To give a counter point, there seem to be lots of small wins that aren't taken, possibly in part because people seem to wait for the big ideas.
Take partial functions like head: You can do what Haskell and Java do and throw an exception. Or you can have dependent types and statically prevent the function from being applied to an empty list. But the obvious and easy solution in the current language would be to return Maybe, which isn't done because there's a feeling that it's not a big enough step to be worth the effort, and dependent types will eventually solve this anyway.
This is all tied into how inflexible the base/Prelude story is currently, etc. If the Prelude were a fully independent library where you could just depend on any old version you like, then there'd be no problem changing the signature. (Other than the usual diamond dependency problems). Of course you can choose NoPrelude and go from there, but then you're already in a place where changing 'head' doesn't matter to you, only the maintainer of your alternative Prelude.
People are working on both of these aspects, and that's got me really excited about where Haskell is going these days!
(I've always loved Haskell as a language, but there have been undeniable ecosystem issues.)
(I do see how a function like that is useful, but I don’t think it’s a good replacement for head.)
Something is eventually going to pattern match on it. But it might well be some handler way way up at the top of my program, and all I want to do right now is `map` and `bind` as normal.
Don't change the meaning of an identifier to something meant for a completely different use. The alternative change involving dependent types or liquid types doesn't break existing code. Changing head so that it returns a Maybe breaks code, because its use case is different.
> Changing head so that it returns a Maybe breaks code
Of course. So did `Applicative`. So did `Foldable` and `Traversable`. So will removing (/=) from Eq, whenever that actually gets merged - and that was imo a far, far less problematic wart than having partial functions in Prelude. Breaking changes need to be made very carefully and very slowly: simplified subsumption was terribly handled, if not an outright mistake. But refusing to make them at all is how you get C++.
They don't have to. Pattern matching is one of the first things they will learn, so they can use that instead.
> and `head` actually means `unsafeHead` and should almost never be used.
They don't need to intuit it. The next version of base will have a warning on `head` telling them to use a safer alternative instead.
By the way, the Haskell community is currently struggling to accept that it should make fewer breaking changes, in order to become a more stable platform for industry use. We're definitely not going to start breaking more code!
That's not why it's not done. listToMaybe already exists[1] and you can't change the type of head without breaking everyone's code, so head in the next version of base will come with a warning[2] and that's about as much as you can do whilst still maintaining backwards compatibility.
[1] https://www.stackage.org/haddock/lts-21.14/base-4.17.2.0/Dat...
[2] https://github.com/haskell/core-libraries-committee/issues/8...
That is what the standardization process is for. I don't think that the parties that could write a new Haskell standard have the time, resources, or bandwidth to work on one. That's why for now we're stuck with 98, 2010 and a bunch of extensions.
That sounds like the Extension lifecycle framework proposal https://github.com/ghc-proposals/ghc-proposals/pull/601
very much second that! haskell has band-aid type-level programming that is so awful, but sometimes so useful, that it's really hurting a lot. I would just really like to deprecate type-families and would like to see as a the first step some non-dependently typed type-promoted functions. There's a great, pragmatic, proposal I would really like to see implemented. I, personally, don't need dependent types thaaaaaat much but type families are so unergonomic and really a dead-end I think. It's just stupid.
it's sad to see that the dependent haskell progress is losing steam and, as it is my impression, getting maybe a bit lost in the weeds?
It’s just really, really expressive without trying to solve the halting problem via some unification failure mode.
Type classes and GADTs already give you 10x the canvas you can get without trouble anywhere else, and if you keep it tight, you have the tooling to really tune it up.
Idris is awesome, do that if you’re doing that. Haskell is changing all the time: it became a serious production tool: I’d really like for it to stay one.
I think the author is just writing down their opinions (which are worth discussing!) and not seriously trying to start a new GHC frontend. Personally, I think Haskell is approximately stuck in a local maximum, which can only be escaped by embracing dependent types (which are actually simpler than where Haskell has been heading) rather than building increasingly complex approximations of them. Once you try a dependently typed language like Agda, Lean, Coq, or Idris, it's hard to go back to the complexity of having two (or more!) separate languages for types and programs.