interpreters/nitfol/linkevil.h

   1 /*  Evil linked-list implementation in C with macros
   2
   3     Copyright (C) 1999  Evin Robertson
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  18
  19     The author can be reached at ecr+@andrew.cmu.edu
  20 */
  21
  22
  23 #define LEaddm(list, member, mallocfunc) do {                              \
  24                               void *temppointer = list;       \
  25                               list = mallocfunc(sizeof(*list)); \
  26                               *list = member;                 \
  27                               list->next = temppointer;       \
  28                             } while(0)
  29
  30 #define LEadd(list, member) LEaddm(list, member, n_malloc)
  31
  32 #define LEremovem(list, freefunc)  do {                       \
  33                               if(list) {                      \
  34                                 void *temppointer = list;     \
  35                                 list = list->next;            \
  36                                 freefunc(temppointer);        \
  37                               }                               \
  38                             } while(0);
  39
  40 #define LEremove(list) LEremovem(list, n_free)
  41
  42
  43 #define LEdestructm(list, destruct, freefunc) do {            \
  44                               while(list) {                   \
  45                                 void *temppointer = list;     \
  46                                 destruct;                     \
  47                                 list = list->next;            \
  48                                 freefunc(temppointer);        \
  49                               }                               \
  50                             } while(0)
  51
  52 #define LEdestruct(list, destruct) LEdestructm(list, destruct, n_free)
  53
  54 #define LEdestroym(list, freefunc) LEdestructm(list, , freefunc)
  55
  56 #define LEdestroy(list) LEdestroym(list, n_free)
  57
  58
  59 #define LEsearch(list, dest, cond)                            \
  60                             do {                              \
  61                               for(dest = list; dest; dest=dest->next)  \
  62                                 if(cond) break;               \
  63                             } while(0)
  64
  65 /* temp != NULL if it successfully performed the removal */
  66 #define LEsearchremovem(list, dest, temp, cond, destruct, freefunc) \
  67                             do {                              \
  68                               dest = list;                    \
  69                               if(dest && (cond)) {            \
  70                                 temp = dest;                  \
  71                                 destruct;                     \
  72                                 LEremovem(list, freefunc);    \
  73                               } else {                        \
  74                                 for(temp = list; temp; temp=temp->next) { \
  75                                   dest=temp->next;            \
  76                                   if(dest && (cond)) {        \
  77                                     temp->next = dest->next;  \
  78                                     destruct;                 \
  79                                     freefunc(dest);           \
  80                                   }                           \
  81                                 }                             \
  82                               }                               \
  83                             } while(0)
  84
  85 #define LEsearchremove(list, dest, temp, cond, destruct) LEsearchremovem(list, dest, temp, cond, destruct, n_free)
  86
  87 #define LEappend(dest, src) do {                              \
  88                               void *temppointer = dest;       \
  89                               if(dest) {                      \
  90                                 while(dest->next)             \
  91                                   dest = dest->next;          \
  92                                 dest->next = src;             \
  93                                 dest = temppointer;           \
  94                               } else {                        \
  95                                 dest = scr;                   \
  96                               }                               \
  97                             } while(0)
  98
  99
 100
 101
 102 /* This is just an example: */
 103 #if 0
 104
 105 /*
 106 Use: Declare a struct like this:
 107 */
 108 typedef struct {
 109   struct mylist *next;     /* The evil linked list library depends on this */
 110   int myint;
 111   char *mystring;
 112 } mylist;
 113
 114
 115 void foo() {
 116   mylist *foo = NULL;
 117   mylist *found;
 118   mylist *another = NULL;
 119
 120   mylist mymember1 = { NULL, 42, "frogs" };
 121   mylist mymember2 = { NULL, 38, "potato" };
 122   mylist mymember3 = { NULL, 21, "monkey" };
 123
 124   LEremove(foo);           /* Remove nonexistent head element - this is safe */
 125
 126   LEadd(foo, mymember1);   /* Add an element to the head */
 127   LEadd(foo, mymember2);   /* Add another element to the head */
 128   LEadd(foo, mymember3);
 129   LEadd(foo, mymember1);
 130
 131   LEremove(foo);           /* Remove the head element */
 132
 133   LEsearch(foo, found, (strcmp(found->mystring, "potato") == 0));
 134
 135   LEdup(another, found);
 136
 137   LEdestroy(foo);
 138
 139   LEadd(foo, mymember3);
 140
 141   LEprepend(another, foo);
 142 }
 143
 144 #endif