jquery/src/ajax/parseJSON.js

define([
	"../core"
], function( jQuery ) {

	var rvalidchars = /^[\],:{}\s]*$/,
		rvalidbraces = /(?:^|:|,)(?:\s*\[)+/g,
		rvalidescape = /\\(?:["\\\/bfnrt]|u[\da-fA-F]{4})/g,
		rvalidtokens = /"[^"\\\r\n]*"|true|false|null|-?(?:\d+\.|)\d+(?:[eE][+-]?\d+|)/g;

	jQuery.parseJSON = function( data ) {
		// Attempt to parse using the native JSON parser first
		if ( window.JSON && window.JSON.parse ) {
			return window.JSON.parse( data );
		}

		if ( data === null ) {
			return data;
		}

		if ( typeof data === "string" ) {

			// Make sure leading/trailing whitespace is removed (IE can't handle it)
			data = jQuery.trim( data );

			if ( data ) {
				// Make sure the incoming data is actual JSON
				// Logic borrowed from http://json.org/json2.js
				if ( rvalidchars.test( data.replace( rvalidescape, "@" )
					.replace( rvalidtokens, "]" )
					.replace( rvalidbraces, "")) ) {

					return ( new Function( "return " + data ) )();
				}
			}
		}

		jQuery.error( "Invalid JSON: " + data );
	};

	return jQuery.parseJSON;
});