kmx.io/prism.js

diff --git a/code.js b/code.js
index 004fb16..4d431f5 100644
--- a/code.js
+++ b/code.js
@@ -31,11 +31,19 @@ var components = {
 			title: 'CSS',
 			option: 'default'
 		},
+		'clike': {
+			title: 'C-like',
+			option: 'default'
+		},
 		'javascript': {
 			title: 'JavaScript',
-			option: 'default'
+			option: 'default',
+			require: 'clike'
 		},
-		'java' : 'Java',
+		'java' : {
+			title: 'Java',
+			require: 'clike'
+		}
 	},
 	plugins: {
 		meta: {
diff --git a/components/prism-clike.js b/components/prism-clike.js
new file mode 100644
index 0000000..0c2ee7d
--- /dev/null
+++ b/components/prism-clike.js
@@ -0,0 +1,13 @@
+Prism.languages.clike = {
+	'comment': {
+		pattern: /(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,
+		lookbehind: true
+	},
+	'string': /("|')(\\?.)*?\1/g,
+	'keyword': /\b(if|else|while|do|for|return|in|instanceof|function|new|try|catch|finally|null|break|continue)\b/g,
+	'boolean': /\b(true|false)\b/g,
+	'number': /\b-?(0x)?[\da-f]*\.?\d+\b/g,
+	'operator': /[-+]{1,2}|!|=?<|=?>|={1,2}|(&){1,2}|\|?\||\?|\*|\//g,
+	'ignore': /&(lt|gt|amp);/gi,
+	'punctuation': /[{}[\];(),.:]/g
+};
\ No newline at end of file
diff --git a/components/prism-clike.min.js b/components/prism-clike.min.js
new file mode 100644
index 0000000..541a40b
--- /dev/null
+++ b/components/prism-clike.min.js
@@ -0,0 +1 @@
+Prism.languages.clike={comment:{pattern:/(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,lookbehind:!0},string:/("|')(\\?.)*?\1/g,keyword:/\b(if|else|while|do|for|return|in|instanceof|function|new|try|catch|finally|null|break|continue)\b/g,"boolean":/\b(true|false)\b/g,number:/\b-?(0x)?[\da-f]*\.?\d+\b/g,operator:/[-+]{1,2}|!|=?<|=?>|={1,2}|(&){1,2}|\|?\||\?|\*|\//g,ignore:/&(lt|gt|amp);/gi,punctuation:/[{}[\];(),.:]/g};
\ No newline at end of file
diff --git a/components/prism-core.js b/components/prism-core.js
index c3abe4f..e3475a0 100644
--- a/components/prism-core.js
+++ b/components/prism-core.js
@@ -10,7 +10,47 @@
 var lang = /\blang(?:uage)?-(?!\*)(\w+)\b/i;
 
 var _ = self.Prism = {
+	util: {
+		type: function (o) { 
+			return Object.prototype.toString.call(o).match(/\[object (\w+)\]/)[1];
+		},
+		
+		// Deep clone a language definition (e.g. to extend it)
+		clone: function (o) {
+			var type = _.util.type(o);
+
+			switch (type) {
+				case 'Object':
+					var clone = {};
+					
+					for (var key in o) {
+						if (o.hasOwnProperty(key)) {
+							clone[key] = _.util.clone(o[key]);
+						}
+					}
+					
+					return clone;
+					
+				case 'Array':
+					return o.slice();
+			}
+			
+			return o;
+		}
+	},
+	
 	languages: {
+		extend: function (id, redef) {
+			var lang = _.util.clone(_.languages[id]);
+			
+			for (var key in redef) {
+				lang[key] = redef[key];
+			}
+			
+			return lang;
+		},
+		
+		// Insert a token before another token in a language literal
 		insertBefore: function (inside, before, insert, root) {
 			root = root || _.languages;
 			var grammar = root[inside];
@@ -37,11 +77,12 @@ var _ = self.Prism = {
 			return root[inside] = ret;
 		},
 		
+		// Traverse a language definition with Depth First Search
 		DFS: function(o, callback) {
 			for (var i in o) {
 				callback.call(o, i, o[i]);
 				
