odf

bounce = (val) -> val = val() while typeof val == 'function'; val

factorial = (n) ->
  fact = (a, n) -> if n > 0 then -> fact a * n, n - 1 else a
  bounce fact 1, n

console.log factorial 10

odf

class Seq {
  toArray() {
    const a = [];
    for (const x of this)
      a.push(x);
    return a;
  }

  toString() {
    return this.toArray().join(' -> ');