internal static Tuple <OperandType> DoUnaryCastOperation(DoubleOperandFunctionMatrix matrix, Stack <IOperand> operandStack, IBackingStore backingStore, Operand castTo)
{
IOperand operand = PopAndResolve(operandStack, backingStore);
IOperand result = matrix.PerformDelegate(operand, castTo);
if (result != null)
{
operandStack.Push(result);
return(null);
}
else
{
// Signal an error ...
return(new Tuple <OperandType>(operand.Type));
}
}
internal static Tuple <OperandType, OperandType> DoOperation(DoubleOperandFunctionMatrix matrix, Stack <IOperand> stack, IBackingStore backingStore)
{
IOperand second = PopAndResolve(stack, backingStore);
IOperand first = PopAndResolve(stack, backingStore);
IOperand result = matrix.PerformDelegate(first, second);
if (result != null)
{
stack.Push(result);
return(null);
}
else
{
// Signal an error ...
return(new Tuple <OperandType, OperandType>(first.Type, second.Type));
}
}
/// <summary>
/// This ought to be implemented with a FunctionMartix but it would be huge.
/// This way is easier!
/// </summary>
internal static Tuple <OperandType, OperandType> DoSetEquals(DoubleOperandFunctionMatrix matrix, Stack <IOperand> stack, IBackingStore backingStore, long parserPosition)
{
IOperand second = PopAndResolve(stack, backingStore);
IOperand first = stack.Pop(); // Not PopAndResolve. LHS must be a variable.
if (first.Type != OperandType.Variable)
{
throw new ExpressionEvaluatorException(parserPosition, ExpressionEvaluatorException.ExceptionCause.BadOperand, "LHS of '=' is a '" + first.Type + "' when it must be a variable");
}
else
{
string varName = (string)first.GetValue();
(OperandType type, object value)valueAndType;
try
{
// We need the type, don't need the value because it's going to be overwritten.
valueAndType = backingStore.GetValue(varName);
}
catch (Exception ex)
{
throw new ExpressionEvaluatorException(-1, ExpressionEvaluatorException.ExceptionCause.UndefinedVariable, $"'{varName}'");
}
// type is needed so we can pick out the correct martrix operation. Value is irrelevant as it is overwritten.
var firstOperand = new Operand(first.ParserPosition, valueAndType.type, valueAndType.value);
IOperand result = matrix.PerformDelegate(firstOperand, second);
if (result != null)
{
backingStore.SetValue(varName, result.GetValue());
stack.Push(result);
return(null);
}
else
{
// Signal an error ...
return(new Tuple <OperandType, OperandType>(first.Type, second.Type));
}
}
}
