Adding Nes and Nec equivalents of Nel functions

[calvinbrown085]

addresses #2539

We might need to merge #2475 first because our changes are going to overlap each other, happy to merge the previous PR then fix conflicts in my branch.

[codecov-io]

Codecov Report

Merging #2543 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2543      +/-   ##
==========================================
+ Coverage   95.17%   95.18%   +<.01%     
==========================================
  Files         359      359              
  Lines        6553     6561       +8     
  Branches      278      278              
==========================================
+ Hits         6237     6245       +8     
  Misses        316      316

Impacted Files	Coverage Δ
core/src/main/scala/cats/data/package.scala	88.88% <ø> (ø)	⬆️
core/src/main/scala/cats/data/Ior.scala	98.54% <100%> (+0.02%)	⬆️
core/src/main/scala/cats/syntax/either.scala	99.26% <100%> (+0.03%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 15f4e59...c693d66. Read the comment docs.

[kubukoz]

#2475 merged :)

[calvinbrown085]

@kubukoz Thanks! I'll clean my PR up

[calvinbrown085]

@kubukoz Hi! I think this is ready for review

[calvinbrown085]

Do we need 2 +1's from reviewers with write access to merge? Not sure how that works, thanks!

[ceedubs]

Thanks @calvinbrown085!

Sorry but I have to ask: are we confident in Nes referring to NonEmptySet? I was thinking that it would stand for NonEmptyStream before I started looking through the code.

[calvinbrown085]

Hrm, that is a good point. I guess I assumed NonEmptySet but I can see either way! Looking at this comment by @kubukoz #2475 (comment) it seems like he was referring to NonEmptySet but he might have to clarify

[kubukoz]

I was referring to NonEmptySet, but I didn't realize there was NonEmptyStream too. I don't think we should have these short names in that case, as NES is ambiguous.

…

On Fri, Oct 5, 2018, 15:32 Calvin Brown ***@***.***> wrote: Hrm, that is a good point. I guess I assumed NonEmptySet but I can see either way! Looking at this comment by @kubukoz <https://github.com/kubukoz> #2475 (comment) <#2475 (comment)> it seems like he was referring to NonEmptySet but he might have to clarify — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#2543 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AA2npOuqH6bxQembah6Idb8ulek-nHcNks5uh19-gaJpZM4XAlyF> .

[LukaJCB]

That's unfortunate, we do already have some precedent with toNes and groupByNes refering to NonEmptySet.