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63f00a3f FB |
1 | <?php |
2 | /*************************************************************************** | |
2ab75571 | 3 | * Copyright (C) 2003-2010 Polytechnique.org * |
63f00a3f FB |
4 | * http://opensource.polytechnique.org/ * |
5 | * * | |
6 | * This program is free software; you can redistribute it and/or modify * | |
7 | * it under the terms of the GNU General Public License as published by * | |
8 | * the Free Software Foundation; either version 2 of the License, or * | |
9 | * (at your option) any later version. * | |
10 | * * | |
11 | * This program 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 * | |
14 | * GNU General Public License for more details. * | |
15 | * * | |
16 | * You should have received a copy of the GNU General Public License * | |
17 | * along with this program; if not, write to the Free Software * | |
18 | * Foundation, Inc., * | |
19 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * | |
20 | ***************************************************************************/ | |
21 | ||
5177a1b5 FB |
22 | class PlIteratorUtils |
23 | { | |
c291ca54 RB |
24 | /** Builds a new empty iterator |
25 | */ | |
26 | public static function emptyIterator() | |
27 | { | |
28 | return new PlEmptyIterator(); | |
29 | } | |
30 | ||
5177a1b5 FB |
31 | /** Build an iterator over an array. |
32 | * @param array The array. | |
33 | * @param depth The depth of iteration. | |
34 | * @return an iterator that return entries in the form | |
35 | * array(key => array(0 => key_for_depth0 [, 1 => key_for_depths1, ...]), | |
36 | * value => the value); | |
37 | */ | |
e94c4a17 | 38 | public static function fromArray(array $array, $depth = 1, $flat = false) |
5177a1b5 | 39 | { |
e94c4a17 | 40 | return new PlArrayIterator($array, $depth, $flat); |
5177a1b5 FB |
41 | } |
42 | ||
43 | ||
44 | /** Sort an iterator using the given sort callback. | |
45 | * @param iterator The iterator to sort. | |
46 | * @param callback The callback for comparison. | |
47 | * @return a new iterator with the entries sorted. | |
48 | */ | |
49 | public static function sort(PlIterator $iterator, $callback) | |
50 | { | |
51 | $heap = new PlHeap($callback); | |
52 | while ($item = $iterator->next()) { | |
53 | $heap->push($item); | |
54 | } | |
55 | return $heap->iterator(); | |
56 | } | |
57 | ||
58 | ||
59 | /** Merge several iterator into a unique one. | |
60 | * @param iterators Array of iterators. | |
61 | * @param callback The callback for comparison. | |
62 | * @param sorted Tell wether the iterators are already sorted using the given callback. | |
63 | * @return an iterator. | |
64 | */ | |
65 | public static function merge(array $iterators, $callback, $sorted = true) | |
66 | { | |
67 | return new PlMergeIterator($iterators, $callback, $sorted); | |
68 | } | |
8d37a362 FB |
69 | |
70 | ||
71 | /** Build an iterator that contains only the elements of the given iterator that | |
72 | * match the given condition. The condition should be a callback that takes an element | |
73 | * and returns a boolean. | |
74 | * @param iterator The source iterator | |
75 | * @param callback The condition | |
76 | * @return an iterator | |
77 | */ | |
78 | public static function filter(PlIterator $iterator, $callback) | |
79 | { | |
80 | return new PlFilterIterator($iterator, $callback); | |
81 | } | |
82 | ||
83 | ||
84 | /** Build an iterator that transforms the element of another iterator. The callback | |
85 | * takes an element and transform it into another one. Be careful: if the result | |
86 | * of the callback is null, the iteration ends. | |
87 | * @param iterator The source iterator | |
88 | * @param callback The transformer. | |
89 | */ | |
90 | public static function map(PlIterator $iterator, $callback) | |
91 | { | |
92 | return new PlMapIterator($iterator, $callback); | |
