/**
* Pops the given number of types from the output frame stack.
*
* @param elements the number of types that must be popped.
*/
private void pop(final int elements) {
if (outputStackTop >= elements) {
outputStackTop -= elements;
} else {
// if the number of elements to be popped is greater than the number
// of elements in the output stack, clear it, and pops the remaining
// elements from the input stack.
owner.inputStackTop -= elements - outputStackTop;
outputStackTop = 0;
}
}
/**
* Pushes a new type onto the output frame stack.
*
* @param type the type that must be pushed.
*/
private void push(final int type) {
// creates and/or resizes the output stack array if necessary
if (outputStack == null) {
outputStack = new int[10];
}
int n = outputStack.length;
if (outputStackTop >= n) {
int[] t = new int[Math.max(outputStackTop + 1, 2 * n)];
System.arraycopy(outputStack, 0, t, 0, n);
outputStack = t;
}
// pushes the type on the output stack
outputStack[outputStackTop++] = type;
// updates the maximun height reached by the output stack, if needed
int top = owner.inputStackTop + outputStackTop;
if (top > owner.outputStackMax) {
owner.outputStackMax = top;
}
}
