moy-fp/src/Functor/ap.js

A functional programming library.

import curry from '../Function/curry'

/**
 * Functor f => f (a -> b) -> f a -> f b
 */
const ap = curry(
  (F2, F1) => Object.prototype.toString.call(F1) === '[object Array]' ?
    F2.reduce(
      (acc, cur) => acc.concat(F1.map(cur)),
      [],
    ):
    F2.ap(F1)
)

export default ap