The argument types of an anonymous function must be fully known. (SLS 8.5)

Question

I have a function literal

{case QualifiedType(preds, ty) =>
               t.ty = ty ;
               Some((emptyEqualityConstraintSet,preds)) }
         


        

Answer 1

Here's the SLS quote, for the rest of us:

The expected type of such an expression must in part be defined. It must be either scala.Functionk[S1, . . . , Sk, R] for some k > 0, or scala.PartialFunction[S1, R], where the argument type(s) S1, . . . , Sk must be fully determined, but the result type R may be undetermined.

Otherwise, you answered your question.