-				if (Object.prototype.toString.call(o) === '[object Object]') {
+				if (_.util.type(o) === 'Object') {
 					_.languages.DFS(o[i], callback);
 				}
 			}
diff --git a/components/prism-core.min.js b/components/prism-core.min.js
index abc6254..2d09be9 100644
--- a/components/prism-core.min.js
+++ b/components/prism-core.min.js
@@ -2,4 +2,4 @@
  * Prism: Lightweight, robust, elegant syntax highlighting
  * MIT license http://www.opensource.org/licenses/mit-license.php/
  * @author Lea Verou http://lea.verou.me
- */(function(){var e=/\blang(?:uage)?-(?!\*)(\w+)\b/i,t=self.Prism={languages:{insertBefore:function(e,n,r,i){i=i||t.languages;var s=i[e],o={};for(var u in s)if(s.hasOwnProperty(u)){if(u==n)for(var a in r)r.hasOwnProperty(a)&&(o[a]=r[a]);o[u]=s[u]}return i[e]=o},DFS:function(e,n){for(var r in e){n.call(e,r,e[r]);Object.prototype.toString.call(e)==="[object Object]"&&t.languages.DFS(e[r],n)}}},highlightAll:function(e,n){var r=document.querySelectorAll('code[class*="language-"], [class*="language-"] code, code[class*="lang-"], [class*="lang-"] code');for(var i=0,s;s=r[i++];)t.highlightElement(s,e===!0,n)},highlightElement:function(r,i,s){var o,u,a=r;while(a&&!e.test(a.className))a=a.parentNode;if(a){o=(a.className.match(e)||[,""])[1];u=t.languages[o]}if(!u)return;r.className=r.className.replace(e,"").replace(/\s+/g," ")+" language-"+o;a=r.parentNode;/pre/i.test(a.nodeName)&&(a.className=a.className.replace(e,"").replace(/\s+/g," ")+" language-"+o);var f=r.textContent;if(!f)return;f=f.replace(/&/g,"&amp;").replace(/</g,"&lt;").replace(/>/g,"&gt;").replace(/\u00a0/g," ");var l={element:r,language:o,grammar:u,code:f};t.hooks.run("before-highlight",l);if(i&&self.Worker){var c=new Worker(t.filename);c.onmessage=function(e){l.highlightedCode=n.stringify(JSON.parse(e.data));l.element.innerHTML=l.highlightedCode;s&&s.call(l.element);t.hooks.run("after-highlight",l)};c.postMessage(JSON.stringify({language:l.language,code:l.code}))}else{l.highlightedCode=t.highlight(l.code,l.grammar);l.element.innerHTML=l.highlightedCode;s&&s.call(r);t.hooks.run("after-highlight",l)}},highlight:function(e,r){return n.stringify(t.tokenize(e,r))},tokenize:function(e,n){var r=t.Token,i=[e],s=n.rest;if(s){for(var o in s)n[o]=s[o];delete n.rest}e:for(var o in n){if(!n.hasOwnProperty(o)||!n[o])continue;var u=n[o],a=u.inside,f=!!u.lookbehind||0;u=u.pattern||u;for(var l=0;l<i.length;l++){var c=i[l];if(i.length>e.length)break e;if(c instanceof r)continue;u.lastIndex=0;var h=u.exec(c);if(h){f&&(f=h[1].length);var p=h.index-1+f,h=h[0].slice(f),d=h.length,v=p+d,m=c.slice(0,p+1),g=c.slice(v+1),y=[l,1];m&&y.push(m);var b=new r(o,a?t.tokenize(h,a):h);y.push(b);g&&y.push(g);Array.prototype.splice.apply(i,y)}}}return i},hooks:{all:{},add:function(e,n){var r=t.hooks.all;r[e]=r[e]||[];r[e].push(n)},run:function(e,n){var r=t.hooks.all[e];if(!r||!r.length)return;for(var i=0,s;s=r[i++];)s(n)}}},n=t.Token=function(e,t){this.type=e;this.content=t};n.stringify=function(e){if(typeof e=="string")return e;if(Object.prototype.toString.call(e)=="[object Array]"){for(var r=0;r<e.length;r++)e[r]=n.stringify(e[r]);return e.join("")}var i={type:e.type,content:n.stringify(e.content),tag:"span",classes:["token",e.type],attributes:{}};i.type=="comment"&&(i.attributes.spellcheck="true");t.hooks.run("wrap",i);var s="";for(var o in i.attributes)s+=o+'="'+(i.attributes[o]||"")+'"';return"<"+i.tag+' class="'+i.classes.join(" ")+'" '+s+">"+i.content+"</"+i.tag+">"};if(!self.document){self.addEventListener("message",function(e){var n=JSON.parse(e.data),r=n.language,i=n.code;self.postMessage(JSON.stringify(t.tokenize(i,t.languages[r])));self.close()},!1);return}var r=document.getElementsByTagName("script");r=r[r.length-1];if(r){t.filename=r.src;document.addEventListener&&!r.hasAttribute("data-manual")&&document.addEventListener("DOMContentLoaded",t.highlightAll)}})();
