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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 | } | |
22c8b530 | 138 | } |
5177a1b5 | 139 | |
c291ca54 RB |
140 | /** Empty iterator |
141 | */ | |
142 | class PlEmptyIterator implements PlIterator | |
143 | { | |
144 | public function first() | |
145 | { | |
146 | return false; | |
147 | } | |
148 | ||
149 | public function last() | |
150 | { | |
151 | return false; | |
152 | } | |
153 | ||
154 | public function next() | |
155 | { | |
156 | return null; | |
157 | } | |
158 | ||
159 | public function total() | |
160 | { | |
161 | return 0; | |
162 | } | |
163 | } | |
164 | ||
5177a1b5 FB |
165 | /** Iterates over an array. |
166 | */ | |
63f00a3f FB |
167 | class PlArrayIterator implements PlIterator |
168 | { | |
169 | private $array; | |
170 | private $depth; | |
171 | ||
172 | private $_its = array(); | |
173 | ||
174 | private $_total; | |
175 | private $_first; | |
176 | private $_last; | |
177 | private $_pos; | |
e94c4a17 | 178 | private $_flat; |
63f00a3f | 179 | |
e94c4a17 | 180 | public function __construct(array &$array, $depth = 1, $flat = false) |
63f00a3f FB |
181 | { |
182 | $this->array =& $array; | |
183 | $this->depth = $depth; | |
184 | $this->_total = $this->count($array, $depth - 1); | |
185 | $this->_pos = 0; | |
186 | $this->_first = false; | |
187 | $this->_last = false; | |
e94c4a17 | 188 | $this->_flat = $flat; |
63f00a3f FB |
189 | |
190 | for ($i = 0 ; $i < $depth ; ++$i) { | |
191 | if ($i == 0) { | |
192 | $this->_its[] = $array; | |
193 | } else { | |
194 | $this->_its[] = current($this->_its[$i - 1]); | |
195 | } | |
196 | reset($this->_its[$i]); | |
197 | } | |
198 | } | |
199 | ||
200 | private function count(array &$array, $depth) | |
201 | { | |
202 | if ($depth == 0) { | |
203 | return count($array); | |
204 | } else { | |
205 | $sum = 0; | |
206 | foreach ($array as &$item) { | |
207 | $sum += $this->count($item, $depth - 1); | |
208 | } | |
209 | return $sum; | |
210 | } | |
211 | } | |
212 | ||
213 | private function nextArray($depth) | |
214 | { | |
215 | if ($depth == 0) { | |
216 | return; | |
217 | } | |
218 | $this->_its[$depth] = next($this->_its[$depth - 1]); | |
219 | if ($this->_its[$depth] === false) { | |
220 | $this->nextArray($depth - 1); | |
221 | if ($this->_its[$depth - 1] === false) { | |
222 | return; | |
223 | } | |
224 | $this->_its[$depth] = current($this->_its[$depth - 1]); | |
225 | } | |
226 | reset($this->_its[$depth]); | |
227 | } | |
228 | ||
229 | public function next() | |
230 | { | |
231 | ++$this->_pos; | |
232 | $this->_first = ($this->_total > 0 && $this->_pos == 1); | |
233 | $this->_last = ($this->_pos == $this->_total); | |
234 | if ($this->_pos > $this->_total) { | |
235 | return null; | |
236 | } | |
237 | ||
238 | $val = current($this->_its[$this->depth - 1]); | |
239 | if ($val === false) { | |
240 | $this->nextArray($this->depth - 1); | |
241 | $val = current($this->_its[$this->depth - 1]); | |
242 | if ($val === false) { | |
243 | return null; | |
244 | } | |
245 | } | |
246 | $keys = array(); | |
247 | for ($i = 0 ; $i < $this->depth ; ++$i) { | |
248 | $keys[] = key($this->_its[$i]); | |
249 | } | |
250 | next($this->_its[$this->depth - 1]); | |
e94c4a17 FB |
251 | if ($this->_flat) { |
252 | return $val; | |
253 | } else { | |
