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welltypedwit.ch
Alice ✨
@welltypedwit.ch
2.5K followers 330 following 4.6K posts
When the limestone of imperative programming has worn away, the granite of functional programming will be revealed underneath -Simon Peyton Jones

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welltypedwit.ch
literally their first example of gleam code is doing an unchecked side effect!
Welcome to the Gleam language Tour. Example code: pub fn main() { io.println("Hello, Joe!") }
November 12, 2025 at 10:12 AM
welltypedwit.ch
see you in 3 hours
GoodTimesWithScar hermitcraft 11 episode 1: 50:52 Grian and GeminiTay Hermitcraft 11 Episode 1: 1:01:41 and 1:17:35
November 8, 2025 at 3:07 PM
welltypedwit.ch
this is a very american quiz though huh ^^
We must reform our elections by expanding ballot access. Citizens should be automatically registered and sent a ballot
October 24, 2025 at 10:07 PM
welltypedwit.ch
wow, that's surprisingly accurate
government: 100% unitary democracy economy: 53.5% social democracy 48.5%: socialism society: 71.4% social justice 28.6% freedom relgiion: 88.2% atheist 11.8% apathy security: 100% humanist foreign policy: 59.1% internationalist 40.9% open borders
October 24, 2025 at 10:07 PM
welltypedwit.ch
1.5 hours later i finally got this minimized omg

