Coyoneda Uses in JS

coyo_uses.js

const daggy = require('daggy')
const compose = (f, g) => x => f(g(x))
const id = x => x

//===============Define Coyoneda=========
const Coyoneda = daggy.tagged('x', 'f')

Coyoneda.prototype.map = function(f) {
  return Coyoneda(this.x, compose(f, this.f))
}

Coyoneda.prototype.lower = function() {
  return this.x.map(this.f)
}

Coyoneda.lift = x => Coyoneda(x, id)

//===============Map over a non-Functor - Set =========
const set = new Set([1, 1, 2, 3, 3, 4])

const coyo_result = Coyoneda.lift(set)
                            .map(x => x + 1)
                            .map(x => `${x}!`)

const {f:f, x:our_set} = coyo_result
our_set.forEach(n => console.log(f(n)))
// 2!
// 3!
// 4!
// 5!


//===============Lift a functor in (Array) and achieve Loop fusion=========
Coyoneda.lift([1,2,3])
        .map(x => x * 2)
        .map(x => x - 1)
        .lower()
// [ 1, 3, 5 ]


//===============Make Any Type a Functor=========
const Container = daggy.tagged('x')

const tunacan = Container("tuna")

const res = Coyoneda.lift(tunacan)
                    .map(x => x.toUpperCase())
                    .map(x => x + '!')


const {f: fn, x: can} = res
console.log(fn(can.x))
// TUNA!