/**
 * @file llist.h
 * (Doubly) Linked lists anchored at both ends
 *
 * $Id$
 *
 * (C) Copyright 2012 flemming.madsen at madsensoft.dk. Notice at end of file
 */

/// Struct mix-in. Use this inside your struct declaration
#define LListField(tn) tn * _llNext; tn * _llPrev

/// Anchor Declaration. Use like: LList(typename) varname;
#define LList(tn) struct { tn *head; tn *tail; int numElm; }

/// List init
#define lListInit(a) ((a)->head = (a)->tail = NULL, (a)->numElm = 0, (a))

/// List empty
#define lListEmpty(a) ((a)->head == NULL)

/// List head
#define lListHead(a) ((a)->head)

/// List tail
#define lListTail(a) ((a)->tail)

/// List length
#define lListLength(a) ((a)->numElm)

/// List element next
#define lListNext(e) ((e)->_llNext)

/// List element prev
#define lListPrev(e) ((e)->_llPrev)

/// Append element e to list e
#define lListAppend(a, e) \
{ \
   if (lListEmpty(a)) (a)->head = (e); \
                 else (a)->tail->_llNext = (e); \
   (e)->_llPrev = (a)->tail; \
   (a)->tail = (e); \
   (e)->_llNext = NULL; \
   (a)->numElm++; \
}

/// Insert element n before element e in list a
#define lListInsertFirst(a, n) lListInsert(a, n, (a)->head)

/// Insert element n before element e in list a
#define lListInsert(a, n, e) \
{ \
   if (!(e) || (a)->head == (e)) { \
      n->_llNext = (a)->head; \
      n->_llPrev = NULL; \
      (a)->head = (n); \
   } else { \
      n->_llNext = (e); \
      n->_llPrev = (e)->_llPrev; \
      (e)->_llPrev->_llNext = n; \
   } \
   if (n->_llNext) n->_llNext->_llPrev = n; \
   (a)->numElm++; \
}

/// Remove element e from list a. Caller must free element.
#define lListRemove(a, e) \
{ \
   if ((a)->head) { \
      if ((e) == (a)->head) (a)->head = (e)->_llNext; \
                   else (e)->_llPrev->_llNext = (e)->_llNext; \
      if ((e) == (a)->tail) (a)->tail = (e)->_llPrev; \
                   else (e)->_llNext->_llPrev = (e)->_llPrev; \
      (a)->numElm--; \
   } \
}

/// Purge list a elements with free()
#define lListPurgeT(a, T) \
{ \
   T p1, p2; \
   for (p1 = (a)->head; p1; ) { \
      p2 = p1; p1 = p1->_llNext; free(p2); \
   } \
   lListInit(a); \
}

/// Remove last element from list a
#define lListRemoveTailT(a, T) \
{ \
   T p; \
   if ((a)->tail) { \
      p = (a)->tail; \
      (a)->tail = (a)->tail->_llPrev; \
      if ((a)->tail) (a)->tail->_llNext = NULL; \
              else (a)->head = NULL; \
      free(p); \
      (a)->numElm--; \
   } \
}

/// Remove first element from list a
#define lListRemoveHeadT(a, T) \
{ \
   T p; \
   if ((a)->head) { \
      p = (a)->head; \
      (a)->head = (a)->head->_llNext; \
      if ((a)->head) (a)->head->_llPrev = NULL; \
              else (a)->tail = NULL; \
      free(p); \
      (a)->numElm--; \
   } \
}

// Convenience
// Only use if you have typeof() eg. gcc
#define lListPurge(a) lListPurgeT(a, typeof((a)->head))
#define lListRemoveTail(a) lListRemoveTailT(a, typeof((a)->head))
#define lListRemoveHead(a) lListRemoveHeadT(a, typeof((a)->head))

/// Traverse the list foreach e in a
#define lListForeachIn(e, a) for (e = (a)->head; e; e = e->_llNext)


/******************************************************************************
* Copyright (C) 2012 flemming.madsen at madsensoft.dk.  All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
******************************************************************************/

// vim: set sw=3 sts=3 et: