libobjc/objc/objc-list.h

   1 /* Generic single linked list to keep various information
   2    Copyright (C) 1993, 1994, 1996 Free Software Foundation, Inc.
   3    Contributed by Kresten Krab Thorup.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* As a special exception, if you link this library with files compiled with
  23    GCC to produce an executable, this does not cause the resulting executable
  24    to be covered by the GNU General Public License. This exception does not
  25    however invalidate any other reasons why the executable file might be
  26    covered by the GNU General Public License.  */
  27
  28 #ifndef __GNU_OBJC_LIST_H
  29 #define __GNU_OBJC_LIST_H
  30
  31 struct objc_list {
  32   void *head;
  33   struct objc_list *tail;
  34 };
  35
  36 /* Return a cons cell produced from (head . tail) */
  37
  38 static inline struct objc_list*
  39 list_cons(void* head, struct objc_list* tail)
  40 {
  41   struct objc_list* cell;
  42
  43   cell = (struct objc_list*)objc_malloc(sizeof(struct objc_list));
  44   cell->head = head;
  45   cell->tail = tail;
  46   return cell;
  47 }
  48
  49 /* Return the length of a list, list_length(NULL) returns zero */
  50
  51 static inline int
  52 list_length(struct objc_list* list)
  53 {
  54   int i = 0;
  55   while(list)
  56     {
  57       i += 1;
  58       list = list->tail;
  59     }
  60   return i;
  61 }
  62
  63 /* Return the Nth element of LIST, where N count from zero.  If N
  64    larger than the list length, NULL is returned  */
  65
  66 static inline void*
  67 list_nth(int index, struct objc_list* list)
  68 {
  69   while(index-- != 0)
  70     {
  71       if(list->tail)
  72         list = list->tail;
  73       else
  74         return 0;
  75     }
  76   return list->head;
  77 }
  78
  79 /* Remove the element at the head by replacing it by its successor */
  80
  81 static inline void
  82 list_remove_head(struct objc_list** list)
  83 {
  84   if ((*list)->tail)
  85     {
  86       struct objc_list* tail = (*list)->tail; /* fetch next */
  87       *(*list) = *tail;         /* copy next to list head */
  88       objc_free(tail);                  /* free next */
  89     }
  90   else                          /* only one element in list */
  91     {
  92       objc_free(*list);
  93       (*list) = 0;
  94     }
  95 }
  96
  97
  98 /* Remove the element with `car' set to ELEMENT */
  99
 100 static inline void
 101 list_remove_elem(struct objc_list** list, void* elem)
 102 {
 103   while (*list) {
 104     if ((*list)->head == elem)
 105       list_remove_head(list);
 106     list = &((*list)->tail);
 107   }
 108 }
 109
 110 /* Map FUNCTION over all elements in LIST */
 111
 112 static inline void
 113 list_mapcar(struct objc_list* list, void(*function)(void*))
 114 {
 115   while(list)
 116     {
 117       (*function)(list->head);
 118       list = list->tail;
 119     }
 120 }
 121
 122 /* Return element that has ELEM as car */
 123
 124 static inline struct objc_list**
 125 list_find(struct objc_list** list, void* elem)
 126 {
 127   while(*list)
 128     {
 129     if ((*list)->head == elem)
 130       return list;
 131     list = &((*list)->tail);
 132     }
 133   return NULL;
 134 }
 135
 136 /* Free list (backwards recursive) */
 137
 138 static void
 139 list_free(struct objc_list* list)
 140 {
 141   if(list)
 142     {
 143       list_free(list->tail);
 144       objc_free(list);
 145     }
 146 }
 147 #endif /* not __GNU_OBJC_LIST_H */