| Total Complexity | 52 |
| Total Lines | 386 |
| Duplicated Lines | 0 % |
| Changes | 0 | ||
Complex classes like LinkedList 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.
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 LinkedList, and based on these observations, apply Extract Interface, too.
| 1 | <?php namespace Mbh\Collection\Traits\Sequenceable; |
||
| 25 | trait LinkedList |
||
| 26 | { |
||
| 27 | use LinkedList\ArrayAccess; |
||
| 28 | use LinkedList\Countable; |
||
| 29 | use LinkedList\Iterator; |
||
| 30 | |||
| 31 | protected $head; |
||
| 32 | protected $tail; |
||
| 33 | protected $size; |
||
| 34 | protected $current; |
||
| 35 | protected $offset = -1; |
||
| 36 | |||
| 37 | /** |
||
| 38 | * Create an fixed array |
||
| 39 | * |
||
| 40 | * @param array|Traversable $array data |
||
| 41 | */ |
||
| 42 | public function __construct($array = null) |
||
| 43 | { |
||
| 44 | $this->head = $head = new LinkedTerminalNode(); |
||
| 45 | $this->tail = $tail = new LinkedTerminalNode(); |
||
| 46 | |||
| 47 | $head->setNext($tail); |
||
| 48 | $tail->setPrev($head); |
||
| 49 | |||
| 50 | $this->current = $this->head; |
||
| 51 | |||
| 52 | if ($array) { |
||
| 53 | $this->pushAll($array); |
||
| 54 | } |
||
| 55 | } |
||
| 56 | |||
| 57 | public function __clone() |
||
| 58 | { |
||
| 59 | $list = $this->copyFromContext($this->head->next()); |
||
| 60 | |||
| 61 | $this->head = $list->head; |
||
| 62 | $this->tail = $list->tail; |
||
| 63 | |||
| 64 | $this->current = $this->head; |
||
| 65 | $this->offset = -1; |
||
| 66 | |||
| 67 | $this->size = $list->size; |
||
| 68 | } |
||
| 69 | |||
| 70 | protected function backward() |
||
| 71 | { |
||
| 72 | $this->current = $this->current->prev(); |
||
| 73 | $this->offset--; |
||
| 74 | } |
||
| 75 | |||
| 76 | public function clear() |
||
| 77 | { |
||
| 78 | $this->head->setNext($this->tail); |
||
| 79 | $this->tail->setPrev($this->head); |
||
| 80 | |||
| 81 | $this->current = $this->head; |
||
| 82 | $this->size = 0; |
||
| 83 | $this->offset = -1; |
||
| 84 | } |
||
| 85 | |||
| 86 | public function contains(...$values): bool |
||
| 87 | { |
||
| 88 | return $this->indexOf($values, $f) >= 0; |
||
|
|
|||
| 89 | } |
||
| 90 | |||
| 91 | public function copy() |
||
| 92 | { |
||
| 93 | return $this->copyFromContext($this->head->next()); |
||
| 94 | } |
||
| 95 | |||
| 96 | protected function copyFromContext(LinkedNode $context) |
||
| 97 | { |
||
| 98 | $list = new static(); |
||
| 99 | |||
| 100 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
||
| 101 | /** |
||
| 102 | * @var LinkedDataNode $n |
||
| 103 | */ |
||
| 104 | $list->push($n->value()); |
||
| 105 | } |
||
| 106 | |||
| 107 | return $list; |
||
| 108 | } |
||
| 109 | |||
| 110 | protected function forward() |
||
| 111 | { |
||
| 112 | $this->current = $this->current->next(); |
||
| 113 | $this->offset++; |
||
| 114 | } |
||
| 115 | |||
| 116 | public function first() |
||
| 117 | { |
||
| 118 | $this->emptyGuard(__METHOD__); |
||
| 119 | return $this->seekHead()->value(); |
||
| 120 | } |
||
| 121 | |||
| 122 | public function get(int $index) |
||
| 123 | { |
||
| 124 | return $this[$index]; |
||
| 125 | } |
||
| 126 | |||
| 127 | protected function getSize() |
||
| 128 | { |
||
| 129 | return $this->size; |
||
| 130 | } |
||
| 131 | |||
| 132 | protected function getValues(): Traversable |
||
| 133 | { |
||
| 134 | return SplFixedArray::fromArray($this->toArray()); |
||
| 135 | } |
||
| 136 | |||
| 137 | protected function guardedSeek($index, $method) |
||
| 138 | { |
||
| 139 | $index = $this->intGuard($index); |
||
