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:
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.
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.
;; Getting rid of explicit indexing was just step one.
-- After a few days/months/years, I now realize that it is more important and less buggy if I think only of the function to call (and whether I want to end up with a new (maybe pruned) collection, a single thing, or "both" (that's how I think of scans))
The #Haskell#Unfolder is now 1 year old! In the anniversary episode, Edsko and I will return to the very first topic and consider (un)folds, but now in a more generic setting. Live on YouTube 2024-05-01 at 1830 UTC.