Innmind /
Immutable
Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Collection often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Collection, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 11 | class Collection implements CollectionInterface |
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| 12 | { |
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| 13 | private $values; |
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| 14 | |||
| 15 | 16 | public function __construct(array $values) |
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| 19 | |||
| 20 | /** |
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| 21 | * {@inheritdoc} |
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| 22 | */ |
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| 23 | 15 | public function toPrimitive() |
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| 27 | |||
| 28 | /** |
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| 29 | * {@inheritdoc} |
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| 30 | */ |
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| 31 | 1 | public function filter(callable $filter = null) |
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| 45 | |||
| 46 | /** |
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| 47 | * {@inheritdoc} |
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| 48 | */ |
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| 49 | 1 | public function intersect(CollectionInterface $collection) |
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| 56 | |||
| 57 | /** |
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| 58 | * {@inheritdoc} |
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| 59 | */ |
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| 60 | 1 | public function chunk($size) |
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| 64 | |||
| 65 | /** |
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| 66 | * {@inheritdoc} |
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| 67 | */ |
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| 68 | 1 | public function shift() |
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| 75 | |||
| 76 | /** |
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| 77 | * {@inheritdoc} |
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| 78 | */ |
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| 79 | 1 | public function reduce(callable $reducer, $initial = null) |
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| 83 | |||
| 84 | /** |
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| 85 | * {@inheritdoc} |
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| 86 | */ |
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| 87 | 1 | public function search($needle, $strict = true) |
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| 91 | |||
| 92 | /** |
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| 93 | * {@inheritdoc} |
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| 94 | */ |
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| 95 | 1 | public function uintersect(CollectionInterface $collection, callable $intersecter) |
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| 103 | |||
| 104 | /** |
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| 105 | * {@inheritdoc} |
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| 106 | */ |
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| 107 | 1 | public function keyIntersect(CollectionInterface $collection) |
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| 114 | |||
| 115 | /** |
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| 116 | * {@inheritdoc} |
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| 117 | */ |
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| 118 | 1 | public function map(callable $mapper) |
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| 122 | |||
| 123 | /** |
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| 124 | * {@inheritdoc} |
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| 125 | */ |
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| 126 | 1 | public function pad($size, $value) |
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| 130 | |||
| 131 | /** |
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| 132 | * {@inheritdoc} |
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| 133 | */ |
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| 134 | 1 | public function pop() |
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| 141 | |||
| 142 | /** |
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| 143 | * {@inheritdoc} |
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| 144 | */ |
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| 145 | 1 | public function sum() |
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| 149 | |||
| 150 | /** |
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| 151 | * {@inheritdoc} |
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| 152 | */ |
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| 153 | 1 | public function diff(CollectionInterface $collection) |
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| 157 | |||
| 158 | /** |
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| 159 | * {@inheritdoc} |
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| 160 | */ |
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| 161 | 1 | public function flip() |
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| 165 | |||
| 166 | /** |
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| 167 | * {@inheritdoc} |
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| 168 | */ |
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| 169 | 1 | public function keys($search = null, $strict = true) |
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| 181 | |||
| 182 | /** |
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| 183 | * {@inheritdoc} |
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| 184 | */ |
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| 185 | public function push($value) |
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| 192 | |||
| 193 | /** |
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| 194 | * {@inheritdoc} |
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| 195 | */ |
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| 196 | public function rand($num = 1) |
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| 213 | |||
| 214 | /** |
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| 215 | * {@inheritdoc} |
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| 216 | */ |
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| 217 | public function merge(CollectionInterface $collection) |
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| 224 | |||
| 225 | /** |
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| 226 | * {@inheritdoc} |
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| 227 | */ |
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| 228 | public function slice($offset, $length = null, $preserveKeys = false) |
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| 237 | |||
| 238 | /** |
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| 239 | * {@inheritdoc} |
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| 240 | */ |
