tom-weatherhead/common-utilities.ts

// github:tom-weatherhead/common-utilities.ts/src/collection-classes/stack.ts

import { CollectionArrayBase } from './collection-array-base';

// import { ICollection, IImmutableCollection } from './icollection';

import { IStack } from './interfaces/istack';

// export interface IImmutableStack<T> extends IImmutableCollection<T> {
//     clone(): Stack<T>;
//     peek(): T;
// }
//
// export interface IStack<T> extends ICollection<T>, IImmutableStack<T> {
//     push(item: T): void;
//     pop(): T;
// }

export class Stack<T> extends CollectionArrayBase<T> implements IStack<T> {
    // Fields (private member data)

    // Constructor

    // Fundamental methods

    // Accessors

    // Other public methods

    public clone(): Stack<T> {
        // Creates a shallow copy

        return new Stack<T>(this);
    }

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

    public pop(): T {
        const result = this.items.pop();

        if (typeof result === 'undefined') {
            // throw new EmptyStackException();
            throw new Error('Stack.pop() : Stack underflow: The stack is empty.');
        }

        return result;
    }

    public peek(): T {
        if (this.isEmpty()) {
            // throw new EmptyStackException();
            throw new Error('Stack.peek() : The stack is empty.');
        }

        return this.items[this.items.length - 1];
    }

    protected protectedAdd(item: T): boolean {
        this.push(item);

        return true;
    }

    // Private methods
}