crockford-fem.js

function add(a, b) {
	return a + b;
}

function sub(a, b) {
	return a - b;
}

function mul(a, b) {
	return a * b;
}

add(4, 5); /*? */
sub(12, 4); /*? */
mul(3, 4); /*? */

function identityf(arg) {
	return function() {
		return arg;
	}
}

var three = identityf(3);
three(); /*? */

function addf(a) {
	return function(b) {
		return a + b;
	}
}

addf(3)(4); /*? */

function liftf(fn) {
	return function(a) {
		return function(b) {
			return fn(a, b); /*? */
		}
	}
}

var addf = liftf(add);
addf(3)(4); /*? */
liftf(mul)(3)(4); /*? */

function curry(fn, arg) {
	return function(x) {
		return fn(arg, x); /*? */
	}
}

var add3 = curry(add, 3); /*? */
add3(4); /*? */
curry(mul, 5)(6);/*? */

// var inc = addf(1); /*? */
// var inc = liftf(add)(1);
var inc = curry(add, 1);
inc(5); /*? */
inc = liftf(add)(1); /*? */
inc(inc(5)); /*? */

function twice(fn) {
	return function(x) {
		return fn(x, x); /*? */
	}
}

add(11, 11); /*? */
var doubl = twice(add);
doubl(11); /*? */

function reverse(fn) {
	return function(...args) {
		return fn(...args.reverse());
	}
}

var bus = reverse(sub); /*? */
bus(3, 2); /*? */

function composeu(fn, fn1) {
	return function(x) {
		return fn1(fn(x));
	}
}

composeu(doubl, mul)(5); /*? */