0.0.17 language and borrowing

In 0.0.17, ordinary owned parameters move by default. &name: T borrows read-only during a synchronous call. Arguments remain ordinary expressions. Borrowing neither consumes nor implicitly clones the source; the callee does not release it.

fn Read(&text: str): int {
    return text.byte_len()
}

fn main() {
    text = "Ku"
    println(Read(text))
    println(Read(text))
    println(text)
}

Save as borrow.ku and run ku run borrow.ku. Output is 2, 2, Ku. A borrow cannot assign through its source, move an owned field, escape into storage or be captured. Explicitly clone to return a new owned string; Copy fields such as integers may be read and returned.

Async borrowed parameters, borrowed returns and first-class references are unsupported. The interpreter and synchronous C implement this mode; LLVM does not. See the 0.0.17 syntax reference.