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| 241 | public function udiff(CollectionInterface $collection, callable $differ) |
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| 249 | |||
| 250 | /** |
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| 251 | * {@inheritdoc} |
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| 252 | */ |
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| 253 | public function column($key, $indexKey = null) |
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| 261 | |||
| 262 | /** |
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| 263 | * {@inheritdoc} |
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| 264 | */ |
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| 265 | public function splice($offset, $length = 0, $replacement = []) |
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| 272 | |||
| 273 | /** |
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| 274 | * {@inheritdoc} |
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| 275 | */ |
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| 276 | public function unique($flags = SORT_REGULAR) |
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| 280 | |||
| 281 | /** |
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| 282 | * {@inheritdoc} |
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| 283 | */ |
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| 284 | public function values() |
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| 288 | |||
| 289 | /** |
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| 290 | * {@inheritdoc} |
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| 291 | */ |
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| 292 | public function product() |
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| 296 | |||
| 297 | /** |
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| 298 | * {@inheritdoc} |
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| 299 | */ |
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| 300 | public function replace(CollectionInterface $collection) |
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| 307 | |||
| 308 | /** |
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| 309 | * {@inheritdoc} |
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| 310 | */ |
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| 311 | public function reverse($preserveKeys = false) |
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| 315 | |||
| 316 | /** |
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| 317 | * {@inheritdoc} |
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| 318 | */ |
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| 319 | public function unshift($value) |
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| 326 | |||
| 327 | /** |
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| 328 | * {@inheritdoc} |
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| 329 | */ |
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| 330 | public function keyDiff(CollectionInterface $collection) |
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| 337 | |||
| 338 | /** |
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| 339 | * {@inheritdoc} |
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| 340 | */ |
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| 341 | public function ukeyDiff(CollectionInterface $collection, callable $differ) |
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| 349 | |||
| 350 | /** |
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| 351 | * {@inheritdoc} |
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| 352 | */ |
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| 353 | public function associativeDiff(CollectionInterface $collection) |
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| 360 | |||
| 361 | /** |
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| 362 | * {@inheritdoc} |
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| 363 | */ |
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| 364 | public function hasKey($key, $strict = true) |
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| 374 | |||
| 375 | /** |
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| 376 | * {@inheritdoc} |
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| 377 | */ |
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| 378 | public function countValues() |
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| 382 | |||
| 383 | /** |
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| 384 | * {@inheritdoc} |
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| 385 | */ |
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| 386 | public function ukeyIntersect(CollectionInterface $collection, callable $intersecter) |
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| 394 | |||
| 395 | /** |
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| 396 | * {@inheritdoc} |
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| 397 | */ |
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| 398 | public function associativeIntersect(CollectionInterface $collection) |
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| 405 | |||
| 406 | /** |
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| 407 | * {@inheritdoc} |
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| 408 | */ |
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| 409 | View Code Duplication | public function sort($flags = SORT_REGULAR) |
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| 420 | |||
| 421 | /** |
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| 422 | * {@inheritdoc} |
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| 423 | */ |
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| 424 | View Code Duplication | public function associativeSort($flags = SORT_REGULAR) |
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| 435 | |||
| 436 | /** |
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| 437 | * {@inheritdoc} |
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| 438 | */ |
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| 439 | View Code Duplication | public function keySort($flags = SORT_REGULAR) |
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| 450 | |||
| 451 | /** |
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| 452 | * {@inheritdoc} |
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| 453 | */ |
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| 454 | View Code Duplication | public function ukeySort(callable $sorter) |
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| 465 | |||
| 466 | /** |
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| 467 | * {@inheritdoc} |
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| 468 | */ |
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| 469 | View Code Duplication | public function reverseSort($flags = SORT_REGULAR) |
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| 480 | |||
| 481 | /** |
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| 482 | * {@inheritdoc} |
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| 483 | */ |
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| 484 | View Code Duplication | public function usort(callable $sorter) |
