pub fn main(world: World) -> Void raises {
    let text: String = "zero language"
    var index: usize = 0
    var found: i32 = -1
    while index < 13 {
        if text[index] == 108 as u8 && found == -1 {
            found = index as i32
        }
        index = index + 1
    }
    if found == 5 {
        check world.out.write("string search ok\n")
    }
}