summary refs log tree commit diff stats
path: root/libs/cocos2d/Support/utlist.h
blob: 34c725b917dd60d13044afe105b2e1aae6bb4d92 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
/*
Copyright (c) 2007-2010, Troy D. Hanson   http://uthash.sourceforge.net
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef UTLIST_H
#define UTLIST_H

#define UTLIST_VERSION 1.9.1

/* 
 * This file contains macros to manipulate singly and doubly-linked lists.
 *
 * 1. LL_ macros:  singly-linked lists.
 * 2. DL_ macros:  doubly-linked lists.
 * 3. CDL_ macros: circular doubly-linked lists.
 *
 * To use singly-linked lists, your structure must have a "next" pointer.
 * To use doubly-linked lists, your structure must "prev" and "next" pointers.
 * Either way, the pointer to the head of the list must be initialized to NULL.
 * 
 * ----------------.EXAMPLE -------------------------
 * struct item {
 *      int id;
 *      struct item *prev, *next;
 * }
 *
 * struct item *list = NULL:
 *
 * int main() {
 *      struct item *item;
 *      ... allocate and populate item ...
 *      DL_APPEND(list, item);
 * }
 * --------------------------------------------------
 *
 * For doubly-linked lists, the append and delete macros are O(1)
 * For singly-linked lists, append and delete are O(n) but prepend is O(1)
 * The sort macro is O(n log(n)) for all types of single/double/circular lists.
 */

/* These macros use decltype or the earlier __typeof GNU extension.
   As decltype is only available in newer compilers (VS2010 or gcc 4.3+
   when compiling c++ code), this code uses whatever method is needed
   or, for VS2008 where neither is available, uses casting workarounds. */
#ifdef _MSC_VER            /* MS compiler */
#if _MSC_VER >= 1600 && defined(__cplusplus)  /* VS2010 or newer in C++ mode */
#define LDECLTYPE(x) decltype(x)
#else                     /* VS2008 or older (or VS2010 in C mode) */
#define NO_DECLTYPE
#define LDECLTYPE(x) char*
#endif
#else                      /* GNU, Sun and other compilers */
#define LDECLTYPE(x) __typeof(x)
#endif

/* for VS2008 we use some workarounds to get around the lack of decltype,
 * namely, we always reassign our tmp variable to the list head if we need
 * to dereference its prev/next pointers, and save/restore the real head.*/
#ifdef NO_DECLTYPE
#define _SV(elt,list) _tmp = (char*)(list); {char **_alias = (char**)&(list); *_alias = (elt); }
#define _NEXT(elt,list) ((char*)((list)->next))
#define _NEXTASGN(elt,list,to) { char **_alias = (char**)&((list)->next); *_alias=(char*)(to); }
#define _PREV(elt,list) ((char*)((list)->prev))
#define _PREVASGN(elt,list,to) { char **_alias = (char**)&((list)->prev); *_alias=(char*)(to); }
#define _RS(list) { char **_alias = (char**)&(list); *_alias=_tmp; }
#define _CASTASGN(a,b) { char **_alias = (char**)&(a); *_alias=(char*)(b); }
#else 
#define _SV(elt,list)
#define _NEXT(elt,list) ((elt)->next)
#define _NEXTASGN(elt,list,to) ((elt)->next)=(to)
#define _PREV(elt,list) ((elt)->prev)
#define _PREVASGN(elt,list,to) ((elt)->prev)=(to)
#define _RS(list)
#define _CASTASGN(a,b) (a)=(b)
#endif

