SFML/DSFML/import/dsfml/system/linkedlist.d

/*
*   DSFML - SFML Library wrapper for the D programming language.
*   Copyright (C) 2008 Julien Dagorn (sirjulio13@gmail.com)
*   Copyright (C) 2010 Andreas Hollandt
*
*   This software is provided 'as-is', without any express or
*   implied warranty. In no event will the authors be held
*   liable for any damages arising from the use of this software.
*
*   Permission is granted to anyone to use this software for any purpose,
*   including commercial applications, and to alter it and redistribute
*   it freely, subject to the following restrictions:
*
*   1.  The origin of this software must not be misrepresented;
*       you must not claim that you wrote the original software.
*       If you use this software in a product, an acknowledgment
*       in the product documentation would be appreciated but
*       is not required.
*
*   2.  Altered source versions must be plainly marked as such,
*       and must not be misrepresented as being the original software.
*
*   3.  This notice may not be removed or altered from any
*       source distribution.
*/

module dsfml.system.linkedlist;

/*
*   Trivial implementation of Queue linked list (for internal use)
*/
class LinkedList(T)
{
    Node!(T) head;
    Node!(T) tail;
    private size_t m_count;
    
    void enqueue(T object)
    {
        if (empty)
            head = tail = new Node!(T)(object);
        else
        {
            tail.Next = new Node!(T)(object);
            tail = tail.Next;
        }
        m_count++;
    }
    
    T dequeue()
    {
        T o;
        if (empty)
            o = T.init;
        else
        {
            o = head.Data;
            head = head.Next;
            m_count--;
        }    
        return o;
    }
    
    bool empty()
    {
        return (head is null);
    }

    size_t getCount()
    {
        return m_count;
    }

    void clear()
    {
        T data;
        while ((data = dequeue()) !is T.init) {}
    }

    int opApply(int delegate(ref T) dg)
    {
        T data;
        int result;
        while ((data = dequeue) !is T.init)
        {
            if ((result = dg(data)) != 0)
                break;
        }
        return result;
    }
}

private class Node(T)
{
    Node Next;
    T Data;
    
    this(T data)
    {
        Data = data;    
    }
}