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( callable $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( callable $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( callable $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( callable $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( callable $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( callable $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 without( callable $condition ) { |
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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( callable $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 $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( callable $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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434 | |||
435 | /** |
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436 | * {@inheritdoc} |
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437 | * |
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438 | * @param int $num Number of elements to drop. |
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439 | * |
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440 | * @return Collection |
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441 | * |
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442 | * @throws InvalidArgumentException |
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443 | */ |
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444 | public function drop_right( $num ) { |
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449 | |||
450 | /** |
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451 | * {@inheritdoc} |
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452 | * |
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453 | * @param callable $condition Condition callback. |
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454 | * |
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455 | * @return Collection |
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456 | */ |
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457 | public function drop_while( callable $condition ) { |
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461 | /** |
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462 | * {@inheritdoc} |
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463 | * |
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464 | * @return Collection |
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465 | * |
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466 | * @throws InvalidArgumentException |
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467 | */ |
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468 | public function tail() { |
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471 | |||
472 | /** |
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473 | * {@inheritdoc} |
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474 | * |
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475 | * @param int $num Number of elements to take. |
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476 | * |
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477 | * @return Collection |
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478 | * |
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479 | * @throws InvalidArgumentException |
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480 | */ |
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481 | public function take( $num ) { |
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484 | |||
485 | /** |
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486 | * {@inheritdoc} |
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487 | * |
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488 | * @param int $num Number of elements to take. |
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489 | * |
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490 | * @return Collection |
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491 | * |
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492 | * @throws InvalidArgumentException |
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493 | */ |
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494 | public function take_right( $num ) { |
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497 | |||
498 | /** |
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499 | * {@inheritdoc} |
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500 | * |
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501 | * @param callable $condition Callback function. |
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502 | * |
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503 | * @return Collection |
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504 | */ |
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505 | public function take_while( callable $condition ) { |
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510 | |||
511 | /** |
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512 | * {@inheritdoc} |
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513 | * |
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514 | * @param callable $callable Callback function. |
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515 | */ |
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516 | public function each( callable $callable ) { |
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521 | |||
522 | /** |
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523 | * {@inheritdoc} |
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524 | * |
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525 | * @param callable $callable Callback function. |
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526 | * |
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527 | * @return Collection |
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528 | */ |
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529 | public function map( callable $callable ) { |
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548 | |||
549 | /** |
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550 | * {@inheritdoc} |
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551 | * |
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552 | * @param callable $callable Reducer function. |
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553 | * @param null $initial Initial value. |
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554 | * |
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555 | * @return mixed |
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556 | */ |
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557 | public function reduce_right( callable $callable, $initial = null ) { |
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564 | |||
565 | /** |
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566 | * {@inheritdoc} |
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567 | * |
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568 | * @return Collection |
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569 | */ |
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570 | public function shuffle() { |
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576 | |||
577 | /** |
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578 | * {@inheritdoc} |
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579 | * |
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580 | * @param array|Collection $elements Array of elements to merge. |
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581 | * |
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582 | * @return Collection |
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583 | * |
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584 | * @throws InvalidArgumentException |
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585 | */ |
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586 | public function merge( $elements ) { |
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601 | |||
602 | /** |
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603 | * {@inheritdoc} |
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604 | * |
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605 | * @return mixed |
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606 | * |
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607 | * @throws OutOfBoundsException |
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608 | */ |
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609 | public function first() { |
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616 | |||
617 | /** |
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618 | * {@inheritdoc} |
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619 | * |
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620 | * @return mixed |
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621 | * |
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622 | * @throws OutOfBoundsException |
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623 | */ |
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624 | public function last() { |
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631 | |||
632 | /** |
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633 | * {@inheritdoc} |
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634 | * |
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635 | * @return int |
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636 | */ |
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637 | public function count() { |
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640 | |||
641 | /** |
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642 | * {@inheritDoc} |
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643 | * |
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644 | * @return array |
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645 | */ |
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646 | public function serialize() { |
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655 | |||
656 | /** |
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657 | * Return the current element. |
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658 | * |
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659 | * @return mixed |
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660 | */ |
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661 | public function current() { |
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664 | |||
665 | /** |
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666 | * Move forward to next element. |
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667 | */ |
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668 | public function next() { |
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671 | |||
672 | /** |
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673 | * Return the key of the current element. |
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674 | * |
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675 | * @return mixed |
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676 | */ |
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677 | public function key() { |
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680 | |||
681 | /** |
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682 | * Checks if current position is valid. |
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683 | * |
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684 | * @return bool |
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685 | */ |
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686 | public function valid() { |
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689 | |||
690 | /** |
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691 | * Rewind the Iterator to the first element. |
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692 | */ |
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693 | public function rewind() { |
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696 | |||
697 | /** |
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698 | * Creates a new instance of the Collection |
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699 | * from a trusted set of elements. |
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700 | * |
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701 | * @param array $elements Array of elements to pass into new collection. |
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702 | * @param null|mixed $type |
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703 | * |
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704 | * @return static |
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705 | */ |
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706 | protected function new_from_trusted( array $elements, $type = null ) { |
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712 | |||
713 | /** |
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714 | * Sets the elements without validating them. |
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715 | * |
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716 | * @param array $elements Pre-validated elements to set. |
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717 | */ |
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718 | protected function set_from_trusted( array $elements ) { |
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721 | |||
722 | /** |
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723 | * Number of elements true for the condition. |
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724 | * |
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725 | * @param callable $condition Condition to check. |
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726 | * @return int |
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727 | */ |
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728 | protected function count_while_true( callable $condition ) { |
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740 | |||
741 | /** |
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742 | * Validates a number to be used as an index. |
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743 | * |
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744 | * @param integer $index The number to be validated as an index. |
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745 | * |
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746 | * @throws OutOfRangeException |
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747 | */ |
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748 | protected function validate_index( $index ) { |
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755 | } |
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756 |