I was thinking of the `Set' type constructor as meaning generic set, which is why I gave that type to `generic-set?'. This interpretation is a problem because TR treats sets as covariant.
If we make sets invariant, could TR support generic sets? [1] Or are there other issues I'm missing? Vincent [1] Better support would also include subtyping between lists and sets. At Fri, 30 Aug 2013 16:38:11 -0700, Eric Dobson wrote: > > Isn't the assymetric check the wrong way? If it returns true, we know > nothing because it might not be a hash-set, but if it returns false > then we know that it is not a hash set? > > On Fri, Aug 30, 2013 at 3:30 PM, Asumu Takikawa <as...@ccs.neu.edu> wrote: > > On 2013-08-30 16:15:23 -0400, Sam Tobin-Hochstadt wrote: > >> I worry about mutable sets here, but I can't think of any bugs it can > >> cause ATM. > > > > I don't have any segfault-causing bugs, but here's a violation of the blame > > theorem: > > > > #lang racket > > > > (module a0 racket > > (define s (mutable-set 1 2 3)) > > (provide s)) > > > > (module a typed/racket > > (require/typed (submod ".." a0) [s Any]) > > (: x (Setof Any)) > > (define x (assert s generic-set?)) > > (provide x)) > > > > (require 'a) > > x > > > > Cheers, > > Asumu > > _________________________ > > Racket Developers list: > > http://lists.racket-lang.org/dev _________________________ Racket Developers list: http://lists.racket-lang.org/dev
