// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

export class MonotonicArray<T extends object> {
  #values = new WeakMap<T, number>();
  #nextId = 1;

  getOrInsert = (node: T): number => {
    const value = this.#values.get(node);
    if (value !== undefined) {
      return value;
    }
    this.#values.set(node, this.#nextId);
    this.#nextId++;
    return this.#nextId - 1;
  };
}