eff
polysemy
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eff  polysemy  

11  4  
476  922  
0.0%  3.3%  
0.2  7.1  
about 1 year ago  5 days ago  
Haskell  Haskell  
ISC License  BSD 3clause "New" or "Revised" License 
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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.

Languages that don't support ErrorCatching as a Control Structure?
There are a few languages that have algebraic effect systems, most notably Haskell, but these systems are implemented as libraries, not baked into the language (which can have advantages and disadvantages).

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.)

Thoughts on polysemy?
eff was supposed to solve (some of) the above problems, but it's stalled now.

A solid GUI Framework for Haskell?
Why do you need a GUI library, if you can write your application using extensible effects frameworks, just choose any and enjoy!
 Monthly Hask Anything (June 2021)

I’ve tried to learn Haskell several times. But keep failing
It means that you can see a type signature like this and you know immediately how it will provide what you want in the context of an arbitrary monad "stack." It means that when you are looking to understand how to use e.g. MegaParsec it doesn't surprise you that the discussion of the relevant monads is the first thing in the tutorial. It means you know why this exists https://hackage.haskell.org/package/scotty0.12/docs/WebScottyTrans.html and maybe you can even fumble through https://docs.servant.dev/en/stable/cookbook/hoistserverwithcontext/HoistServerWithContext.html and use it in your app even if you don't otherwise understand all the typelevel magic happening in Servant. You'll also understand what to do if you're faced with a type signature in IO or Maybe or whatever concrete monad and you have to integrate it with a more generalized monad. You may also start to understand why everyone is so interested in effect systems.
polysemy

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)

Trouble Reinterpreting Higher Order Effects in PolySemy
Looking at the interpreter for Reader might give some clues if this doesn't work. https://github.com/polysemyresearch/polysemy/blob/master/src/Polysemy/Reader.hs#L38L45

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)—albeit with a completely different implementation.
What are some alternatives?
fusedeffects  A fast, flexible, fused effect system for Haskell
Exercism  Scala Exercises  Crowdsourced code mentorship. Practice having thoughtful conversations about code.
purescript  A stronglytyped language that compiles to JavaScript
freersimple  A friendly effect system for Haskell
astmonad  A library for constructing AST by using donotation
linear  Lowdimensional linear algebra primitives for Haskell.
frpzoo  Comparing many FRP implementations by reimplementing the same toy app in each.
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).
liquidhaskell  Liquid Types For Haskell
extensibleeffects  Extensible Effects: An Alternative to Monad Transformers