Total Complexity | 66 |
Total Lines | 505 |
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 | $this->init(); |
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56 | |||
57 | if ($array) { |
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58 | $this->pushAll($array); |
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59 | } |
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60 | } |
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61 | |||
62 | private function init() |
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63 | { |
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64 | $this->head = $head = new LinkedTerminalNode(); |
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65 | $this->tail = $tail = new LinkedTerminalNode(); |
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66 | |||
67 | $head->setNext($tail); |
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68 | $tail->setPrev($head); |
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69 | |||
70 | $this->current = $this->head; |
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71 | } |
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72 | |||
73 | public function copy() |
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74 | { |
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75 | return $this->copyFromContext($this->head->next()); |
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76 | } |
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77 | |||
78 | public function isEmpty(): bool |
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79 | { |
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80 | return $this->size === 0; |
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81 | } |
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82 | |||
83 | private function pushAll($values) |
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84 | { |
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85 | foreach ($values as $key => $value) { |
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86 | $this->insertBetween($this->tail->prev(), $this->tail, $value); |
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87 | $this->offset = $this->size - 1; |
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88 | } |
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89 | } |
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90 | |||
91 | public function push(...$values) |
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92 | { |
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93 | $this->pushAll($values); |
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94 | } |
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95 | |||
96 | public function unshift(...$values) |
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97 | { |
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98 | foreach ($values as &$value) { |
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99 | $this->insertBetween($this->head, $this->head->next(), $value); |
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100 | $this->offset = 0; |
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101 | } |
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102 | } |
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103 | |||
104 | public function pop() |
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105 | { |
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106 | $this->emptyGuard(__METHOD__); |
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107 | |||
108 | $n = $this->seekTail(); |
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109 | $this->removeNode($n); |
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110 | |||
111 | return $n->value(); |
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112 | } |
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113 | |||
114 | public function shift() |
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115 | { |
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116 | $this->emptyGuard(__METHOD__); |
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117 | |||
118 | $n = $this->seekHead(); |
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119 | $this->removeNode($n); |
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120 | |||
121 | return $n->value(); |
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122 | } |
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123 | |||
124 | public function first() |
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125 | { |
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126 | $this->emptyGuard(__METHOD__); |
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127 | return $this->seekHead()->value(); |
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128 | } |
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129 | |||
130 | public function last() |
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131 | { |
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132 | $this->emptyGuard(__METHOD__); |
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133 | return $this->seekTail()->value(); |
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134 | } |
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135 | |||
136 | /** |
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137 | * @link http://php.net/manual/en/countable.count.php |
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138 | * @return int |
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139 | */ |
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140 | public function count(): int |
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141 | { |
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142 | return $this->size; |
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143 | } |
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144 | |||
145 | public function get(int $index) |
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146 | { |
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147 | return $this[$index]; |
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148 | } |
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149 | |||
150 | /** |
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151 | * @inheritDoc |
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152 | */ |
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153 | public function set(int $index, $value) |
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154 | { |
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155 | $this->offsetSet($index, $value); |
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156 | } |
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157 | |||
158 | /** |
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159 | * @link http://php.net/manual/en/arrayaccess.offsetexists.php |
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160 | * @param int $offset |
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161 | * @return boolean |
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162 | */ |
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163 | public function offsetExists($offset) |
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164 | { |
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165 | $index = $this->intGuard($offset); |
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166 | return $index >= 0 && $index < $this->count(); |
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167 | } |
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168 | |||
169 | /** |
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170 | * @link http://php.net/manual/en/arrayaccess.offsetget.php |
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171 | * @param int $offset |
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172 | * @return mixed |
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173 | * @throws OutOfBoundsException |
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174 | */ |
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175 | public function offsetGet($offset) |
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176 | { |
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177 | $n = $this->guardedSeek($offset, __METHOD__); |
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178 | return $n->value(); |
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179 | } |
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180 | |||
181 | /** |
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182 | * @link http://php.net/manual/en/arrayaccess.offsetset.php |
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183 | * @param int|null $offset |
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184 | * @param mixed $value |
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185 | * @return void |
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186 | * @throws OutOfBoundsException |
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187 | */ |
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188 | public function offsetSet($offset, $value) |
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189 | { |
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190 | if ($offset === null) { |
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191 | $this->push($value); |
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192 | return; |
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193 | } |
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194 | $n = $this->guardedSeek($offset, __METHOD__); |
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195 | $n->setValue($value); |
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196 | } |
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197 | |||
198 | /** |
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199 | * @link http://php.net/manual/en/arrayaccess.offsetunset.php |
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200 | * @param int $offset |
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201 | * @return void |
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202 | */ |
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203 | public function offsetUnset($offset) |
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204 | { |
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205 | $index = $this->intGuard($offset); |
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206 | if ($this->offsetExists($index)) { |
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207 | $n = $this->seekTo($index); |
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208 | $this->removeNode($n); |
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209 | $this->current = $n->prev(); |
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210 | $this->offset--; |
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211 | } |
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212 | } |
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213 | |||
