eff VS linear

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.

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.

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.

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/.

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.

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)

cleff's Eff monad is esentially implemented as a ReaderT IO. [...] This is first done by eff, [...]

Here is link number 1 - Previous text "eff"

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.

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).

Linear.Quaternion.Quaterion from the linear package has a Num instance, and quaternion multiplication is noncommutative.

That's pretty much exactly the abstraction used in the 'linear' package's Affine class, in which we find points separated by vectors.

Linear algebra: hmatrix again with its own array type (and linear but this is restricted to low dimensions)

This is very niche, but something I've wanted to do for a while is to generate some cool physics example on the surface of a sphere with https://hackage.haskell.org/package/hamilton, and display it with https://reanimate.github.io/ (using https://hackage.haskell.org/package/linear for the projection)

Do check out the linear package. It has some complicated parts, but the types work out very nicely. Your Coords type is called V3 in that package, it has a huge list of instances for all kinds of different type classes.

I've come to love the linear approach, where instead of working with Naperian (Representable) functors, you work with Distributive functors.

See also the linear library, it contains types like data V3 a = V3 a a a with all of the useful instances.