this only happens if one module defines a type like this with RequiredTypeArguments, that is used in another module where RequiredTypeArguments is turned *off*, but ApplicativeDo is turned *on* **and** the bound type variable is used at least twice
A.hs: {-# LANGUAGE RequiredTypeArguments #-} module A where import Data.Kind (Type) higherRankRTA :: (forall s -> a) -> a higherRankRTA _ = undefined B.hs: {-# LANGUAGE GHC2021 #-} {-# LANGUAGE ApplicativeDo #-} {-# LANGUAGE NoRequiredTypeArguments #-} module B where import A (higherRankRTA) import Data.Functor.Identity (Identity) import Data.Proxy (Proxy) danger :: Identity () danger = higherRankRTA $ \s -> do _ :: Proxy s <- undefined _ :: Proxy s <- undefined pure ()
October 22, 2025 at 9:26 PM
welltypedwit.ch
oops
/home/prophet/Code/vega-graph/src/Vega/SCC.hs:33:28: error: [GHC-76329] • GHC internal error: ‘s’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [a6x5 :-> Type variable ‘node’ = node :: *, a6x6 :-> Type variable ‘es’ = es :: [Effect], a6xG :-> Identifier[outEdgesOrPrecomputedSCC::node -> Eff es (Maybe [node]), NotLetBound], a6xH :-> Identifier[node::node, NotLetBound], a6xR :-> Type variable ‘s’ = s :: k0, r5cb :-> Identifier[computeSCC::forall node (es :: [Effect]). (Show node, Hashable node, Trace :> es) => (node -> Eff es (Maybe [node])) -> node -> Eff es (HashMap node SCCId), TopLevelLet {} True], r6x4 :-> Identifier[newSCCId::forall (es :: [Effect]). (IOE :> es) => Eff es SCCId, TopLevelLet]]
October 22, 2025 at 7:48 PM
welltypedwit.ch
i hate sccs (no, they're actually really cool but this is like the fifth time i got this panic omg)
ERROR: PANIC (the 'impossible' happened): SCC map for declaration MkDeclarationName {moduleName = MkModuleName {package = MkPackageName "knucklebones", subModules = fromList ["Main"]}, name = "TurnResult"} is missing its own binding. SCCs: fromList [] CallStack (from HasCallStack): error, called at src/Relude/Debug.hs:283:11 in relude-1.2.2.2-49XUvkEaanJEVa9xYTIMnb:Relude.Debug error, called at src/Vega/Effect/GraphPersistence/InMemory.hs:365:28 in vega-0.1.0.0-9MZYQnIf4mmoTzMmugakT:Vega.Effect.GraphPersistence.InMemory
October 22, 2025 at 7:18 PM
welltypedwit.ch
welp
[compile/types/existential-dependent.vega]: FAILED Expected error message: Actual error message: ERROR: PANIC (the 'impossible' happened): type variable not found in type checker: MkLocalName {parent = MkDeclarationName {moduleName = MkModuleName {package = MkPackageName "existential-dependent", subModules = fromList ["Main"]}, name = "f"}, name = "r", count = 0} CallStack (from HasCallStack): error, called at src/Relude/Debug.hs:283:11 in relude-1.2.2.2-49XUvkEaanJEVa9xYTIMnb:Relude.Debug error, called at src/Vega/TypeCheck.hs:69:20 in vega-0.1.0.0-9MZYQnIf4mmoTzMmugakT:Vega.TypeCheck typeVariableKind, called at src/Vega/TypeCheck.hs:802:28 in vega-0.1.0.0-9MZYQnIf4mmoTzMmugakT:Vega.TypeCheck
October 21, 2025 at 12:24 PM
welltypedwit.ch
omg i hate error recovery. this is so subtle
-- TODO: If the program is well-typed, this is definitely okay since the body kind cannot mention any of the variables -- bound by the existential anyway (they're parametric). If it isn't, this might cause panics about unresolved type variables -- later on though.
October 21, 2025 at 12:17 PM
welltypedwit.ch
what did she mean by this
[compile/types/existential.vega]: FAILED /home/prophet/Code/vega-graph/test/run/./Main.vega:2:13: ERROR: Expected: identifier Actual: ) ┃ 2 ┃ f : forall () -> exists (a : Type(IntRep)). (Int -> a, a -> String); ┃ ▔
October 21, 2025 at 11:34 AM
welltypedwit.ch
oh that works! this seems wrong though? the point of ! is that it can be coerced to any type (including ones that satisfy Drop) so I would have expected an ambiguity error?
same code but with drop(panic!()) called in main error[E0277]: the trait bound `!: !Drop` is not satisfied --> src/main.rs:11:10 | 11 | drop(panic!()); | ---- ^^^^^^^^ the trait bound `!: !Drop` is not satisfied | | | required by a bound introduced by this call | note: required by a bound in `drop` --> src/main.rs:6:8 | 4 | fn drop<T>(_t: T) | ---- required by a bound in this function 5 | where 6 | T: !Drop, | ^^^^^ required by this bound in `drop`
October 20, 2025 at 11:27 PM
welltypedwit.ch
i tried a boxed iterator as well and this took a whole 1.2ms so i'm not sure that's it? boxing is obviously going to be slower than in haskell and ocaml but not by a factor of 100 right?
fn repeated_cons(n: u64) -> u64 { let mut iterator: Box<dyn Iterator<Item = u64>> = Box::new((0..=0).into_iter()); for i in 1..n { iterator = Box::new((std::iter::once(i)).chain(iterator)) } iterator.sum::<u64>() }
October 20, 2025 at 2:51 PM
welltypedwit.ch
oh noo ^^ mine is just this