| 140 | $this->indexGuard($index, $method); |
||
| 141 | |||
| 142 | return $this->seekTo($index); |
||
| 143 | } |
||
| 144 | |||
| 145 | protected function indexGuard($offset, $method) |
||
| 146 | { |
||
| 147 | if (!$this->offsetExists($offset)) { |
||
| 148 | throw new OutOfBoundsException( |
||
| 149 | "{$method} was called with invalid index: {$offset}" |
||
| 150 | ); |
||
| 151 | } |
||
| 152 | } |
||
| 153 | |||
| 154 | /** |
||
| 155 | * @param $value |
||
| 156 | * @param callable $callback |
||
| 157 | * @return int |
||
| 158 | */ |
||
| 159 | public function indexOf($value, callable $callback = null) |
||
| 160 | { |
||
| 161 | $equal = $f ?? function ($a, $b) { |
||
| 162 | return $a === $b; |
||
| 163 | }; |
||
| 164 | |||
| 165 | $filter = $this->filter(function ($item) use ($equal, $value) { |
||
| 166 | return $equal($item, $value); |
||
| 167 | }); |
||
| 168 | |||
| 169 | foreach ($filter as $key => $value) { |
||
| 170 | return $key; |
||
| 171 | } |
||
| 172 | |||
| 173 | return -1; |
||
| 174 | } |
||
| 175 | |||
| 176 | public function insert(int $index, ...$values) |
||
| 177 | { |
||
| 178 | foreach ($values as &$value) { |
||
| 179 | $this->insertBefore($index++, $value); |
||
| 180 | } |
||
| 181 | } |
||
| 182 | |||
| 183 | /** |
||
| 184 | * @param int $position |
||
| 185 | * @param mixed $value |
||
| 186 | * @return void |
||
| 187 | * |
||
| 188 | * @throws OutOfBoundsException |
||
| 189 | */ |
||
| 190 | public function insertAfter(int $position, $value) |
||
| 191 | { |
||
| 192 | $n = $this->guardedSeek($position, __METHOD__); |
||
| 193 | $this->insertBetween($n, $n->next(), $value); |
||
| 194 | $this->current = $this->current->prev(); |
||
| 195 | } |
||
| 196 | |||
| 197 | /** |
||
| 198 | * @param int $position |
||
| 199 | * @param mixed $value |
||
| 200 | * @return void |
||
| 201 | * |
||
| 202 | * @throws OutOfBoundsException |
||
| 203 | */ |
||
| 204 | public function insertBefore(int $position, $value) |
||
| 205 | { |
||
| 206 | $n = $this->guardedSeek($position, __METHOD__); |
||
| 207 | $this->insertBetween($n->prev(), $n, $value); |
||
| 208 | $this->current = $this->current->next(); |
||
| 209 | $this->offset++; |
||
| 210 | } |
||
| 211 | |||
| 212 | protected function insertBetween(LinkedNode $a, LinkedNode $b, $value) |
||
| 213 | { |
||
| 214 | $n = new LinkedDataNode($value); |
||
| 215 | |||
| 216 | $a->setNext($n); |
||
| 217 | $b->setPrev($n); |
||
| 218 | |||
| 219 | $n->setPrev($a); |
||
| 220 | $n->setNext($b); |
||
| 221 | |||
| 222 | $this->current = $n; |
||
| 223 | $this->size++; |
||
| 224 | } |
||
| 225 | |||
| 226 | /** |
||
| 227 | * @param mixed $i |
||
| 228 | * @return int |
||
| 229 | * @throws Exception |
||
| 230 | */ |
||
| 231 | protected function intGuard($i) |
||
| 232 | { |
||
| 233 | if (filter_var($i, FILTER_VALIDATE_INT) === false) { |
||
| 234 | throw new Exception; |
||
| 235 | } |
||
| 236 | |||
| 237 | return (int) $i; |
||
| 238 | } |
||
| 239 | |||
| 240 | public function last() |
||
| 241 | { |
||
| 242 | $this->emptyGuard(__METHOD__); |
||
| 243 | return $this->seekTail()->value(); |
||
| 244 | } |
||
| 245 | |||
| 246 | public function pop() |
||
| 247 | { |
||
| 248 | $this->emptyGuard(__METHOD__); |
||
| 249 | |||
| 250 | $n = $this->seekTail(); |
||
| 251 | $this->removeNode($n); |
||
| 252 | |||
| 253 | return $n->value(); |
||
| 254 | } |
||
| 255 | |||
| 256 | public function push(...$values) |
||
| 257 | { |
||
| 258 | $this->pushAll($values); |
||
| 259 | } |
||
| 260 | |||
| 261 | protected function pushAll($values) |
||
| 262 | { |
||
| 263 | foreach ($values as $key => $value) { |