93 | } | |
5177a1b5 | 94 | |
22c8b530 | 95 | /** Build an iterator whose values are iterators too; such a 'subIterator' will end |
a52d0af8 RB |
96 | * when the value of $callback changes; |
97 | * WARNING: will fast-forward the current subiterator until it is over ! | |
22c8b530 | 98 | * @param iterator The source iterator |
21f0c57c | 99 | * @param callback The callback for detecting changes. XXX: Might be called twice on a given object |
22c8b530 RB |
100 | * @return an iterator |
101 | */ | |
102 | public static function subIterator(PlIterator $iterator, $callback) | |
103 | { | |
21f0c57c | 104 | return new PlSubIterator($iterator, $callback); |
22c8b530 RB |
105 | } |
106 | ||
851962db RB |
107 | /** Build an iterator that will iterate over the given set of iterators, returning consistent |
108 | * sets of values (i.e only the values for which the result of the callback is the same as that | |
109 | * for the master) | |
110 | * @param iterators The set of iterators | |
111 | * @param callbacks A list of callbacks (one for each iterator), or a single, common, callback | |
112 | * @param master The id of the "master" iterator in the first list | |
113 | */ | |
114 | public static function parallelIterator(array $iterators, $callbacks, $master) | |
115 | { | |
116 | return new PlParallelIterator($iterators, $callbacks, $master); | |
117 | } | |
118 | ||
22c8b530 RB |
119 | /** Returns the callback for '$x -> $x[$key]'; |
120 | * @param $key the index to retrieve in arrays | |
121 | * @return a callback | |
122 | */ | |
123 | public static function arrayValueCallback($key) | |
124 | { | |
125 | $callback = new _GetArrayValueCallback($key); | |
126 | return array($callback, 'get'); | |
127 | } | |
ce06a3ea RB |
128 | |
129 | /** Returns the callback for '$x -> $x->prop'; | |
130 | * @param $property The property to retrieve | |
131 | * @return a callback | |
132 | */ | |
d40e45a2 | 133 | public static function objectPropertyCallback($property) |
ce06a3ea RB |
134 | { |
135 | $callback = new _GetObjectPropertyCallback($property); | |
136 | return array($callback, 'get'); | |
137 | } | |
0e95424b FB |
138 | |
139 | /** Returns a wrapper around the PlIterator suitable for foreach() iterations | |
140 | */ | |
141 | public static function foreachIterator(PlIterator $iterator) | |
142 | { | |
143 | return new SPLIterator($iterator); | |
144 | } | |
22c8b530 | 145 | } |
5177a1b5 | 146 | |
c291ca54 RB |
147 | /** Empty iterator |
148 | */ | |
149 | class PlEmptyIterator implements PlIterator | |
150 | { | |
151 | public function first() | |
152 | { | |
153 | return false; | |
154 | } | |
155 | ||
156 | public function last() | |
157 | { | |
158 | return false; | |
159 | } | |
160 | ||
161 | public function next() | |
162 | { | |
163 | return null; | |
164 | } | |
165 | ||
166 | public function total() | |
167 | { | |
168 | return 0; | |
169 | } | |
170 | } | |
171 | ||
5177a1b5 FB |
172 | /** Iterates over an array. |
173 | */ | |
63f00a3f FB |
174 | class PlArrayIterator implements PlIterator |
175 | { | |
176 | private $array; | |
177 | private $depth; | |
178 | ||
179 | private $_its = array(); | |
180 | ||
181 | private $_total; | |
182 | private $_first; | |
183 | private $_last; | |
184 | private $_pos; | |
e94c4a17 | 185 | private $_flat; |
63f00a3f | 186 | |
e94c4a17 | 187 | public function __construct(array &$array, $depth = 1, $flat = false) |
63f00a3f FB |
188 | { |
189 | $this->array =& $array; | |
190 | $this->depth = $depth; | |
191 | $this->_total = $this->count($array, $depth - 1); | |
192 | $this->_pos = 0; | |
193 | $this->_first = false; | |
194 | $this->_last = false; | |
e94c4a17 | 195 | $this->_flat = $flat; |
63f00a3f FB |
196 | |
197 | for ($i = 0 ; $i < $depth ; ++$i) { | |
198 | if ($i == 0) { | |
199 | $this->_its[] = $array; | |
200 | } else { | |
201 | $this->_its[] = current($this->_its[$i - 1]); | |
