Complex classes like Collection often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Collection, and based on these observations, apply Extract Interface, too.
1 | <?php |
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16 | class Collection implements CollectionContract { |
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17 | |||
18 | /** |
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19 | * Collection elements. |
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20 | * |
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21 | * @var array |
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22 | */ |
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23 | protected $elements = array(); |
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24 | |||
25 | /** |
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26 | * Collection type to enforce. |
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27 | * |
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28 | * @var Type |
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29 | */ |
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30 | private $type; |
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31 | |||
32 | /** |
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33 | * Where Collection is in loop. |
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34 | * |
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35 | * @var int |
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36 | */ |
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37 | protected $position = 0; |
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38 | |||
39 | /** |
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40 | * Collection constructor. |
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41 | * |
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42 | * @param string $type |
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43 | * @param array $elements |
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44 | */ |
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45 | public function __construct( $type, array $elements = array() ) { |
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54 | 57 | ||
55 | 24 | /** |
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56 | 57 | * {@inheritdoc} |
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57 | 57 | * |
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58 | * @return string |
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59 | */ |
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60 | public function get_type() { |
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63 | |||
64 | /** |
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65 | * {@inheritdoc} |
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66 | * |
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67 | * @param mixed $element |
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68 | 27 | * |
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69 | 27 | * @return Collection |
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70 | 9 | * |
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71 | 9 | * @throws InvalidArgumentException |
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72 | */ |
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73 | 27 | public function add( $element ) { |
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88 | |||
89 | /** |
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90 | * {@inheritdoc} |
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91 | * |
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92 | * @return Collection |
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93 | */ |
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94 | public function clear() { |
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97 | |||
98 | /** |
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99 | * {@inheritdoc} |
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100 | * |
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101 | * @param callable $condition Condition to satisfy. |
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102 | * |
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103 | * @return bool |
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104 | */ |
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105 | public function contains( callable $condition ) { |
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108 | |||
109 | /** |
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110 | * {@inheritdoc} |
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111 | * |
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112 | * @param callable $condition Condition to satisfy. |
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113 | * |
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114 | 12 | * @return mixed |
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115 | 12 | */ |
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116 | public function find( callable $condition ) { |
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121 | |||
122 | /** |
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123 | * {@inheritdoc} |
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124 | * |
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125 | * @param callable $condition Condition to satisfy. |
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126 | * |
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127 | * @return int |
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128 | */ |
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129 | public function find_index( callable $condition ) { |
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141 | |||
142 | /** |
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143 | * Fetches the element at the provided index. |
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144 | * |
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145 | * @param int $index Index to get element from. |
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146 | * |
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147 | * @return mixed |
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148 | * |
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149 | * @throws OutOfRangeException |
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150 | */ |
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151 | public function at( $index ) { |
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156 | |||
157 | /** |
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158 | * {@inheritdoc} |
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159 | * |
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160 | * @param int $index Index to check for existence. |
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161 | * |
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162 | * @return bool |
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163 | 9 | * |
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164 | 6 | * @throws InvalidArgumentException |
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165 | 3 | */ |
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166 | public function index_exists( $index ) { |
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177 | 3 | ||
178 | 3 | /** |
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179 | * {@inheritdoc} |
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180 | * |
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181 | * @param callable $condition Condition to satisfy. |
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182 | * |
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183 | * @return mixed |
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184 | 3 | */ |
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185 | 3 | public function filter( callable $condition ) { |
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196 | /** |
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197 | * {@inheritdoc} |
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198 | * |
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199 | * @param callable $condition Condition to satisfy. |
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200 | * |
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201 | * @return mixed |
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202 | 3 | */ |
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203 | 3 | public function find_last( callable $condition ) { |
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208 | |||
209 | 3 | /** |
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210 | 3 | * {@inheritdoc} |
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211 | 3 | * |
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212 | * @param callable $condition |
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213 | * @return int |
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214 | */ |
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215 | public function find_last_index( callable $condition ) { |
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227 | |||
228 | /** |
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229 | 60 | * {@inheritdoc} |
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230 | 60 | * |
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231 | 15 | * @param int $start Begining index to slice from. |
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232 | * @param int $end End index to slice to. |
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233 | 15 | * |
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234 | 3 | * @return Collection |
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235 | * |
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236 | * @throws InvalidArgumentException |
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237 | 12 | */ |
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238 | 12 | public function slice( $start, $end ) { |
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263 | |||
264 | /** |
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265 | * {@inheritdoc} |
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266 | * |
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267 | * @param int $index Index to start at. |
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268 | * @param mixed $element Element to insert. |
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269 | * |
