//When a variable value is changed by a self modifying operator.
public override object VisitStat_setvar_op([NotNull] algoParser.Stat_setvar_opContext context)
{
//Get variable reference.
AlgoValue oldValue = Particles.ParseParticleBlock(this, context, context.IDENTIFIER(), context.particle());
if (oldValue == null)
{
Error.Fatal(context, "No value returned to modify with operator.");
return(null);
}
//Does, evaluate the expression to set the value.
AlgoValue value = (AlgoValue)VisitExpr(context.expr());
//Switching on selfmod value.
AlgoValue newValue;
if (context.selfmod_op().ADDFROM_OP() != null)
{
//Attempt to add.
newValue = AlgoOperators.Add(context, oldValue, value);
}
else if (context.selfmod_op().DIVFROM_OP() != null)
{
//Attempt to divide.
newValue = AlgoOperators.Div(context, oldValue, value);
}
else if (context.selfmod_op().MULFROM_OP() != null)
{
//Attempt to multiply.
newValue = AlgoOperators.Mul(context, oldValue, value);
}
else if (context.selfmod_op().TAKEFROM_OP() != null)
{
//Attempt to subtract.
newValue = AlgoOperators.Sub(context, oldValue, value);
}
else
{
//Invalid operator type, oopsie! Implemented in parser but not here.
Error.Fatal(context, "Invalid operator given for self modifying variable, implemented in parser but not in interpreter.");
return(null);
}
//Set the value of the variable.
oldValue.Value = newValue.Value;
oldValue.Type = newValue.Type;
return(null);
}
//When a single term is parsed in Algo.
public override object VisitTerm([NotNull] algoParser.TermContext context)
{
//Is it a multiplication?
if (context.MUL_OP() != null)
{
//Multiplication.
//Evaluate the left side (term).
AlgoValue left = (AlgoValue)VisitTerm(context.term());
//Evaluate the right side.
AlgoValue right = (AlgoValue)VisitFactor(context.factor());
//Perform multiplication.
return(AlgoOperators.Mul(context, left, right));
}
else if (context.DIV_OP() != null)
{
//Division.
//Evaluate the left side (term).
AlgoValue left = (AlgoValue)VisitTerm(context.term());
//Evaluate the right side.
AlgoValue right = (AlgoValue)VisitFactor(context.factor());
//Perform division.
return(AlgoOperators.Div(context, left, right));
}
else if (context.MOD_OP() != null)
{
//Modulus.
AlgoValue left = (AlgoValue)VisitTerm(context.term());
AlgoValue right = (AlgoValue)VisitFactor(context.factor());
//Perform modulus.
return(AlgoOperators.Mod(context, left, right));
}
else
{
//No, just a factor, evaluate.
return((AlgoValue)VisitFactor(context.factor()));
}
//Error.
throw new Exception("Invalid expression type.");
}