Comparing fizzbuzz implementations in Haskell and JavaScript

basic-fizzbuzz-haskell.hs

fizzes = cycle ["", "", "Fizz"]
buzzes = cycle ["", "", "", "", "Buzz"]
fbs = zipWith (++) fizzes buzzes

nums = map show [1..]
fizzbuzz n = take n (zipWith max nums fbs)

-- Usage:
-- fizzbuzz 3
-- -> ["1", "2", "Fizz"] 

equivalent-js-implementation.js

function* cycle(vals) {
  let len = vals.length
  let index = 0
  while (true) {
    yield vals[index % len]
    index += 1
  }
}

function* zipStreams(...streams) {
  while (true) {
    yield streams.map(g => g.next().value)
  }
}

function* zipStreamsWith(f, ...streams) {
  while (true) {
    yield streams
      .map(g => g.next().value)
      .reduce(f)
  }
}

function take(n, stream) {
  let result = []
  for (let i = 0; i < n; i++) {
    result.push(stream.next().value)
  }
  return result
}

function* range(start, stop = Infinity) {
  let i = start
  while (i < stop) {
    yield i
    i += 1
  }
}

const concat = (a, b) => a + b
const longer = (a, b) => String(a).length > String(b).length ? String(a) : String(b)

const fizzes = cycle(["", "", "fizz"])
const buzzes = cycle(["", "", "", "", "buzz"])
const fbs = zipStreamsWith(concat, fizzes, buzzes)

const nums = range(1)
const fizzBuzz = (n) => take(n, zipStreamsWith(longer, nums, fbs))