Total Complexity | 65 |
Total Lines | 499 |
Duplicated Lines | 0 % |
Changes | 0 |
Complex classes like DoublyLinkedList 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 DoublyLinkedList, and based on these observations, apply Extract Interface, too.
1 | <?php namespace Mbh\Collection; |
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32 | final class DoublyLinkedList implements AllocatedInterface, SequenceableInterface |
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33 | { |
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34 | use Traits\Collection; |
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35 | use Traits\Functional; |
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36 | use Traits\Builder; |
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37 | use Capacity; |
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38 | use EmptyGuard; |
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39 | |||
40 | const MIN_CAPACITY = 8.0; |
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41 | |||
42 | private $head; |
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43 | private $tail; |
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44 | private $size = 0; |
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45 | private $current; |
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46 | private $offset = -1; |
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47 | |||
48 | /** |
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49 | * Create an fixed array |
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50 | * |
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51 | * @param array|Traversable $array data |
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52 | */ |
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53 | public function __construct($array = null) |
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54 | { |
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55 | $this->head = $head = new LinkedTerminalNode(); |
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56 | $this->tail = $tail = new LinkedTerminalNode(); |
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57 | |||
58 | $head->setNext($tail); |
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59 | $tail->setPrev($head); |
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60 | |||
61 | $this->current = $this->head; |
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62 | |||
63 | if ($array) { |
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64 | $this->pushAll($array); |
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65 | } |
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66 | } |
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67 | |||
68 | public function copy() |
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69 | { |
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70 | return $this->copyFromContext($this->head->next()); |
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71 | } |
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72 | |||
73 | public function isEmpty(): bool |
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74 | { |
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75 | return $this->size === 0; |
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76 | } |
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77 | |||
78 | private function pushAll($values) |
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79 | { |
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80 | foreach ($values as $key => $value) { |
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81 | $this->insertBetween($this->tail->prev(), $this->tail, $value); |
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82 | $this->offset = $this->size - 1; |
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83 | } |
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84 | } |
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85 | |||
86 | public function push(...$values) |
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87 | { |
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88 | $this->pushAll($values); |
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89 | } |
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90 | |||
91 | public function unshift(...$values) |
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96 | } |
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97 | } |
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98 | |||
99 | public function pop() |
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100 | { |
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101 | $this->emptyGuard(__METHOD__); |
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102 | |||
103 | $n = $this->seekTail(); |
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104 | $this->removeNode($n); |
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105 | |||
106 | return $n->value(); |
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107 | } |
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108 | |||
109 | public function shift() |
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110 | { |
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111 | $this->emptyGuard(__METHOD__); |
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112 | |||
113 | $n = $this->seekHead(); |
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114 | $this->removeNode($n); |
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115 | |||
116 | return $n->value(); |
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117 | } |
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118 | |||
119 | public function first() |
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120 | { |
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121 | $this->emptyGuard(__METHOD__); |
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122 | return $this->seekHead()->value(); |
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123 | } |
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124 | |||
125 | public function last() |
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126 | { |
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127 | $this->emptyGuard(__METHOD__); |
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128 | return $this->seekTail()->value(); |
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129 | } |
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130 | |||
131 | /** |
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132 | * @link http://php.net/manual/en/countable.count.php |
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133 | * @return int |
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134 | */ |
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135 | public function count(): int |
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136 | { |
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137 | return $this->size; |
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138 | } |
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139 | |||
140 | public function get(int $index) |
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141 | { |
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142 | return $this[$index]; |
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143 | } |
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144 | |||
145 | /** |
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146 | * @inheritDoc |
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147 | */ |
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148 | public function set(int $index, $value) |
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149 | { |
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150 | $this->offsetSet($index, $value); |
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151 | } |
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152 | |||
153 | /** |
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154 | * @link http://php.net/manual/en/arrayaccess.offsetexists.php |
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155 | * @param int $offset |
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156 | * @return boolean |
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157 | */ |
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158 | public function offsetExists($offset) |
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159 | { |
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160 | $index = $this->intGuard($offset); |
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161 | return $index >= 0 && $index < $this->count(); |
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162 | } |
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163 | |||
164 | /** |
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165 | * @link http://php.net/manual/en/arrayaccess.offsetget.php |
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166 | * @param int $offset |
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167 | * @return mixed |
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168 | * @throws OutOfBoundsException |
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169 | */ |
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170 | public function offsetGet($offset) |
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174 | } |
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175 | |||
176 | /** |
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177 | * @link http://php.net/manual/en/arrayaccess.offsetset.php |
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178 | * @param int|null $offset |
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179 | * @param mixed $value |
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180 | * @return void |
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181 | * @throws OutOfBoundsException |
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182 | */ |
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183 | public function offsetSet($offset, $value) |
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184 | { |
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185 | if ($offset === null) { |
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186 | $this->push($value); |
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187 | return; |
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188 | } |
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189 | $n = $this->guardedSeek($offset, __METHOD__); |
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190 | $n->setValue($value); |
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191 | } |
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192 | |||
193 | /** |
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194 | * @link http://php.net/manual/en/arrayaccess.offsetunset.php |
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195 | * @param int $offset |
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196 | * @return void |
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197 | */ |
