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
    Create Namespaced Classes with MooTools

    MooTools has always gotten a bit of grief for not inherently using and standardizing namespaced-based JavaScript classes like the Dojo Toolkit does.  Many developers create their classes as globals which is generally frowned up.  I mostly disagree with that stance, but each to their own.  In any event...

  • By
    Page Visibility API

    One event that's always been lacking within the document is a signal for when the user is looking at a given tab, or another tab. When does the user switch off our site to look at something else? When do they come back?

Incredible Demos

  • By
    MooTools History Plugin

    One of the reasons I love AJAX technology so much is because it allows us to avoid unnecessary page loads.  Why download the header, footer, and other static data multiple times if that specific data never changes?  It's a waste of time, processing, and bandwidth.  Unfortunately...

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

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!