\ No newline at end of file
+ */(function(){var e=/\blang(?:uage)?-(?!\*)(\w+)\b/i,t=self.Prism={util:{type:function(e){return Object.prototype.toString.call(e).match(/\[object (\w+)\]/)[1]},clone:function(e){var n=t.util.type(e);switch(n){case"Object":var r={};for(var i in e)e.hasOwnProperty(i)&&(r[i]=t.util.clone(e[i]));return r;case"Array":return e.slice()}return e}},languages:{extend:function(e,n){var r=t.util.clone(t.languages[e]);for(var i in n)r[i]=n[i];return r},insertBefore:function(e,n,r,i){i=i||t.languages;var s=i[e],o={};for(var u in s)if(s.hasOwnProperty(u)){if(u==n)for(var a in r)r.hasOwnProperty(a)&&(o[a]=r[a]);o[u]=s[u]}return i[e]=o},DFS:function(e,n){for(var r in e){n.call(e,r,e[r]);t.util.type(e)==="Object"&&t.languages.DFS(e[r],n)}}},highlightAll:function(e,n){var r=document.querySelectorAll('code[class*="language-"], [class*="language-"] code, code[class*="lang-"], [class*="lang-"] code');for(var i=0,s;s=r[i++];)t.highlightElement(s,e===!0,n)},highlightElement:function(r,i,s){var o,u,a=r;while(a&&!e.test(a.className))a=a.parentNode;if(a){o=(a.className.match(e)||[,""])[1];u=t.languages[o]}if(!u)return;r.className=r.className.replace(e,"").replace(/\s+/g," ")+" language-"+o;a=r.parentNode;/pre/i.test(a.nodeName)&&(a.className=a.className.replace(e,"").replace(/\s+/g," ")+" language-"+o);var f=r.textContent;if(!f)return;f=f.replace(/&/g,"&amp;").replace(/</g,"&lt;").replace(/>/g,"&gt;").replace(/\u00a0/g," ");var l={element:r,language:o,grammar:u,code:f};t.hooks.run("before-highlight",l);if(i&&self.Worker){var c=new Worker(t.filename);c.onmessage=function(e){l.highlightedCode=n.stringify(JSON.parse(e.data));l.element.innerHTML=l.highlightedCode;s&&s.call(l.element);t.hooks.run("after-highlight",l)};c.postMessage(JSON.stringify({language:l.language,code:l.code}))}else{l.highlightedCode=t.highlight(l.code,l.grammar);l.element.innerHTML=l.highlightedCode;s&&s.call(r);t.hooks.run("after-highlight",l)}},highlight:function(e,r){return n.stringify(t.tokenize(e,r))},tokenize:function(e,n){var r=t.Token,i=[e],s=n.rest;if(s){for(var o in s)n[o]=s[o];delete n.rest}e:for(var o in n){if(!n.hasOwnProperty(o)||!n[o])continue;var u=n[o],a=u.inside,f=!!u.lookbehind||0;u=u.pattern||u;for(var l=0;l<i.length;l++){var c=i[l];if(i.length>e.length)break e;if(c instanceof r)continue;u.lastIndex=0;var h=u.exec(c);if(h){f&&(f=h[1].length);var p=h.index-1+f,h=h[0].slice(f),d=h.length,v=p+d,m=c.slice(0,p+1),g=c.slice(v+1),y=[l,1];m&&y.push(m);var b=new r(o,a?t.tokenize(h,a):h);y.push(b);g&&y.push(g);Array.prototype.splice.apply(i,y)}}}return i},hooks:{all:{},add:function(e,n){var r=t.hooks.all;r[e]=r[e]||[];r[e].push(n)},run:function(e,n){var r=t.hooks.all[e];if(!r||!r.length)return;for(var i=0,s;s=r[i++];)s(n)}}},n=t.Token=function(e,t){this.type=e;this.content=t};n.stringify=function(e){if(typeof e=="string")return e;if(Object.prototype.toString.call(e)=="[object Array]"){for(var r=0;r<e.length;r++)e[r]=n.stringify(e[r]);return e.join("")}var i={type:e.type,content:n.stringify(e.content),tag:"span",classes:["token",e.type],attributes:{}};i.type=="comment"&&(i.attributes.spellcheck="true");t.hooks.run("wrap",i);var s="";for(var o in i.attributes)s+=o+'="'+(i.attributes[o]||"")+'"';return"<"+i.tag+' class="'+i.classes.join(" ")+'" '+s+">"+i.content+"</"+i.tag+">"};if(!self.document){self.addEventListener("message",function(e){var n=JSON.parse(e.data),r=n.language,i=n.code;self.postMessage(JSON.stringify(t.tokenize(i,t.languages[r])));self.close()},!1);return}var r=document.getElementsByTagName("script");r=r[r.length-1];if(r){t.filename=r.src;document.addEventListener&&!r.hasAttribute("data-manual")&&document.addEventListener("DOMContentLoaded",t.highlightAll)}})();
\ No newline at end of file
diff --git a/components/prism-java.js b/components/prism-java.js
index a5a0a97..1e61ad0 100644
--- a/components/prism-java.js