/******************************************************************************
 * The sort macro is an adaptation of Simon Tatham's O(n log(n)) mergesort    *
 * Unwieldy variable names used here to avoid shadowing passed-in variables.  *
 *****************************************************************************/
#define LL_SORT(list, cmp)                                                                     \
do {                                                                                           \
  LDECLTYPE(list) _ls_p;                                                                       \
  LDECLTYPE(list) _ls_q;                                                                       \
  LDECLTYPE(list) _ls_e;                                                                       \
  LDECLTYPE(list) _ls_tail;                                                                    \
  LDECLTYPE(list) _ls_oldhead;                                                                 \
  LDECLTYPE(list) _tmp;                                                                        \
  int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping;                       \
  if (list) {                                                                                  \
    _ls_insize = 1;                                                                            \
    _ls_looping = 1;                                                                           \
    while (_ls_looping) {                                                                      \
      _CASTASGN(_ls_p,list);                                                                   \
      _CASTASGN(_ls_oldhead,list);                                                             \
      list = NULL;                                                                             \
      _ls_tail = NULL;                                                                         \
      _ls_nmerges = 0;                                                                         \
      while (_ls_p) {                                                                          \
        _ls_nmerges++;                                                                         \
        _ls_q = _ls_p;                                                                         \
        _ls_psize = 0;                                                                         \
        for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) {                                         \
          _ls_psize++;                                                                         \
          _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list);                               \
          if (!_ls_q) break;                                                                   \
        }                                                                                      \
        _ls_qsize = _ls_insize;                                                                \
        while (_ls_psize > 0 || (_ls_qsize > 0 && _ls_q)) {                                    \
          if (_ls_psize == 0) {                                                                \
            _ls_e = _ls_q; _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list); _ls_qsize--; \
          } else if (_ls_qsize == 0 || !_ls_q) {                                               \
            _ls_e = _ls_p; _SV(_ls_p,list); _ls_p = _NEXT(_ls_p,list); _RS(list); _ls_psize--; \
          } else if (cmp(_ls_p,_ls_q) <= 0) {                                                  \
            _ls_e = _ls_p; _SV(_ls_p,list); _ls_p = _NEXT(_ls_p,list); _RS(list); _ls_psize--; \
          } else {                                                                             \
            _ls_e = _ls_q; _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list); _ls_qsize--; \
          }                                                                                    \
          if (_ls_tail) {                                                                      \
            _SV(_ls_tail,list); _NEXTASGN(_ls_tail,list,_ls_e); _RS(list);                     \
          } else {                                                                             \
            _CASTASGN(list,_ls_e);                                                             \
          }                                                                                    \
          _ls_tail = _ls_e;                                                                    \
        }                                                                                      \
        _ls_p = _ls_q;                                                                         \
      }                                                                                        \
      _SV(_ls_tail,list); _NEXTASGN(_ls_tail,list,NULL); _RS(list);                            \
      if (_ls_nmerges <= 1) {                                                                  \
        _ls_looping=0;                                                                         \
      }                                                                                        \
      _ls_insize *= 2;                                                                         \
    }                                                                                          \
  } else _tmp=NULL; /* quiet gcc unused variable warning */                                    \
} while (0)

#define DL_SORT(list, cmp)                                                                     \
do {                                                                                           \
  LDECLTYPE(list) _ls_p;                                                                       \
  LDECLTYPE(list) _ls_q;                                                                       \
  LDECLTYPE(list) _ls_e;                                                                       \
  LDECLTYPE(list) _ls_tail;                                                                    \
  LDECLTYPE(list) _ls_oldhead;                                                                 \
  LDECLTYPE(list) _tmp;                                                                        \
  int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping;                       \
  if (list) {                                                                                  \
    _ls_insize = 1;                                                                            \
    _ls_looping = 1;                                                                           \
    while (_ls_looping) {                                                                      \
      _CASTASGN(_ls_p,list);                                                                   \
      _CASTASGN(_ls_oldhead,list);                                                             \
      list = NULL;                                                                             \
      _ls_tail = NULL;                                                                         \
      _ls_nmerges = 0;                                                                         \
      while (_ls_p) {                                                                          \
        _ls_nmerges++;                                                                         \
        _ls_q = _ls_p;                                                                         \
        _ls_psize = 0;                                                                         \
        for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) {                                         \
          _ls_psize++;                                                                         \
          _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list);                               \
          if (!_ls_q) break;                                                                   \
        }                                                                                      \
        _ls_qsize = _ls_insize;                                                                \
        while (_ls_psize > 0 || (_ls_qsize > 0 && _ls_q)) {                                    \
          if (_ls_psize == 0) {                                                                \
            _ls_e = _ls_q; _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list); _ls_qsize--; \
          } else if (_ls_qsize == 0 || !_ls_q) {                                               \
            _ls_e = _ls_p; _SV(_ls_p,list); _ls_p = _NEXT(_ls_p,list); _RS(list); _ls_psize--; \
          } else if (cmp(_ls_p,_ls_q) <= 0) {                                                  \
            _ls_e = _ls_p; _SV(_ls_p,list); _ls_p = _NEXT(_ls_p,list); _RS(list); _ls_psize--; \
          } else {                                                                             \
            _ls_e = _ls_q; _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list); _ls_qsize--; \
          }                                                                                    \
          if (_ls_tail) {                                                                      \
            _SV(_ls_tail,list); _NEXTASGN(_ls_tail,list,_ls_e); _RS(list);                     \
          } else {                                                                             \
            _CASTASGN(list,_ls_e);                                                             \
          }                                                                                    \
          _SV(_ls_e,list); _PREVASGN(_ls_e,list,_ls_tail); _RS(list);                          \
          _ls_tail = _ls_e;                                                                    \
        }                                                                                      \
        _ls_p = _ls_q;                                                                         \
      }                                                                                        \
      _CASTASGN(list->prev, _ls_tail);                                                         \
      _SV(_ls_tail,list); _NEXTASGN(_ls_tail,list,NULL); _RS(list);                            \
      if (_ls_nmerges <= 1) {                                                                  \
        _ls_looping=0;                                                                         \
      }                                                                                        \
      _ls_insize *= 2;                                                                         \
    }                                                                                          \
  } else _tmp=NULL; /* quiet gcc unused variable warning */                                    \
} while (0)

