public void Visit(RelationalCondition relCond)
{
int operandCntr = 1;
relCond.Operands[0].Accept(this);
foreach (string oper in relCond.Operators)
{
switch (oper)
{
case "<":
Console.Write("<");
break;
case "<=":
Console.Write("<=");
break;
case ">":
Console.Write(">");
break;
case ">=":
Console.Write(">=");
break;
}
relCond.Operands[operandCntr++].Accept(this);
}
}
private EqualCondition parseCondition()
{
RelationalCondition firstOperand = parseRelationalCondition();
if (firstOperand != null)
{
EqualCondition equalCondition = new EqualCondition();
equalCondition.Operands.Add(firstOperand);
while (lexer.Token is EqualToken || lexer.Token is NotEqualToken)
{
switch (lexer.Token)
{
case EqualToken _:
equalCondition.Operators.Add(EqualToken.Text);
break;
case NotEqualToken _:
equalCondition.Operators.Add(NotEqualToken.Text);
break;
}
lexer.NextToken();
equalCondition.Operands.Add(parseRelationalCondition());
}
return(equalCondition);
}
else
{
return(null);
}
}
private RelationalCondition parseRelationalCondition()
{
AddExpression firstOperand = parseExpression();
if (firstOperand != null)
{
RelationalCondition relCond = new RelationalCondition();
relCond.Operands.Add(firstOperand);
while (lexer.Token is LessThanToken || lexer.Token is LessEqualThanToken ||
lexer.Token is GreaterThanToken || lexer.Token is GreaterEqualThanToken)
{
switch (lexer.Token)
{
case LessThanToken _:
relCond.Operators.Add(LessThanToken.Text);
break;
case LessEqualThanToken _:
relCond.Operators.Add(LessEqualThanToken.Text);
break;
case GreaterThanToken _:
relCond.Operators.Add(GreaterThanToken.Text);
break;
case GreaterEqualThanToken _:
relCond.Operators.Add(GreaterEqualThanToken.Text);
break;
}
lexer.NextToken();
relCond.Operands.Add(parseExpression());
}
return(relCond);
}
else
{
return(null);
}
}
public void Visit(RelationalCondition relCond)
{
int operandCntr = 1;
relCond.Operands[0].Accept(this);
foreach (string oper in relCond.Operators)
{
relCond.Operands[operandCntr++].Accept(this);
dynamic rightOper = Environment.PopFromTheStack();
dynamic leftOper = Environment.PopFromTheStack();
if (rightOper.GetType() != leftOper.GetType())
{
throw new ExecutorException("Cannot perform relational condition on operands different than double");
}
else if (leftOper is TurtleItem || leftOper is TurtleItem)
{
throw new ExecutorException("Cannot perform an arithmetic operation on operands of type Turtle");
}
else if (!(rightOper is double) && !(leftOper is double))
{
throw new ExecutorException("Cannot apply relational condition on types different than num");
}
dynamic result = oper switch
{
"<" => leftOper <rightOper?true : false,
"<=" => leftOper <= rightOper?true : false,
">" => leftOper> rightOper ? true : false,
">=" => leftOper >= rightOper ? true : false,
_ => throw new ExecutorException($"Unknown relational operator {oper}")
};
Environment.PushToTheStack(result);
}
}