Stack.cpp

//
// Created by brett on 06/02/18.
//

#include <iostream>
#include "Stack.h"


/**
 * Default Construction Function for a Stack.
 */
Stack::Stack() : _top(nullptr) { }

/**
 * Custom Destruction Function for a Stack. Loop while _top != nullptr and Pop().
 */
Stack::~Stack() {
    while (_top != nullptr) {
        Pop();
    }
}

/**
 * Push a new Point to the Stack.
 * @param data Stack being pushed to Stack.
 */
void Stack::Push(Point data) {
    _top = new StackNode(data, _top);
}

/**
 * Peek into the Stack and return the current _top Point.
 * @return Point from the topmost StackNode.
 */
Point Stack::Peek() {
    return _top->getPoint();
}

void Stack::Pop() {
    if (_top != nullptr) {
        StackNode* node = _top;
        _top = _top->getNext();
        delete node;
    } else {
        std::cerr << "error: can not Pop() an empty Stack!" << std::endl;
    }
}

/**
 * Checks if the Stack is empty.
 * @return Boolean if _top is a nullptr.
 */
bool Stack::empty() {
    return _top == nullptr;
}

/**
 * Return the topmost Point from the Stack.
 * @return Point from the topmost portion of Stack.
 */
Point Stack::getTop() {
    return _top->getPoint();
}