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| 495 | |||
| 496 | /** |
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| 497 | * {@inheritdoc} |
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| 498 | */ |
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| 499 | View Code Duplication | public function associativeReverseSort($flags = SORT_REGULAR) |
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| 510 | |||
| 511 | /** |
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| 512 | * {@inheritdoc} |
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| 513 | */ |
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| 514 | View Code Duplication | public function keyReverseSort($flags = SORT_REGULAR) |
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| 525 | |||
| 526 | /** |
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| 527 | * {@inheritdoc} |
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| 528 | */ |
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| 529 | View Code Duplication | public function uassociativeSort(callable $sorter) |
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| 540 | |||
| 541 | /** |
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| 542 | * {@inheritdoc} |
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| 543 | */ |
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| 544 | public function naturalSort() |
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| 555 | |||
| 556 | /** |
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| 557 | * {@inheritdoc} |
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| 558 | */ |
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| 559 | View Code Duplication | public function first() |
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| 567 | |||
| 568 | /** |
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| 569 | * {@inheritdoc} |
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| 570 | */ |
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| 571 | View Code Duplication | public function last() |
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| 581 | |||
| 582 | /** |
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| 583 | * {@inheritdoc} |
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| 584 | */ |
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| 585 | public function each(callable $callback) |
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| 593 | |||
| 594 | /** |
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| 595 | * {@inheritdoc} |
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| 596 | */ |
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| 597 | public function join($separator) |
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| 601 | |||
| 602 | /** |
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| 603 | * {@inheritdoc} |
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| 604 | */ |
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| 605 | public function shuffle() |
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| 616 | |||
| 617 | /** |
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| 618 | * {@inheritdoc} |
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| 619 | */ |
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| 620 | public function take($size, $preserveKeys = false) |
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| 639 | |||
| 640 | /** |
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| 641 | * {@inheritdoc} |
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| 642 | */ |
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| 643 | public function count() |
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| 647 | |||
| 648 | /** |
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| 649 | * {@inheritdoc} |
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| 650 | */ |
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| 651 | public function current() |
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| 655 | |||
| 656 | /** |
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| 657 | * {@inheritdoc} |
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| 658 | */ |
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| 659 | public function key() |
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| 663 | |||
| 664 | /** |
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| 665 | * {@inheritdoc} |
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| 666 | */ |
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| 667 | public function next() |
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| 671 | |||
| 672 | /** |
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| 673 | * {@inheritdoc} |
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| 674 | */ |
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| 675 | public function rewind() |
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| 679 | |||
| 680 | /** |
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| 681 | * {@inheritdoc} |
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| 682 | */ |
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| 683 | public function valid() |
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| 687 | |||
| 688 | /** |
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| 689 | * {@inheritdoc} |
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| 690 | */ |
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| 691 | public function offsetExists($offset) |
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| 695 | |||
| 696 | /** |
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| 697 | * {@inheritdoc} |
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| 698 | */ |
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| 699 | public function offsetGet($offset) |
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| 710 | |||
| 711 | /** |
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| 712 | * {@inheritdoc} |
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| 713 | */ |
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| 714 | public function offsetSet($offset, $value) |
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| 718 | |||
| 719 | /** |
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| 720 | * {@inheritdoc} |
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| 721 | */ |
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| 722 | public function offsetUnset($offset) |
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| 726 | } |
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| 727 |
Loading history...
Let’s assume that you have a directory layout like this:
. |-- OtherDir | |-- Bar.php | `-- Foo.php `-- SomeDir `-- Foo.phpand let’s assume the following content of
Bar.php:If both files
OtherDir/Foo.phpandSomeDir/Foo.phpare loaded in the same runtime, you will see a PHP error such as the following:PHP Fatal error: Cannot use SomeDir\Foo as Foo because the name is already in use in OtherDir/Foo.phpHowever, as
OtherDir/Foo.phpdoes not necessarily have to be loaded and the error is only triggered if it is loaded beforeOtherDir/Bar.php, this problem might go unnoticed for a while. In order to prevent this error from surfacing, you must import the namespace with a different alias: