non-word non-underscore
               //     |
               //     \*\*(?:[^*]|$)               for asterisk-bolding, any non-asterisk is allowed (note we already ensured above that it's not a word character if the last bolded character wasn't one)
               // )
               // \2                               actually capture the closing delimiter (and make sure that it matches the opening one)
             
               text = text.replace(/(?=[^\r][*_]|[*_])(^|(?=\W__|(?!\*)[\W_]\*\*|\w\*\*\w)[^\r])(\*\*|__)(?!\2)(?=\S)((?:|[^\r]*?(?!\2)[^\r])(?=\S_|\w|\S\*\*(?:[\W_]|$)).)(?=__(?:\W|$)|\*\*(?:[^*]|$))\2/g,
               "$1$3");
    
               // now :
               // (?=[^\r][*_]|[*_])               Optimization, see above.
               // (                                Store in \1. This is the last character before the delimiter
               //     ^                            Either we're at the start of the string (i.e. there is no last character)...
               //     |                            ... or we allow one of the following:
               //     (?=                          (lookahead; we're not capturing this, just listing legal possibilities)
               //         \W_                      If the delimiter is _, then this last character must be non-word non-underscore (extra-word emphasis only)
               //         |
               //         (?!\*)                   otherwise, we list two possiblities for * as the delimiter; in either case, the last characters cannot be an asterisk itself
               //         (?:
               //             [\W_]\*              this last character can be non-word (extra-word emphasis)...
               //             |
               //             \D\*(?=\w)\D         ...or it can be word (otherwise the first alternative would've matched), but only if
               //                                      a) the first italicized character is such a character as well (intra-word emphasis), and
               //                                      b) neither character on either side of the asterisk is a digit            
               //         )
               //     )
               //     [^\r]                        actually capture the character (can't use `.` since it could be \n)
               // )
               // (\*|_)                           Store in \2: the actual delimiter
               // (?!\2\2\2)                       not followed by more than two more instances of the delimiter
               // (?=\S)                           the first italicized character can't be a space
               // (                                Store in \3: the italicized string
               //     (?:(?!\2)[^\r])*?            arbitrary characters except for the delimiter itself, minimally matching
               //     (?=                          lookahead at the very last italicized char and what comes after
               //         [^\s_]_                  for underscore-italicizing, it can be any non-space non-underscore
               //         |
               //         (?=\w)\D\*\D             for asterisk-italicizing, either the last char is word/underscore *and* neither character on either side of the asterisk is a digit...
               //         |
               //         [^\s*]\*(?:[\W_]|$)      ... or that last char is any other non-space non-asterisk, but then the character after the delimiter (if any) must be non-word
               //     )
               //     .                            actually capture the last character (can use `.` this time because the lookahead ensures \S in all cases)
               // )
               // (?=                              lookahead; list the legal possibilities for the closing delimiter and its following character
               //     _(?:\W|$)                    for underscore-italicizing, the following character (if any) must be non-word non-underscore
               //     |
               //     \*(?:[^*]|$)                 for asterisk-italicizing, any non-asterisk is allowed; all other restrictions have already been ensured in the previous lookahead
               // )
               // \2                               actually capture the closing delimiter (and make sure that it matches the opening one)
    
               text = text.replace(/(?=[^\r][*_]|[*_])(^|(?=\W_|(?!\*)(?:[\W_]\*|\D\*(?=\w)\D))[^\r])(\*|_)(?!\2\2\2)(?=\S)((?:(?!\2)[^\r])*?(?=[^\s_]_|(?=\w)\D\*\D|[^\s*]\*(?:[\W_]|$)).)(?=_(?:\W|$)|\*(?:[^*]|$))\2/g,
               "$1$3");
               
               return deasciify(text);
           }        
    


           function _DoBlockQuotes(text) {
    
               /*
               text = text.replace(/
                   (                           // Wrap whole match in $1
                       (
                           ^[ \t]*>[ \t]?      // '>' at the start of a line
                           .+\n                // rest of the first line
                           (.+\n)*             // subsequent consecutive lines
                           \n*                 // blanks
                       )+
                   )
               /gm, function(){...});
               */
    
               text = text.replace(/((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)/gm,
                   function (wholeMatch, m1) {
                       var bq = m1;
    
