frontmen-workshop/41-example.js at master · Blockshot12/frontmen-workshop · GitHub

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class Maybe {
  constructor(val, nothing) {
    this.nothing = nothing ? true : false;
    this.value = nothing ? null : val;
  }

  static of(val) {
    return new Maybe(val);
  }

  static nothing() {
    return new Maybe(null, true);
  }

  map(fn) {
    return this.nothing ? this : new Maybe(fn(this.value));
  }

  chain(valToMaybe) {
    return this.nothing ? this : valToMaybe(this.value);
  }
}

const obj = {
  address:
    Math.random() < 0.5
      ? null
      : {
          street:
            Math.random() < 0.5
              ? null
              : {
                  num: Math.random() < 0.5 ? null : '17'
                }
        }
};

// Use chain to pick obj.address.street.num