// from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set#Implementing_basic_set_operations

export function isSuperset<T>(set: Set<T>, subset: Set<T>) {
  for (let elem of subset) {
    if (!set.has(elem)) {
      return false;
    }
  }
  return true;
}

export function union<T>(setA: Set<T>, setB: Set<T>) {
  let _union = new Set(setA);
  for (let elem of setB) {
    _union.add(elem);
  }
  return _union;
}

export function intersection<T>(setA: Set<T>, setB: Set<T>) {
  let _intersection = new Set<T>();
  for (let elem of setB) {
    if (setA.has(elem)) {
      _intersection.add(elem);
    }
  }
  return _intersection;
}

export function symmetricDifference<T>(setA: Set<T>, setB: Set<T>) {
  let _difference = new Set(setA);
  for (let elem of setB) {
    if (_difference.has(elem)) {
      _difference.delete(elem);
    } else {
      _difference.add(elem);
    }
  }
  return _difference;
}

export function difference<T>(setA: Set<T>, setB: Set<T>) {
  let _difference = new Set(setA);
  for (let elem of setB) {
    _difference.delete(elem);
  }
  return _difference;
}