utils.js

define([],function() {
	function debug(/*...*/) {
		// console.log.apply(console,arguments);
	}
	function findIndex(xs,f) {
		for(var i=0;i<xs.length;i++) {
			if (f(xs[i],i)) { return i; }
		}
		return -1;
	}
	function contains(xs,x) { return xs.indexOf(x) >= 0; }
	function remove(xs,x) {
		var i = xs.indexOf(x);
		xs.splice(i,1);
	}
	function extend(a,b) {
		for(var n in b) { a[n] = b[n]; }
	}
	function assert(b) {
		if(!b) {
			debugger;
			throw new Error('Assertion failed');
		}
	}
	function hashCode(str) {
		var hash = 0, i, c;
		if (str.length == 0) {
			return hash;
		}
		for (i = 0, l = str.length; i < l; i++) {
			c = str.charCodeAt(i);
			hash = ((hash<<5)-hash)+c;
			hash |= 0; // Convert to 32bit integer
		}
		return hash;
	}

	// A JSON.stringify that always represents objects the same way (sorted
	// by key) and always represent numbers as their byte value (or else it
	// will get rounded).
	function JSONstringify(obj) {
		return JSON.stringify(obj,JSONreplacer);
	}
	function JSONreplacer(key,value) {
		if (key && key[0] === '@') { return value; }
		if (value === undefined) {
			return value;
		} else if (value === null) {
			return value;
		} else if(Object.prototype.toString.call(value) === '[object Array]') {
			return value;
		} else if (typeof value === 'object') {

			// Sort the keys of the object.
			var keys = Object.keys(value).sort();
			var r = {};
			for(var i=0;i<keys.length;i++) {
				r[keys[i]] = value[keys[i]];
			}
			return r;
		} else if (typeof value === 'string') {
			return value;
		} else if (typeof value === 'number') {
			// // We need to make sure number values are not just
			// // rounded by 'toString', we need the absolute exact value.
			// // The EMCA specifications say it should be a double, so
			// // an 8-byte float.
			// var buffer = new ArrayBuffer(8);
			// var floatView = new Float64Array(buffer);
			// floatView[0] = value;
			// var intView = new Int32Array(buffer);
			// var a = intView[0];
			// var b = intView[1];
			// return {'@t':'f','@va':i,'@vb':b};
		}
		return value;
	}

	// Parses the output of JSONstringify.
	function JSONparse(str) {
		return JSON.parse(str,JSONreviver);
	}
	function JSONreviver(key,value) {
		// if (value !== null && typeof value === 'object') {
		// 	if (value['@t'] === 'f') {
		// 		var buffer = new ArrayBuffer(8);
		// 		var intView = new Int32Array(buffer);
		// 		intView[0] = value['@va'];
		// 		intView[1] = value['@vb'];
		// 		var floatView = new Float64Array(buffer);
		// 		return floatView[0];
		// 	}
		// }
		return value;
	}


	return {
		debug: debug,
		findIndex: findIndex,
		contains: contains,
		remove: remove,
		extend: extend,
		assert: assert,
		hashCode: hashCode,
		JSONstringify: JSONstringify,
		JSONparse: JSONparse
	};
});