public override IToken Evaluate(IToken first, IToken last, TokenTreeList parameters, bool isFinal)
{
if (_function == null)
{
if (first == null)
throw new Exception($"Operation {Text} can not be unary.");
IToken functionToken = first.Evaluate(parameters, isFinal);
if (functionToken == null || functionToken is ListToken)
throw new Exception($"First element of Operation {Text} is not unique.");
string function = functionToken.Text;
switch (function)
{
case AndFunction.ID:
_function = new AndFunction();
break;
case AggregateFunction.ID:
_function = new AggregateFunction();
break;
case CaseFunction.ID:
_function = new CaseFunction();
break;
case ComparisonFunction.ID:
_function = new ComparisonFunction();
break;
case ContainsFunction.ID:
_function = new ContainsFunction();
break;
case CountFunction.ID:
_function = new CountFunction();
break;
case DoubleFunction.ID:
_function = new DoubleFunction();
break;
case IfFunction.ID:
_function = new IfFunction();
break;
case IntFunction.ID:
_function = new IntFunction();
break;
case JoinFunction.ID:
_function = new JoinFunction();
break;
case OrFunction.ID:
_function = new OrFunction();
break;
case OverFunction.ID:
_function = new OverFunction();
break;
case RangeFunction.ID:
_function = new RangeFunction();
break;
case RegexFunction.ID:
_function = new RegexFunction();
break;
case ReverseFunction.ID:
_function = new ReverseFunction();
break;
case SplitFunction.ID:
_function = new SplitFunction();
break;
case SumFunction.ID:
_function = new SumFunction();
break;
case UserFunction.ID:
_function = new UserFunction();
break;
default:
ListToken newList = new ListToken
{
new ExpressionToken(null, new SubstitutionOperator(), new StringToken(function))
};
ListToken oldList = last.Evaluate(parameters, isFinal) as ListToken;
if (oldList != null)
{
foreach (IToken token in oldList.Tokens)
newList.Add(token);
}
else
{
newList.Add(last);
}
ExpressionToken expression = new ExpressionToken(null, new FunctionOperator(new UserFunction()), newList);
return expression.Evaluate(parameters, isFinal);
}
}
IToken parameterList;
if (isFinal && _function is UserFunction)
{
parameterList = PrepareUserFunction(last, parameters);
}
else if (_function.IsComparisonFunction)
{
parameterList = last.EvaluateList();
}
else
{
parameterList = last.Evaluate(parameters, !_function.FinalCanBeExpression && isFinal);
ExpressionToken expression = parameterList as ExpressionToken;
if (expression != null)
{
if (isFinal)
{
IToken substitute = _function.ValueIfFinalValueIsExpression(expression);
if (substitute is NullToken)
return new ExpressionToken(null, new FunctionOperator(_function), parameterList);
parameterList = substitute;
}
else
{
return new ExpressionToken(null, new FunctionOperator(_function), parameterList);
}
}
}
return _function.Perform(parameterList, parameters, isFinal);
}