202 | } | |
203 | reset($this->_its[$i]); | |
204 | } | |
205 | } | |
206 | ||
207 | private function count(array &$array, $depth) | |
208 | { | |
209 | if ($depth == 0) { | |
210 | return count($array); | |
211 | } else { | |
212 | $sum = 0; | |
213 | foreach ($array as &$item) { | |
214 | $sum += $this->count($item, $depth - 1); | |
215 | } | |
216 | return $sum; | |
217 | } | |
218 | } | |
219 | ||
220 | private function nextArray($depth) | |
221 | { | |
222 | if ($depth == 0) { | |
223 | return; | |
224 | } | |
225 | $this->_its[$depth] = next($this->_its[$depth - 1]); | |
226 | if ($this->_its[$depth] === false) { | |
227 | $this->nextArray($depth - 1); | |
228 | if ($this->_its[$depth - 1] === false) { | |
229 | return; | |
230 | } | |
231 | $this->_its[$depth] = current($this->_its[$depth - 1]); | |
232 | } | |
233 | reset($this->_its[$depth]); | |
234 | } | |
235 | ||
236 | public function next() | |
237 | { | |
238 | ++$this->_pos; | |
239 | $this->_first = ($this->_total > 0 && $this->_pos == 1); | |
240 | $this->_last = ($this->_pos == $this->_total); | |
241 | if ($this->_pos > $this->_total) { | |
242 | return null; | |
243 | } | |
244 | ||
245 | $val = current($this->_its[$this->depth - 1]); | |
246 | if ($val === false) { | |
247 | $this->nextArray($this->depth - 1); | |
248 | $val = current($this->_its[$this->depth - 1]); | |
249 | if ($val === false) { | |
250 | return null; | |
251 | } | |
252 | } | |
253 | $keys = array(); | |
254 | for ($i = 0 ; $i < $this->depth ; ++$i) { | |
255 | $keys[] = key($this->_its[$i]); | |
256 | } | |
257 | next($this->_its[$this->depth - 1]); | |
e94c4a17 FB |
258 | if ($this->_flat) { |
259 | return $val; | |
260 | } else { | |
261 | return array('keys' => $keys, | |
262 | 'value' => $val); | |
263 | } | |
63f00a3f FB |
264 | } |
265 | ||
266 | public function total() | |
267 | { | |
268 | return $this->_total; | |
269 | } | |
270 | ||
271 | public function first() | |
272 | { | |
273 | return $this->_first; | |
274 | } | |
275 | ||
276 | public function last() | |
277 | { | |
278 | return $this->_last; | |
279 | } | |
280 | } | |
281 | ||
5177a1b5 FB |
282 | |
283 | /** Iterator that return the result of a merge of several iterators. | |
284 | */ | |
285 | class PlMergeIterator implements PlIterator | |
286 | { | |
287 | /* The heap is field with entries with the form: | |
288 | * array('it' => id of the iterator this entry come from, | |
289 | * 'value' => value of the entry). | |
290 | */ | |
291 | private $heap; | |
292 | private $preComputed = false; | |
293 | private $comparator; | |
294 | private $iterators; | |
295 | private $_total; | |
296 | private $pos; | |
297 | ||
298 | public function __construct(array $iterators, $callback, $sorted = true) | |
299 | { | |
300 | $this->heap = new PlHeap(array($this, 'compare')); | |
301 | $this->_total = 0; | |
302 | $this->comparator = $callback; | |
303 | if ($sorted) { | |
304 | $this->iterators = $iterators; | |
305 | foreach ($this->iterators as $key => &$it) { | |
306 | $this->_total += $it->total(); | |
307 | $item = $it->next(); | |
308 | if (!is_null($item)) { | |
309 | $this->heap->push(array('it' => $key, 'value' => $item)); | |
310 | } | |
311 | } | |
312 | } else { | |
313 | $this->preComputed = true; | |
314 | foreach ($iterators as $key => &$it) { | |
315 | $this->_total += $it->total(); | |
316 | while (!is_null($item = $it->next())) { | |
317 | $this->heap->push(array('it' => $key, 'value' => $item)); | |
318 | } | |
319 | } | |
320 | } | |
321 | $this->pos = 0; | |
322 | } | |
323 | ||
324 | /** Compare two entries of the heap using the comparator of the user. | |
325 | */ | |
326 | public function compare($a, $b) | |
327 | { | |
328 | $cp = call_user_func($this->comparator, $a['value'], $b['value']); | |
329 | if ($cp == 0) { | |
330 | return $a['it'] - $b['it']; | |
