prime.zig

const warn = @import("std").debug.warn;

fn prime(n: u32) type {
    if (n < 2) return noreturn;
    var divisor = 2;
    while (divisor < n) : (divisor += 1) {
        if (n % divisor == 0) return noreturn;
    }
    return void;
}

fn print_prime(comptime n: u32, verified: prime(n)) void {
    warn("{}\n", n);
}

test "primality" {
    print_prime(3, {});
}

const warn = @import("std").debug.warn;

fn prime(n: u32) bool {
    if (n < 2) return false;
    var divisor: u32 = 2;
    while (divisor < n) : (divisor += 1) {
        if (n % divisor == 0) return false;
    }
    return true;
}

fn print_prime(comptime n: u32) void {
    comptime {
        if (!prime(n)) {
            @compileError("not prime");
        }
    }
    warn("{}\n", n);
}

test "primality" {
    print_prime(3);
}