| Total Complexity | 47 |
| Total Lines | 376 |
| 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; |
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| 25 | trait LinkedList |
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| 26 | { |
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| 27 | use LinkedList\ArrayAccess; |
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| 28 | use LinkedList\Countable; |
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| 29 | use LinkedList\Iterator; |
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| 30 | |||
| 31 | protected $head; |
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| 32 | protected $tail; |
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| 33 | protected $size = 0; |
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| 34 | protected $current; |
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| 35 | protected $offset = -1; |
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| 36 | |||
| 37 | /** |
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| 38 | * Create an fixed array |
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| 39 | * |
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| 40 | * @param array|Traversable $array data |
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| 41 | */ |
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| 42 | public function __construct($array = []) |
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| 43 | { |
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| 44 | $this->head = $head = new LinkedTerminalNode(); |
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| 45 | $this->tail = $tail = new LinkedTerminalNode(); |
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| 46 | |||
| 47 | $head->setNext($tail); |
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| 48 | $tail->setPrev($head); |
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| 49 | |||
| 50 | $this->current = $this->head; |
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| 51 | |||
| 52 | $this->pushAll($array); |
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| 53 | } |
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| 54 | |||
| 55 | public function __clone() |
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| 56 | { |
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| 57 | $list = $this->copyFromContext($this->head->next()); |
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| 58 | |||
| 59 | $this->head = $list->head; |
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| 60 | $this->tail = $list->tail; |
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| 61 | |||
| 62 | $this->current = $this->head; |
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| 63 | $this->offset = -1; |
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| 64 | |||
| 65 | $this->size = $list->size; |
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| 66 | } |
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| 67 | |||
| 68 | protected function backward() |
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| 72 | } |
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| 73 | |||
| 74 | public function clear() |
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| 75 | { |
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| 76 | $this->head->setNext($this->tail); |
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| 77 | $this->tail->setPrev($this->head); |
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| 78 | |||
| 79 | $this->current = $this->head; |
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| 80 | $this->size = 0; |
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| 81 | $this->offset = -1; |
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| 82 | |||
| 83 | $this->capacity = self::MIN_CAPACITY; |
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| 84 | } |
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| 85 | |||
| 86 | protected function copyFromContext(LinkedNode $context) |
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| 87 | { |
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| 88 | $list = new static(); |
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| 89 | |||
| 90 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
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| 91 | /** |
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| 92 | * @var LinkedDataNode $n |
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| 93 | */ |
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| 94 | $list->push($n->value()); |
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| 95 | } |
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| 96 | |||
| 97 | return $list; |
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| 98 | } |
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| 99 | |||
| 100 | protected function forward() |
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| 101 | { |
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| 102 | $this->current = $this->current->next(); |
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| 103 | $this->offset++; |
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| 104 | } |
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| 105 | |||
| 106 | public function first() |
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| 110 | } |
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| 111 | |||
| 112 | public function get(int $index) |
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| 113 | { |
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| 114 | return $this[$index]; |
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| 115 | } |
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| 116 | |||
| 117 | protected function getSize() |
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| 118 | { |
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| 119 | return $this->size; |
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| 120 | } |
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| 121 | |||
| 122 | protected function getValues(): Traversable |
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| 123 | { |
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| 124 | return SplFixedArray::fromArray($this->toArray()); |
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| 125 | } |
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| 126 | |||
| 127 | protected function guardedSeek($index, $method) |
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| 128 | { |
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| 129 | $index = $this->intGuard($index); |
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| 130 | $this->indexGuard($index, $method); |
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| 131 | |||
| 132 | return $this->seekTo($index); |
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| 133 | } |
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| 134 | |||
| 135 | protected function indexGuard($offset, $method) |
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| 136 | { |
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| 137 | if (!$this->offsetExists($offset)) { |
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| 138 | throw new OutOfBoundsException( |
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| 139 | "{$method} was called with invalid index: {$offset}" |
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| 140 | ); |
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| 141 | } |
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| 142 | } |
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| 143 | |||
| 144 | /** |
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| 145 | * @param $value |
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| 146 | * @return int |
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| 147 | */ |
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| 148 | public function indexOf($value) |
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| 149 | { |
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| 150 | if (($index = $this->search($value)) === null) { |
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| 151 | return -1; |