#define CDL_SORT(list, cmp)                                                                    \
do {                                                                                           \
  LDECLTYPE(list) _ls_p;                                                                       \
  LDECLTYPE(list) _ls_q;                                                                       \
  LDECLTYPE(list) _ls_e;                                                                       \
  LDECLTYPE(list) _ls_tail;                                                                    \
  LDECLTYPE(list) _ls_oldhead;                                                                 \
  LDECLTYPE(list) _tmp;                                                                        \
  LDECLTYPE(list) _tmp2;                                                                       \
  int _ls_insize, _ls_nmerges, _ls_psize, _ls_qsize, _ls_i, _ls_looping;                       \
  if (list) {                                                                                  \
    _ls_insize = 1;                                                                            \
    _ls_looping = 1;                                                                           \
    while (_ls_looping) {                                                                      \
      _CASTASGN(_ls_p,list);                                                                   \
      _CASTASGN(_ls_oldhead,list);                                                             \
      list = NULL;                                                                             \
      _ls_tail = NULL;                                                                         \
      _ls_nmerges = 0;                                                                         \
      while (_ls_p) {                                                                          \
        _ls_nmerges++;                                                                         \
        _ls_q = _ls_p;                                                                         \
        _ls_psize = 0;                                                                         \
        for (_ls_i = 0; _ls_i < _ls_insize; _ls_i++) {                                         \
          _ls_psize++;                                                                         \
          _SV(_ls_q,list);                                                                     \
          if (_NEXT(_ls_q,list) == _ls_oldhead) {                                              \
            _ls_q = NULL;                                                                      \
          } else {                                                                             \
            _ls_q = _NEXT(_ls_q,list);                                                         \
          }                                                                                    \
          _RS(list);                                                                           \
          if (!_ls_q) break;                                                                   \
        }                                                                                      \
        _ls_qsize = _ls_insize;                                                                \
        while (_ls_psize > 0 || (_ls_qsize > 0 && _ls_q)) {                                    \
          if (_ls_psize == 0) {                                                                \
            _ls_e = _ls_q; _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list); _ls_qsize--; \
            if (_ls_q == _ls_oldhead) { _ls_q = NULL; }                                        \
          } else if (_ls_qsize == 0 || !_ls_q) {                                               \
            _ls_e = _ls_p; _SV(_ls_p,list); _ls_p = _NEXT(_ls_p,list); _RS(list); _ls_psize--; \
            if (_ls_p == _ls_oldhead) { _ls_p = NULL; }                                        \
          } else if (cmp(_ls_p,_ls_q) <= 0) {                                                  \
            _ls_e = _ls_p; _SV(_ls_p,list); _ls_p = _NEXT(_ls_p,list); _RS(list); _ls_psize--; \
            if (_ls_p == _ls_oldhead) { _ls_p = NULL; }                                        \
          } else {                                                                             \
            _ls_e = _ls_q; _SV(_ls_q,list); _ls_q = _NEXT(_ls_q,list); _RS(list); _ls_qsize--; \
            if (_ls_q == _ls_oldhead) { _ls_q = NULL; }                                        \
          }                                                                                    \
          if (_ls_tail) {                                                                      \
            _SV(_ls_tail,list); _NEXTASGN(_ls_tail,list,_ls_e); _RS(list);                     \
          } else {                                                                             \
            _CASTASGN(list,_ls_e);                                                             \
          }                                                                                    \
          _SV(_ls_e,list); _PREVASGN(_ls_e,list,_ls_tail); _RS(list);                          \
          _ls_tail = _ls_e;                                                                    \
        }                                                                                      \
        _ls_p = _ls_q;                                                                         \
      }                                                                                        \
      _CASTASGN(list->prev,_ls_tail);                                                          \
      _CASTASGN(_tmp2,list);                                                                   \
      _SV(_ls_tail,list); _NEXTASGN(_ls_tail,list,_tmp2); _RS(list);                           \
      if (_ls_nmerges <= 1) {                                                                  \
        _ls_looping=0;                                                                         \
      }                                                                                        \
      _ls_insize *= 2;                                                                         \
    }                                                                                          \
  } else _tmp=NULL; /* quiet gcc unused variable warning */                                    \
} while (0)

