"Compiler and runtime support for continuation marks" (PLDI 2020) https://dl.acm.org/doi/10.1145/3385412.3385981
"Continuation marks enable dynamic binding and context inspection in a language with proper handling of tail calls and first-class, multi-prompt, delimited continuations."

GHC proposal: "scoped thread-locals" https://github.com/ghc-proposals/ghc-proposals/pull/751
"efficient storage and lookup for immutable context
attached to the current Haskell thread, which is inherited by child threads."

#Haskell #ghc

Packages like `text` reach into the unstable bowels of #GHC to avoid allocating intermediate structures when reading IO.

But it is possible to do fusible lazy IO:

```
produce :: IO [Char]
produce = IO $ \s0 ->
(# s0 , build $ \c n ->
let go s = case runIO getChar s of
(# s' , x #) -> c x (go s')
in go s0
#)
```

Perhaps GHC could expose something like that and the text package could use it.

#haskell

GHC amplia compras da agricultura familiar e reforça alimentação como política de saúde no SUS

https://fed.brid.gy/r/https://www.brasildefato.com.br/2026/03/18/ghc-amplia-compras-da-agricultura-familiar-e-reforca-alimentacao-como-politica-de-saude-no-sus/

TIL #GHC already has some functionality in place to check that a function is only used at a monomorphic type. Currently, I think it is only used for `tagToEnum#` but it would be useful to properly integrate it into the type system.

#haskell

#haskell development be mostly busywork for new #ghc versions...

2d61b20 relax dependencies for ghc-9.14
df41b88 relax dependencies for ghc-9.8
f5ce400 relax dependencies for ghc-9.6
4b4417f (tag: v0.1.2.1) v0.1.2.1
28330e6 relax dependencies for ghc-9.4
eac7560 fix incorrect wrapper on Win64
4ea1b67 bump dependencies for ghc 9.2

An new proposal for passing implicit parameters to #Haskell functions: https://github.com/ghc-proposals/ghc-proposals/pull/741

Done the right way; as opposed to the existing ImplicitParams extension, which is practically useless.

#GHC

-fno-show-error-context

"Controls whether GHC displays information about the context in which an error occurred"

https://discourse.haskell.org/t/is-in-the-first-argument-of-etc-in-type-error-messages-useful/13502/9

https://downloads.haskell.org/ghc/latest/docs/users_guide/using.html#ghc-flag-fshow-error-context

#Haskell #GHC

https://www.reddit.com/r/haskell/comments/plfotc/comment/hcd0le4/

I just learnt two important examples that #GHC fails to optimise code:
one being `Map.fromSet` on polymorphic type, the other being improperly inlining `Set.fromList somelist`.

#Haskell #Compiler

impurepics - #Haskell Extensions
https://impurepics.com/posts/2019-08-01-haskell-extensions.html

A collection of short descriptions and examples of #GHC extensions

#PL #FP

#Haskell New Year Resolutions
https://discourse.haskell.org/t/haskell-new-year-resolutions/13478

These are very useful advices!

I learnt:
- Generically and DerivingVia
- StarIsType
- DuplicateRecordFields, NoFieldSelectors, and OverloadedRecordDot

I must admits that there are just too many extensions in #GHC...

#NewYearResolution #newyear2026 #FP #Programming