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| 152 | } |
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| 153 | |||
| 154 | return $index; |
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| 155 | } |
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| 156 | |||
| 157 | public function insert(int $index, ...$values) |
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| 158 | { |
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| 159 | foreach ($values as &$value) { |
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| 160 | $this->insertBefore($index++, $value); |
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| 161 | } |
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| 162 | } |
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| 163 | |||
| 164 | /** |
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| 165 | * @param int $position |
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| 166 | * @param mixed $value |
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| 167 | * @return void |
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| 168 | * |
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| 169 | * @throws OutOfBoundsException |
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| 170 | */ |
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| 171 | public function insertAfter(int $position, $value) |
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| 172 | { |
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| 173 | $n = $this->guardedSeek($position, __METHOD__); |
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| 174 | $this->insertBetween($n, $n->next(), $value); |
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| 175 | $this->current = $this->current->prev(); |
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| 176 | } |
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| 177 | |||
| 178 | /** |
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| 179 | * @param int $position |
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| 180 | * @param mixed $value |
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| 181 | * @return void |
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| 182 | * |
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| 183 | * @throws OutOfBoundsException |
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| 184 | */ |
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| 185 | public function insertBefore(int $position, $value) |
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| 186 | { |
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| 187 | $n = $this->guardedSeek($position, __METHOD__); |
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| 188 | $this->insertBetween($n->prev(), $n, $value); |
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| 189 | $this->current = $this->current->next(); |
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| 190 | $this->offset++; |
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| 191 | } |
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| 192 | |||
| 193 | protected function insertBetween(LinkedNode $a, LinkedNode $b, $value) |
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| 194 | { |
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| 195 | $n = new LinkedDataNode($value); |
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| 196 | |||
| 197 | $a->setNext($n); |
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| 198 | $b->setPrev($n); |
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| 199 | |||
| 200 | $n->setPrev($a); |
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| 201 | $n->setNext($b); |
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| 202 | |||
| 203 | $this->current = $n; |
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| 204 | $this->size++; |
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| 205 | |||
| 206 | $this->checkCapacity(); |
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| 207 | } |
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| 208 | |||
| 209 | /** |
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| 210 | * @param mixed $i |
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| 211 | * @return int |
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| 212 | * @throws Exception |
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| 213 | */ |
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| 214 | protected function intGuard($i) |
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| 215 | { |
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| 216 | if (filter_var($i, FILTER_VALIDATE_INT) === false) { |
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| 217 | throw new Exception; |
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| 218 | } |
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| 219 | |||
| 220 | return (int) $i; |
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| 221 | } |
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| 222 | |||
| 223 | public function last() |
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| 224 | { |
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| 225 | $this->emptyGuard(__METHOD__); |
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| 226 | return $this->seekTail()->value(); |
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| 227 | } |
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| 228 | |||
| 229 | public function pop() |
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| 230 | { |
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| 231 | $this->emptyGuard(__METHOD__); |
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| 232 | |||
| 233 | $n = $this->seekTail(); |
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| 234 | $this->removeNode($n); |
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| 235 | |||
| 236 | $this->checkCapacity(); |
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| 237 | return $n->value(); |
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| 238 | } |
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| 239 | |||
| 240 | public function push(...$values) |
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| 241 | { |
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| 242 | $this->pushAll($values); |
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| 243 | } |
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| 244 | |||
| 245 | protected function pushAll($values) |
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| 246 | { |
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| 247 | foreach ($values as $key => $value) { |
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| 248 | $this->insertBetween($this->tail->prev(), $this->tail, $value); |
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| 249 | $this->offset = $this->size - 1; |
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| 250 | } |
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| 251 | |||
| 252 | $this->checkCapacity(); |
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| 253 | } |
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| 254 | |||
| 255 | public function remove(int $index) |
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| 256 | { |
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| 257 | $this->removeNode($this->guardedSeek($index, __METHOD__)); |
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| 258 | } |
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| 259 | |||
| 260 | protected function removeNode(LinkedNode $n) |
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| 261 | { |
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| 262 | $prev = $n->prev(); |
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| 263 | $next = $n->next(); |
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| 264 | |||
| 265 | $prev->setNext($next); |
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| 266 | $next->setPrev($prev); |
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| 267 | |||
| 268 | $this->size--; |
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| 269 | |||
| 270 | $this->checkCapacity(); |
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| 271 | } |
