Currying method with holes for JavaScript.

curry.js

'use strict';

/*
 * Currying method.
 *
 * Usage:
 *   >>> function test(a, b, c) {console.log(a, b, c); }
 *   >>> c = curry(test, '->', curry.hole, '<-');
 *   >>> c('Hello');
 *   <<< -> Hello World <-
 *
 */


// We make it an object literal {} so that we can test for reference-equality
// via the === operator later on.
curry.hole = {};

function curry(fn) {
	// Curry arguments.
	var curried = arguments;

	return function() {
		// Arguments to fill holes. Remainders will be appended.
		var filler = arguments;

		// Indices: i for curried und j for fillers.
		var i=1; // arg 0 is fn
		var j=0;

		// New constructed args.
		var args = [];

		// Create new args from curried args and fill holes with filled args.
		for (; i < curried.length; i++) {
			if(curried[i] === curry.hole) {
				args.push(filler[j++]);
			} else {
				args.push(curried[i]);
			}
		}

		// Append remainders.
		for (; j<filler.length;j++) {
			args.push(filler[j]);
		}

		// Finally, call method.
		return fn.apply(this, args);

	}
}