Infinite Loop

Infinite loops follow Rust syntax.

Like Rust, continue can be used to skip to the next iteration, by-passing all following statements; break can be used to break out of the loop unconditionally.

Tip: Disable loop

loop can be disabled via Engine::set_allow_looping.

let x = 10;

loop {
    x -= 1;

    if x > 5 { continue; }  // skip to the next iteration

    print(x);

    if x == 0 { break; }    // break out of loop
}

Remember the break statement

A loop statement without a break statement inside its loop block is infinite. There is no way for the loop to stop iterating.

Loop Expression

Like Rust, loop statements can also be used as expressions.

The break statement takes an optional expression that provides the return value.

The default return value of a loop expression is ().

Tip: Disable all loop expressions

Loop expressions can be disabled via Engine::set_allow_loop_expressions.

let x = 0;

// 'loop' can be used just like an expression
let result = loop {
    if is_magic_number(x) {
        // if the loop breaks here, return a specific value
        break get_magic_result(x);
    }

    x += 1;

    // ... if the loop exits here, the return value is ()
};

if result == () {
    print("Magic number not found!");
} else {
    print(`Magic result = ${result}!`);
}