                       // attacklab: hack around Konqueror 3.5.4 bug:
                       // "----------bug".replace(/^-/g,"") == "bug"
    
                       bq = bq.replace(/^[ \t]*>[ \t]?/gm, "~0"); // trim one level of quoting
    
                       // attacklab: clean up hack
                       bq = bq.replace(/~0/g, "");
    
                       bq = bq.replace(/^[ \t]+$/gm, "");     // trim whitespace-only lines
                       bq = _RunBlockGamut(bq);             // recurse
    
                       bq = bq.replace(/(^|\n)/g, "$1  ");
    
    // These leading spaces screw with
     content, so we need to fix that:
                        bq = bq.replace(
                                /(\s*<pre>[^\r]+?<\/pre>)/gm,
                            function (wholeMatch, m1) {
                                var pre = m1;
                                // attacklab: hack around Konqueror 3.5.4 bug:
                                pre = pre.replace(/^  /mg, "~0");
                                pre = pre.replace(/~0/g, "");
                                return pre;
                            });
    
                        return hashBlock("<blockquote>\n" + bq + "\n</blockquote>");
                    }
                );
                return text;
            }
    
            function _FormParagraphs(text, doNotUnhash) {
                //
                //  Params:
                //    $text - string to process with html <p> tags
                //
    
                // Strip leading and trailing lines:
                text = text.replace(/^\n+/g, "");
                text = text.replace(/\n+$/g, "");
    
                var grafs = text.split(/\n{2,}/g);
                var grafsOut = [];
                
                var markerRe = /~K(\d+)K/;
    
                //
                // Wrap <p> tags.
                //
                var end = grafs.length;
                for (var i = 0; i < end; i++) {
                    var str = grafs[i];
    
                    // if this is an HTML marker, copy it
                    if (markerRe.test(str)) {
                        grafsOut.push(str);
                    }
                    else if (/\S/.test(str)) {
                        str = _RunSpanGamut(str);
                        str = str.replace(/^([ \t]*)/g, "<p>");
                        str += "</p>"
                        grafsOut.push(str);
                    }
    
                }
                //
                // Unhashify HTML blocks
                //
                if (!doNotUnhash) {
                    end = grafsOut.length;
                    for (var i = 0; i < end; i++) {
                        var foundAny = true;
                        while (foundAny) { // we may need several runs, since the data may be nested
                            foundAny = false;
                            grafsOut[i] = grafsOut[i].replace(/~K(\d+)K/g, function (wholeMatch, id) {
                                foundAny = true;
                                return g_html_blocks[id];
                            });
                        }
                    }
                }
                return grafsOut.join("\n\n");
            }
    
            function _EncodeAmpsAndAngles(text) {
                // Smart processing for ampersands and angle brackets that need to be encoded.
    
                // Ampersand-encoding based entirely on Nat Irons's Amputator MT plugin:
                //   http://bumppo.net/projects/amputator/
                text = text.replace(/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/g, "&");
    
                // Encode naked <'s
                text = text.replace(/<(?![a-z\/?!]|~D)/gi, "<");
    
                return text;
            }
    
            function _EncodeBackslashEscapes(text) {
                //
                //   Parameter:  String.
                //   Returns:    The string, with after processing the following backslash
                //               escape sequences.
                //
    
                // attacklab: The polite way to do this is with the new
                // escapeCharacters() function:
                //
                //     text = escapeCharacters(text,"\\",true);
                //     text = escapeCharacters(text,"`*_{}[]()>#+-.!",true);
                //
                // ...but we're sidestepping its use of the (slow) RegExp constructor
                // as an optimization for Firefox.  This function gets called a LOT.
    
                text = text.replace(/\\(\\)/g, escapeCharacters_callback);
                text = text.replace(/\\([`*_{}\[\]()>#+-.!])/g, escapeCharacters_callback);
                return text;
            }
    
            var charInsideUrl = "[-A-Z0-9+&@#/%?=~_|[\\]()!:,.;]",
                charEndingUrl = "[-A-Z0-9+&@#/%=~_|[\\])]",
                autoLinkRegex = new RegExp("(=\"|<)?\\b(https?|ftp)(://" + charInsideUrl + "*" + charEndingUrl + ")(?=$|\\W)", "gi"),
                endCharRegex = new RegExp(charEndingUrl, "i");
    
