NonEmptySet: change 2nd param of constructor to `Iterable`. Optimize`nonEmptySetOf` and `toNonEmptySetOrNull`

[hoc081098]

• Change the second param of constructor to Iterable (instead of Set).
• Avoid unnecessary copying in nonEmptySetOf and toNonEmptySetOrNull.

[serras]

I am not really sure what is the optimization here. How are you ensuring that elements are not duplicated when using nonEmptySetOf?

Furthermore, note that we are soon going to make arrow-2 the new main branch. There NonEmptySet is defined differently, using an inline value class. It would be better if optimizations would be applied there, as we don't expect to make any further 1.2.x release.

[hoc081098]

I am not really sure what is the optimization here. How are you ensuring that elements are not duplicated when using nonEmptySetOf?

In constructor, we have used setOf(first) + rest, it returns a Set.

[hoc081098]

• Prev code: res (varargs === Array) -> toSet -> setOf(first) + res uses 2 loops internally.

• After code : res (varargs === Array) -> asList -> setOf(first) + res uses 1 loops internally (because asList does not copy the array to List, but returns a read-only wrapper) 🙏

[hoc081098]

• Prev code: res (varargs === Array) -> toSet -> setOf(first) + res uses 2 loops internally.
• After code : res (varargs === Array) -> asList -> setOf(first) + res uses 1 loops internally (because asList does not copy the array to List, but returns a read-only wrapper) 🙏

I have changed the target branch to arrow-2 branch. @serras Please review it again 🙏

[serras]

@hoc081098 sorry for the unnecesary noise but, would it be possible for you to rebase these changes into the new main? Otherwise it's impossible for us to merge properly this.