bingo-functional-js/src/Algorithms/Collection/reverse.js

A port of the PHP bingo-functional library

const fold = require('./fold')

const reverseArray = (list) => list.reverse()

const reverseObject = (list) => {
  const keys = Object.keys(list).reverse()

  return fold(
    (obj, value) => {
      const result = obj
      result[value] = list[value]

      return result
    },
    keys,
    {},
  )
}

/**
 * reverse function
 *
 * reverse :: [a, b] -> [b, a]
 * @param {(array|object)} list
 * @returns {(array|object)}
 * @example
 *
 * reverse(['foo', 'bar'])
 * // => ['bar', 'foo']
 */
const reverse = (list) => (Array.isArray(list) ? reverseArray(list) : reverseObject(list))

module.exports = reverse