331 | } | |
332 | return $cp; | |
333 | } | |
334 | ||
335 | public function total() | |
336 | { | |
337 | return $this->_total; | |
338 | } | |
339 | ||
340 | public function next() | |
341 | { | |
342 | ++$this->pos; | |
343 | $entry = $this->heap->pop(); | |
344 | if (is_null($entry)) { | |
345 | return null; | |
346 | } | |
347 | if ($this->preComputed) { | |
348 | return $entry['value']; | |
349 | } | |
350 | $it = $entry['it']; | |
351 | $item = $this->iterators[$it]->next(); | |
352 | if (!is_null($item)) { | |
353 | $this->heap->push(array('it' => $it, 'value' => $item)); | |
354 | } | |
355 | return $entry['value']; | |
356 | } | |
357 | ||
358 | public function last() | |
359 | { | |
360 | return $this->heap->count() == 0; | |
361 | } | |
362 | ||
363 | public function first() | |
364 | { | |
365 | return $this->pos == 1; | |
366 | } | |
367 | } | |
368 | ||
8d37a362 | 369 | |
8b48f8d7 FB |
370 | class PlFilterIterator implements PlIterator |
371 | { | |
372 | private $pos; | |
8d37a362 FB |
373 | private $source; |
374 | private $callback; | |
375 | private $element; | |
8d37a362 FB |
376 | |
377 | public function __construct(PlIterator $source, $callback) | |
378 | { | |
8b48f8d7 | 379 | $this->source = $source; |
8d37a362 | 380 | $this->callback = $callback; |
8b48f8d7 FB |
381 | $this->pos = 0; |
382 | $this->element = $this->fetchNext(); | |
8d37a362 FB |
383 | } |
384 | ||
385 | private function fetchNext() | |
386 | { | |
387 | do { | |
388 | $current = $this->source->next(); | |
8b48f8d7 FB |
389 | if (is_null($current) || call_user_func($this->callback, $current)) { |
390 | return $current; | |
8d37a362 FB |
391 | } |
392 | } while (true); | |
393 | } | |
394 | ||
395 | public function next() | |
396 | { | |
8b48f8d7 | 397 | ++$this->pos; |
8d37a362 | 398 | $elt = $this->element; |
8b48f8d7 FB |
399 | if (!is_null($this->element)) { |
400 | $this->element = $this->fetchNext(); | |
8d37a362 FB |
401 | } |
402 | return $elt; | |
403 | } | |
404 | ||
405 | public function total() | |
406 | { | |
407 | /* This is an approximation since the correct total | |
408 | * cannot be computed without fetching all the elements | |
409 | */ | |
410 | return $this->source->total(); | |
411 | } | |
412 | ||
413 | public function first() | |
414 | { | |
8b48f8d7 | 415 | return $this->pos == 1; |
8d37a362 FB |
416 | } |
417 | ||
418 | public function last() | |
419 | { | |
8b48f8d7 | 420 | return is_null($this->element); |
8d37a362 FB |
421 | } |
422 | } | |
423 | ||
424 | ||
425 | class PlMapIterator implements PlIterator | |
426 | { | |
427 | private $source; | |
428 | private $callback; | |
429 | ||
430 | public function __construct(PlIterator $source, $callback) | |
431 | { | |
432 | $this->source = $source; | |
433 | $this->callback = $callback; | |
434 | } | |
435 | ||
436 | public function next() | |
437 | { | |
438 | $elt = $this->source->next(); | |
439 | if ($elt) { | |
440 | return call_user_func($this->callback, $elt); | |
441 | } else { | |
442 | return null; | |
443 | } | |
444 | } | |
445 | ||
446 | public function total() | |
447 | { | |
448 | return $this->source->total(); | |
449 | } | |
450 | ||
451 | public function first() | |
452 | { | |
453 | return $this->source->first(); | |
454 | } | |
455 | ||
456 | public function last() | |
457 | { | |
458 | return $this->source->last(); | |
459 | } | |
460 | } | |
461 | ||
22c8b530 RB |
462 | class PlSubIterator implements PlIterator |
463 | { | |
464 | private $source; | |
465 | private $callback; | |
466 | private $next = null; // The next item, if it has been fetched too early by a subiterator | |
a52d0af8 RB |
467 | private $pos = 0; |
468 | private $sub = null; | |
22c8b530 RB |
469 | |
470 | public function __construct(PlIterator $source, $callback) | |
471 | { | |
472 | $this->source = $source; | |
473 | $this->callback = $callback; | |
