Shorter feedback cycles for contributors and higher quality of releases, these are a few of our favourite things about the Haddock documentation generation tool coming home to the GHC repository.
how the hell do you add dependencies in Haskell stack, I add yesod to the build-depends in the cabal file like shown in the stack example but on running stack build it fails saying it couldn't find yesod, and then the line is removed from the cabal file. Haskell ecosystem is hell.
usually, it is used to define methods, but in function arguments, it serves as syntactic sugar so you don't have to name generic types... but in a return type, it has a meaning that is slightly different, and actually expresses a semantic not even vanilla haskell can represent!
basically, instead of being able to return any type implementing a trait, it states that it can return at least one type that implements a trait.
in haskell terminology, specifying a generic type parameter is "forall a", while returning an "impl" is "exists a".
The GHC developers are very pleased to announce the release of GHC 9.10.1! 🎉
On the menu:
→ GHC2024 language edition
→ Linear let and where
bindings
→ Annotation of exceptions with backtraces
→ Required type arguments for functions
→ Javascript FFI support in the WebAssembly backend
… and many more!
Between the continued iteration on the GHC20xx meta-extension mechanisms, further improvements in the JS/wasm backends, and (my favorite) the availability of exception backtraces in base, there is lots in this release to be excited about.
See the Haskell Discourse thread for the full announcement:
If like me, you use ghcup tui, and constantly find yourself pressing "u" thinking it means "use" only to find it means "uninstall", you can change the keybindings by editing ~/.ghcup/config.yaml
On Wednesday, 2024-05-15, at 1830 UTC, we'll stream the 25th episode of the #Haskell#Unfolder. This episode should be interesting for Haskellers and non-Haskellers alike. Edsko and I will translate a #gRPC server from #Java to Haskell, contrasting the programming paradigms.
Note to self: type variables in #purescript and #haskell cannot be bound to partially applied type synonyms.
If you try to do so, in a sufficiently polymorphic way, you'll get very confusing type errors as the checker attempts to solve things with the variable bound to the "head" of the (parametrically expanded) type alias.
Last night it was (forall r. (forall f. Foldable1 f => f a -> r) -> r) and tonight it was (a -> Term a). Introducing a newtype can help, but beware impredicativity.
Last week I prototyped a git remote helper in a shell script, and now I'm rewriting that in #haskell as part of #gitAnnex.
I don't do this often and I wonder if it was a mistake, probably I should have written the prototype in haskell and then integrated it into git-annex. It's kind of amazing how a lot of complexity is melting away and also how I'm adding So Many Types and also throwing in a lot of robustness improvements.