(the black_box calls are there to prevent it from cheating and constant folding the iterator away but it did compile without them)
repeated_direct_cons() -> u64 { let iter = std::iter::once(1000).chain(black_box(std::iter::once(999).chain(black_box(std::iter::once(998).chain... iter.sum::<u64>() }
October 20, 2025 at 12:42 AM
welltypedwit.ch
A4 Noah (farmer): There are more innocents among witches than any other profession
October 18, 2025 at 12:07 AM
welltypedwit.ch
{- NOTE: Ord instances ----------------------------------------------------- Nearly all derived `Ord` instances in this module are entirely meaningless. We only need to derive them because megaparsec stores its custom parse errors in a `Set` and we sometimes need to store AST nodes to improve our error messages (e.g. InvalidExistentialBinders contains the ForallBinderS values the user actually wrote) -}
October 17, 2025 at 2:36 PM
welltypedwit.ch
achievement unlocked
[27 of 36] Compiling Vega.TypeCheck [Source file changed] <no location info>: error: panic! (the 'impossible' happened) GHC version 9.10.2: lookupConstructorInfo: not a ConLike name: GenericInstantiation Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/GHC/Utils/Panic.hs:190:37 in ghc-9.10.2-d434:GHC.Utils.Panic pprPanic, called at compiler/GHC/Rename/Env.hs:439:18 in ghc-9.10.2-d434:GHC.Rename.Env CallStack (from HasCallStack): panic, called at compiler/GHC/Utils/Error.hs:507:29 in ghc-9.10.2-d434:GHC.Utils.Error Please report this as a GHC bug: https://www.haskell.org/ghc/reportabug
October 17, 2025 at 1:46 PM
welltypedwit.ch
omg i found it. so what happened is that the precedence for --> here is wrong and *also* the pretty printer for types has a bug that makes it print this incorrectly: this is actually
`((Int, ?a) -> Array)(?a)` (which is ill-kinded obviously)
builtinTypes :: HashMap GlobalName Type builtinTypes = [ (internalName "replicateArray", forall_ "a" \a -> [intType, a] --> arrayType @@ [a])
October 16, 2025 at 3:29 PM
welltypedwit.ch
uh oh
/home/prophet/Code/vega-graph/teeest/src/Main.vega:5:17: ERROR: Type mismatch Unable to unify expected type (internal:Internal:Int, internal:Internal:String) -{?e}> internal:Internal:Array(?w) actual type (internal:Internal:Int, ?a) -> internal:Internal:Array(?a) ┃ 5 ┃ let array = replicateArray(5, "a"); ┃ ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
October 16, 2025 at 3:07 PM
welltypedwit.ch
C2 Hilda, pilot: There are more criminals among cops than any other profession
October 16, 2025 at 1:13 PM
welltypedwit.ch
i wasn't expecting south african either lol

(fwiw i think you sound quite british ^^)
german: 42%, south african: 35%, albanian: 10%, accent sterngth: 71%
October 15, 2025 at 3:39 PM
welltypedwit.ch
i'm so confused by what their politics are? like, misandry, environmentalism, anti-semitisim and anti-antifa are an... interesting combination lol
clearsky post from this person: Decades ago when I worked with Citizen Action and Greenpeace many Americans mocked progressives. Same as this era. Thanks to those who took us in. Soros or antifas were never with us.
October 14, 2025 at 1:19 PM
welltypedwit.ch
OH WAIT NEVERMIND
i did not read this correctly lol. it's 54% *of the 15% that said they were already part of a marginalized group*. so the real answer is just 8.1%, which is *lower* than haskell, wow
We also asked whether respondents consider themselves members of a marginalized community. Out of those who answered, 74.5% selected no, 15.5% selected yes, and 10% preferred not to say.
October 7, 2025 at 11:43 AM
welltypedwit.ch
the python survey didn't ask this exact question, but given this gender ratio, 20% seems... high ^^
Demographics: Gender: Male: 89% Female: 7% Prefer not to say: 3% Non-binary, genderqueer or gender non-conforming: 1%
October 7, 2025 at 10:34 AM
welltypedwit.ch
the rust one is real fwiw (pretty impressive)
blog.rust-lang.org/2025/02/13/2...

the haskell one is... not (as of 2022)
taylor.fausak.me/2022/11/18/h...
from the rust survey results: Which of the following underrepresented or marginalized groups in technology do you consider yourself a part of? lesbian, gay, queer or otherwise non-heterosexual: 54.1% from the state of haskell 2022 results: do you consider yourself a member of an underrepresented or marginalized group in technology? lesbian, gay, bisexual, queer or otherwise non-heterosexual: 10%
October 7, 2025 at 10:23 AM
welltypedwit.ch
haskell yeeaaaahh!! logo (https://wiki.haskell.org/Haskell_logos/New_logo_ideas)
October 6, 2025 at 4:46 PM