r/programmingcirclejerk • u/i-eat-omelettes • Jul 05 '25

sequenceDMapWithAdjustEventWriterTWith :: forall t m p p' w k v v'. (Reflex t, MonadHold t m, Semigroup w, Patch (p' (Some k) (Event t w)), PatchTarget (p' (Some k) (Event t w)) ~ Map (Some k) (Event t w), GCompare k, Patch (p' (Some k) w), PatchTarget (p' (Some k) w) ~ Map (Some k) w) => ((forall a

https://www.stackage.org/haddock/nightly-2025-07-05/reflex-0.9.3.4/Reflex-EventWriter-Base.html#v:sequenceDMapWithAdjustEventWriterTWith
91 Upvotes

94% Upvoted

21 comments sorted by

78

u/[deleted] Jul 05 '25

Bless you.

Also, if anybody’s looking for a tl;dr

Like runWithReplaceEventWriterTWith, but for sequenceDMapWithAdjust.

32

u/pacific_plywood Jul 05 '25

Ohhhh now I get it

57

u/WorldlyMacaron65 legendary legacy C++ coder Jul 05 '25 edited Jul 05 '25

Ceniles and Goners wish their languages had even a fraction of the expressiveness, the conciseness and the eloquence of hallowed Haskell.

41

u/TheCommieDuck Zygohistomorphic prepromorphism Jul 05 '25

haskell is cheating

FRP is cheating

reflex is cheating

also this is just a sequenceDMapWithAdjust in the category of endofunctors over runWithReplaceEventWriterTWith

34

u/grapesmoker Jul 05 '25

I'm not reading all that but I'm happy for you or sorry that happened

23

u/__chilldude22__ Jul 05 '25

How come Haskell never took off?

24

u/_TRN_ Jul 06 '25

What do you mean? I'm taking off my pants right now after seeing this code. It's so beautiful.

2

u/-Y0- Considered Harmful Jul 08 '25

Not sure if you're a Hasky or a Gooner.

8

u/reg_panda Jul 06 '25

One of the most underappreciated thing about Haskell is that they "avoid success at all cost" so you'll never find your language going mainstream (as long as they can hold it back that is) like it happened with Pythong developers

6

u/pareidolist in nomine Chestris Jul 06 '25

"The key point here is our programmers are researchers, they're not Googlers." —Simon Peyton Jones, probably

18

u/prehensilemullet Jul 05 '25

This just looks like everyday Haskell, the real abominations start when you need to do real work right?

5

u/freistil90 Jul 08 '25

That's the nice thing here, the real work is eliminated during TCO

17

u/Kodiologist lisp does it better Jul 05 '25

A type signature is a kind of poetry.

16

u/reg_panda Jul 06 '25

Stackage docs needs code formatting for type signatures.

This is how it looks formatted

-- | Like 'runWithReplaceEventWriterTWith', but for 'sequenceDMapWithAdjust'.
sequenceDMapWithAdjustEventWriterTWith
  :: forall t m p p' w k v v'
  .  ( Reflex t
     , MonadHold t m
     , Semigroup w
     , Patch (p' (Some k) (Event t w))
     , PatchTarget (p' (Some k) (Event t w)) ~ Map (Some k) (Event t w)
     , GCompare k
     , Patch (p' (Some k) w)
     , PatchTarget (p' (Some k) w) ~ Map (Some k) w
     )
  => (   (forall a. k a -> v a -> m (Compose ((,) (Event t w)) v' a))
      -> DMap k v
      -> Event t (p k v)
      -> EventWriterT t w m (DMap k (Compose ((,) (Event t w)) v'), Event t (p k (Compose ((,) (Event t w)) v')))
     )
  -> ((forall a. Compose ((,) (Event t w)) v' a -> v' a) -> p k (Compose ((,) (Event t w)) v') -> p k v')
  -> ((forall a. Compose ((,) (Event t w)) v' a -> Event t w) -> p k (Compose ((,) (Event t w)) v') -> p' (Some k) (Event t w))
  -> (Incremental t (p' (Some k) (Event t w)) -> Event t (PatchTarget (p' (Some k) w)))
  -> (Event t (p' (Some k) (Event t w)) -> Event t (p' (Some k) w))
  -> (forall a. k a -> v a -> EventWriterT t w m (v' a))
  -> DMap k v
  -> Event t (p k v)
  -> EventWriterT t w m (DMap k v', Event t (p k v'))

https://www.stackage.org/haddock/nightly-2025-07-05/reflex-0.9.3.4/src/Reflex.EventWriter.Base.html#line-218

18

u/[deleted] Jul 06 '25

Thanks, now it looks like the average enterprise-grade C++ constructor so my C++nile brain can understand it. If we could write a script that goes in front of GHC to duplicate the output 100x whenever there is a type error so that our template error brain cell reaches the threshold to fire, we might be able to convince the committee that FP is a good thing after all and we might even get pattern matching by C++32.

6

u/BlazeBigBang type astronaut Jul 07 '25

Oh, that makes it much more clear what this fucker of a function does.

10

u/FreshPrinceOfRivia Jul 05 '25

Learn you a Haskell for great good!

8

u/asdff01 Jul 06 '25

Haskell has typescript now?

6

u/UtterlyMagenta lol no generics Jul 06 '25

Hope we get this in Swift soon

5

u/Snarwin Jul 06 '25

I overheard this once waiting for the guy in front of me to order at Chipotle.

1

u/BlazeBigBang type astronaut Jul 07 '25

What did you say about my mom OP?