Since apparently I am not the only one wanting to use graphs in Typed Racket, I will prepare a typed interface to Stephen Chang's graph library: typed-graph. I am planning to upload it to the main package catalog.
If you have any advice or ideas, or want to contribute to the effort, do tell me. - Sergiu On Wednesday, December 23, 2020 at 11:59:16 PM UTC+1 unlimitedscolobb wrote: > Hello, > > Again, a question out of curiosity, because I think I found a solution, > but I'd like to have something more elegant. > > I'm trying to use the (untyped) Racket generic graph library from my Typed > Racket code: > > #lang typed/racket > > (require/typed graph > [#:opaque Graph graph?] > [directed-graph (->* ((Listof (List Any Any))) ((Listof Any)) Graph)]) > > (directed-graph '((a b) (b c))) > > When I load this code in the REPL I get > > graph?: contract violation > any-wrap/c: Unable to protect opaque value passed as `Any` > value: #<unweighted-graph> > This warning will become an error in a future release. > in: the 1st argument of > a part of the or/c of > (or/c > struct-predicate-procedure?/c > (-> Any boolean?)) > contract from: (interface for graph?) > blaming: <pkgs>/dds/tmp.rkt > (assuming the contract is correct) > at: <pkgs>/dds/tmp.rkt:4.18 > #<unweighted-graph> > > I found this solution by Alex Knauth: > https://stackoverflow.com/questions/65386334/racket-generic-graph-library-in-typed-racket > > , which essentially consists in wrapping the opaque graph struct into > another struct. Alex says that the problem comes from the fact that graph? > essentially encompasses a couple different internal representations the > graph library uses. > > While this solution should fit me, I was wondering whether anybody here > has encountered this issue and has a different solution. > > - > Sergiu > -- 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 racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/0073afbf-4309-4573-a8fc-aa4bfd4e4d77n%40googlegroups.com.