/******************************************************************************
 * singly linked list macros (non-circular)                                   *
 *****************************************************************************/
#define LL_PREPEND(head,add)                                                                   \
do {                                                                                           \
  (add)->next = head;                                                                          \
  head = add;                                                                                  \
} while (0)

#define LL_APPEND(head,add)                                                                    \
do {                                                                                           \
  LDECLTYPE(head) _tmp;                                                                        \
  (add)->next=NULL;                                                                            \
  if (head) {                                                                                  \
    _tmp = head;                                                                               \
    while (_tmp->next) { _tmp = _tmp->next; }                                                  \
    _tmp->next=(add);                                                                          \
  } else {                                                                                     \
    (head)=(add);                                                                              \
  }                                                                                            \
} while (0)

#define LL_DELETE(head,del)                                                                    \
do {                                                                                           \
  LDECLTYPE(head) _tmp;                                                                        \
  if ((head) == (del)) {                                                                       \
    (head)=(head)->next;                                                                       \
  } else {                                                                                     \
    _tmp = head;                                                                               \
    while (_tmp->next && (_tmp->next != (del))) {                                              \
      _tmp = _tmp->next;                                                                       \
    }                                                                                          \
    if (_tmp->next) {                                                                          \
      _tmp->next = ((del)->next);                                                              \
    }                                                                                          \
  }                                                                                            \
} while (0)

/* Here are VS2008 replacements for LL_APPEND and LL_DELETE */
#define LL_APPEND_VS2008(head,add)                                                             \
do {                                                                                           \
  if (head) {                                                                                  \
    (add)->next = head;     /* use add->next as a temp variable */                             \
    while ((add)->next->next) { (add)->next = (add)->next->next; }                             \
    (add)->next->next=(add);                                                                   \
  } else {                                                                                     \
    (head)=(add);                                                                              \
  }                                                                                            \
  (add)->next=NULL;                                                                            \
} while (0)

#define LL_DELETE_VS2008(head,del)                                                             \
do {                                                                                           \
  if ((head) == (del)) {                                                                       \
    (head)=(head)->next;                                                                       \
  } else {                                                                                     \
    char *_tmp = (char*)(head);                                                                \
    while (head->next && (head->next != (del))) {                                              \
      head = head->next;                                                                       \
    }                                                                                          \
    if (head->next) {                                                                          \
      head->next = ((del)->next);                                                              \
    }                                                                                          \
    {                                                                                          \
      char **_head_alias = (char**)&(head);                                                    \
      *_head_alias = _tmp;                                                                     \
    }                                                                                          \
  }                                                                                            \
} while (0)
#ifdef NO_DECLTYPE
#undef LL_APPEND
#define LL_APPEND LL_APPEND_VS2008
#undef LL_DELETE
#define LL_DELETE LL_DELETE_VS2008
#endif
/* end VS2008 replacements */

#define LL_FOREACH(head,el)                                                                    \
    for(el=head;el;el=el->next)

#define LL_FOREACH_SAFE(head,el,tmp)                                                           \
  for((el)=(head);(el) && (tmp = (el)->next, 1); (el) = tmp)

#define LL_SEARCH_SCALAR(head,out,field,val)                                                   \
do {                                                                                           \
    LL_FOREACH(head,out) {                                                                     \
      if ((out)->field == (val)) break;                                                        \
    }                                                                                          \
} while(0) 