254 | return array('keys' => $keys, | |
255 | 'value' => $val); | |
256 | } | |
63f00a3f FB |
257 | } |
258 | ||
259 | public function total() | |
260 | { | |
261 | return $this->_total; | |
262 | } | |
263 | ||
264 | public function first() | |
265 | { | |
266 | return $this->_first; | |
267 | } | |
268 | ||
269 | public function last() | |
270 | { | |
271 | return $this->_last; | |
272 | } | |
273 | } | |
274 | ||
5177a1b5 FB |
275 | |
276 | /** Iterator that return the result of a merge of several iterators. | |
277 | */ | |
278 | class PlMergeIterator implements PlIterator | |
279 | { | |
280 | /* The heap is field with entries with the form: | |
281 | * array('it' => id of the iterator this entry come from, | |
282 | * 'value' => value of the entry). | |
283 | */ | |
284 | private $heap; | |
285 | private $preComputed = false; | |
286 | private $comparator; | |
287 | private $iterators; | |
288 | private $_total; | |
289 | private $pos; | |
290 | ||
291 | public function __construct(array $iterators, $callback, $sorted = true) | |
292 | { | |
293 | $this->heap = new PlHeap(array($this, 'compare')); | |
294 | $this->_total = 0; | |
295 | $this->comparator = $callback; | |
296 | if ($sorted) { | |
297 | $this->iterators = $iterators; | |
298 | foreach ($this->iterators as $key => &$it) { | |
299 | $this->_total += $it->total(); | |
300 | $item = $it->next(); | |
301 | if (!is_null($item)) { | |
302 | $this->heap->push(array('it' => $key, 'value' => $item)); | |
303 | } | |
304 | } | |
305 | } else { | |
306 | $this->preComputed = true; | |
307 | foreach ($iterators as $key => &$it) { | |
308 | $this->_total += $it->total(); | |
309 | while (!is_null($item = $it->next())) { | |
310 | $this->heap->push(array('it' => $key, 'value' => $item)); | |
311 | } | |
312 | } | |
313 | } | |
314 | $this->pos = 0; | |
315 | } | |
316 | ||
317 | /** Compare two entries of the heap using the comparator of the user. | |
318 | */ | |
319 | public function compare($a, $b) | |
320 | { | |
321 | $cp = call_user_func($this->comparator, $a['value'], $b['value']); | |
322 | if ($cp == 0) { | |
323 | return $a['it'] - $b['it']; | |
324 | } | |
325 | return $cp; | |
326 | } | |
327 | ||
328 | public function total() | |
329 | { | |
330 | return $this->_total; | |
331 | } | |
332 | ||
333 | public function next() | |
334 | { | |
335 | ++$this->pos; | |
336 | $entry = $this->heap->pop(); | |
337 | if (is_null($entry)) { | |
338 | return null; | |
339 | } | |
340 | if ($this->preComputed) { | |
341 | return $entry['value']; | |
342 | } | |
343 | $it = $entry['it']; | |
344 | $item = $this->iterators[$it]->next(); | |
345 | if (!is_null($item)) { | |
346 | $this->heap->push(array('it' => $it, 'value' => $item)); | |
347 | } | |
348 | return $entry['value']; | |
349 | } | |
350 | ||
351 | public function last() | |
352 | { | |
353 | return $this->heap->count() == 0; | |
354 | } | |
355 | ||
356 | public function first() | |
357 | { | |
358 | return $this->pos == 1; | |
359 | } | |
360 | } | |
361 | ||
8d37a362 | 362 | |
8b48f8d7 FB |
363 | class PlFilterIterator implements PlIterator |
364 | { | |
365 | private $pos; | |
8d37a362 FB |
366 | private $source; |
367 | private $callback; | |
368 | private $element; | |
8d37a362 FB |
369 | |
370 | public function __construct(PlIterator $source, $callback) | |