||
| 264 | $this->insertBetween($this->tail->prev(), $this->tail, $value); |
||
| 265 | $this->offset = $this->size - 1; |
||
| 266 | } |
||
| 267 | } |
||
| 268 | |||
| 269 | public function remove(int $index) |
||
| 270 | { |
||
| 271 | return $this->removeNode($this->guardedSeek($index, __METHOD__)); |
||
| 272 | } |
||
| 273 | |||
| 274 | protected function removeNode(LinkedNode $n) |
||
| 275 | { |
||
| 276 | $prev = $n->prev(); |
||
| 277 | $next = $n->next(); |
||
| 278 | |||
| 279 | $prev->setNext($next); |
||
| 280 | $next->setPrev($prev); |
||
| 281 | |||
| 282 | $this->size--; |
||
| 283 | } |
||
| 284 | |||
| 285 | /** |
||
| 286 | * @link http://php.net/manual/en/seekableiterator.seek.php |
||
| 287 | * @param int $position |
||
| 288 | * @return mixed |
||
| 289 | * @throws OutOfBoundsException |
||
| 290 | * @throws Exception |
||
| 291 | */ |
||
| 292 | public function seek($position) |
||
| 304 | } |
||
| 305 | |||
| 306 | /** |
||
| 307 | * @return LinkedDataNode |
||
| 308 | */ |
||
| 309 | protected function seekTail() |
||
| 310 | { |
||
| 311 | $this->offset = $this->size - 1; |
||
| 312 | return $this->current = $this->tail->prev(); |
||
| 313 | } |
||
| 314 | |||
| 315 | /** |
||
| 316 | * @return LinkedDataNode |
||
| 317 | */ |
||
| 318 | protected function seekHead() |
||
| 319 | { |
||
| 320 | $this->offset = 0; |
||
| 321 | return $this->current = $this->head->next(); |
||
| 322 | } |
||
| 323 | |||
| 324 | /** |
||
| 325 | * @param $offset |
||
| 326 | * @return LinkedDataNode |
||
| 327 | */ |
||
| 328 | protected function seekTo($offset) |
||
| 329 | { |
||
| 330 | $n = abs($diff = $this->offset - $offset); |
||
| 331 | $action = ($diff < 0) ? 'forward' : 'backward'; |
||
| 332 | |||
| 333 | for ($i = 0; $i < $n; $i++) { |
||
| 334 | $this->$action(); |
||
| 335 | } |
||
| 336 | |||
| 337 | return $this->current; |
||
| 338 | } |
||
| 339 | |||
| 340 | /** |
||
| 341 | * @inheritDoc |
||
| 342 | */ |
||
| 343 | public function set(int $index, $value) |
||
| 344 | { |
||
| 345 | $this->offsetSet($index, $value); |
||
| 346 | } |
||
| 347 | |||
| 348 | protected function setValues(Traversable $traversable) |
||
| 349 | { |
||
| 350 | $this->clear(); |
||
| 351 | $this->pushAll($traversable); |
||
| 352 | } |
||
| 353 | |||
| 354 | public function shift() |
||
| 362 | } |
||
| 363 | |||
| 364 | /** |
||
| 365 | * Extract the elements after the first of a list, which must be non-empty. |
||
| 366 | * @return DoublyLinkedList |
||
| 367 | * @throws EmptyException |
||
| 368 | */ |
||
| 369 | public function tail() |
||
| 370 | { |
||
| 371 | $this->emptyGuard(__METHOD__); |
||
| 372 | return $this->copyFromContext($this->head->next()->next()); |
||
| 373 | } |
||
| 374 | |||
| 375 | public function toArray(): array |
||
| 376 | { |
||
| 377 | $array = []; |
||
| 378 | $context = $this->head->next(); |
||
| 379 | |||
| 380 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
||
| 381 | /** |
||
| 382 | * @var LinkedDataNode $n |
||
| 383 | */ |
||
| 384 | $array[] = $n->value(); |
||
| 385 | } |
||
| 386 | |||
| 387 | return $array; |
||
| 388 | } |
||
| 389 | |||
| 390 | public function unserialize($serialized) |
||
| 391 | { |
||
| 392 | } |
||
| 393 | |||
| 394 | public function unshift(...$values) |
||
| 399 | } |
||
| 400 | } |
||
| 401 | |||
| 402 | /** |
||
| 403 | * @inheritDoc |
||
| 404 | */ |
||
| 405 | protected function validIndex(int $index) |
||
| 406 | { |
||
| 407 | return $index >= 0 && $index < $this->count(); |
||
| 408 | } |
||
| 409 | |||
| 410 | abstract public function isEmpty(): bool; |
||
| 411 | } |
||
| 412 |