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| 272 | |||
| 273 | /** |
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| 274 | * @link http://php.net/manual/en/seekableiterator.seek.php |
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| 275 | * @param int $position |
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| 276 | * @return mixed |
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| 277 | * @throws OutOfBoundsException |
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| 278 | * @throws Exception |
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| 279 | */ |
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| 280 | public function seek($position) |
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| 281 | { |
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| 282 | $index = $this->intGuard($position); |
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| 283 | $this->indexGuard($index, __METHOD__); |
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| 284 | |||
| 285 | if ($index === 0) { |
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| 286 | return $this->seekHead()->value(); |
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| 287 | } elseif ($index === $this->size - 1) { |
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| 288 | return $this->seekTail()->value(); |
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| 289 | } |
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| 290 | |||
| 291 | return $this->seekTo($index)->value(); |
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| 292 | } |
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| 293 | |||
| 294 | /** |
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| 295 | * @return LinkedDataNode |
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| 296 | */ |
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| 297 | protected function seekTail() |
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| 298 | { |
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| 299 | $this->offset = $this->size - 1; |
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| 300 | return $this->current = $this->tail->prev(); |
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| 301 | } |
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| 302 | |||
| 303 | /** |
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| 304 | * @return LinkedDataNode |
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| 305 | */ |
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| 306 | protected function seekHead() |
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| 310 | } |
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| 311 | |||
| 312 | /** |
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| 313 | * @param $offset |
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| 314 | * @return LinkedDataNode |
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| 315 | */ |
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| 316 | protected function seekTo($offset) |
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| 317 | { |
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| 318 | $n = abs($diff = $this->offset - $offset); |
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| 319 | $action = ($diff < 0) ? 'forward' : 'backward'; |
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| 320 | |||
| 321 | for ($i = 0; $i < $n; $i++) { |
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| 322 | $this->$action(); |
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| 323 | } |
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| 324 | |||
| 325 | return $this->current; |
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| 326 | } |
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| 327 | |||
| 328 | /** |
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| 329 | * @inheritDoc |
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| 330 | */ |
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| 331 | public function set(int $index, $value) |
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| 332 | { |
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| 333 | $this->offsetSet($index, $value); |
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| 334 | } |
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| 335 | |||
| 336 | protected function setValues(Traversable $traversable) |
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| 340 | } |
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| 341 | |||
| 342 | public function shift() |
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| 343 | { |
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| 344 | $this->emptyGuard(__METHOD__); |
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| 345 | |||
| 346 | $n = $this->seekHead(); |
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| 347 | $this->removeNode($n); |
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| 348 | |||
| 349 | return $n->value(); |
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| 350 | } |
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| 351 | |||
| 352 | /** |
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| 353 | * Extract the elements after the first of a list, which must be non-empty. |
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| 354 | * @return SequenceableInterface |
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| 355 | * @throws EmptyException |
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| 356 | */ |
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| 357 | public function tail() |
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| 361 | } |
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| 362 | |||
| 363 | public function toArray(): array |
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| 364 | { |
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| 365 | $array = []; |
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| 366 | $context = $this->head->next(); |
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| 367 | |||
| 368 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
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| 369 | /** |
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| 370 | * @var LinkedDataNode $n |
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| 371 | */ |
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| 372 | $array[] = $n->value(); |
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| 373 | } |
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| 374 | |||
| 375 | return $array; |
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| 376 | } |
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| 377 | |||
| 378 | public function unshift(...$values) |
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| 379 | { |
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| 380 | foreach ($values as &$value) { |
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| 381 | $this->insertBetween($this->head, $this->head->next(), $value); |
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| 382 | $this->offset = 0; |
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| 383 | } |
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| 384 | } |
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| 385 | |||
| 386 | /** |
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| 387 | * @inheritDoc |
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| 388 | */ |
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| 389 | protected function validIndex(int $index) |
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| 392 | } |
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| 393 | |||
| 394 | abstract protected function checkCapacity(); |
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| 395 | |||
| 396 | abstract protected function emptyGuard($method); |
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| 397 | |||
| 398 | abstract public function isEmpty(): bool; |
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| 399 | |||
| 400 | abstract public function search($value); |
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| 401 | } |
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| 402 |