371 | { | |
8b48f8d7 | 372 | $this->source = $source; |
8d37a362 | 373 | $this->callback = $callback; |
8b48f8d7 FB |
374 | $this->pos = 0; |
375 | $this->element = $this->fetchNext(); | |
8d37a362 FB |
376 | } |
377 | ||
378 | private function fetchNext() | |
379 | { | |
380 | do { | |
381 | $current = $this->source->next(); | |
8b48f8d7 FB |
382 | if (is_null($current) || call_user_func($this->callback, $current)) { |
383 | return $current; | |
8d37a362 FB |
384 | } |
385 | } while (true); | |
386 | } | |
387 | ||
388 | public function next() | |
389 | { | |
8b48f8d7 | 390 | ++$this->pos; |
8d37a362 | 391 | $elt = $this->element; |
8b48f8d7 FB |
392 | if (!is_null($this->element)) { |
393 | $this->element = $this->fetchNext(); | |
8d37a362 FB |
394 | } |
395 | return $elt; | |
396 | } | |
397 | ||
398 | public function total() | |
399 | { | |
400 | /* This is an approximation since the correct total | |
401 | * cannot be computed without fetching all the elements | |
402 | */ | |
403 | return $this->source->total(); | |
404 | } | |
405 | ||
406 | public function first() | |
407 | { | |
8b48f8d7 | 408 | return $this->pos == 1; |
8d37a362 FB |
409 | } |
410 | ||
411 | public function last() | |
412 | { | |
8b48f8d7 | 413 | return is_null($this->element); |
8d37a362 FB |
414 | } |
415 | } | |
416 | ||
417 | ||
418 | class PlMapIterator implements PlIterator | |
419 | { | |
420 | private $source; | |
421 | private $callback; | |
422 | ||
423 | public function __construct(PlIterator $source, $callback) | |
424 | { | |
425 | $this->source = $source; | |
426 | $this->callback = $callback; | |
427 | } | |
428 | ||
429 | public function next() | |
430 | { | |
431 | $elt = $this->source->next(); | |
432 | if ($elt) { | |
433 | return call_user_func($this->callback, $elt); | |
434 | } else { | |
435 | return null; | |
436 | } | |
437 | } | |
438 | ||
439 | public function total() | |
440 | { | |
441 | return $this->source->total(); | |
442 | } | |
443 | ||
444 | public function first() | |
445 | { | |
446 | return $this->source->first(); | |
447 | } | |
448 | ||
449 | public function last() | |
450 | { | |
451 | return $this->source->last(); | |
452 | } | |
453 | } | |
454 | ||
22c8b530 RB |
455 | class PlSubIterator implements PlIterator |
456 | { | |
457 | private $source; | |
458 | private $callback; | |
459 | private $next = null; // The next item, if it has been fetched too early by a subiterator | |
a52d0af8 RB |
460 | private $pos = 0; |
461 | private $sub = null; | |
22c8b530 RB |
462 | |
463 | public function __construct(PlIterator $source, $callback) | |
464 | { | |
465 | $this->source = $source; | |
466 | $this->callback = $callback; | |
467 | } | |
468 | ||
a52d0af8 RB |
469 | /** WARNING: this will "fast-forward" the subiterator to its end |
470 | */ | |
22c8b530 RB |
471 | public function next() |
472 | { | |
473 | if ($this->last()) { | |
474 | return null; | |
475 | } else { | |
a52d0af8 RB |
476 | if ($this->sub != null) { |
477 | while (!$this->sub->last()) { | |
478 | $this->sub->next(); | |
479 | } | |
480 | } | |
481 | ||
482 | if ($this->last()) { | |
483 | return null; | |
484 | } | |
485 | ||
486 | ++$this->pos; | |
487 | $this->sub = new PlInnerSubIterator($this->source, $this->callback, $this, $this->next); | |
488 | return $this->sub; | |