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198 | public function offsetUnset($offset) |
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206 | } |
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207 | } |
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208 | |||
209 | public function insert(int $index, ...$values) |
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210 | { |
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211 | foreach ($values as &$value) { |
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212 | $this->insertBefore($index++, $value); |
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213 | } |
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214 | } |
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215 | |||
216 | protected function getValues(): Traversable |
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217 | { |
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218 | return SplFixedArray::fromArray($this->toArray()); |
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219 | } |
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220 | |||
221 | protected function setValues(Traversable $traversable) |
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222 | { |
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223 | $this->clear(); |
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224 | $this->pushAll($traversable); |
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225 | } |
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226 | |||
227 | /** |
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228 | * @param int $position |
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229 | * @param mixed $value |
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230 | * @return void |
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231 | * |
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232 | * @throws OutOfBoundsException |
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233 | */ |
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234 | public function insertBefore(int $position, $value) |
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235 | { |
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236 | $n = $this->guardedSeek($position, __METHOD__); |
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237 | $this->insertBetween($n->prev(), $n, $value); |
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238 | $this->current = $this->current->next(); |
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239 | $this->offset++; |
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240 | } |
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241 | |||
242 | /** |
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243 | * @param int $position |
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244 | * @param mixed $value |
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245 | * @return void |
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246 | * |
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247 | * @throws OutOfBoundsException |
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248 | */ |
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249 | public function insertAfter(int $position, $value) |
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250 | { |
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251 | $n = $this->guardedSeek($position, __METHOD__); |
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252 | $this->insertBetween($n, $n->next(), $value); |
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253 | $this->current = $this->current->prev(); |
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254 | } |
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255 | |||
256 | /** |
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257 | * @link http://php.net/manual/en/iterator.current.php |
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258 | * @return mixed |
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259 | */ |
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260 | public function current() |
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263 | } |
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264 | |||
265 | /** |
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266 | * @link http://php.net/manual/en/iterator.next.php |
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267 | * @return void |
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268 | */ |
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269 | public function next() |
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270 | { |
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271 | $this->forward(); |
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272 | } |
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273 | |||
274 | /** |
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275 | * @return void |
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276 | */ |
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277 | public function prev() |
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278 | { |
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279 | $this->backward(); |
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280 | } |
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281 | |||
282 | /** |
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283 | * @link http://php.net/manual/en/iterator.key.php |
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284 | * @return mixed |
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285 | */ |
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286 | public function key() |
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287 | { |
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288 | return $this->offset; |
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289 | } |
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290 | |||
291 | /** |
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292 | * @link http://php.net/manual/en/iterator.valid.php |
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293 | * @return boolean |
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294 | */ |
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295 | public function valid() |
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296 | { |
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297 | return $this->current instanceof LinkedDataNode; |
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298 | } |
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299 | |||
300 | /** |
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301 | * @link http://php.net/manual/en/iterator.rewind.php |
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302 | * @return void |
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303 | */ |
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304 | public function rewind() |
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305 | { |
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306 | $this->current = $this->head; |
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307 | $this->offset = -1; |
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308 | $this->forward(); |
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309 | } |
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310 | |||
311 | public function search($value) |
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312 | { |
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313 | return $this->indexOf($value); |
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314 | } |
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315 | |||
316 | /** |
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317 | * @link http://php.net/manual/en/seekableiterator.seek.php |
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318 | * @param int $position |
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319 | * @return mixed |
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320 | * @throws OutOfBoundsException |
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321 | * @throws Exception |
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322 | */ |
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323 | public function seek($position) |
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324 | { |
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325 | $index = $this->intGuard($position); |
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326 | $this->indexGuard($index, __METHOD__); |
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327 | |||
328 | if ($index === 0) { |
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329 | return $this->seekHead()->value(); |
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330 | } elseif ($index === $this->size - 1) { |
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331 | return $this->seekTail()->value(); |
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332 | } |
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333 | |||
334 | return $this->seekTo($index)->value(); |
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335 | } |
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336 | |||
337 | /** |
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338 | * @param mixed $i |
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339 | * @return int |
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340 | * @throws Exception |
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341 | */ |
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342 | private function intGuard($i) |
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343 | { |
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344 | if (filter_var($i, FILTER_VALIDATE_INT) === false) { |
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345 | throw new Exception; |
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346 | } |
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347 | |||
348 | return (int) $i; |
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349 | } |
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350 | |||
351 | |||
352 | /** |
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353 | * @param $value |
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354 | * @param callable $callback |
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355 | * @return int |
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356 | */ |
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357 | public function indexOf($value, callable $callback = null) |
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358 | { |
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359 | $equal = $f ?? function ($a, $b) { |
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360 | return $a === $b; |
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361 | }; |
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362 | |||
363 | $filter = $this->filter(function ($item) use ($equal, $value) { |
