u/edwardkmettin r/haskell • Recommends
Edward Kmett - Monad Homomorphisms - Google Tech Talk @ ZuriHac 2016
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#monads#monadtransformers#haskell
ZuriHac 2016: Monad Homomorphisms
Google TechTalks
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- Presented by Edward Kmett
Advanced. Deep dive for people who know the field.
5.3K views10 years ago1 recommendation
Programming languagesSoftware designHaskellFunctional programmingPerformance and optimization
Edward Kmett explores monad homomorphisms as a solution to the pathological performance problems caused by traditional monad transformer libraries.
A Google TechTalk, July 23, 2016, presented by Edward Kmett ABSTRACT: The way that we use the monad transformer library today leads to code that has pathological performance problems. Can we do better? wiki.haskell.org/ZuriHac2016Why it's here
1 person recommends thisWhat people say. Recommended as a brilliant talk on solving performance issues in Haskell's monad transformer library.
u/tomejaguarin r/haskell • Mentions
Monad transformer optics
Yesterday I asked a question about a certain form of commutation operation for monad transformers. I've followed it a bit further and (re)discovered that you can make optics for monad transformers. See the source file on my GitHub account for full details, but as a taster,
```
type a ~> b = forall r . a r -> b r
type LensLike f s (t :: * -> *) a b = (a ~> f b) -> (s ~> f t)
type ASetter s t a b = (a ~> IdentityT b) -> (s ~> IdentityT t)
lensIdentity
:: (MFunctor t, Monad a, Monad b)
=> (a ~> t b)
-> (IdentityT a ~> t (IdentityT b))
affineState
:: (MonadTrans t, MFunctor t, Monad (t (StateT s b)), Monad a, Monad b)
=> LensLike t (StateT s a) (StateT…