22c8b530 RB |
489 | } |
490 | } | |
491 | ||
492 | /** This will always be a too big number, but the actual result can't be easily computed | |
493 | */ | |
494 | public function total() | |
495 | { | |
496 | return $this->source->total(); | |
497 | } | |
498 | ||
a52d0af8 RB |
499 | /** This will only return true if the current subiterator was the last one, |
500 | * and if it has been fully used | |
501 | */ | |
22c8b530 RB |
502 | public function last() |
503 | { | |
a52d0af8 RB |
504 | if ($this->sub != null && !$this->sub->last()) { |
505 | return false; | |
506 | } | |
22c8b530 RB |
507 | return ($this->source->last() && $this->next == null); |
508 | } | |
509 | ||
9d865d03 FB |
510 | public function first() |
511 | { | |
a52d0af8 | 512 | return $this->pos == 1; |
9d865d03 FB |
513 | } |
514 | ||
22c8b530 RB |
515 | // Called by a subiterator to "rewind" the core iterator |
516 | public function setNext($item) | |
517 | { | |
518 | $this->next = $item; | |
519 | } | |
520 | } | |
521 | ||
522 | class PlInnerSubIterator implements PlIterator | |
523 | { | |
524 | private $source; | |
525 | private $callback; | |
526 | private $parent; | |
527 | ||
528 | private $next; // Not null if the source has to be "rewinded" | |
529 | ||
530 | private $curval = null; | |
531 | private $curelt = null; | |
a52d0af8 RB |
532 | private $val = null; |
533 | private $pos = 0; | |
22c8b530 RB |
534 | private $stepped = false; |
535 | private $over = false; | |
536 | ||
537 | public function __construct(PlIterator $source, $callback, PlSubIterator $parent, $next = null) | |
538 | { | |
539 | $this->source = $source; | |
540 | $this->callback = $callback; | |
541 | $this->parent = $parent; | |
542 | $this->next = $next; | |
a52d0af8 | 543 | $this->parent->setNext(null); |
22c8b530 RB |
544 | } |
545 | ||
546 | public function value() | |
547 | { | |
548 | $this->_step(); | |
549 | return $this->curval; | |
550 | } | |
551 | ||
552 | // Move one step, if the current element has been used | |
553 | private function _step() | |
554 | { | |
555 | if ($this->stepped) { | |
556 | return; | |
557 | } | |
558 | ||
559 | if ($this->next != null) { | |
560 | $this->curelt = $this->next; | |
561 | $this->next = null; | |
562 | } else { | |
a52d0af8 RB |
563 | if ($this->source->last()) { |
564 | $this->over = true; | |
565 | return; | |
566 | } | |
21f0c57c | 567 | $this->curelt = $this->source->next(); |
22c8b530 | 568 | } |
21f0c57c | 569 | |
a52d0af8 RB |
570 | if ($this->pos == 0) { |
571 | $this->val = call_user_func($this->callback, $this->curelt); | |
572 | $this->curval = $this->val; | |
573 | } else { | |
21f0c57c | 574 | $this->curval = call_user_func($this->callback, $this->curelt); |
21f0c57c RB |
575 | } |
576 | ||
22c8b530 RB |
577 | $this->stepped = true; |
578 | } | |
579 | ||
580 | public function next() | |
581 | { | |
a52d0af8 RB |
582 | if ($this->over) { |
583 | return null; | |
584 | } | |
585 | ||
22c8b530 | 586 | $this->_step(); |
a52d0af8 RB |
587 | |
588 | if ($this->over) { | |
589 | return null; | |
590 | } | |
591 | ||
592 | ++$this->pos; | |
22c8b530 RB |
593 | $this->stepped = false; |
594 | ||
a52d0af8 RB |
595 | if ($this->val == $this->curval) { |
596 | return $this->curelt; | |
22c8b530 | 597 | } |
a52d0af8 RB |
598 | |
599 | $this->parent->setNext($this->curelt); | |
