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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46 | $this->type = new Type( $type ); |
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47 | |||
48 | if ( $this->type->is_model() ) { |
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49 | foreach ( $elements as $idx => $element ) { |
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50 | if ( is_array( $element ) ) { |
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51 | 60 | $elements[ $idx ] = $this->type->create_model( $element ); |
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52 | 60 | } |
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53 | } |
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54 | 57 | } |
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55 | 24 | ||
56 | 57 | if ( $elements ) { |
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57 | 57 | $this->type->validate_elements( $elements ); |
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58 | } |
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59 | |||
60 | $this->elements = $elements; |
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61 | } |
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62 | |||
63 | /** |
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64 | * {@inheritdoc} |
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65 | * |
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66 | * @return string |
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67 | */ |
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68 | 27 | public function get_type() { |
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69 | 27 | return $this->type->get_type(); |
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70 | 9 | } |
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71 | 9 | ||
72 | /** |
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73 | 27 | * {@inheritdoc} |
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74 | 3 | * |
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75 | * @param mixed $element |
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76 | * |
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77 | 24 | * @return Collection |
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78 | * |
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79 | 24 | * @throws InvalidArgumentException |
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80 | */ |
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81 | public function add( $element ) { |
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82 | if ( $this->type->is_model() && is_array( $element ) ) { |
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83 | $element = $this->type->create_model( $element ); |
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84 | } |
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85 | |||
86 | $this->type->validate_element( $element ); |
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87 | |||
88 | $elements = $this->elements; |
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89 | $elements[] = $element; |
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90 | |||
91 | $collection = new static( $this->get_type() ); |
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92 | $collection->set_from_trusted( $elements ); |
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93 | |||
94 | return $collection; |
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95 | } |
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96 | |||
97 | /** |
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98 | * {@inheritdoc} |
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99 | * |
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100 | * @return Collection |
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101 | */ |
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102 | public function clear() { |
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105 | |||
106 | /** |
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107 | * {@inheritdoc} |
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108 | * |
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109 | * @param callable $condition Condition to satisfy. |
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110 | * |
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111 | * @return bool |
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112 | */ |
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113 | public function contains( $condition ) { |
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116 | |||
117 | /** |
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118 | * {@inheritdoc} |
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119 | * |
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120 | * @param callable $condition Condition to satisfy. |
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121 | * |
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122 | * @return mixed |
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123 | */ |
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124 | public function find( $condition ) { |
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129 | |||
130 | /** |
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131 | * {@inheritdoc} |
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132 | * |
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133 | * @param callable $condition Condition to satisfy. |
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134 | * |
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135 | * @return int |
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136 | */ |
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137 | public function find_index( $condition ) { |
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149 | |||
150 | /** |
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151 | * Fetches the element at the provided index. |
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152 | * |
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153 | * @param int $index Index to get element from. |
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154 | * |
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155 | * @return mixed |
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156 | * |
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157 | * @throws OutOfRangeException |
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158 | */ |
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159 | public function at( $index ) { |
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164 | 6 | ||
165 | 3 | /** |
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166 | * {@inheritdoc} |
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167 | * |
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168 | 3 | * @param int $index Index to check for existence. |
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169 | 9 | * |
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170 | * @return bool |
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171 | * |
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172 | * @throws InvalidArgumentException |
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173 | */ |
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174 | public function index_exists( $index ) { |
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185 | 3 | ||
186 | 3 | /** |
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187 | * {@inheritdoc} |
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188 | * |
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189 | * @param callable $condition Condition to satisfy. |
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190 | * |
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191 | * @return mixed |
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192 | */ |
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193 | 3 | public function filter( $condition ) { |
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204 | /** |
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205 | * {@inheritdoc} |
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206 | * |
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207 | * @param callable $condition Condition to satisfy. |
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208 | * |
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209 | 3 | * @return mixed |
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210 | 3 | */ |
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211 | 3 | public function find_last( $condition ) { |
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216 | |||
217 | /** |
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218 | 6 | * {@inheritdoc} |
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219 | 6 | * |
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220 | * @param callable $condition |
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221 | * @return int |
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222 | */ |
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223 | public function find_last_index( $condition ) { |
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235 | |||
236 | /** |
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237 | 12 | * {@inheritdoc} |
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238 | 12 | * |
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239 | 57 | * @param int $start Begining index to slice from. |
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240 | * @param int $end End index to slice to. |
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241 | * |
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242 | * @return Collection |
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243 | * |
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244 | * @throws InvalidArgumentException |
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245 | */ |
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246 | public function slice( $start, $end ) { |
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267 | |||
268 | /** |
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269 | * {@inheritdoc} |
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270 | * |
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271 | * @param int $index Index to start at. |
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272 | * @param mixed $element Element to insert. |
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273 | * |
