public override void visit(un_expr node)
{
node.visit(this);
int val = intStack.Pop();
switch (node.operation_type)
{
case Operators.Minus:
intStack.Push(-val);
break;
case Operators.Plus:
intStack.Push(val);
break;
case Operators.BitwiseNOT:
intStack.Push(~val);
break;
case Operators.LogicalNOT:
intStack.Push(val == 0 ? 1 : 0);
break;
default:
throw new InvalidIntegerExpression();
}
}
