compose.js 560 Bytes
'use strict';

var callable = require('../../object/valid-callable')
  , aFrom    = require('../../array/from')

  , apply = Function.prototype.apply, call = Function.prototype.call
  , callFn = function (arg, fn) { return call.call(fn, this, arg); };

module.exports = function (fn/*, …fnn*/) {
	var fns, first;
	if (!fn) callable(fn);
	fns = [this].concat(aFrom(arguments));
	fns.forEach(callable);
	fns = fns.reverse();
	first = fns[0];
	fns = fns.slice(1);
	return function (arg) {
		return fns.reduce(callFn, apply.call(first, this, arguments));
	};
};