factorial.clay

factorial1(n) {
    if (n == 0)
        return 1;
    return n*factorial1(n-1);
}

factorial2(n) {
    var p = 1;
    again :
    if (n == 0)
        return p;
    p *= n;
    n -= 1;
    goto again;
}

factorial3(n) {
    var p = 1;
    while (true) {
        if (n == 0) break;
        p *= n;
        n -= 1;
    }
    return p;
}

factorial4(n) {
    var p = 1;
    for (i in range(n))
        p *= i+1;
    return p;
}

main() {
    var n = 7;
    n -= 1;
    var f = factorial4(n);
    println("factorial(", n, ") = ", f);
    return 0;
}