22c8b530 RB |
600 | $this->over = true; |
601 | return null; | |
602 | } | |
603 | ||
604 | /** This will always be a too big number, but the actual result can't be easily computed | |
605 | */ | |
606 | public function total() | |
607 | { | |
608 | return $this->source->total(); | |
609 | } | |
610 | ||
611 | public function last() | |
612 | { | |
a52d0af8 RB |
613 | if ($this->over) { |
614 | return true; | |
615 | } | |
616 | $this->_step(); | |
617 | return $this->over || ($this->val != $this->curval); | |
22c8b530 RB |
618 | } |
619 | ||
9d865d03 FB |
620 | public function first() |
621 | { | |
a52d0af8 | 622 | return $this->pos == 1; |
9d865d03 FB |
623 | } |
624 | ||
22c8b530 RB |
625 | } |
626 | ||
851962db RB |
627 | /** Builds an iterator over a set of iterators, from which one is given as 'master'; |
628 | * The arguments are : | |
629 | * - An array of iterators, to iterate simultaneously | |
630 | * - An array of callbacks (one attached to each iterator), or a single callback (to | |
631 | * use for all iterators) | |
632 | * - The id of the 'master' iterator | |
633 | * | |
634 | * This ParallelIterator will iterate over the iterators, and, at each | |
635 | * step of the master iterator, it will apply the callbacks to the corresponding | |
636 | * iterators and return the values of the "slaves" for which the callback returned the | |
637 | * same value as the callback of the master. | |
638 | * | |
639 | * The callback should compute some kind of index, and never return the same value | |
640 | * twice for a given iterator | |
641 | * | |
642 | * It is assumed that, if the callback for a slave doesn't have the same value | |
643 | * as the value for the master, this means that there is a "hole" in the values | |
644 | * of that slave. | |
645 | * | |
646 | * Example : | |
647 | * - The callback is 'get the first cell' | |
648 | * - The master is : | |
649 | * [0, 1], [1, 13], [2, 42] | |
650 | * - The first slave (slave1) is : | |
651 | * [0, 'a'], [2, 'b'] | |
652 | * - The second slave (slave2) is : | |
653 | * [1, 42], [2, 0] | |
654 | * The resulting iterator would yield : | |
655 | * - array(master => [0, 1], slave1 => [0, 'a'], slave2 => null) | |
656 | * - array(master => [1, 13], slave1 => null, slave2 => [1, 42]) | |
657 | * - array(master => [2, 42], slave1 => [1, 'b'], slave2 => [2, 0]) | |
658 | */ | |
659 | class PlParallelIterator implements PlIterator | |
660 | { | |
661 | private $iterators; | |
662 | private $ids; | |
663 | private $callbacks; | |
664 | ||
665 | private $master_id; | |
666 | private $master; | |
667 | ||
a797e4f7 RB |
668 | private $over = array(); |
669 | private $stepped = array(); | |
851962db RB |
670 | private $current_elts = array(); |
671 | private $callback_res = array(); | |
672 | ||
673 | public function __construct(array $iterators, $callbacks, $master) | |
674 | { | |
675 | $this->iterators = $iterators; | |
676 | $this->master_id = $master; | |
677 | $this->master = $iterators[$master]; | |
678 | ||
679 | $this->ids = array_keys($iterators); | |
680 | ||
ff539a07 RB |
681 | $v = array_values($callbacks); |
682 | if (is_array($v[0])) { | |
851962db RB |
683 | $this->callbacks = $callbacks; |
684 | } else { | |
685 | $this->callbacks = array(); | |
686 | foreach ($this->ids as $id) { | |
