Code.require_file "../../test_helper", __FILE__

defmodule Kernel.LoopTest do
  use ExUnit.Case

  test :do_loop do
    list = [1,2,3]

    result = loop list, [] do
      [[h|t], acc] -> recur t, [h*2|acc]
      [[], acc] -> acc
    end

    assert result == [6,4,2]
  end

  test :do_nested_loop do
    list = [[1,2],[2,3],[3,4]]

    result = loop list, [] do
      [[h|t], acc] ->
        result = loop h, 0 do
          [[h|t], acc] -> recur t, acc + h*2
          [[], acc] -> acc
        end
        recur t, [result|acc]
      [[], acc] -> acc
    end

    assert result == [14,10,6]
  end

  test :do_loop_base do
    fun = fn ->
      [{ 1, 2 }, []] -> 1
      [[], x] when x == [] -> 2
    end

    assert fun.({ 1, 2 }, []) == 1
    assert fun.([], []) == 2
  end

  test :do_argless_loop do
    try do
      Process.self <- 1
      Process.self <- 2
      Process.self <- 3

      result = loop do
        receive do
          x -> Process.put x, -x; recur
        after
          0 -> :ok
        end
      end

      assert result == :ok
      assert Process.get(1) == -1
      assert Process.get(2) == -2
      assert Process.get(3) == -3
    after
      Process.delete(1)
      Process.delete(2)
      Process.delete(3)
    end
  end
end