'use strict';

const getter = (prop) => (obj) => obj[prop];
const setter = (prop) => (val, obj) => ({ ...obj, [prop]: val });

const over = (lens, map, obj) => lens.set(map(lens.get(obj)), obj);

const lens = (getter, setter) => ({
  get: (obj) => getter(obj),
  set: (val, obj) => setter(val, obj),
});

// Usage

const person = {
  name: 'Marcus Aurelius',
  city: 'Rome',
  born: 121,
};

const nameLens = lens(getter('name'), setter('name'));

const upper = (s) => s.toUpperCase();

console.log('over name:', over(nameLens, upper, person));