func! pkgs: [{.a = Int}; _] =
    arr = ![]
    for! pkgs, pkg =>
        arr.push! pkg.a
    arr

assert func!([{.a = 1}, {.a = 2}]) == [1, 2]

.Name = Class { .name = Str }
.Name.
    parse(_: Str): Name = todo()
.collect!(names: [{ .name = Str; }; _]) =
    for! names, rec =>
        discard .Name.parse(rec.name)