+++ b/components/prism-java.js
@@ -1,16 +1,8 @@
-Prism.languages.java = {
-	'comment': {
-		pattern: /(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,
-		lookbehind: true
-	},
-	'string': /("|')(\\?.)*?\1/g,
+Prism.languages.java = Prism.languages.extend('clike', {
 	'keyword': /\b(abstract|continue|for|new|switch|assert|default|goto|package|synchronized|boolean|do|if|private|this|break|double|implements|protected|throw|byte|else|import|public|throws|case|enum|instanceof|return|transient|catch|extends|int|short|try|char|final|interface|static|void|class|finally|long|strictfp|volatile|const|float|native|super|while)\b/g,
-	'boolean': /\b(true|false)\b/g,
 	'number': /\b0b[01]+\b|\b0x[\da-f]*\.?[\da-fp\-]+\b|\b\d*\.?\d+[e]?[\d]*[df]\b|\W\d*\.?\d+\b/gi,
 	'operator': {
 		pattern: /([^\.]|^)([-+]{1,2}|!|=?&lt;|=?&gt;|={1,2}|(&amp;){1,2}|\|?\||\?|\*|\/|%|\^|(&lt;){2}|($gt;){2,3}|:|~)/g,
 		lookbehind: true
-	},
-	'ignore': /&(lt|gt|amp);/gi,
-	'punctuation': /[{}[\];(),.:]/g,
-};
\ No newline at end of file
+	}
+});
\ No newline at end of file
diff --git a/components/prism-java.min.js b/components/prism-java.min.js
index 936ef92..e6f9a77 100644
--- a/components/prism-java.min.js
+++ b/components/prism-java.min.js
@@ -1 +1 @@
-Prism.languages.java={comment:{pattern:/(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,lookbehind:!0},string:/("|')(\\?.)*?\1/g,keyword:/\b(abstract|continue|for|new|switch|assert|default|goto|package|synchronized|boolean|do|if|private|this|break|double|implements|protected|throw|byte|else|import|public|throws|case|enum|instanceof|return|transient|catch|extends|int|short|try|char|final|interface|static|void|class|finally|long|strictfp|volatile|const|float|native|super|while)\b/g,"boolean":/\b(true|false)\b/g,number:/\b0b[01]+\b|\b0x[\da-f]*\.?[\da-fp\-]+\b|\b\d*\.?\d+[e]?[\d]*[df]\b|\W\d*\.?\d+\b/gi,operator:{pattern:/([^\.]|^)([-+]{1,2}|!|=?&lt;|=?&gt;|={1,2}|(&amp;){1,2}|\|?\||\?|\*|\/|%|\^|(&lt;){2}|($gt;){2,3}|:|~)/g,lookbehind:!0},ignore:/&(lt|gt|amp);/gi,punctuation:/[{}[\];(),.:]/g};
\ No newline at end of file
+Prism.languages.java=Prism.languages.extend("clike",{keyword:/\b(abstract|continue|for|new|switch|assert|default|goto|package|synchronized|boolean|do|if|private|this|break|double|implements|protected|throw|byte|else|import|public|throws|case|enum|instanceof|return|transient|catch|extends|int|short|try|char|final|interface|static|void|class|finally|long|strictfp|volatile|const|float|native|super|while)\b/g,number:/\b0b[01]+\b|\b0x[\da-f]*\.?[\da-fp\-]+\b|\b\d*\.?\d+[e]?[\d]*[df]\b|\W\d*\.?\d+\b/gi,operator:{pattern:/([^\.]|^)([-+]{1,2}|!|=?&lt;|=?&gt;|={1,2}|(&amp;){1,2}|\|?\||\?|\*|\/|%|\^|(&lt;){2}|($gt;){2,3}|:|~)/g,lookbehind:!0}});
\ No newline at end of file
diff --git a/components/prism-javascript.js b/components/prism-javascript.js
index f33fd11..3495dfb 100644
--- a/components/prism-javascript.js
+++ b/components/prism-javascript.js
@@ -1,20 +1,13 @@
-Prism.languages.javascript = {
-	'comment': {
-		pattern: /(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,
-		lookbehind: true
-	},
-	'string': /("|')(\\?.)*?\1/g,
+Prism.languages.javascript = Prism.languages.extend('clike', {
+	'keyword': /\b(var|let|if|else|while|do|for|return|in|instanceof|function|new|with|typeof|try|catch|finally|null|break|continue)\b/g
+});
+
+Prism.languages.insertBefore('javascript', 'keyword', {
 	'regex': {
 		pattern: /(^|[^/])\/(?!\/)(\[.+?]|\\.|[^/\r\n])+\/[gim]{0,3}(?=\s*($|[\r\n,.;})]))/g,
 		lookbehind: true
-	},
-	'keyword': /\b(var|let|if|else|while|do|for|return|in|instanceof|function|new|with|typeof|try|catch|finally|null|break|continue)\b/g,
-	'boolean': /\b(true|false)\b/g,
-	'number': /\b-?(0x)?\d*\.?\d+\b/g,
-	'operator': /[-+]{1,2}|!|=?&lt;|=?&gt;|={1,2}|(&amp;){1,2}|\|?\||\?|\*|\//g,
-	'ignore': /&(lt|gt|amp);/gi,
-	'punctuation': /[{}[\];(),.:]/g
-};
+	}
+});
 
