cache.js

const p1Cache = f => {
  const store = new Map;
  console.log(store);
  return a => store.has(a) ? store.get(a) : store.set(a, f(a)).get(a);
};

const p2Cache = f => {
  const store = new Map;
  
  return (a, b) => {
    console.log(a, b, store);
    return store.has(a) 
    ? store.get(a).has(b) 
      ? store.get(a).get(b) 
      : store.get(a).set(b, f(a, b)).get(b)
    : store.set(a, new Map).get(a).set(b, f(a, b)).get(b);
  };
};

const p3Cache = f => {
  const store = new Map;
  return (a, b, c) => {
    console.log(store);
    return store.has(a)
    ? store.get(a).has(b)
      ? store.get(a).get(b).has(c)
        ? store.get(a).get(b).get(c)
        : store.get(a).get(b).set(c, f(a, b, c)).get(c)
      : store.get(b).set(b, new Map).get(b).set(c, f(a,b,c))
    : store.set(a, new Map).get(a).set(b, new Map).get(b).get(c, f(a, b, c));
  };
};

const pNCache = f => {
  const store = new Map;
  return (...p) => {
    const len = p.length;
    console.log(store)
    const cp = [...p];
    let chn = store.has(len) ? store.get(len) : store.set(len, new Map).get(len);
    let prop = cp.shift();
    do {
      chn = chn.has(prop) ? chn.get(prop) : chn.set(prop, cp.length ? new Map : f(...p)).get(prop);
    } while (prop = cp.shift());
    return chn;
  };
};