474 | } | |
475 | ||
a52d0af8 RB |
476 | /** WARNING: this will "fast-forward" the subiterator to its end |
477 | */ | |
22c8b530 RB |
478 | public function next() |
479 | { | |
480 | if ($this->last()) { | |
481 | return null; | |
482 | } else { | |
a52d0af8 RB |
483 | if ($this->sub != null) { |
484 | while (!$this->sub->last()) { | |
485 | $this->sub->next(); | |
486 | } | |
487 | } | |
488 | ||
489 | if ($this->last()) { | |
490 | return null; | |
491 | } | |
492 | ||
493 | ++$this->pos; | |
494 | $this->sub = new PlInnerSubIterator($this->source, $this->callback, $this, $this->next); | |
495 | return $this->sub; | |
22c8b530 RB |
496 | } |
497 | } | |
498 | ||
499 | /** This will always be a too big number, but the actual result can't be easily computed | |
500 | */ | |
501 | public function total() | |
502 | { | |
503 | return $this->source->total(); | |
504 | } | |
505 | ||
a52d0af8 RB |
506 | /** This will only return true if the current subiterator was the last one, |
507 | * and if it has been fully used | |
508 | */ | |
22c8b530 RB |
509 | public function last() |
510 | { | |
a52d0af8 RB |
511 | if ($this->sub != null && !$this->sub->last()) { |
512 | return false; | |
513 | } | |
22c8b530 RB |
514 | return ($this->source->last() && $this->next == null); |
515 | } | |
516 | ||
9d865d03 FB |
517 | public function first() |
518 | { | |
a52d0af8 | 519 | return $this->pos == 1; |
9d865d03 FB |
520 | } |
521 | ||
22c8b530 RB |
522 | // Called by a subiterator to "rewind" the core iterator |
523 | public function setNext($item) | |
524 | { | |
525 | $this->next = $item; | |
526 | } | |
527 | } | |
528 | ||
529 | class PlInnerSubIterator implements PlIterator | |
530 | { | |
531 | private $source; | |
532 | private $callback; | |
533 | private $parent; | |
534 | ||
535 | private $next; // Not null if the source has to be "rewinded" | |
536 | ||
537 | private $curval = null; | |
538 | private $curelt = null; | |
a52d0af8 RB |
539 | private $val = null; |
540 | private $pos = 0; | |
22c8b530 RB |
541 | private $stepped = false; |
542 | private $over = false; | |
543 | ||
544 | public function __construct(PlIterator $source, $callback, PlSubIterator $parent, $next = null) | |
545 | { | |
546 | $this->source = $source; | |
547 | $this->callback = $callback; | |
548 | $this->parent = $parent; | |
549 | $this->next = $next; | |
a52d0af8 | 550 | $this->parent->setNext(null); |
22c8b530 RB |
551 | } |
552 | ||
553 | public function value() | |
554 | { | |
555 | $this->_step(); | |
556 | return $this->curval; | |
557 | } | |
558 | ||
559 | // Move one step, if the current element has been used | |
560 | private function _step() | |
561 | { | |
562 | if ($this->stepped) { | |
563 | return; | |
564 | } | |
565 | ||
566 | if ($this->next != null) { | |
567 | $this->curelt = $this->next; | |
568 | $this->next = null; | |
569 | } else { | |
a52d0af8 RB |
570 | if ($this->source->last()) { |
571 | $this->over = true; | |
572 | return; | |
573 | } | |
21f0c57c | 574 | $this->curelt = $this->source->next(); |
22c8b530 | 575 | } |
21f0c57c | 576 | |
a52d0af8 RB |
577 | if ($this->pos == 0) { |
578 | $this->val = call_user_func($this->callback, $this->curelt); | |
579 | $this->curval = $this->val; | |
580 | } else { | |
21f0c57c | 581 | $this->curval = call_user_func($this->callback, $this->curelt); |
21f0c57c RB |
582 | } |
583 | ||
22c8b530 RB |
584 | $this->stepped = true; |
585 | } | |
586 | ||
587 | public function next() | |
588 | { | |
a52d0af8 RB |
589 | if ($this->over) { |
590 | return null; | |
591 | } | |
592 | ||
22c8b530 | 593 | $this->_step(); |
a52d0af8 RB |
594 | |
595 | if ($this->over) { | |
596 | return null; | |
597 | } | |
598 | ||
599 | ++$this->pos; | |
22c8b530 RB |
600 | $this->stepped = false; |
601 | ||
a52d0af8 RB |
602 | if ($this->val == $this->curval) { |
603 | return $this->curelt; | |
