effectful VS ghcup-hs

Also a much simpler alternative in my opinion to monad transformers is effectful:

https://github.com/haskell-effectful/effectful

Here's a talk on it:

https://www.youtube.com/watch?v=BUoYKBLOOrE

effectful got rid of all issues I listed (I expanded a little on it here).

There is also a long document on Issues with the Transformer/mtl library.

cats-effects -> https://github.com/haskell-effectful/effectful

I think ReaderT over IO or an algebraic effect system that uses it under the hood like effectful is the way to go. However, you mentioned redux, so perhaps you'd be comfortable with organizing things using TEA (the elm architecture)? You would have actions that different components listen to , and your async stuff could be handled using subscriptions.

API for basic usage is very similar, but things quickly go south once you want to use higher order effects (i.e. effects that make use of the m type parameter). A lot of things then become very hard to write due to complex types or outright impossible (this issue is a good example - a reasonable thing to do that is very straightforward to write with effectful, apparently impossible to do with polysemy).

> Lets say you have a huge overly-convoluted Haskell program. Somewhere deep down a call hierachy of pure functions you need to print something to the console. That is not easy to refactor.

> Or vice-versa you have a huge convoluted program where everything happens inside an IO monad because at some point something is written to the console. Now you realize you dont need to write to the console.

These problems are essentially completely resolved these days by a modern effect system like effectful. Basically, they allow you to do arbitrary effects deep down a call stack with minimal plumbing (you still have adjust the types, as you should: that's the point of effect tracking!) and also to remove effects, so you can easily convert between pure code and "effectful code that just so happens to do no effects".

https://github.com/haskell-effectful/effectful

Also note that Polysemy has some really bad performance characteristics. Don't know how much of a problem it could be at such a small scale, but if you need to use an effect system, maybe something faster like effectful would be a better choice.

See also https://github.com/haskell-effectful/effectful/issues/99.

FYI, transformers and mtl have several subtle traps. You can read about them here.

I'd recommend using ghcup to install Haskell nowadays. (https://www.haskell.org/ghcup/) It makes it easy to install and switch versions of the compiler, language server, and build tools.

The compiler now shows more helpful error messages and GHCup allows us to manage multiple versions of GHC, Stack, and HLS (Haskell Language Server) in a breeze. Compilation time is faster now, but I believe it is because hardware has become faster over the years. Unfortunately, cross-compiling is not yet as simple.

Install Haskell using GHCup. In days of old installing Haskell used to be a pain, but nowadays Haskell comes with a self-isolated thing call ghcup - you install it once, and then it installs the rest of the universe in its own isolated directory that can be independently deleted or updated without affecting the rest of your system.

Try this https://www.haskell.org/ghcup/ but with Window's WSL2.

I've downloaded GHCup, hls and stack from the command from this link https://www.haskell.org/ghcup/

The instructions to install ghcup are here: https://www.haskell.org/ghcup/

I have been using helix with ghcup installed ghc(s) and language servers. It works with Haskell out of box, no configuration necessary. Helix is a modal editor, similar to but distinctly different from the vi family. Although a long time vim user I have found the switch to helix not too difficult and definitely worth the trouble.

What method were you thinking of using? The recommended method is ghcup