#define LL_SEARCH(head,out,elt,cmp)                                                            \
do {                                                                                           \
    LL_FOREACH(head,out) {                                                                     \
      if ((cmp(out,elt))==0) break;                                                            \
    }                                                                                          \
} while(0) 

/******************************************************************************
 * doubly linked list macros (non-circular)                                   *
 *****************************************************************************/
#define DL_PREPEND(head,add)                                                                   \
do {                                                                                           \
 (add)->next = head;                                                                           \
 if (head) {                                                                                   \
   (add)->prev = (head)->prev;                                                                 \
   (head)->prev = (add);                                                                       \
 } else {                                                                                      \
   (add)->prev = (add);                                                                        \
 }                                                                                             \
 (head) = (add);                                                                               \
} while (0)

#define DL_APPEND(head,add)                                                                    \
do {                                                                                           \
  if (head) {                                                                                  \
      (add)->prev = (head)->prev;                                                              \
      (head)->prev->next = (add);                                                              \
      (head)->prev = (add);                                                                    \
      (add)->next = NULL;                                                                      \
  } else {                                                                                     \
      (head)=(add);                                                                            \
      (head)->prev = (head);                                                                   \
      (head)->next = NULL;                                                                     \
  }                                                                                            \
} while (0);

#define DL_DELETE(head,del)                                                                    \
do {                                                                                           \
  if ((del)->prev == (del)) {                                                                  \
      (head)=NULL;                                                                             \
  } else if ((del)==(head)) {                                                                  \
      (del)->next->prev = (del)->prev;                                                         \
      (head) = (del)->next;                                                                    \
  } else {                                                                                     \
      (del)->prev->next = (del)->next;                                                         \
      if ((del)->next) {                                                                       \
          (del)->next->prev = (del)->prev;                                                     \
      } else {                                                                                 \
          (head)->prev = (del)->prev;                                                          \
      }                                                                                        \
  }                                                                                            \
} while (0);


#define DL_FOREACH(head,el)                                                                    \
    for(el=head;el;el=el->next)

/* this version is safe for deleting the elements during iteration */
#define DL_FOREACH_SAFE(head,el,tmp)                                                           \
  for((el)=(head);(el) && (tmp = (el)->next, 1); (el) = tmp)

/* these are identical to their singly-linked list counterparts */
#define DL_SEARCH_SCALAR LL_SEARCH_SCALAR
#define DL_SEARCH LL_SEARCH

/******************************************************************************
 * circular doubly linked list macros                                         *
 *****************************************************************************/
#define CDL_PREPEND(head,add)                                                                  \
do {                                                                                           \
 if (head) {                                                                                   \
   (add)->prev = (head)->prev;                                                                 \
   (add)->next = (head);                                                                       \
   (head)->prev = (add);                                                                       \
   (add)->prev->next = (add);                                                                  \
 } else {                                                                                      \
   (add)->prev = (add);                                                                        \
   (add)->next = (add);                                                                        \
 }                                                                                             \
(head)=(add);                                                                                  \
} while (0)

#define CDL_DELETE(head,del)                                                                   \
do {                                                                                           \
  if ( ((head)==(del)) && ((head)->next == (head))) {                                          \
      (head) = 0L;                                                                             \
  } else {                                                                                     \
     (del)->next->prev = (del)->prev;                                                          \
     (del)->prev->next = (del)->next;                                                          \
     if ((del) == (head)) (head)=(del)->next;                                                  \
  }                                                                                            \
} while (0);

#define CDL_FOREACH(head,el)                                                                   \
    for(el=head;el;el=(el->next==head ? 0L : el->next)) 

#define CDL_FOREACH_SAFE(head,el,tmp1,tmp2)                                                    \
  for((el)=(head), ((tmp1)=(head)?((head)->prev):NULL);                                        \
      (el) && ((tmp2)=(el)->next, 1);                                                          \
      ((el) = (((el)==(tmp1)) ? 0L : (tmp2))))

#define CDL_SEARCH_SCALAR(head,out,field,val)                                                  \
do {                                                                                           \
    CDL_FOREACH(head,out) {                                                                    \
      if ((out)->field == (val)) break;                                                        \
    }                                                                                          \
} while(0) 

#define CDL_SEARCH(head,out,elt,cmp)                                                           \
do {                                                                                           \
    CDL_FOREACH(head,out) {                                                                    \
      if ((cmp(out,elt))==0) break;                                                            \
    }                                                                                          \
} while(0) 

#endif /* UTLIST_H */