redux/lib/compose.js

Predictable state container for JavaScript apps

"use strict";

exports.__esModule = true;
exports["default"] = compose;
/**
 * Composes single-argument functions from right to left.
 *
 * @param {...Function} funcs The functions to compose.
 * @returns {Function} A function obtained by composing functions from right to
 * left. For example, compose(f, g, h) is identical to arg => f(g(h(arg))).
 */
function compose() {
  for (var _len = arguments.length, funcs = Array(_len), _key = 0; _key < _len; _key++) {
    funcs[_key] = arguments[_key];
  }

  return function () {
    if (funcs.length === 0) {
      return arguments.length <= 0 ? undefined : arguments[0];
    }

    var last = funcs[funcs.length - 1];
    var rest = funcs.slice(0, -1);

    return rest.reduceRight(function (composed, f) {
      return f(composed);
    }, last.apply(undefined, arguments));
  };
}