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

A port of the PHP bingo-functional library

const fold = require('./fold')

/**
 * flatten function
 *
 * flatten :: [[a], [b]] -> [a, b]
 * @param {array} list
 * @returns {array}
 * @example
 *
 * flatten([['foo', 'bar'], ['baz', 'fooz']])
 * // => ['foo', 'bar', 'baz', 'fooz']
 */
const flatten = (list) => fold(
  (acc, val) => (Array.isArray(val) ? [...acc, ...flatten(val)] : [...acc, val]),
  list,
  [],
)

module.exports = flatten