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270 | * @return Collection |
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271 | * |
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272 | * @throws InvalidArgumentException |
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273 | * @throws OutOfRangeException |
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274 | */ |
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275 | public function insert( $index, $element ) { |
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286 | |||
287 | /** |
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288 | * {@inheritdoc} |
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289 | * |
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290 | * @param int $index Index to start insertion at. |
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291 | * @param array $elements Elements in insert. |
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292 | * |
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293 | * @return Collection |
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294 | * |
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295 | * @throws OutOfRangeException |
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296 | */ |
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297 | public function insert_range( $index, array $elements ) { |
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315 | |||
316 | /** |
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317 | * {@inheritdoc} |
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318 | * |
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319 | * @param callable $condition Condition to satisfy. |
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320 | * |
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321 | * @return Collection |
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322 | */ |
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323 | public function without( callable $condition ) { |
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330 | |||
331 | /** |
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332 | * {@inheritdoc} |
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333 | * |
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334 | * @param int $index Index to remove. |
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335 | * |
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336 | * @return Collection |
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337 | * |
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338 | * @throws OutOfRangeException |
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339 | */ |
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340 | public function remove_at( $index ) { |
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352 | /** |
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353 | * {@inheritdoc} |
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354 | * |
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355 | * @return Collection |
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356 | */ |
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357 | public function reverse() { |
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362 | |||
363 | /** |
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364 | * {@inheritdoc} |
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365 | * |
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366 | * @param callable $callback Sort callback. |
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367 | * |
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368 | * @return Collection |
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369 | */ |
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370 | public function sort( callable $callback ) { |
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375 | |||
376 | /** |
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377 | * {@inheritdoc} |
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378 | * |
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379 | * @return array |
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380 | */ |
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381 | public function to_array() { |
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384 | |||
385 | /** |
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386 | * {@inheritdoc} |
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387 | * |
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388 | * @param callable $callable Reducer function. |
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389 | * |
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390 | * @param null $initial Initial reducer value. |
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391 | * |
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392 | * @return mixed |
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393 | */ |
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394 | public function reduce( callable $callable, $initial = null ) { |
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397 | |||
398 | /** |
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399 | * {@inheritdoc} |
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400 | * |
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401 | * @param callable $condition Condition callback. |
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402 | * |
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403 | * @return bool |
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404 | */ |
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405 | public function every( callable $condition ) { |
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419 | |||
420 | /** |
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421 | * {@inheritdoc} |
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422 | * |
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423 | * @param int $num Number of elements to drop. |
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424 | * |
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425 | * @return Collection |
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426 | * |
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427 | * @throws InvalidArgumentException |
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428 | */ |
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429 | public function drop( $num ) { |
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432 | |||
433 | /** |
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434 | * {@inheritdoc} |
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435 | * |
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436 | * @param int $num Number of elements to drop. |
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437 | * |
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438 | * @return Collection |
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439 | * |
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440 | * @throws InvalidArgumentException |
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441 | */ |
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442 | public function drop_right( $num ) { |
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447 | |||
448 | /** |
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449 | * {@inheritdoc} |
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450 | * |
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451 | * @param callable $condition Condition callback. |
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452 | * |
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453 | * @return Collection |
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454 | */ |
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455 | public function drop_while( callable $condition ) { |
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459 | /** |
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460 | * {@inheritdoc} |
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461 | * |
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462 | * @return Collection |
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463 | * |
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464 | * @throws InvalidArgumentException |
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465 | */ |
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466 | public function tail() { |
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469 | |||
470 | /** |
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471 | * {@inheritdoc} |
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472 | * |
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473 | * @param int $num Number of elements to take. |
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474 | * |
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475 | * @return Collection |
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476 | * |
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477 | * @throws InvalidArgumentException |
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478 | */ |
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479 | public function take( $num ) { |
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482 | |||
483 | /** |
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484 | * {@inheritdoc} |
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485 | * |
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486 | * @param int $num Number of elements to take. |
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487 | * |
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488 | * @return Collection |
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489 | * |
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490 | * @throws InvalidArgumentException |
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491 | */ |
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492 | public function take_right( $num ) { |
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495 | |||
496 | /** |
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497 | * {@inheritdoc} |
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498 | * |
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499 | * @param callable $condition Callback function. |
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500 | * |
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501 | * @return Collection |
