Code-Parsing Regular Expressions via Lighter.js

By  on  

Perfecting a regular expression can take a lot of time and testing but once achieved can be a absolutely golden. While looking through the source code of MooTools syntax highlighter Lighter.js I stumbled upon a few code-parsing regular expressions that you might be interested in.

The JavaScript

	// Matches a C style single-line comment.
	slashComments: /(?:^|[^\\])\/\/.*$/gm,
	
	// Matches a Perl style single-line comment.
	poundComments: /#.*$/gm,
	
	// Matches a C style multi-line comment.
	multiComments: /\/\*[\s\S]*?\*\//gm,
	
	// Matches a string enclosed by single quotes.
	aposStrings:   /'[^'\\]*(?:\\.[^'\\]*)*'/gm, 
	
	// Matches a string enclosed by double quotes.
	quotedStrings: /"[^"\\]*(?:\\.[^"\\]*)*"/gm, 
	
	// Matches both.
	strings:       /'[^'\\]*(?:\\.[^'\\]*)*'|"[^"\\]*(?:\\.[^"\\]*)*"/gm,
	
	// Matches a property: .property style.
	properties:    /\.([\w]+)\s*/gi,   
	
	// Matches a method call: .methodName() style.
	methodCalls:   /\.([\w]+)\s*\(/gm, 
	
	// Matches a function call: functionName() style.
	functionCalls: /\b([\w]+)\s*\(/gm,   
	
	// Matches any of the common brackets.
	brackets:      /\{|\}|\(|\)|\[|\]/g, 
	
	// Matches integers, decimals, hexadecimals.
	numbers:       /\b((?:(\d+)?\.)?[0-9]+|0x[0-9A-F]+)\b/gi 

Regular expressions can look heinous so I apologize to anyone whose brains imploded after looking at the above hieroglyphics text. Have useful regular expressions you use often? Share them!

Recent Features

  • By
    CSS vs. JS Animation: Which is Faster?

    How is it possible that JavaScript-based animation has secretly always been as fast — or faster — than CSS transitions? And, how is it possible that Adobe and Google consistently release media-rich mobile sites that rival the performance of native apps? This article serves as a point-by-point...

  • By
    Serving Fonts from CDN

    For maximum performance, we all know we must put our assets on CDN (another domain).  Along with those assets are custom web fonts.  Unfortunately custom web fonts via CDN (or any cross-domain font request) don't work in Firefox or Internet Explorer (correctly so, by spec) though...

Incredible Demos

Discussion

  1. David: very interesting, could you provide examples for each expression? ty so much!

  2. That’s pretty neat

    I’ve always used http://www.gskinner.com/RegExr/ to text my RegExp

  3. Well, im not a veteran programmer but i did a noobMatcher to test my regExp hehe

    http://vrs.host56.com/noobMatcher/

  4. Thanks for this Tutorial. Can u provide Demo for this.

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!