using uCalcSoftware; var uc = new uCalc(); static void MyHandler(Handle_uCalc h) { var uc = new uCalc(h); // This handler just logs the error and aborts Console.WriteLine($"Error Handler Caught: {uc.Error.Message}"); } static void MyFunc(uCalc.Callback cb) { // This function always fails with a custom message cb.Error.Raise("Validation failed for input."); } uc.Error.AddHandler(MyHandler); uc.DefineFunction("Validate()", MyFunc); uc.EvalStr("Validate()"); // This call will trigger the error