public override int VisitCalculation([NotNull] CBluntParser.CalculationContext context)
{
#if DEBUG
Console.WriteLine("VisitCalculation");
#endif
//operator has @ because operator is normally a reserved keyword
Visit(context.@operator());
//Visits either a parameter or expression
Visit(context.GetChild(1));
return(0);
}
/// <summary>
/// Visit a parse tree produced by <see cref="CBluntParser.calculation"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitCalculation([NotNull] CBluntParser.CalculationContext context)
{
return(VisitChildren(context));
}
public override int VisitCalculation([NotNull] CBluntParser.CalculationContext context)
{
#if DEBUG
Console.WriteLine("VisitCalculation");
#endif
var operatorContext = context.@operator().GetText();
// If a parameter was found, add it to the store
if (context.parameter() != null)
{
var parameter = context.parameter();
var parameterType = GetParameterType(context, parameter);
var prevExpressionStoreType = SymbolTable.ExpressionStoreLinkedList.Last.Value.ExpressionTypes.Last;
if (prevExpressionStoreType == null)
{
if (!AddToExpressionStore(parameterType))
{
return(1);
}
return(0);
}
var prevExpressionStoreValue = prevExpressionStoreType.Value;
// Perform semantics on operator, it is not possible to subtract ex. a string from a number
// If the type is already text, the numbers cannot turn the expression store into a number again. It will remain text
switch (operatorContext)
{
case "+":
if (prevExpressionStoreValue == "number" && parameterType == "number")
{
if (SymbolTable.ExpressionStoreLinkedList.Last.Value.Type == "text")
{
break;
}
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "number";
break;
}
if (prevExpressionStoreValue == "text" && parameterType == "text")
{
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "text";
break;
}
if (prevExpressionStoreValue == "number" && parameterType == "text")
{
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "text";
break;
}
if (prevExpressionStoreValue == "text" && parameterType == "number")
{
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "text";
break;
}
SyntaxError(context, "Cannot add a variable of type " + prevExpressionStoreValue + " with a variable of type " + parameterType);
return(1);
case "-":
if (prevExpressionStoreValue == "number" && parameterType == "number")
{
if (SymbolTable.ExpressionStoreLinkedList.Last.Value.Type == "text")
{
break;
}
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "number";
break;
}
SyntaxError(context, "Cannot subtract a variable of type " + prevExpressionStoreValue + " with a variable of type " + parameterType);
return(1);
case "*":
if (prevExpressionStoreValue == "number" && parameterType == "number")
{
if (SymbolTable.ExpressionStoreLinkedList.Last.Value.Type == "text")
{
break;
}
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "number";
break;
}
SyntaxError(context, "Cannot multiply a variable of type " + prevExpressionStoreValue + " with a variable of type " + parameterType);
return(1);
case "/":
if (prevExpressionStoreValue == "number" && parameterType == "number")
{
if (SymbolTable.ExpressionStoreLinkedList.Last.Value.Type == "text")
{
break;
}
SymbolTable.ExpressionStoreLinkedList.Last.Value.Type = "number";
break;
}
SyntaxError(context, "Cannot divide a variable of type " + prevExpressionStoreValue + " with a variable of type " + parameterType);
return(1);
}
if (!AddToExpressionStore(parameterType))
{
return(1);
}
}
// If there is an expression instead, visit it
if (context.expression() != null)
{
if (Visit(context.expression()) == 1)
{
return(1);
}
}
return(base.VisitCalculation(context));
}