 if (Prism.languages.markup) {
 	Prism.languages.insertBefore('markup', 'tag', {
diff --git a/components/prism-javascript.min.js b/components/prism-javascript.min.js
index 1e6ea08..2dd6012 100644
--- a/components/prism-javascript.min.js
+++ b/components/prism-javascript.min.js
@@ -1 +1 @@
-Prism.languages.javascript={comment:{pattern:/(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,lookbehind:!0},string:/("|')(\\?.)*?\1/g,regex:{pattern:/(^|[^/])\/(?!\/)(\[.+?]|\\.|[^/\r\n])+\/[gim]{0,3}(?=\s*($|[\r\n,.;})]))/g,lookbehind:!0},keyword:/\b(var|let|if|else|while|do|for|return|in|instanceof|function|new|with|typeof|try|catch|finally|null|break|continue)\b/g,"boolean":/\b(true|false)\b/g,number:/\b-?(0x)?\d*\.?\d+\b/g,operator:/[-+]{1,2}|!|=?&lt;|=?&gt;|={1,2}|(&amp;){1,2}|\|?\||\?|\*|\//g,ignore:/&(lt|gt|amp);/gi,punctuation:/[{}[\];(),.:]/g};Prism.languages.markup&&Prism.languages.insertBefore("markup","tag",{script:{pattern:/(&lt;|<)script[\w\W]*?(>|&gt;)[\w\W]*?(&lt;|<)\/script(>|&gt;)/ig,inside:{tag:{pattern:/(&lt;|<)script[\w\W]*?(>|&gt;)|(&lt;|<)\/script(>|&gt;)/ig,inside:Prism.languages.markup.tag.inside},rest:Prism.languages.javascript}}});
\ No newline at end of file
+Prism.languages.javascript=Prism.languages.extend("clike",{keyword:/\b(var|let|if|else|while|do|for|return|in|instanceof|function|new|with|typeof|try|catch|finally|null|break|continue)\b/g});Prism.languages.insertBefore("javascript","keyword",{regex:{pattern:/(^|[^/])\/(?!\/)(\[.+?]|\\.|[^/\r\n])+\/[gim]{0,3}(?=\s*($|[\r\n,.;})]))/g,lookbehind:!0}});Prism.languages.markup&&Prism.languages.insertBefore("markup","tag",{script:{pattern:/(&lt;|<)script[\w\W]*?(>|&gt;)[\w\W]*?(&lt;|<)\/script(>|&gt;)/ig,inside:{tag:{pattern:/(&lt;|<)script[\w\W]*?(>|&gt;)|(&lt;|<)\/script(>|&gt;)/ig,inside:Prism.languages.markup.tag.inside},rest:Prism.languages.javascript}}});
\ No newline at end of file
diff --git a/download.js b/download.js
index e6e3ce8..57b6d01 100644
--- a/download.js
+++ b/download.js
@@ -9,6 +9,8 @@ var cache = {};
 var form = $('form');
 var minified = true;
 
