fn main() {
    auto x = [1, 2, 3];
    auto y = 0;
    for (int i in x) { log i; y += i; }
    log y;
    assert (y == 6);
    auto s = "hello there";
    let int i = 0;
    for (u8 c in s) {
        if (i == 0) { assert (c == 'h' as u8); }
        if (i == 1) { assert (c == 'e' as u8); }
        if (i == 2) { assert (c == 'l' as u8); }
        if (i == 3) { assert (c == 'l' as u8); }
        if (i == 4) { assert (c == 'o' as u8); }
        // ...

        i += 1;
        log i;
        log c;
    }
    assert (i == 11);
}