Maybe.js

const Maybe = {
  of (val) {
    return val === null || val === undefined ? new Nothing : new Just(val)
  },

  catMaybes(xs) {
    return xs
      .filter(x => x instanceof Just)
      .map(x => x.unwrap())
  }
}

class Nothing {
  map(fn) {
    return new Nothing;
  }

  unwrap() {
    throw Error('attempted to unwrap Nothing')
  }
}

class Just {
  constructor(val) {
    this.val = val;
  }
  map(fn) {
    return Maybe.of(fn(this.val))
  }

  unwrap() {
    return this.val;
  }

}

const query = table => where => order => limit =>
  Maybe.catMaybes([
    Maybe.of(`select * from ${table}`),
    Maybe.of(where).map(w => ` where ${w}`),
    Maybe.of(order).map(o => ` order by ${o}`),
    Maybe.of(limit).map(l => ` limit ${l}`)
  ]).join('')

const albums = query(`albums`);
const queenAlbums = albums(`artist = 'Queen'`);

console.log(queenAlbums(`title`)(1))