Thanks for the fast response. "Instantiate the type of e with types t" in the documentation was crypt to me. The examples helped to clarify that if you have generic types A and B in a type `(All (A B) A -> B)`, then the instantiate the type `(A -> B)` with `(U Number False) Number)` means that `A` and `B` will be substituted by `(U Number False)` and `Number` respectively.
That is cool! Em seg, 24 de dez de 2018 às 13:46, Matthias Felleisen < [email protected]> escreveu: > > > #lang typed/racket > > > > (define-type MaybePB (U Positive-Byte False)) > > > > (: f ( [Listof MaybePB] -> [Listof Positive-Byte])) > > (define (f x) > > ((inst filter MaybePB Positive-Byte) number? x)) > > > > (f '(1 #false)) > > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
