protected void pushIdentifier(int flag) {
	/*push a special flag on the stack :
	-zero stands for optional Name
	-negative number for direct ref to base types.
	identifierLengthPtr points on the top */

	int stackLength = this.identifierLengthStack.length;
	if (++this.identifierLengthPtr >= stackLength) {
		System.arraycopy(
			this.identifierLengthStack, 0,
			this.identifierLengthStack = new int[stackLength + 10], 0,
			stackLength);
	}
	this.identifierLengthStack[this.identifierLengthPtr] = flag;
}