214 | public function insert(int $index, ...$values) |
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215 | { |
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216 | foreach ($values as &$value) { |
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217 | $this->insertBefore($index++, $value); |
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218 | } |
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219 | } |
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220 | |||
221 | protected function getValues(): Traversable |
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222 | { |
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223 | return SplFixedArray::fromArray($this->toArray()); |
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224 | } |
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225 | |||
226 | protected function setValues(Traversable $traversable) |
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227 | { |
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228 | $this->clear(); |
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229 | $this->pushAll($traversable); |
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230 | } |
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231 | |||
232 | /** |
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233 | * @param int $position |
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234 | * @param mixed $value |
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235 | * @return void |
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236 | * |
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237 | * @throws OutOfBoundsException |
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238 | */ |
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239 | public function insertBefore(int $position, $value) |
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240 | { |
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241 | $n = $this->guardedSeek($position, __METHOD__); |
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242 | $this->insertBetween($n->prev(), $n, $value); |
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243 | $this->current = $this->current->next(); |
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244 | $this->offset++; |
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245 | } |
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246 | |||
247 | /** |
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248 | * @param int $position |
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249 | * @param mixed $value |
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250 | * @return void |
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251 | * |
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252 | * @throws OutOfBoundsException |
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253 | */ |
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254 | public function insertAfter(int $position, $value) |
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255 | { |
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256 | $n = $this->guardedSeek($position, __METHOD__); |
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257 | $this->insertBetween($n, $n->next(), $value); |
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258 | $this->current = $this->current->prev(); |
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259 | } |
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260 | |||
261 | /** |
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262 | * @link http://php.net/manual/en/iterator.current.php |
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263 | * @return mixed |
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264 | */ |
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265 | public function current() |
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268 | } |
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269 | |||
270 | /** |
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271 | * @link http://php.net/manual/en/iterator.next.php |
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272 | * @return void |
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273 | */ |
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274 | public function next() |
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275 | { |
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276 | $this->forward(); |
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277 | } |
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278 | |||
279 | /** |
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280 | * @return void |
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281 | */ |
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282 | public function prev() |
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283 | { |
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284 | $this->backward(); |
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285 | } |
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286 | |||
287 | /** |
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288 | * @link http://php.net/manual/en/iterator.key.php |
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289 | * @return mixed |
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290 | */ |
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291 | public function key() |
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292 | { |
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293 | return $this->offset; |
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294 | } |
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295 | |||
296 | /** |
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297 | * @link http://php.net/manual/en/iterator.valid.php |
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298 | * @return boolean |
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299 | */ |
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300 | public function valid() |
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301 | { |
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302 | return $this->current instanceof LinkedDataNode; |
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303 | } |
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304 | |||
305 | /** |
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306 | * @link http://php.net/manual/en/iterator.rewind.php |
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307 | * @return void |
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308 | */ |
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309 | public function rewind() |
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310 | { |
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311 | $this->current = $this->head; |
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312 | $this->offset = -1; |
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313 | $this->forward(); |
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314 | } |
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315 | |||
316 | public function search($value) |
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317 | { |
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318 | return $this->indexOf($value); |
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319 | } |
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320 | |||
321 | /** |
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322 | * @link http://php.net/manual/en/seekableiterator.seek.php |
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323 | * @param int $position |
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324 | * @return mixed |
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325 | * @throws OutOfBoundsException |
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326 | * @throws Exception |
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327 | */ |
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328 | public function seek($position) |
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329 | { |
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330 | $index = $this->intGuard($position); |
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331 | $this->indexGuard($index, __METHOD__); |
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332 | |||
333 | if ($index === 0) { |
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334 | return $this->seekHead()->value(); |
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335 | } elseif ($index === $this->size - 1) { |
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336 | return $this->seekTail()->value(); |
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337 | } |
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338 | |||
339 | return $this->seekTo($index)->value(); |
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340 | } |
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341 | |||
342 | /** |
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343 | * @param mixed $i |
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344 | * @return int |
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345 | * @throws Exception |
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346 | */ |
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347 | private function intGuard($i) |
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348 | { |
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349 | if (filter_var($i, FILTER_VALIDATE_INT) === false) { |
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350 | throw new Exception; |
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351 | } |
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352 | |||
353 | return (int) $i; |
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354 | } |
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355 | |||
356 | |||
357 | /** |
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358 | * @param $value |
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359 | * @param callable $callback |
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360 | * @return int |
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361 | */ |
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362 | public function indexOf($value, callable $callback = null) |
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363 | { |
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364 | $equal = $f ?? function ($a, $b) { |
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365 | return $a === $b; |
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366 | }; |
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367 | |||
368 | $filter = $this->filter(function ($item) use ($equal, $value) { |
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369 | return $equal($item, $value); |
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370 | }); |