+var dependencies = {};
+
 for (var category in components) {
 	var all = components[category];
 	
@@ -40,6 +42,7 @@ for (var category in components) {
 			title: all[id].title || all[id],
 			hasCSS: all[id].hasCSS !== undefined? all[id].hasCSS : all.meta.hasCSS,
 			enabled: checked,
+			require: all[id].require,
 			files: {
 				minified: {
 					paths: [],
@@ -52,6 +55,10 @@ for (var category in components) {
 			}
 		};
 		
+		if (info.require) {
+			dependencies[info.require] = (dependencies[info.require] || []).concat(id);
+		}
+		
 		if (!/\.css$/.test(filepath)) {
 			info.files.minified.paths.push(filepath.replace(/(\.js)?$/, '.min.js'));
 			info.files.dev.paths.push(filepath.replace(/(\.js)?$/, '.js'));
@@ -82,6 +89,22 @@ for (var category in components) {
 								$$('input[name="' + this.name + '"]').forEach(function(input) {
 									all[input.value].enabled = input.checked;
 								});
+
+								if (all[id].require && this.checked) {
+									var input = $('label[data-id="' + all[id].require + '"] > input');
+									input.checked = true;
+									
+									input.onclick();
+								}
+
+								if (dependencies[id] && !this.checked) { // It’s required by others
+									dependencies[id].forEach(function(dependent) {
+										var input = $('label[data-id="' + dependent + '"] > input');
+										input.checked = false;
+
+										input.onclick();
+									});
+								}
 								
 								update(category, id);
 							};
diff --git a/index.html b/index.html
index ddeeabb..53741d4 100644
--- a/index.html
+++ b/index.html
@@ -32,7 +32,7 @@
 		</li>
 		<li>
 			<strong>Light as a feather</strong>
-			The core is 1.5KB minified &amp; gzipped. Languages add 0.3-0.5KB each, themes are around 1KB.
+			The core is 1.6KB minified &amp; gzipped. Languages add 0.3-0.5KB each, themes are around 1KB.
 		</li>
 		<li>
 			<strong>Blazing fast</strong>
@@ -72,7 +72,7 @@
 <section id="features-full">
 	<h1>Full list of features</h1>
 	<ul>
-		<li><strong>Only 1.5KB</strong> minified &amp; gzipped (core). Each language definition adds roughly 300-500 bytes.</li>
+		<li><strong>Only 1.6KB</strong> minified &amp; gzipped (core). Each language definition adds roughly 300-500 bytes.</li>
 		<li>Encourages good author practices. Other highlighters encourage or even force you to use elements that are semantically wrong, 
 			like <code>&lt;pre></code> (on its own) or <code>&lt;script></code>. 
 			Prism forces you to use the correct element for marking up code: <code>&lt;code></code>. 
diff --git a/prism.js b/prism.js
index c5f064f..9ef455d 100644
--- a/prism.js
+++ b/prism.js
@@ -16,7 +16,47 @@
 var lang = /\blang(?:uage)?-(?!\*)(\w+)\b/i;
 
