Open for review 😁

Can someone who understands comonads and more specifically cobindings help me understand

cobinding

or

coflatmap

? I am currently looking at the

cobinding

test, because with https://github.com/arrow-kt/arrow/pull/1844 the input data test coverage is higher and it showed a bug when used with

NonEmptyList

of size greater than 1. But tbh: I have no idea what's even going on there 😅

I wrote that

IIRC

now, cobinding should be broken af

as in, do not touch levels of broken

lemme check coflatmap

right, so coflatmap

a: A

{ a }: Kind<ForFunction0, A>

{ b -> { a } }: Kind<ForFunction0, B> this one is wrong

wait no, fuck

how was this

ye

{ a }.coflatMap { makeBFromA(it()) }

it executes A

in the case of lists, it’ll use extract to get the head

or something like that

while in monad you avoid executing/extract, in here it’s encouraged

Good to see that this method is just as weird as I thought it is 😉 Sorta looks like contravariant

it is part of the contravariant family

Ok I think I somehow get the function0 example, but this is still very arcane with nel because it actually iterates the nel from what I can tell

let’s check

right?

no, wait

that’s a Nel<B> inside, it has to be B

a.fold(::plus, 0)

?