making me think that the supremely clever people behind
these projects (no sarcasm!) never experienced the pain
that comes from split ecosystems. Because if they had,
they wouldn't have started "cats" without getting
concensus first.
It was created because it was impossible to work with these terrible, obnoxious (ex-)Haskell people anymore.
The main change from scalaz to cats is not the code, but the community: Friendly people behaving like adults who don't act gravely offended when people discuss potential approaches which don't look like 100% what Haskell came up with.
I think scalaz will fall out of use mid-term, because everyone is sick of their shit behavior.
Consensus as in: Get the approval of the community or at least lobby for the inclusion of Monad/Functor/etc. in the Scala standard library. My point was that the inclusion in the standard library is key to making Monad/Functor/etc. work. If you don't have that then you end up with the sad sad situation of monad-tf/monad-fd except this time it's not Transformers[1], but the fundamental Monad/Functor/etc.
As for the rest of your comment: ... WHAT?
[1] Which, to be fair, were fairly controversial at the time.
You're complaining about "inclusiveness" and you say "terrible people" in the same breath. No. Fuck you, and fuck off.
Where?
> No. Fuck you, and fuck off.
That's exactly the kind of immature behavior which is not welcome in the community. Please stay in the Haskell land.
> for/yield is fine. Haskell people love to get excited about the one extra flatten but it's really not a big deal.
No, it's a big deal. It pollutes everything you do in "do" / "for/yield" notation.
Part of why do notation in Haskell is so amazingly beatiful and concise is that it doesn't force this absurd amount of pointless boilerplate on you.
(We can agree that they're technically equivalent, but SYNTAX FUCKING MATTERS, YO)
My thinking here is that Martin Odersky actually understood what was going on at a technical level, but didn't appreciate what was going on at the cognitive level of the programmer... and so just implemented the mechanism.
If you compound this with the semi-recent "cats"/"scalaz" schism over Monad and Functor, thus making us reexperience the monads-tf/monads-fd schism in Haskell-land... making me think that the supremely clever people behind these projects (no sarcasm!) never experienced the pain that comes from split ecosystems. Because if they had, they wouldn't have started "cats" without getting concensus first. My point is that you cannot meaningfully talk about Monad/Functor without that type definition being a core part of the language -- which it isn't in Scala.
Listen, I appreciate that they have a more difficult problem in some sense, because they've accepted subtyping as an actual thing that's useful. But that's their problem. Subtyping generally isn't very useful[1] and they're driven by OOP ideology... which is fine per se, but don't complain when it doesn't work out -- when the problems of subtyping are well-known and have been for the last 20-30 years.
[1] Use lenses and contra-/covariant functors instead when you actually need it.
> One little unmanaged println isn't going to destroy the universe. The fact that Haskell will invisibly transform your code into lazy thunks, radically altering its performance characteristics, causes a lot more trouble IME.
Yes, it will. Because it isn't just a little "println" here and there (in practice). The deal here is: I can mechanically scan all the code for unsafePerformIO and unsafeInterleaveIO, etc. I cannot scan Scala code mechanically for unsafe things because the possibilities are almost literally infinte. It's about "permit evil selectively" vs. "forbid evil when you see it". The latter doesn't work.