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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/0073afbf-4309-4573-a8fc-aa4bfd4e4d77n%40googlegroups.com.
