eff
🚧 a work in progress effect system for Haskell 🚧 (by hasura)
mtl-style-example
A small example of using mtl style to unit test effectful code (by lexi-lambda)
eff | mtl-style-example | |
---|---|---|
18 | 2 | |
557 | 107 | |
0.0% | 0.9% | |
0.0 | 0.0 | |
about 2 years ago | over 7 years ago | |
Haskell | Haskell | |
ISC License | ISC License |
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
eff
Posts with mentions or reviews of eff.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2023-07-12.
-
Haskellers who moved to Rust: What has been your experience?
You can swap-out implementations for testing, avoid the crazy N^2 instances issues, etc. They're pretty cool. Currently there are many competing libraries. polysemy and eff both have good examples on their homepages.
-
What are the current hot topics in type theory and static analysis?
Effect systems and Algebraic effects. ocaml has just released a stripped-down effect system. People are also working on Effect systems for Haskell (eff, fused-effects, effet). Koka is a language built with effects first and foremost and it’s rapidly gaining popularity. Unison also has effects.
-
[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 | Paweł 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 — 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 + Continuation-based IO?
Here is link number 1 - Previous text "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 fused-effects and polysemy, but they turned out to have some weird semantics. eff is her effort to fix that.
-
Languages that don't support Error-Catching 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).
mtl-style-example
Posts with mentions or reviews of mtl-style-example.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2023-03-17.
-
Haskell ecosystem questions.
Re: effects libraries, it's probably worth starting with e.g. https://www.fpcomplete.com/blog/2017/06/readert-design-pattern/ https://www.parsonsmatt.org/2018/03/22/three_layer_haskell_cake.html https://github.com/lexi-lambda/mtl-style-example if you're just getting familiar with the ecosystem. I'll add, anything written by the the people I linked to in this comment is probably worth reading as well.
-
I’ve tried to learn Haskell several times. But keep failing
Personally, it felt to me like, once I really understood monad transformers (https://hackage.haskell.org/package/transformers) and mtl (https://hackage.haskell.org/package/mtl), the reasons they both exist and how they are distinct, how you use them generally and what common patterns are around structuring your app (see e.g. https://github.com/lexi-lambda/mtl-style-example and the 3-layer-cake link someone else provided here for two), a lot of stuff in the ecosystem suddenly became comprehensible and useful to me, in a practical, "real world" way. In fact I'd go so far as to assert that getting comfortable with mtl in particular is the biggest single step you can take to being able to build arbitrarily useful real-world apps that are no longer toys.
What are some alternatives?
When comparing eff and mtl-style-example you can also consider the following projects:
frp-zoo - Comparing many FRP implementations by reimplementing the same toy app in each.
effectful - An easy to use, fast extensible effects library with seamless integration with the existing Haskell ecosystem.
freer-simple - A friendly effect system for Haskell
haskellweekly - Publishes curated news about the Haskell programming language.
fused-effects - A fast, flexible, fused effect system for Haskell
scrabble - An extended tutorial/book on Haskell development. A library for playing Scrabble is developed as well as two clients, one of which is networked and allows for remote one or two-player games over the web.