public override Token Minify(Evaluator evaluator)
{
LeftSideOperand = LeftSideOperand.Minify(evaluator);
RightSideOperand = RightSideOperand.Minify(evaluator);
if (LeftSideOperand is ConstantToken && RightSideOperand is ConstantToken)
{
return(new ConstantToken(Evaluate(evaluator)));
}
return(this);
}
internal override double Evaluate(Evaluator evaluator)
{
if (Operator == Operators.Set)
{
VariableToken variable = LeftSideOperand as VariableToken;
if (variable == null)
{
throw new EvaluationException(
string.Format("Could assign a value to a token of type `{0}`.",
LeftSideOperand.GetType().Name),
this);
}
double result = RightSideOperand.Evaluate(evaluator);
evaluator.Variables[variable.VariableName] = result;
return(result);
}
double a, b;
a = LeftSideOperand.Evaluate(evaluator);
b = RightSideOperand.Evaluate(evaluator);
switch (Operator)
{
case Operators.Addition:
return(a + b);
case Operators.Substraction:
return(a - b);
case Operators.Multiplication:
return(a * b);
case Operators.Division:
return(a / b);
case Operators.Carry:
return(a % b);
case Operators.Exponentiation:
return(Math.Pow(a, b));
default:
throw new Exception();
}
}
public override string ToString()
{
string leftOpr = LeftSideOperand.ToString();
string rightOpr = RightSideOperand.ToString();
if (LeftSideOperand is OperatorToken)
{
if (Utils.Presedence(Operator, (LeftSideOperand as OperatorToken).Operator) > 0)
{
leftOpr = "(" + leftOpr + ")";
}
}
if (RightSideOperand is OperatorToken)
{
if (Utils.Presedence(Operator, (RightSideOperand as OperatorToken).Operator) > 0)
{
rightOpr = "(" + rightOpr + ")";
}
}
return(string.Format("{0} {1} {2}", leftOpr, (char)Operator, rightOpr));
}
