bimap.js

class BiMap {
  #k_to_v = new Map();
  #v_to_k = new Map();

  set(key, value) {
    if (this.#k_to_v.get(key) === value) return this;
    this.deleteKey(key);
    this.deleteValue(value);
    this.#k_to_v.set(key, value);
    this.#v_to_k.set(value, key);
    return this;
  }

  get(key) {
    return this.#k_to_v.get(key);
  }

  getByValue(value) {
    return this.#v_to_k.get(value);
  }

  hasKey(key) {
    return this.#k_to_v.has(key);
  }

  hasValue(value) {
    return this.#v_to_k.has(value);
  }

  deleteKey(key) {
    const value = this.#k_to_v.get(key);
    if (value === undefined) return false;
    this.#k_to_v.delete(key);
    this.#v_to_k.delete(value);
    return true;
  }

  deleteValue(value) {
    const key = this.#v_to_k.get(value);
    if (key === undefined) return false;
    this.#v_to_k.delete(value);
    this.#k_to_v.delete(key);
    return true;
  }
}