@finos/legend-shared/src/data-structure/Stack.ts

Legend Studio shared utilities and helpers

/**
 * Copyright (c) 2020-present, Goldman Sachs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

interface StackInterface<T> {
  push(item: T): void;
  pop(): T | undefined;
  peek(): T | undefined;
  size(): number;
}

export class Stack<T> implements StackInterface<T> {
  private storage: T[] = [];

  push(item: T): void {
    this.storage.push(item);
  }

  pop(): T | undefined {
    return this.storage.pop();
  }

  peek(): T | undefined {
    return this.storage[this.size() - 1];
  }

  peekAll(): T[] {
    return [...this.storage];
  }

  size(): number {
    return this.storage.length;
  }

  clone(): Stack<T> {
    const stack = new Stack<T>();
    this.storage.forEach((item) => stack.push(item));
    return stack;
  }
}