Intro To FP Concepts, part2

script.js

const Maybe = val => {
  return {
    val: val,
    fmap: function(fn) {
      if(this.val === null) return Maybe(null);
      return Maybe(fn(this.val));
    }
  }
};

const map = R.curry((fn, functor) => functor.fmap(fn));

// composing partially applied Ramda functions!
const firstInitial = R.pipe(    
  R.split(" "), 
  R.nth(1), 
  R.nth(0) 
);

const getFirstInitial = map(firstInitial);

// let's try it out
const user = Maybe("Time-traveler Marty McFly");
document.write(getFirstInitial(user).val);     // "M"

const noUser = Maybe(null);
document.write(getFirstInitial(noUser).val)  // null

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.18.0/ramda.min.js"></script>