Syntax Validation

Syntax validation can be done through TryCreate method from IFunctionFactory. This method will return an TryCreateFunctionResult object with the following behaviour.

Field	Type	Description
Success	bool	Indicates if the expression was succesfuly parsed.
Errors	IEnumerable<string>	If Success is false here is where you can find the reasons.
Function	Function?	If Success is true here is when you can find the resulting Function.

Using the predefined variables provider

When you’re using the predefined variable you can only pass the expression to TryCreate, like this:

var factory = FunctionFactoryBuilder.ConfigureFactory(options =>
{
    options
        .WithPredefinedVariables("X")        
        .WithDefaultsTokenProvider()
        .WithCompiledEvaluator();
});

string fx = "(X*4)^2";
TryCreateFunctionResult result = factory.TryCreate(fx);

Using the evaluation context variable provider

When you’re using the evaluation context you will need to supply the variables as well:

var factory = FunctionFactoryBuilder.ConfigureFactory(options =>
{
    options
        .WithEvaluationContextVariablesProvider()        
        .WithDefaultsTokenProvider()
        .WithCompiledEvaluator();
});

string fx = "(X*4)^2";
var allowedVariables = new PredefinedVariablesProvider("X");
TryCreateFunctionResult result = factory.TryCreate(fx, allowedVariables);

What’s next

You can learn the more about the Functions or go to the docs.