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274 | * @return Collection |
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275 | * |
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276 | * @throws InvalidArgumentException |
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277 | * @throws OutOfRangeException |
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278 | */ |
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279 | public function insert( $index, $element ) { |
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290 | |||
291 | /** |
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292 | * {@inheritdoc} |
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293 | * |
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294 | * @param int $index Index to start insertion at. |
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295 | * @param array $elements Elements in insert. |
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296 | * |
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297 | * @return Collection |
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298 | * |
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299 | * @throws OutOfRangeException |
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300 | */ |
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301 | public function insert_range( $index, array $elements ) { |
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317 | |||
318 | /** |
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319 | * {@inheritdoc} |
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320 | * |
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321 | * @param callable $condition Condition to satisfy. |
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322 | * |
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323 | * @return Collection |
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324 | */ |
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325 | public function reject( $condition ) { |
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326 | $inverse = function ( $element ) use ( $condition ) { |
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327 | return ! call_user_func( $condition, $element ); |
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328 | }; |
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329 | |||
330 | return $this->filter( $inverse ); |
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331 | } |
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332 | |||
333 | /** |
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334 | * {@inheritdoc} |
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335 | * |
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336 | * @param int $index Index to remove. |
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337 | * |
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338 | * @return Collection |
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339 | * |
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340 | * @throws OutOfRangeException |
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341 | */ |
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342 | public function remove_at( $index ) { |
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354 | /** |
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355 | * {@inheritdoc} |
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356 | * |
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357 | * @return Collection |
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358 | */ |
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359 | public function reverse() { |
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364 | |||
365 | /** |
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366 | * {@inheritdoc} |
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367 | * |
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368 | * @param callable $callback Sort callback. |
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369 | * |
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370 | * @return Collection |
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371 | */ |
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372 | public function sort( $callback ) { |
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377 | |||
378 | /** |
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379 | * {@inheritdoc} |
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380 | * |
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381 | * @return array |
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382 | */ |
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383 | public function to_array() { |
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386 | |||
387 | /** |
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388 | * {@inheritdoc} |
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389 | * |
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390 | * @param callable $callable Reducer function. |
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391 | * |
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392 | * @param null $initial Initial reducer value. |
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393 | * |
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394 | * @return mixed |
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395 | */ |
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396 | public function reduce( $callable, $initial = null ) { |
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399 | |||
400 | /** |
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401 | * {@inheritdoc} |
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402 | * |
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403 | * @param callable $condition Condition callback. |
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404 | * |
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405 | * @return bool |
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406 | */ |
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407 | public function every( $condition ) { |
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421 | |||
422 | /** |
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423 | * {@inheritdoc} |
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424 | * |
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425 | * @param int $num Number of elements to drop. |
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426 | * |
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427 | * @return Collection |
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428 | * |
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429 | * @throws InvalidArgumentException |
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430 | */ |
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431 | public function drop( $num ) { |
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438 | |||
439 | /** |
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440 | * {@inheritdoc} |
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441 | * |
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442 | * @param int $num Number of elements to drop. |
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443 | * |
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444 | * @return Collection |
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445 | * |
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446 | * @throws InvalidArgumentException |
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447 | */ |
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448 | public function drop_right( $num ) { |
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453 | |||
454 | /** |
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455 | * {@inheritdoc} |
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456 | * |
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457 | * @param callable $condition Condition callback. |
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458 | * |
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459 | * @return Collection |
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460 | */ |
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461 | public function drop_while( $condition ) { |
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465 | /** |
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466 | * {@inheritdoc} |
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467 | * |
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468 | * @return Collection |
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469 | * |
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470 | * @throws InvalidArgumentException |
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471 | */ |
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472 | public function tail() { |
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475 | |||
476 | /** |
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477 | * {@inheritdoc} |
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478 | * |
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479 | * @param int $num Number of elements to take. |
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480 | * |
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481 | * @return Collection |
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482 | * |
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483 | * @throws InvalidArgumentException |
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484 | */ |
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485 | public function take( $num ) { |
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488 | |||
489 | /** |
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490 | * {@inheritdoc} |
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491 | * |
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492 | * @param int $num Number of elements to take. |
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493 | * |
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494 | * @return Collection |
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495 | * |
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496 | * @throws InvalidArgumentException |
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497 | */ |
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498 | public function take_right( $num ) { |
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501 | |||
