% crochet

test "For .. in" do
  let M = [1, 2];
  let N = [1, 2, 3, 4];

  let Succ = for X in N do X + 1 end;
  assert Succ =:= [2, 3, 4, 5];

  let Pair = for X in M, Y in N do [X, Y] end;
  assert Pair =:= [
    [1, 1],
    [1, 2],
    [1, 3],
    [1, 4],
    [2, 1],
    [2, 2],
    [2, 3],
    [2, 4]
  ];

  let Filter = for X in N if (X % 2) === 0 do X end;
  assert Filter =:= [2, 4];
end