public IOperation CreateOperation(OperationTypes operationType)
{
IOperation newOperation = null;
switch (operationType)
{
case OperationTypes.Addition:
newOperation = new AdditionOperation();
break;
case OperationTypes.Subtraction:
newOperation = new SubtractionOperation();
break;
case OperationTypes.Multiplication:
newOperation = new MultiplicationOperation();
break;
case OperationTypes.Division:
newOperation = new DivisionOperation();
break;
case OperationTypes.Modulus:
newOperation = new ModulusOperation();
break;
case OperationTypes.Undefined:
newOperation = new NullOperation();
break;
}
return(newOperation);
}
public string Visit(NullOperation operation)
{
Contract.RequiresNotNull(operation, "operation != null");
return($"{Visit(operation.LeftSide)} is null");
}
private MyNull()
{
Calculator = NullOperation.GetInstance();
}