502 | /** |
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503 | * {@inheritdoc} |
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504 | * |
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505 | * @param callable $condition Callback function. |
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506 | * |
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507 | * @return Collection |
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508 | */ |
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509 | public function take_while( $condition ) { |
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514 | |||
515 | /** |
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516 | * {@inheritdoc} |
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517 | * |
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518 | * @param callable $callable Callback function. |
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519 | */ |
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520 | public function each( $callable ) { |
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525 | |||
526 | /** |
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527 | * {@inheritdoc} |
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528 | * |
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529 | * @param callable $callable Callback function. |
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530 | * |
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531 | * @return Collection |
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532 | */ |
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533 | public function map( $callable ) { |
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552 | |||
553 | /** |
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554 | * {@inheritdoc} |
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555 | * |
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556 | * @param callable $callable Reducer function. |
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557 | * @param null $initial Initial value. |
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558 | * |
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559 | * @return mixed |
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560 | */ |
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561 | public function reduce_right( $callable, $initial = null ) { |
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568 | |||
569 | /** |
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570 | * {@inheritdoc} |
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571 | * |
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572 | * @return Collection |
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573 | */ |
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574 | public function shuffle() { |
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580 | |||
581 | /** |
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582 | * {@inheritdoc} |
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583 | * |
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584 | * @param array|Collection $elements Array of elements to merge. |
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585 | * |
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586 | * @return Collection |
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587 | * |
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588 | * @throws InvalidArgumentException |
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589 | */ |
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590 | public function merge( $elements ) { |
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605 | |||
606 | /** |
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607 | * {@inheritdoc} |
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608 | * |
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609 | * @return mixed |
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610 | * |
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611 | * @throws OutOfBoundsException |
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612 | */ |
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613 | public function first() { |
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620 | |||
621 | /** |
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622 | * {@inheritdoc} |
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623 | * |
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624 | * @return mixed |
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625 | * |
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626 | * @throws OutOfBoundsException |
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627 | */ |
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628 | public function last() { |
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635 | |||
636 | /** |
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637 | * {@inheritdoc} |
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638 | * |
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639 | * @return int |
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640 | */ |
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641 | public function count() { |
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644 | |||
645 | /** |
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646 | * {@inheritDoc} |
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647 | * |
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648 | * @return array |
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649 | */ |
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650 | public function serialize() { |
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659 | |||
660 | /** |
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661 | * Return the current element. |
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662 | * |
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663 | * @return mixed |
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664 | */ |
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665 | public function current() { |
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668 | |||
669 | /** |
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670 | * Move forward to next element. |
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671 | */ |
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672 | public function next() { |
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675 | |||
676 | /** |
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677 | * Return the key of the current element. |
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678 | * |
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679 | * @return mixed |
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680 | */ |
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681 | public function key() { |
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684 | |||
685 | /** |
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686 | * Checks if current position is valid. |
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687 | * |
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688 | * @return bool |
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689 | */ |
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690 | public function valid() { |
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693 | |||
694 | /** |
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695 | * Rewind the Iterator to the first element. |
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696 | */ |
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697 | public function rewind() { |
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700 | |||
701 | /** |
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702 | * Creates a new instance of the Collection |
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703 | * from a trusted set of elements. |
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704 | * |
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705 | * @param array $elements Array of elements to pass into new collection. |
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706 | * @param null|mixed $type |
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707 | * |
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708 | * @return static |
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709 | */ |
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710 | protected function new_from_trusted( array $elements, $type = null ) { |
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716 | |||
717 | /** |
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718 | * Sets the elements without validating them. |
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719 | * |
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720 | * @param array $elements Pre-validated elements to set. |
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721 | */ |
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722 | protected function set_from_trusted( array $elements ) { |
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725 | |||
726 | /** |
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727 | * Number of elements true for the condition. |
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728 | * |
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729 | * @param callable $condition Condition to check. |
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730 | * @return int |
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731 | */ |
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732 | protected function count_while_true( $condition ) { |
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744 | |||
745 | /** |
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746 | * Validates a number to be used as an index. |
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747 | * |
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748 | * @param integer $index The number to be validated as an index. |
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749 | * |
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750 | * @throws OutOfRangeException |
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751 | */ |
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752 | protected function validate_index( $index ) { |
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759 | } |
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760 |