javascript - Can this be refactored to use generic functional principles?

Question

A comparator function ascending accepts two arguments - a and b. It must return an integer comparing the two.

I have a list that I want to sort by name, so I wrote the following functions.

Is there a functional idiom I can use to combine these two functions, rather than having byName take responsibility for composing the resulting function?

const ascending = (a, b) => a.localeCompare(b);
const byName = (i) => i.get('name');
const useTogether = (...fns) => ...; // is there an idiomatic function like this?

// usage
items.sort(useTogether(byName(ascending))); 

Answer 1

You're looking for contravariant functors

To appreciate them properly, let's start by examining the most basic sorting program

const compare = (a, b) =>
  a.localeCompare (b)

const data =
  [ 'Cindy'
  , 'Alice'
  , 'Darius'
  , 'Bertrand'
  ]
  
data.sort (compare)

console.log (data)
// Alice, Bertrand, Cindy, Darius