// ISCNode members
public void Evaluate(Scope scope)
{
Debug.Assert(Left != null && Right != null, "Null operand in binary expression");
Left.Evaluate(scope);
Right.Evaluate(scope);
switch (Type)
{
case BinaryExpressionType.ADD:
intValue_ = Left.IntValue + Right.IntValue;
break;
case BinaryExpressionType.SUB:
intValue_ = Left.IntValue - Right.IntValue;
break;
case BinaryExpressionType.MUL:
intValue_ = Left.IntValue * Right.IntValue;
break;
case BinaryExpressionType.DIV:
intValue_ = Left.IntValue / Right.IntValue;
break;
case BinaryExpressionType.MOD:
intValue_ = Left.IntValue % Right.IntValue;
break;
case BinaryExpressionType.ASSIGN:
IdentNode IDENTNode = Left as IdentNode;
if (IDENTNode == null)
throw new InterpreterException("Left operand of '=' must be an lvalue");
if (!scope.IsDefined(IDENTNode.Name))
throw new InterpreterException("Undefined variable: " + IDENTNode.Name);
intValue_ = Right.IntValue;
scope.Get(IDENTNode.Name).Value = intValue_;
break;
default:
throw new InterpreterException("Unexpected expression type");
}
}
// ISCNode members
public void Evaluate(Scope scope)
{
if (!scope.IsDefined(Name))
throw new InterpreterException("Undefined variable: " + Name);
intValue_ = scope.Get(Name).Value;
}