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502 | */ |
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503 | public function take_while( callable $condition ) { |
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508 | |||
509 | /** |
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510 | * {@inheritdoc} |
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511 | * |
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512 | * @param callable $callable Callback function. |
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513 | */ |
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514 | public function each( callable $callable ) { |
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519 | |||
520 | /** |
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521 | * {@inheritdoc} |
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522 | * |
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523 | * @param callable $callable Callback function. |
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524 | * |
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525 | * @return Collection |
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526 | */ |
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527 | public function map( callable $callable ) { |
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546 | |||
547 | /** |
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548 | * {@inheritdoc} |
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549 | * |
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550 | * @param callable $callable Reducer function. |
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551 | * @param null $initial Initial value. |
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552 | * |
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553 | * @return mixed |
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554 | */ |
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555 | public function reduce_right( callable $callable, $initial = null ) { |
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562 | |||
563 | /** |
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564 | * {@inheritdoc} |
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565 | * |
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566 | * @return Collection |
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567 | */ |
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568 | public function shuffle() { |
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574 | |||
575 | /** |
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576 | * {@inheritdoc} |
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577 | * |
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578 | * @param array|Collection $elements Array of elements to merge. |
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579 | * |
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580 | * @return Collection |
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581 | * |
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582 | * @throws InvalidArgumentException |
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583 | */ |
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584 | public function merge( $elements ) { |
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599 | |||
600 | /** |
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601 | * {@inheritdoc} |
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602 | * |
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603 | * @return mixed |
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604 | * |
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605 | * @throws OutOfBoundsException |
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606 | */ |
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607 | public function first() { |
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614 | |||
615 | /** |
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616 | * {@inheritdoc} |
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617 | * |
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618 | * @return mixed |
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619 | * |
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620 | * @throws OutOfBoundsException |
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621 | */ |
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622 | public function last() { |
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629 | |||
630 | /** |
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631 | * {@inheritdoc} |
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632 | * |
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633 | * @return int |
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634 | */ |
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635 | public function count() { |
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638 | |||
639 | /** |
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640 | * {@inheritDoc} |
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641 | * |
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642 | * @return array |
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643 | */ |
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644 | public function serialize() { |
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653 | |||
654 | /** |
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655 | * Return the current element. |
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656 | * |
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657 | * @return mixed |
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658 | */ |
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659 | public function current() { |
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662 | |||
663 | /** |
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664 | * Move forward to next element. |
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665 | */ |
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666 | public function next() { |
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669 | |||
670 | /** |
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671 | * Return the key of the current element. |
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672 | * |
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673 | * @return mixed |
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674 | */ |
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675 | public function key() { |
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678 | |||
679 | /** |
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680 | * Checks if current position is valid. |
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681 | * |
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682 | * @return bool |
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683 | */ |
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684 | public function valid() { |
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687 | |||
688 | /** |
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689 | * Rewind the Iterator to the first element. |
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690 | */ |
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691 | public function rewind() { |
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694 | |||
695 | /** |
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696 | * Creates a new instance of the Collection |
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697 | * from a trusted set of elements. |
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698 | * |
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699 | * @param array $elements Array of elements to pass into new collection. |
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700 | * @param null|mixed $type |
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701 | * |
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702 | * @return static |
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703 | */ |
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704 | protected function new_from_trusted( array $elements, $type = null ) { |
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710 | |||
711 | /** |
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712 | * Sets the elements without validating them. |
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713 | * |
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714 | * @param array $elements Pre-validated elements to set. |
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715 | */ |
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716 | protected function set_from_trusted( array $elements ) { |
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719 | |||
720 | /** |
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721 | * Number of elements true for the condition. |
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722 | * |
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723 | * @param callable $condition Condition to check. |
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724 | * @return int |
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725 | */ |
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726 | protected function count_while_true( callable $condition ) { |
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738 | |||
739 | /** |
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740 | * Validates a number to be used as an index. |
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741 | * |
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742 | * @param integer $index The number to be validated as an index. |
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743 | * |
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744 | * @throws OutOfRangeException |
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745 | */ |
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746 | protected function validate_index( $index ) { |
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753 | } |
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754 |
It seems like the type of the argument is not accepted by the function/method which you are calling.
In some cases, in particular if PHP’s automatic type-juggling kicks in this might be fine. In other cases, however this might be a bug.
We suggest to add an explicit type cast like in the following example: