fn main() {
    #macro([#zip_or_unzip([[x, ...], [y, ...]]), [[x, y], ...]],
           [#zip_or_unzip([[xx, yy], ...]), [[xx, ...], [yy, ...]]]);


    assert(#zip_or_unzip([[1,2,3,4],[5,6,7,8]]) == [[1,5],[2,6],[3,7],[4,8]]);
    assert(#zip_or_unzip([[1,5],[2,6],[3,7],[4,8]]) == [[1,2,3,4],[5,6,7,8]]);


    #macro([#nested([[[x, ...], ...], [[y, ...], ...]]),
            [[[x, y], ...], ...]]);
    assert(#nested([[[1,2,3,4,5], [7,8,9,10,11,12]],
                    [[-1,-2,-3,-4,-5], [-7,-8,-9,-10,-11,-12]]])
           ==
           [[[1, -1], [2, -2], [3, -3], [4, -4], [5, -5]],
            [[7, -7], [8, -8], [9, -9], [10, -10], [11, -11], [12, -12]]]);

    #macro([#dup([y, [x, ...]]), [[y, x], ...]]);

    assert(#dup([1,[1,2,3,4]]) == [[1,1], [1,2], [1,3], [1,4]]);


    #macro([#lambda(x, #<t>, body, #<s>),
            {fn result(t x) -> s { ret body }; result}]);

    assert(#lambda(i, #<uint>, i+4u, #<uint>)(12u) == 16u)

}