687 | $this->callbacks[$id] = $callbacks; | |
688 | } | |
689 | } | |
690 | ||
691 | foreach ($this->ids as $id) { | |
692 | $this->stepped[$id] = false; | |
a797e4f7 | 693 | $this->over[$id] = false; |
851962db RB |
694 | $this->current_elts[$id] = null; |
695 | $this->callback_res[$id] = null; | |
696 | } | |
697 | } | |
698 | ||
699 | private function step($id) | |
700 | { | |
701 | if ($this->stepped[$id]) { | |
702 | return; | |
703 | } | |
704 | ||
a797e4f7 RB |
705 | // Don't do anything if the iterator is at its end |
706 | if ($this->over[$id]) { | |
707 | $this->stepped[$id] = true; | |
708 | return; | |
709 | } | |
710 | ||
851962db RB |
711 | $it = $this->iterators[$id]; |
712 | $nxt = $it->next(); | |
a797e4f7 RB |
713 | $this->stepped[$id] = true; |
714 | if ($nxt === null) { | |
715 | $this->over[$id] = true; | |
716 | $this->current_elts[$id] = null; | |
717 | $this->callback_res[$id] = null; | |
718 | return; | |
719 | } | |
851962db RB |
720 | $res = call_user_func($this->callbacks[$id], $nxt); |
721 | $this->current_elts[$id] = $nxt; | |
722 | $this->callback_res[$id] = $res; | |
851962db RB |
723 | } |
724 | ||
725 | private function stepAll() | |
726 | { | |
727 | foreach ($this->ids as $id) { | |
728 | $this->step($id); | |
729 | } | |
730 | } | |
731 | ||
732 | public function next() | |
733 | { | |
734 | $this->stepAll(); | |
a797e4f7 | 735 | if ($this->current_elts[$this->master_id] === null) { |
851962db RB |
736 | return null; |
737 | } | |
738 | ||
739 | $res = array(); | |
740 | $master = $this->callback_res[$this->master_id]; | |
741 | foreach ($this->ids as $id) { | |
742 | if ($this->callback_res[$id] == $master) { | |
743 | $res[$id] = $this->current_elts[$id]; | |
744 | $this->stepped[$id] = false; | |
745 | } else { | |
746 | $res[$id] = null; | |
747 | } | |
748 | } | |
749 | ||
750 | return $res; | |
751 | } | |
752 | ||
753 | public function first() | |
754 | { | |
755 | return $this->master->first(); | |
756 | } | |
757 | ||
758 | public function total() | |
759 | { | |
760 | return $this->master->total(); | |
761 | } | |
762 | ||
763 | public function last() | |
764 | { | |
765 | return $this->master->last(); | |
766 | } | |
767 | } | |
768 | ||
22c8b530 RB |
769 | // Wrapper class for 'arrayValueCallback' (get field $key of the given array) |
770 | class _GetArrayValueCallback | |
771 | { | |
772 | private $key; | |
773 | ||
774 | public function __construct($key) | |
775 | { | |
776 | $this->key = $key; | |
777 | } | |
778 | ||
779 | public function get(array $arr) | |
780 | { | |
381a28e9 RB |
781 | if (array_key_exists($this->key, $arr)) { |
782 | return $arr[$this->key]; | |
22c8b530 RB |
783 | } else { |
784 | return null; | |
785 | } | |
786 | } | |
787 | } | |
8d37a362 | 788 | |
ce06a3ea RB |
789 | // Wrapper class for 'objectPropertyCallback' (get property ->$blah of the given object) |
790 | class _GetObjectPropertyCallback | |
791 | { | |
792 | private $property; | |
793 | ||
794 | public function __construct($property) | |
795 | { | |
796 | $this->property = $property; | |
797 | } | |
798 | ||
799 | public function get($obj) | |
800 | { | |
801 | $p = $this->property; | |
802 | return @$obj->$p; | |
803 | } | |
804 | } | |
805 | ||
63f00a3f FB |
806 | // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8: |
807 | ?> |