On Mon, Jun 16, 2014 at 3:06 PM, Alexander D. Knauth <alexan...@knauth.org> wrote: > >> Typed Racket functions are >> just plain Racket functions. We could add some extra metadata to every >> value that held its type, > > It wouldn’t have to be every value, it could just put that information in for > :has-type expressions, right? > Would that still require fundamental changes to Racket?
The problem is that the information needs to get attached to the value where the value is created, not where you use `:has-type?`. The `:has-type?` could even be in some other module, so you'd have to add this information to every value, everywhere. That's why it would need to be part of the runtime. >> and then implement this operation, but that >> would require fundamental changes to Racket. >> >> Even if we wanted to do that, what if `f` came in from untyped Racket? > > If f comes from untyped Racket, then the type checker says to use > require/typed to import it. But what if it was imported with `require/typed` -- the value wouldn't have the necessary runtime tags for determining if it has a particular type. Sam ____________________ Racket Users list: http://lists.racket-lang.org/users
