Is resolve() function supported?

[jackliums]

Hi there,

As part of the issue discussed here, I've updated the expression to use the resolve() function but it seems like the library does not currently support it? When I try to evaluate the expression, it throws the following exception:

ArgumentException: Unknown symbol 'resolve'
Hl7.FhirPath.Expressions.EvaluatorVisitor.resolve(SymbolTable scope, string name, IEnumerable<Type> argumentTypes)

The expression it's trying to evaluate is:

Appointment.participant.actor.where(resolve() is Location)

[brianpos]

Yes we haven't updated it yet. In my server I plan to shortcut it to only process the reference itself, and not read the resource for performance reasons.

[ewoutkramer]

But the question is about resolve(), which we have built in, but it's a FHIR-specific function (FhirPath is used more generally than just within FHIR) so make sure you use a symbol table that is initialized with the FHIR-specific functions. You could either use the extension methods like Select() coming from the Hl7.Fhir.[DSTU].Core libraries or create your own compiler like so:

   var symbolTable = new SymbolTable();
   symbolTable.AddStandardFP();
   symbolTable.AddFhirExtensions();

   var fpCompiler = new FhirPathCompiler(symbolTable);
   // do stuff

[jackliums]

I am using Select() extension methods from the Core libraries and that was the exception I was getting.