src/list.h

   1 /*
   2  * list.h: Simple generic list manipulation
   3  *
   4  * Copyright (C) 2007-2015 David Lutterkort
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
  19  *
  20  * Author: David Lutterkort <dlutter@redhat.com>
  21  */
  22
  23 #ifndef LIST_H_
  24 #define LIST_H_
  25
  26 #define list_append(head, tail)                                         \
  27     do {                                                                \
  28         if ((head) == NULL) {                                           \
  29             head = tail;                                                \
  30             break;                                                      \
  31         }                                                               \
  32         typeof(head) _p;                                                \
  33         for (_p = (head); _p->next != NULL; _p = _p->next);             \
  34         _p->next = (tail);                                              \
  35     } while (0)
  36
  37 #define list_for_each(iter, list)                                       \
  38     for (typeof(list) (iter) = list; (iter) != NULL; (iter) = (iter)->next)
  39
  40 #define list_remove(elt, list)                                          \
  41     do {                                                                \
  42         typeof(elt) _e = (elt);                                         \
  43         if (_e == (list)) {                                             \
  44             (list) = _e->next;                                          \
  45         } else {                                                        \
  46             typeof(_e) _p;                                              \
  47             for (_p = (list); _p != NULL && _p->next != _e; _p = _p->next); \
  48             if (_p != NULL)                                             \
  49                 _p->next = _e->next;                                    \
  50         }                                                               \
  51         _e->next = NULL;                                                \
  52     } while(0)
  53
  54 /* Insert NEW in list LIST before element AC. NEW->next must be null,
  55    and ELT must really be on LIST, otherwise chaos will ensue
  56 */
  57 #define list_insert_before(new, elt, list)                              \
  58     do {                                                                \
  59         if ((list) == NULL) {                                           \
  60             (list) = (new);                                             \
  61         } else if ((elt) == (list)) {                                   \
  62             (new)->next = (elt);                                        \
  63             (list) = (new);                                             \
  64         } else {                                                        \
  65             typeof(elt) _p;                                             \
  66             for (_p = (list); _p != NULL && _p->next != (elt); _p = _p->next); \
  67             if (_p != NULL) {                                           \
  68                 (new)->next = (elt);                                    \
  69                 _p->next = (new);                                       \
  70             }                                                           \
  71         }                                                               \
  72     } while(0)
  73
  74 #endif
  75
  76 #define list_free(list)                                                 \
  77     while ((list) != NULL) {                                            \
  78         typeof(list) _p = list;                                         \
  79         (list) = (list)->next;                                          \
  80         free((void *) _p);                                              \
  81     }
  82
  83 #define list_length(len, list)                                          \
  84     do {                                                                \
  85         typeof(list) _p;                                                \
  86         for (len=0, _p = (list); _p != NULL; len += 1, _p = _p->next);  \
  87     } while(0)
  88
  89 /* Make ELT the new head of LIST and set LIST to it */
  90 #define list_cons(list, elt)                                            \
  91     do {                                                                \
  92         typeof(elt) _e = (elt);                                         \
  93         _e->next = (list);                                              \
  94         (list) = _e;                                                    \
  95     } while(0)
  96
  97 #define list_reverse(list)                                              \
  98     do {                                                                \
  99         typeof(list) _head = (list);                                    \
 100         typeof(list) _prev = NULL;                                      \
 101         while (_head != NULL) {                                         \
 102             typeof(list) _next = _head->next;                           \
 103             _head->next = _prev;                                        \
 104             _prev = _head;                                              \
 105             _head = _next;                                              \
 106         }                                                               \
 107         (list) = _prev;                                                 \
 108     } while (0)
 109
 110 /* Append ELT to the end of LIST. TAIL must be NULL or a pointer to
 111    the last element of LIST. ELT may also be a list
 112 */
 113 #define list_tail_cons(list, tail, elt)                                 \
 114     do {                                                                \
 115         /* Append ELT at the end of LIST */                             \
 116         if ((list) == NULL) {                                           \
 117             (list) = (elt);                                             \
 118         } else {                                                        \
 119             if ((tail) == NULL)                                         \
 120                 for ((tail) = (list); (tail)->next != NULL;             \
 121                      (tail) = (tail)->next);                            \
 122             (tail)->next = (elt);                                       \
 123         }                                                               \
 124         /* Make sure TAIL is the last element on the combined LIST */   \
 125         (tail) = (elt);                                                 \
 126         if ((tail) != NULL)                                             \
 127             while ((tail)->next != NULL)                                \
 128                 (tail) = (tail)->next;                                  \
 129     } while(0)
 130
 131 /*
 132  * Local variables:
 133  *  indent-tabs-mode: nil
 134  *  c-indent-level: 4
 135  *  c-basic-offset: 4
 136  *  tab-width: 4
 137  * End:
 138  */