let list1 = [1, 2, 3, 4];
let list2 = ["foo", "bar", "foo", "bar"];

let mapper = macro(item) => { result = item + 1 };
let filtrator = macro(item) => {
    result = select item, NULL, {
        foo = item,
    },
};

let boolfiltrator = macro(item) => {
    result = item < 5,
};

assert |
map mapper.result list1 == [2, 3, 4, 5];
|;
assert |
    (map mapper.result [1, 2, 3, 4]) == [2, 3, 4, 5];
|;
assert |
    map mapper.result [1, 2, 3, 4] == [2, 3, 4, 5];
|;

assert |
    filter filtrator.result list2 == ["foo", "foo"];
|;
assert |
    (filter filtrator.result ["foo", "bar", "foo", "bar"]) == ["foo", "foo"];
|;
assert |
    filter filtrator.result ["foo", "bar", "foo", "bar"] == ["foo", "foo"];
|;
assert |
    filter boolfiltrator.result [1, 2, 3, 4, 5, 6, 7] == [1, 2, 3, 4];
|;