json-format.js

/*
	json-format v.1.1
	http://github.com/phoboslab/json-format

	Released under MIT license:
	http://www.opensource.org/licenses/mit-license.php
*/

(function(window) {
	var p = [],
		push = function( m ) { return '\\' + p.push( m ) + '\\'; },
		pop = function( m, i ) { return p[i-1] },
		tabs = function( count ) { return new Array( count + 1 ).join( '\t' ); };

	window.JSONFormat = function( json ) {
		p = [];
		var out = "",
			indent = 0;
		
		// Extract backslashes and strings
		json = json
			.replace( /\\./g, push )
			.replace( /(".*?"|'.*?')/g, push )
			.replace( /\s+/, '' );		
		
		// Indent and insert newlines
		for( var i = 0; i < json.length; i++ ) {
			var c = json.charAt(i);
			
			switch(c) {
				case '{':
				case '[':
					out += c + "\n" + tabs(++indent);
					break;
				case '}':
				case ']':
					out += "\n" + tabs(--indent) + c;
					break;
				case ',':
					out += ",\n" + tabs(indent);
					break;
				case ':':
					out += ": ";
					break;
				default:
					out += c;
					break;      
			}					
		}
		
		// Strip whitespace from numeric arrays and put backslashes 
		// and strings back in
		out = out
			.replace( /\[[\d,\s]+?\]/g, function(m){ return m.replace(/\s/g,''); } )
			.replace( /\\(\d+)\\/g, pop ) // strings
			.replace( /\\(\d+)\\/g, pop ); // backslashes in strings
		
		return out;
	};
})(window);