js can be fun(ctional) too. A new hope

Reviewing my latest gists, I re-discovered one in which I copied a js snippet that implemented foldr, one of those great higher order functions. As a proof of concept, I implemented some of the functions on 'Why functional programming matters' paper. In fact, I reimplemented nearly all builtins.scm (from my Half Assed Scheme implementation)

	// foldr function shamelessly stolen from
	// http://blog.thatscaptaintoyou.com/haskells-foldr-in-javascript/
	// Added 'any' function for my own needs. More at http://puntoblogspot.blogspot.com/
	function foldr(fn, ult, xs) {
	if (xs.length == 0) {
	return ult;
	}
	if (xs.length == 1) {
	return fn(
	xs[0],
	ult
	);
	}
	else {
	return fn(
	xs.splice(0, 1)[0],
	foldr(
	fn,
	ult,
	xs
	)
	);
	}
	}
	function any(needle,haystack){
	return foldr(
	function(a,b){
	return (b || (a==needle))
	},
	false,
	haystack
	)
	}
	any('hola' , 'hola ke tal'.split(' '))

view raw any.js hosted with ❤ by GitHub

I recently took a quick look at coffeescript, and it seems very promising. Unfortunately, I didn't even try it (just the online interpreter). Maybe when I try rails 3.1