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364 | return $equal($item, $value); |
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365 | }); |
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366 | |||
367 | foreach ($filter as $key => $value) { |
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368 | return $key; |
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369 | } |
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370 | |||
371 | return -1; |
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372 | } |
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373 | |||
374 | public function contains(...$values): bool |
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375 | { |
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376 | return $this->indexOf($values, $f) >= 0; |
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377 | } |
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378 | |||
379 | /** |
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380 | * Extract the elements after the first of a list, which must be non-empty. |
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381 | * @return LinkedList |
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382 | * @throws EmptyException |
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383 | */ |
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384 | public function tail() |
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385 | { |
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386 | $this->emptyGuard(__METHOD__); |
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387 | return $this->copyFromContext($this->head->next()->next()); |
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388 | } |
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389 | |||
390 | public function __clone() |
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391 | { |
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392 | $list = $this->copyFromContext($this->head->next()); |
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393 | |||
394 | $this->head = $list->head; |
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395 | $this->tail = $list->tail; |
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396 | |||
397 | $this->current = $this->head; |
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398 | $this->offset = -1; |
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399 | |||
400 | $this->size = $list->size; |
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401 | } |
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402 | |||
403 | private function copyFromContext(LinkedNode $context) |
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404 | { |
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405 | $list = new static(); |
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406 | |||
407 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
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408 | /** |
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409 | * @var LinkedDataNode $n |
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410 | */ |
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411 | $list->push($n->value()); |
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412 | } |
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413 | |||
414 | return $list; |
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415 | } |
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416 | |||
417 | private function insertBetween(LinkedNode $a, LinkedNode $b, $value) |
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418 | { |
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419 | $n = new LinkedDataNode($value); |
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420 | |||
421 | $a->setNext($n); |
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422 | $b->setPrev($n); |
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423 | |||
424 | $n->setPrev($a); |
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425 | $n->setNext($b); |
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426 | |||
427 | $this->current = $n; |
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428 | $this->size++; |
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429 | } |
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430 | |||
431 | private function forward() |
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432 | { |
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433 | $this->current = $this->current->next(); |
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434 | $this->offset++; |
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435 | } |
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436 | |||
437 | private function backward() |
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438 | { |
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439 | $this->current = $this->current->prev(); |
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440 | $this->offset--; |
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441 | } |
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442 | |||
443 | public function remove(int $index) |
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444 | { |
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445 | return $this->removeNode($this->guardedSeek($index, __METHOD__)); |
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446 | } |
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447 | |||
448 | private function removeNode(LinkedNode $n) |
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449 | { |
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450 | $prev = $n->prev(); |
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451 | $next = $n->next(); |
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452 | |||
453 | $prev->setNext($next); |
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454 | $next->setPrev($prev); |
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455 | |||
456 | $this->size--; |
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457 | } |
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458 | |||
459 | /** |
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460 | * @return LinkedDataNode |
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461 | */ |
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462 | private function seekTail() |
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463 | { |
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464 | $this->offset = $this->size - 1; |
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465 | return $this->current = $this->tail->prev(); |
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466 | } |
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467 | |||
468 | /** |
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469 | * @return LinkedDataNode |
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470 | */ |
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471 | private function seekHead() |
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472 | { |
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473 | $this->offset = 0; |
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474 | return $this->current = $this->head->next(); |
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475 | } |
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476 | |||
477 | /** |
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478 | * @param $offset |
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479 | * @return LinkedDataNode |
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480 | */ |
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481 | private function seekTo($offset) |
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482 | { |
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483 | $n = abs($diff = $this->offset - $offset); |
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484 | $action = ($diff < 0) ? 'forward' : 'backward'; |
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485 | |||
486 | for ($i = 0; $i < $n; $i++) { |
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487 | $this->$action(); |
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488 | } |
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489 | |||
490 | return $this->current; |
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491 | } |
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492 | |||
493 | private function indexGuard($offset, $method) |
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494 | { |
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495 | if (!$this->offsetExists($offset)) { |
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496 | throw new OutOfBoundsException( |
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497 | "{$method} was called with invalid index: {$offset}" |
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498 | ); |
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499 | } |
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500 | } |
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501 | |||
502 | private function guardedSeek($index, $method) |
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503 | { |
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504 | $index = $this->intGuard($index); |
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505 | $this->indexGuard($index, $method); |
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506 | |||
507 | return $this->seekTo($index); |
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508 | } |
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509 | |||
510 | public function toArray(): array |
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511 | { |
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512 | $array = []; |
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513 | $context = $this->head->next(); |
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514 | |||
515 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
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516 | /** |
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517 | * @var LinkedDataNode $n |
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518 | */ |
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519 | $array[] = $n->value(); |
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520 | } |
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521 | |||
522 | return $array; |
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523 | } |
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524 | |||
525 | public function unserialize($serialized) |
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526 | { |
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527 | } |
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528 | |||
529 | public function clear() |
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531 | } |
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532 | } |
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533 |