22c8b530 | 604 | } |
a52d0af8 RB |
605 | |
606 | $this->parent->setNext($this->curelt); | |
22c8b530 RB |
607 | $this->over = true; |
608 | return null; | |
609 | } | |
610 | ||
611 | /** This will always be a too big number, but the actual result can't be easily computed | |
612 | */ | |
613 | public function total() | |
614 | { | |
615 | return $this->source->total(); | |
616 | } | |
617 | ||
618 | public function last() | |
619 | { | |
a52d0af8 RB |
620 | if ($this->over) { |
621 | return true; | |
622 | } | |
623 | $this->_step(); | |
624 | return $this->over || ($this->val != $this->curval); | |
22c8b530 RB |
625 | } |
626 | ||
9d865d03 FB |
627 | public function first() |
628 | { | |
a52d0af8 | 629 | return $this->pos == 1; |
9d865d03 FB |
630 | } |
631 | ||
22c8b530 RB |
632 | } |
633 | ||
851962db RB |
634 | /** Builds an iterator over a set of iterators, from which one is given as 'master'; |
635 | * The arguments are : | |
636 | * - An array of iterators, to iterate simultaneously | |
637 | * - An array of callbacks (one attached to each iterator), or a single callback (to | |
638 | * use for all iterators) | |
639 | * - The id of the 'master' iterator | |
640 | * | |
641 | * This ParallelIterator will iterate over the iterators, and, at each | |
642 | * step of the master iterator, it will apply the callbacks to the corresponding | |
643 | * iterators and return the values of the "slaves" for which the callback returned the | |
644 | * same value as the callback of the master. | |
645 | * | |
646 | * The callback should compute some kind of index, and never return the same value | |
647 | * twice for a given iterator | |
648 | * | |
649 | * It is assumed that, if the callback for a slave doesn't have the same value | |
650 | * as the value for the master, this means that there is a "hole" in the values | |
651 | * of that slave. | |
652 | * | |
653 | * Example : | |
654 | * - The callback is 'get the first cell' | |
655 | * - The master is : | |
656 | * [0, 1], [1, 13], [2, 42] | |
657 | * - The first slave (slave1) is : | |
658 | * [0, 'a'], [2, 'b'] | |
659 | * - The second slave (slave2) is : | |
660 | * [1, 42], [2, 0] | |
661 | * The resulting iterator would yield : | |
662 | * - array(master => [0, 1], slave1 => [0, 'a'], slave2 => null) | |
663 | * - array(master => [1, 13], slave1 => null, slave2 => [1, 42]) | |
664 | * - array(master => [2, 42], slave1 => [1, 'b'], slave2 => [2, 0]) | |
665 | */ | |
666 | class PlParallelIterator implements PlIterator | |
667 | { | |
668 | private $iterators; | |
669 | private $ids; | |
670 | private $callbacks; | |
671 | ||
672 | private $master_id; | |
673 | private $master; | |
674 | ||
a797e4f7 RB |
675 | private $over = array(); |
676 | private $stepped = array(); | |
851962db RB |
677 | private $current_elts = array(); |
678 | private $callback_res = array(); | |
679 | ||
680 | public function __construct(array $iterators, $callbacks, $master) | |
681 | { | |
682 | $this->iterators = $iterators; | |
683 | $this->master_id = $master; | |
684 | $this->master = $iterators[$master]; | |
685 | ||
686 | $this->ids = array_keys($iterators); | |
687 | ||
ff539a07 RB |
688 | $v = array_values($callbacks); |
689 | if (is_array($v[0])) { | |
851962db RB |
690 | $this->callbacks = $callbacks; |
691 | } else { | |
692 | $this->callbacks = array(); | |
693 | foreach ($this->ids as $id) { | |
694 | $this->callbacks[$id] = $callbacks; | |
695 | } | |
696 | } | |
697 | ||
698 | foreach ($this->ids as $id) { | |
699 | $this->stepped[$id] = false; | |
a797e4f7 | 700 | $this->over[$id] = false; |
851962db RB |
701 | $this->current_elts[$id] = null; |
702 | $this->callback_res[$id] = null; | |
703 | } | |
704 | } | |
705 | ||
706 | private function step($id) | |
707 | { | |
708 | if ($this->stepped[$id]) { | |
709 | return; | |
710 | } | |
711 | ||
a797e4f7 RB |
