CODEWITHSUNDEEP
c#ncalc
Marian
Marian

Reputation: 33

NCalc expression validation

How can I validate NCalc expression? I want to use NCalc for evaluating if/else/endif condition in my simple custom language for defining sequence of steps. Main program will provide some parameters for conditions. Sequences are defined by user, so my parser have to validate if condition is ok and uses only provided parameters.

I already tried some tests, but don't know how to do this. HasErrors() methods doesn't check used parameters. Evaluate() uses optimalizations, so if I write expression "true or XXXX", it will end with true result and doesn't find out that XXXX parameter is invalid. How can I do this? I want to validate it already in compilation time.

Thanks.

Upvotes: 1

Views: 1882

Answers (1)

Marian
Marian

Reputation: 33

I found the answer in this question (marked as answer), maybe I should have used also other keywords in google. Get the parameters in an expression using NCalc

I tested that solution with my visitor based on LogicalExpressionVisitor and it's working. But, theoretically, maybe it's not the same as validation, because I get the list of parameter names, but from parsed expression, without supplied parameter values. So maybe the expression can fail in case of special "bad" parameter values supplied for evaluation. But it's enough for my case, I know all parameters I will supply to expression, so for me it's enough to get just parameter names.

Upvotes: 0

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