Nested Functions

Listing 3: Nested functions eliminate some common problems.

void func()
{
    ubyte* ip;      // byte code instruction pointer
    int[] stack;    // operand stack
    int spi;        // stack pointer
    ...
    int pop()        { return stack[--spi]; }
    void push(int i) { stack[spi++] = i; }
    while (1)
    {
    switch (*ip++)
    {
        case ADD:
        op1 = pop();
        op2 = pop();
        push(op1 + op2);
        break;
        case SUB:
        ...
    }
    }
}