Alias for List for Every

[nomisRev]

We've never added an every() aliases because we cannot define multiple (in the same package), but I think I am in favor of adding one for List now. We can only use one, but List is by far the most used Collection in Kotlin so I think it makes sense adding a "special" alias.

However, I found we can also work around this issue by creating the alias in different packages. The problem is JvmName name, but seems to work fine on resolution in Kotlin. Not sure if this was previously not possible, this was tested last with the old inferrer algorithm... 😅

It seems I can define:

package arrow.optics.dsl.list

public val <T, A> Traversal<T, List<A>>.every: Traversal<T, A>
  get() = this.compose(Every.list())

and

package arrow.optics.dsl.sequence

public val <T, A> Traversal<T, Sequence<A>>.every: Traversal<T, A>
  get() = this.compose(Every.sequence())

This seems to completely remove the need to explicitly pass typeclasses instances, since the compiler can resolve the correct package, and thus the instance at the cost of defining them in different packages. WDYT @serras? This can be applied to all type classes in Optics, and users can do the same.

[github-actions[bot]]

Kover Report

File	Coverage [50.00%]
arrow-libs/optics/arrow-optics/src/commonMain/kotlin/arrow/optics/dsl/every.kt	50.00%

Total Project Coverage	61.00%

[serras]

I am not so sure about the package-as-namespace thing... If you need to use both, then the compiler won't be able to figure it out anymore.

Maybe it's useful to define every for list, but also everyInSet, everyInMap for the other main collection types? I agree that the current way of working with it is by no means simple.

[nomisRev]

I am not so sure about the package-as-namespace thing... If you need to use both, then the compiler won't be able to figure it out anymore.

Huh, I tried this yesterday and it resolved fine. The example I shared with sequence, and list. To be honest I was also surprised, but then it got me thinking where I got stuck last time (couple years ago).

So my understanding was that this should resolve correctly, since it turns into a function fun every(original: Traversal<S, List<A>>): Traversal<S, A>, and the compiler can distinct between functions with parameter Traversal<S, List<A>> and Traversal<S, Sequence<A>>.

Since if it can resolve in different package, it should also resolve in the same package, so JvmName should solve it in the same was as the package does.

Guess I need to write it all out, and try 😅 Feel free to take over the PR, and take a STAB (🥁) at it. I probably won't pick this up again until after KotlinConf.