polysemy
eff
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polysemy  eff  

6  16  
982  523  
0.6%  1.7%  
4.5  0.8  
about 2 months ago  over 2 years ago  
Haskell  Haskell  
BSD 3clause "New" or "Revised" License  ISC License 
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polysemy

Introduction to Doctests in Haskell
Looking for a few projects that make use of it, I found accelerate, hawk, polysemy and prettysimple, so I'll be interested to poke around in their code and see how they have things set up.

ReaderT pattern is just extensible effects
Right, I think I'll just give it a shot to see. Polysemy is nice but I'm still having trouble getting what I want out of it (which may very well be entirely a fault of my own understanding)

Where's more discussion of the designs of effect systems?
Languages such as Koka only support algebraic effects, not scoping operations such as catch and listen. The Effect Handlers in Scope paper introduces scoping operations, which lead to the Haskell libraries fusedeffects and polysemy, but they turned out to have some weird semantics. eff is her effort to fix that.
 Monthly Hask Anything (June 2021)

Structuring Code with ZIO & ZLayers
*But I'm not terribly well versed in Scala's other DI offerings. I came from Haskell and didn't find anything in Scala that clicked with me until I found ZIO. It reminded me a lot of my favorite way of writing Haskell programs (https://github.com/polysemyresearch/polysemy)â€”albeit with a completely different implementation.
eff

[ANNOUNCE] GHC 9.6.1 is now available
There are also a few subtle issues that arise with delconts related to semantics of higher order effects (see here and here), but they might be solvable.

Effectful  PaweÅ‚ Szulc  Lambda Days 2022
Details are in https://github.com/hasura/eff/issues/12 and https://www.reddit.com/r/haskell/comments/pywuqg/unresolved_challenges_of_scoped_effects_and_what/.

Looking for languages that combine algebraic effects with parallel execution
You'll get fearless parallel with STM in the mixture, and GHC is getting a work in progress effect system for Haskell, as Delimited continuation primops has been merged.

Should I pick up OCaml or Haskell?
My last example is algebraic effects, some of which have been made possible in a both practical and efficient way thanks to extremely recent research, and that I can use to implement architectures like Ports and Adapters or Clean Architecture and have very maintainable code. (Extensible Effects â€” An Alternative to Monad Transformers was published in 2013, Effect Handlers in Scope was published in 2014 and they are behind Polysemy, while there is ongoing work on effects with even better performance, like Eff)

[ANN] cleff  fast and consise extensible effects
cleff's Eff monad is esentially implemented as a ReaderT IO. [...] This is first done by eff, [...]

Opinions on Reader + Continuationbased IO?
Here is link number 1  Previous text "eff"
This is essentially how continuation based effect systems work, check out eveff and eff.

Where's more discussion of the designs of effect systems?
Languages such as Koka only support algebraic effects, not scoping operations such as catch and listen. The Effect Handlers in Scope paper introduces scoping operations, which lead to the Haskell libraries fusedeffects and polysemy, but they turned out to have some weird semantics. eff is her effort to fix that.
While her eff is still under construction, there are relative more mature pieces like Koka etc. I'd very much like to understand how her concerns map to those other effect systems, but can't find more writeups about the design space of effect systems.

The Problem of Effects (2020)
Let me tell you what I'm worried about with effects systems: One of the smartest people I know of has a library called Eff https://github.com/hasura/eff that efficiently implements effects through some modifications to GHC. The thing is, she's pretty much stopped working on because she found some really nasty semantic edgecases that she couldn't resolve to her satisfaction. (I don't understand the problems well enough to describe them, and I think they're specific to lazy languages, but it has left me cautious about the effect model in general.)
What are some alternatives?
fusedeffects  A fast, flexible, fused effect system for Haskell
purescript  A stronglytyped language that compiles to JavaScript
Exercism  Scala Exercises  Crowdsourced code mentorship. Practice having thoughtful conversations about code.
freersimple  A friendly effect system for Haskell
astmonad  A library for constructing AST by using donotation
ghc  Mirror of the Glasgow Haskell Compiler. Please submit issues and patches to GHC's Gitlab instance (https://gitlab.haskell.org/ghc/ghc). First time contributors are encouraged to get started with the newcomers info (https://gitlab.haskell.org/ghc/ghc/wikis/contributing).
haskell.nix  Alternative Haskell Infrastructure for Nixpkgs
frpzoo  Comparing many FRP implementations by reimplementing the same toy app in each.
linear  Lowdimensional linear algebra primitives for Haskell.
extensibleeffects  Extensible Effects: An Alternative to Monad Transformers