Function compose

src/utils.js:15–27

(...funcs)

 * Thank you Dan Abramov for this code!
 */
export function compose(...funcs) {
  return (...args) => {
    /* istanbul ignore next */
    if (funcs.length === 0) {
      return args[0];
    }

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

    return rest.reduceRight((composed, f) => f(composed), last(...args));
  };
}

// :: (a -> boolean) => [a] => [a]
export const filter = f => x => x.filter(f);