Playing with JS.

gistfile1.js

/*
var named = (function(n) { return namedArguments(arguments); })(5, 10);
 named.n = 5
 named["-1"] = (the arguments)
 named[0] = 5
 named[1] = 10
*/
function namedArguments(args) {
	var params = args.callee.toString().replace(/function\ ?([A-Za-z_]+[A-Za-z0-9_]+)*\((.*)\)\ ?\{.*/, "$2");
	params = params.split(/,\ ?/);
	var j = 0;
	var named = {"-1": args};
	for (var i = 0; i < args.length; i++) {
		named[i] = args[i];
		if (typeof params[j] != 'undefined')
			named[params[j++]] = args[i];
	}
	return named;
}

function cacheFunc(func) {
	var dict = {};
	var callCount = 0;
	var show = !!arguments[1];
	return function(){
		var key = JSON.stringify(arguments);
		if (typeof dict[key] == "undefined") {
			callCount++;
			if (show) console.log(show, arguments, callCount);
			dict[key] = func.apply(this, arguments);
		}
		return dict[key];
	}
}

var factorial = cacheFunc(function(n){
	if (n <= 0) return 1;
	return n*factorial(n-1);
});

var fib = cacheFunc(function(n){
	if (n < 2) return 1;
	return fib(n - 1) + fib(n - 2);
})

console.log(factorial(5) + factorial(4) + factorial(4));
console.log(fib(5) + fib(4) + fib(4));