            function handleTrailingParens(wholeMatch, lookbehind, protocol, link) {
                if (lookbehind)
                    return wholeMatch;
                if (link.charAt(link.length - 1) !== ")")
                    return "<" + protocol + link + ">";
                var parens = link.match(/[()]/g);
                var level = 0;
                for (var i = 0; i < parens.length; i++) {
                    if (parens[i] === "(") {
                        if (level <= 0)
                            level = 1;
                        else
                            level++;
                    }
                    else {
                        level--;
                    }
                }
                var tail = "";
                if (level < 0) {
                    var re = new RegExp("\\){1," + (-level) + "}$");
                    link = link.replace(re, function (trailingParens) {
                        tail = trailingParens;
                        return "";
                    });
                }
                if (tail) {
                    var lastChar = link.charAt(link.length - 1);
                    if (!endCharRegex.test(lastChar)) {
                        tail = lastChar + tail;
                        link = link.substr(0, link.length - 1);
                    }
                }
                return "<" + protocol + link + ">" + tail;
            }
            
            function _DoAutoLinks(text) {
    
                // note that at this point, all other URL in the text are already hyperlinked as <a href=""></a>
                // *except* for the <http://www.foo.com> case
    
                // automatically add < and > around unadorned raw hyperlinks
                // must be preceded by a non-word character (and not by =" or <) and followed by non-word/EOF character
                // simulating the lookbehind in a consuming way is okay here, since a URL can neither and with a " nor
                // with a <, so there is no risk of overlapping matches.
                text = text.replace(autoLinkRegex, handleTrailingParens);
    
                //  autolink anything like <http://example.com>
                
    
                var replacer = function (wholematch, m1) {
                    var url = attributeSafeUrl(m1);
                    
                    return "<a href=\"" + url + "\">" + pluginHooks.plainLinkText(m1) + "</a>";
                };
                text = text.replace(/<((https?|ftp):[^'">\s]+)>/gi, replacer);
    
                // Email addresses: <address@domain.foo>
                /*
                text = text.replace(/
                    <
                    (?:mailto:)?
                    (
                        [-.\w]+
                        \@
                        [-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
                    )
                    >
                /gi, _DoAutoLinks_callback());
                */
    
                /* disabling email autolinking, since we don't do that on the server, either
                text = text.replace(/<(?:mailto:)?([-.\w]+\@[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+)>/gi,
                    function(wholeMatch,m1) {
                        return _EncodeEmailAddress( _UnescapeSpecialChars(m1) );
                    }
                );
                */
                return text;
            }
    
            function _UnescapeSpecialChars(text) {
                //
                // Swap back in all the special characters we've hidden.
                //
                text = text.replace(/~E(\d+)E/g,
                    function (wholeMatch, m1) {
                        var charCodeToReplace = parseInt(m1);
                        return String.fromCharCode(charCodeToReplace);
                    }
                );
                return text;
            }
    
            function _Outdent(text) {
                //
                // Remove one level of line-leading tabs or spaces
                //
    
                // attacklab: hack around Konqueror 3.5.4 bug:
                // "----------bug".replace(/^-/g,"") == "bug"
    
                text = text.replace(/^(\t|[ ]{1,4})/gm, "~0"); // attacklab: g_tab_width
    
                // attacklab: clean up hack
                text = text.replace(/~0/g, "")
    
                return text;
            }
    
            function _Detab(text) {
                if (!/\t/.test(text))
                    return text;
    
                var spaces = ["    ", "   ", "  ", " "],
                skew = 0,
                v;
    
                return text.replace(/[\n\t]/g, function (match, offset) {
                    if (match === "\n") {
                        skew = offset + 1;
                        return match;
                    }
                    v = (offset - skew) % 4;
                    skew = offset + 1;
                    return spaces[v];
                });
            }
    
            //
            //  attacklab: Utility functions
            //
    
            function attributeSafeUrl(url) {
                url = attributeEncode(url);
                url = escapeCharacters(url, "*_:()[]")
                return url;
            }
    
            function escapeCharacters(text, charsToEscape, afterBackslash) {
                // First we have to escape the escape characters so that
                // we can build a character class out of them
                var regexString = "([" + charsToEscape.replace(/([\[\]\\])/g, "\\$1") + "])";
    
                if (afterBackslash) {
                    regexString = "\\\\" + regexString;
                }
    
                var regex = new RegExp(regexString, "g");
                text = text.replace(regex, escapeCharacters_callback);
    
                return text;
            }
    
    
            function escapeCharacters_callback(wholeMatch, m1) {
                var charCodeToEscape = m1.charCodeAt(0);
                return "~E" + charCodeToEscape + "E";
            }
    
        }; // end of the Markdown.Converter constructor
    
    })();