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371 | |||
372 | foreach ($filter as $key => $value) { |
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373 | return $key; |
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374 | } |
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375 | |||
376 | return -1; |
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377 | } |
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378 | |||
379 | public function contains(...$values): bool |
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380 | { |
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381 | return $this->indexOf($values, $f) >= 0; |
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382 | } |
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383 | |||
384 | /** |
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385 | * Extract the elements after the first of a list, which must be non-empty. |
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386 | * @return LinkedList |
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387 | * @throws EmptyException |
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388 | */ |
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389 | public function tail() |
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390 | { |
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391 | $this->emptyGuard(__METHOD__); |
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392 | return $this->copyFromContext($this->head->next()->next()); |
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393 | } |
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394 | |||
395 | public function __clone() |
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396 | { |
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397 | $list = $this->copyFromContext($this->head->next()); |
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398 | |||
399 | $this->head = $list->head; |
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400 | $this->tail = $list->tail; |
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401 | |||
402 | $this->current = $this->head; |
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403 | $this->offset = -1; |
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404 | |||
405 | $this->size = $list->size; |
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406 | } |
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407 | |||
408 | private function copyFromContext(LinkedNode $context) |
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409 | { |
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410 | $list = new static(); |
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411 | |||
412 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
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413 | /** |
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414 | * @var LinkedDataNode $n |
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415 | */ |
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416 | $list->push($n->value()); |
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417 | } |
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418 | |||
419 | return $list; |
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420 | } |
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421 | |||
422 | private function insertBetween(LinkedNode $a, LinkedNode $b, $value) |
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423 | { |
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424 | $n = new LinkedDataNode($value); |
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425 | |||
426 | $a->setNext($n); |
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427 | $b->setPrev($n); |
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428 | |||
429 | $n->setPrev($a); |
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430 | $n->setNext($b); |
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431 | |||
432 | $this->current = $n; |
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433 | $this->size++; |
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434 | } |
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435 | |||
436 | private function forward() |
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437 | { |
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438 | $this->current = $this->current->next(); |
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439 | $this->offset++; |
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440 | } |
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441 | |||
442 | private function backward() |
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443 | { |
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444 | $this->current = $this->current->prev(); |
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445 | $this->offset--; |
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446 | } |
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447 | |||
448 | public function remove(int $index) |
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449 | { |
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450 | return $this->removeNode($this->guardedSeek($index, __METHOD__)); |
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451 | } |
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452 | |||
453 | private function removeNode(LinkedNode $n) |
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454 | { |
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455 | $prev = $n->prev(); |
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456 | $next = $n->next(); |
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457 | |||
458 | $prev->setNext($next); |
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459 | $next->setPrev($prev); |
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460 | |||
461 | $this->size--; |
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462 | } |
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463 | |||
464 | /** |
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465 | * @return LinkedDataNode |
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466 | */ |
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467 | private function seekTail() |
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468 | { |
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469 | $this->offset = $this->size - 1; |
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470 | return $this->current = $this->tail->prev(); |
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471 | } |
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472 | |||
473 | /** |
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474 | * @return LinkedDataNode |
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475 | */ |
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476 | private function seekHead() |
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477 | { |
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478 | $this->offset = 0; |
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479 | return $this->current = $this->head->next(); |
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480 | } |
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481 | |||
482 | /** |
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483 | * @param $offset |
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484 | * @return LinkedDataNode |
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485 | */ |
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486 | private function seekTo($offset) |
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487 | { |
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488 | $n = abs($diff = $this->offset - $offset); |
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489 | $action = ($diff < 0) ? 'forward' : 'backward'; |
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490 | |||
491 | for ($i = 0; $i < $n; $i++) { |
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492 | $this->$action(); |
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493 | } |
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494 | |||
495 | return $this->current; |
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496 | } |
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497 | |||
498 | private function indexGuard($offset, $method) |
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499 | { |
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500 | if (!$this->offsetExists($offset)) { |
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501 | throw new OutOfBoundsException( |
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502 | "{$method} was called with invalid index: {$offset}" |
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503 | ); |
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504 | } |
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505 | } |
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506 | |||
507 | private function guardedSeek($index, $method) |
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508 | { |
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509 | $index = $this->intGuard($index); |
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510 | $this->indexGuard($index, $method); |
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511 | |||
512 | return $this->seekTo($index); |
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513 | } |
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514 | |||
515 | public function toArray(): array |
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516 | { |
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517 | $array = []; |
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518 | $context = $this->head->next(); |
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519 | |||
520 | for ($n = $context; $n !== $this->tail; $n = $n->next()) { |
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521 | /** |
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522 | * @var LinkedDataNode $n |
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523 | */ |
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524 | $array[] = $n->value(); |
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525 | } |
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526 | |||
527 | return $array; |
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528 | } |
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529 | |||
530 | public function unserialize($serialized) |
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531 | { |
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532 | } |
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533 | |||
534 | public function clear() |
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537 | } |
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538 | } |
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539 |