Conversation

I’ve been working for several weeks on Yet Another Haskell Effect System. In this model, effects are literally just typeclasses! I’ve been using this `Can` constraint to make things feel a little more like other effect systems, but I’m starting to wonder if it’s actually useful.

Rakesλ Emmadi

@rakesh_kky

Oct 21, 2019

Hey, have you checked out polysemy library (hackage.haskell.org/package/polyse)? It has similar(not exactly mean same) type notation to express effects. :)

hackage.haskell.org

polysemy

Higher-order, low-boilerplate free monads.

Alexis King

@lexi_lambda

Oct 21, 2019

I have! polysemy is closely related to the freer family of libraries, which provides a `Member` constraint. My library, however, is much faster. :)

Replying to

and

Sounds really cool! How does it compare to fused-effects?

8:40 PM · Oct 21, 2019Twitter Web App

Replying to

and

It’s simpler and slightly faster but slightly less expressive (though not in ways I personally find important). Otherwise there are a lot of similarities… it’s heavily inspired by fused-effects, but it reformulates a lot of the concepts to better cooperate with the optimizer.

Rob Rix‎

@rob_rix

Oct 21, 2019

I’m personally hoping fused-effects can borrow back some of what you’ve learned in the process, too 😊 “let a thousand flowers bloom” doesn’t quite capture my joy at the sort of nonsense we can do in libraries in Haskell!