@Leo how d o I index into the existing sequence in fix?

Hmmmmm, I'll need more details to answer this

@Leo codegolf.stackexchange.com/a/223708/80214 this except using fix

You might be able to use plain recursion instead

Oh wait nvm

That'd probably turn out longer

plain recursion is longer

:(

onixes may come in handy here?

might

Honestly I don't even know how it works

@user lets say you have a function which returns values from an array

instead of the values it gives indices

Not sure how you'd get the n in the fix, perhaps using Ẋ,?

@Razetime I don't understand :(

Does it just find the index of an element?

So it wouldn't work with duplicate elements?

take any higher order function

say m

m maps each thing to a different thing right

Yeah

when you add onixes

it tries to get the values and tries to relate them to indices

now on f

it filters things right

Yeah

so onixes f

takes the truthy elements

@Razetime Wait so what would ηm do to a list?

and returns the indices

Oh

Truthy according to which function, though? edit: nvm

@user leave it as is

since there's no relation between indices and the result

@user plain truthy /falsy

when you add onixes you can't add a predicate afaik

Ah

I guess onixes won't work, but what about using Ẋe to group adjacent pairs, then use z to zip with the index aka n and do n - a(?)? Then at the end you could use fork to index into the original list

hmm

sounds complicated

might work

I'm working on a Haskell version but it isn't working :(

Goes into a loop

not very good at haskell

gotta wait for leo

Yeah