Dynamic indexes

The compiler can reject a constant out-of-range index. It cannot prove every runtime path:

function curve_value(i) {
    if(i < 0) i = 0;
    if(i >= sizeof(CURVE)) i = sizeof(CURVE) - 1;
    return CURVE[i];
}

When an index expression includes a function call, store the result first. The compiler can warn that a dynamic index call might be evaluated twice.