@unsafe

What is @unsafe?

@unsafe is an annotation you place directly before a while, for, orfor-in loop to disable the built-in loop protection.

Without @unsafe, a loop is halted when an iteration takes more than 2 seconds of real work or the loop exceeds 1,000,000 iterations. With @unsafe, the loop runs with no checks.

Syntax

@unsafe while (condition) {
    // loop body — no speed protection
}

@unsafe for (let i = 0; i < n; i = i + 1) {
    // loop body — no speed protection
}

@unsafe for (item in array) {
    // loop body — no speed protection
}

Example

class App {
    fn fastCount(n) {
        @unsafe while (n > 0) {
            print("count:", n);
            n = n - 1;
        }
    }

    fastCount(1000);
}

When to use @unsafe

• Tight computational loops (math, sorting, processing)
• Game loops that run at high frame rates
• Benchmarking or performance testing
• Any loop where you are certain it will terminate

When NOT to use @unsafe

• When you are unsure if the loop will terminate
• In production code where stability matters more than speed
• When learning VDX — let the safety system help you

What @unsafe disables

Rules

• @unsafe can be placed directly before while, for, orfor-in loops
• It cannot be used on other statements (if, fn, let, etc.)
• Using @unsafe before anything other than a loop is a compile error