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

A port of the PHP bingo-functional library

const sizeOf = require('./sizeOf')
const extend = require('./extend')

/**
 * partition function
 *
 * partition :: Int -> [a] -> [[a], [a]]
 * @param {number} num
 * @param {array} list
 * @returns {array}
 * @example
 *
 * partition(2, [3, 4, 5, 6, 7])
 * // => [[3, 4, 5], [6, 7]]
 */
const partition = (num, list) => {
  const count = sizeOf(list)

  if (num < 2 || count < 2) {
    return [list]
  }

  const partitionSize = Math.ceil(count / num)

  return extend(
    [list.slice(0, partitionSize)],
    partition(num - 1, list.slice(partitionSize)),
  )
}

module.exports = partition