712 | // Don't do anything if the iterator is at its end |
713 | if ($this->over[$id]) { | |
714 | $this->stepped[$id] = true; | |
715 | return; | |
716 | } | |
717 | ||
851962db RB |
718 | $it = $this->iterators[$id]; |
719 | $nxt = $it->next(); | |
a797e4f7 RB |
720 | $this->stepped[$id] = true; |
721 | if ($nxt === null) { | |
722 | $this->over[$id] = true; | |
723 | $this->current_elts[$id] = null; | |
724 | $this->callback_res[$id] = null; | |
725 | return; | |
726 | } | |
851962db RB |
727 | $res = call_user_func($this->callbacks[$id], $nxt); |
728 | $this->current_elts[$id] = $nxt; | |
729 | $this->callback_res[$id] = $res; | |
851962db RB |
730 | } |
731 | ||
732 | private function stepAll() | |
733 | { | |
734 | foreach ($this->ids as $id) { | |
735 | $this->step($id); | |
736 | } | |
737 | } | |
738 | ||
739 | public function next() | |
740 | { | |
741 | $this->stepAll(); | |
a797e4f7 | 742 | if ($this->current_elts[$this->master_id] === null) { |
851962db RB |
743 | return null; |
744 | } | |
745 | ||
746 | $res = array(); | |
747 | $master = $this->callback_res[$this->master_id]; | |
748 | foreach ($this->ids as $id) { | |
749 | if ($this->callback_res[$id] == $master) { | |
750 | $res[$id] = $this->current_elts[$id]; | |
751 | $this->stepped[$id] = false; | |
752 | } else { | |
753 | $res[$id] = null; | |
754 | } | |
755 | } | |
756 | ||
757 | return $res; | |
758 | } | |
759 | ||
760 | public function first() | |
761 | { | |
762 | return $this->master->first(); | |
763 | } | |
764 | ||
765 | public function total() | |
766 | { | |
767 | return $this->master->total(); | |
768 | } | |
769 | ||
770 | public function last() | |
771 | { | |
772 | return $this->master->last(); | |
773 | } | |
774 | } | |
775 | ||
22c8b530 RB |
776 | // Wrapper class for 'arrayValueCallback' (get field $key of the given array) |
777 | class _GetArrayValueCallback | |
778 | { | |
779 | private $key; | |
780 | ||
781 | public function __construct($key) | |
782 | { | |
783 | $this->key = $key; | |
784 | } | |
785 | ||
786 | public function get(array $arr) | |
787 | { | |
381a28e9 RB |
788 | if (array_key_exists($this->key, $arr)) { |
789 | return $arr[$this->key]; | |
22c8b530 RB |
790 | } else { |
791 | return null; | |
792 | } | |
793 | } | |
794 | } | |
8d37a362 | 795 | |
ce06a3ea RB |
796 | // Wrapper class for 'objectPropertyCallback' (get property ->$blah of the given object) |
797 | class _GetObjectPropertyCallback | |
798 | { | |
799 | private $property; | |
800 | ||
801 | public function __construct($property) | |
802 | { | |
803 | $this->property = $property; | |
804 | } | |
805 | ||
806 | public function get($obj) | |
807 | { | |
808 | $p = $this->property; | |
809 | return @$obj->$p; | |
810 | } | |
811 | } | |
812 | ||
0e95424b FB |
813 | // Wrapper class to build a SPL iterator from a PlIterator |
814 | class SPLIterator implements Iterator | |
815 | { | |
816 | private $it; | |
817 | private $pos; | |
818 | private $value; | |
819 | ||
820 | public function __construct(PlIterator $it) | |
821 | { | |
822 | $this->it = $it; | |
823 | $this->pos = 0; | |
824 | $this->value = $this->it->next(); | |
825 | } | |
826 | ||
827 | public function rewind() | |
828 | { | |
829 | if ($this->pos != 0) { | |
830 | throw new Exception("Rewind not supported on this iterator"); | |
831 | } | |
832 | } | |
833 | ||
834 | public function current() | |
835 | { | |
836 | return $this->value; | |
837 | } | |
838 | ||
839 | public function key() | |
840 | { | |
841 | return $this->pos; | |
842 | } | |
843 | ||
844 | public function next() | |
845 | { | |
846 | ++$this->pos; | |
847 | $this->value = $this->it->next(); | |
848 | } | |
849 | ||
850 | public function valid() | |
851 | { | |
852 | return !!$this->value; | |
853 | } | |
854 | } | |
855 | ||
63f00a3f FB |
856 | // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8: |
857 | ?> |