 var _ = self.Prism = {
+	util: {
+		type: function (o) { 
+			return Object.prototype.toString.call(o).match(/\[object (\w+)\]/)[1];
+		},
+		
+		// Deep clone a language definition (e.g. to extend it)
+		clone: function (o) {
+			var type = _.util.type(o);
+
+			switch (type) {
+				case 'Object':
+					var clone = {};
+					
+					for (var key in o) {
+						if (o.hasOwnProperty(key)) {
+							clone[key] = _.util.clone(o[key]);
+						}
+					}
+					
+					return clone;
+					
+				case 'Array':
+					return o.slice();
+			}
+			
+			return o;
+		}
+	},
+	
 	languages: {
+		extend: function (id, redef) {
+			var lang = _.util.clone(_.languages[id]);
+			
+			for (var key in redef) {
+				lang[key] = redef[key];
+			}
+			
+			return lang;
+		},
+		
+		// Insert a token before another token in a language literal
 		insertBefore: function (inside, before, insert, root) {
 			root = root || _.languages;
 			var grammar = root[inside];
@@ -43,11 +83,12 @@ var _ = self.Prism = {
 			return root[inside] = ret;
 		},
 		
+		// Traverse a language definition with Depth First Search
 		DFS: function(o, callback) {
 			for (var i in o) {
 				callback.call(o, i, o[i]);
 				
-				if (Object.prototype.toString.call(o) === '[object Object]') {
+				if (_.util.type(o) === 'Object') {
 					_.languages.DFS(o[i], callback);
 				}
 			}
@@ -391,27 +432,38 @@ if (Prism.languages.markup) {
 }
 
 /* **********************************************
-     Begin prism-javascript.js
+     Begin prism-clike.js
 ********************************************** */
 
-Prism.languages.javascript = {
+Prism.languages.clike = {
 	'comment': {
 		pattern: /(^|[^\\])(\/\*[\w\W]*?\*\/|\/\/.*?(\r?\n|$))/g,
 		lookbehind: true
 	},
 	'string': /("|')(\\?.)*?\1/g,
-	'regex': {
-		pattern: /(^|[^/])\/(?!\/)(\[.+?]|\\.|[^/\r\n])+\/[gim]{0,3}(?=\s*($|[\r\n,.;})]))/g,
-		lookbehind: true
-	},
-	'keyword': /\b(var|let|if|else|while|do|for|return|in|instanceof|function|new|with|typeof|try|catch|finally|null|break|continue)\b/g,
+	'keyword': /\b(if|else|while|do|for|return|in|instanceof|function|new|try|catch|finally|null|break|continue)\b/g,
 	'boolean': /\b(true|false)\b/g,
-	'number': /\b-?(0x)?\d*\.?\d+\b/g,
+	'number': /\b-?(0x)?[\da-f]*\.?\d+\b/g,
 	'operator': /[-+]{1,2}|!|=?&lt;|=?&gt;|={1,2}|(&amp;){1,2}|\|?\||\?|\*|\//g,
 	'ignore': /&(lt|gt|amp);/gi,
 	'punctuation': /[{}[\];(),.:]/g
 };
 
+/* **********************************************
+     Begin prism-javascript.js
+********************************************** */
+
+Prism.languages.javascript = Prism.languages.extend('clike', {
+	'keyword': /\b(var|let|if|else|while|do|for|return|in|instanceof|function|new|with|typeof|try|catch|finally|null|break|continue)\b/g
+});
+
+Prism.languages.insertBefore('javascript', 'keyword', {
+	'regex': {
+		pattern: /(^|[^/])\/(?!\/)(\[.+?]|\\.|[^/\r\n])+\/[gim]{0,3}(?=\s*($|[\r\n,.;})]))/g,
+		lookbehind: true
+	}
+});
+
 if (Prism.languages.markup) {
 	Prism.languages.insertBefore('markup', 'tag', {
 		'script': {