Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Enum 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 Enum, and based on these observations, apply Extract Interface, too.
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16 | abstract class Enum |
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17 | { |
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18 | /** |
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19 | * The selected enumerator value |
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20 | * |
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21 | * @var null|bool|int|float|string |
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22 | */ |
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23 | private $value; |
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24 | |||
25 | /** |
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26 | * The ordinal number of the enumerator |
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27 | * |
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28 | * @var null|int |
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29 | */ |
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30 | private $ordinal; |
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31 | |||
32 | /** |
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33 | * An array of available constants by class |
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34 | * |
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35 | * @var array ["$class" => ["$name" => $value, ...], ...] |
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36 | */ |
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37 | private static $constants = array(); |
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38 | |||
39 | /** |
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40 | * Already instantiated enumerators |
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41 | * |
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42 | * @var array ["$class" => ["$name" => $instance, ...], ...] |
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43 | */ |
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44 | private static $instances = array(); |
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45 | |||
46 | /** |
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47 | * Constructor |
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48 | * |
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49 | * @param null|bool|int|float|string $value The value of the enumerator |
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50 | * @param int|null $ordinal The ordinal number of the enumerator |
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51 | */ |
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52 | 14 | final private function __construct($value, $ordinal = null) |
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57 | |||
58 | /** |
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59 | * Get the name of the enumerator |
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60 | * |
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61 | * @return string |
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62 | * @see getName() |
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63 | */ |
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64 | 1 | public function __toString() |
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68 | |||
69 | /** |
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70 | * @throws LogicException Enums are not cloneable |
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71 | * because instances are implemented as singletons |
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72 | */ |
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73 | 1 | final private function __clone() |
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77 | |||
78 | /** |
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79 | * @throws LogicException Enums are not serializable |
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80 | * because instances are implemented as singletons |
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81 | */ |
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82 | 1 | final public function __sleep() |
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86 | |||
87 | /** |
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88 | * @throws LogicException Enums are not serializable |
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89 | * because instances are implemented as singletons |
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90 | */ |
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91 | 1 | final public function __wakeup() |
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95 | |||
96 | /** |
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97 | * Get the value of the enumerator |
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98 | * |
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99 | * @return null|bool|int|float|string |
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100 | */ |
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101 | 21 | final public function getValue() |
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105 | |||
106 | /** |
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107 | * Get the name of the enumerator |
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108 | * |
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109 | * @return string |
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110 | */ |
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111 | 7 | final public function getName() |
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115 | |||
116 | /** |
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117 | * Get the ordinal number of the enumerator |
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118 | * |
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119 | * @return int |
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120 | */ |
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121 | 40 | final public function getOrdinal() |
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140 | |||
141 | /** |
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142 | * Compare this enumerator against another and check if it's the same. |
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143 | * |
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144 | * @param mixed $enumerator |
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145 | * @return bool |
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146 | */ |
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147 | 2 | final public function is($enumerator) |
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157 | |||
158 | /** |
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159 | * Get an enumerator instance of the given value or instance |
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160 | * |
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161 | * @param static|null|bool|int|float|string $value |
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162 | * @return static |
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163 | * @throws InvalidArgumentException On an unknwon or invalid value |
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164 | * @throws LogicException On ambiguous constant values |
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165 | */ |
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166 | 61 | final public static function get($value) |
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167 | { |
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168 | 61 | if ($value instanceof static && get_class($value) === static::class) { |
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169 | 22 | return $value; |
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170 | } |
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171 | |||
172 | 46 | return static::byValue($value); |
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173 | } |
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174 | |||
175 | /** |
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176 | * Get an enumerator instance by the given value |
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177 | * |
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178 | * @param mixed $value |
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179 | * @return static |
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180 | * @throws InvalidArgumentException On an unknwon or invalid value |
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181 | * @throws LogicException On ambiguous constant values |
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182 | */ |
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183 | 46 | final public static function byValue($value) |
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184 | { |
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185 | 46 | $class = static::class; |
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186 | 46 | $constants = self::detectConstants($class); |
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187 | 44 | $name = array_search($value, $constants, true); |
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188 | 44 | View Code Duplication | if ($name === false) { |
189 | 7 | $message = is_scalar($value) |
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190 | 7 | ? 'Unknown value ' . var_export($value, true) |
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191 | 7 | : 'Invalid value of type ' . (is_object($value) ? get_class($value) : gettype($value)); |
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192 | 7 | throw new InvalidArgumentException($message); |
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193 | } |
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194 | |||
195 | 38 | if (!isset(self::$instances[$class][$name])) { |
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196 | 7 | self::$instances[$class][$name] = new $class($constants[$name]); |
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197 | 7 | } |
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198 | |||
199 | 38 | return self::$instances[$class][$name]; |
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200 | } |
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201 | |||
202 | /** |
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203 | * Get an enumerator instance by the given name |
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204 | * |
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205 | * @param string $name The name of the enumerator |
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206 | * @return static |
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207 | * @throws InvalidArgumentException On an invalid or unknown name |
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208 | * @throws LogicException On ambiguous values |
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209 | */ |
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210 | 32 | final public static function byName($name) |
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211 | { |
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212 | 32 | $name = (string) $name; |
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213 | 32 | $class = static::class; |
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214 | 32 | if (isset(self::$instances[$class][$name])) { |
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215 | 27 | return self::$instances[$class][$name]; |
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216 | } |
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217 | |||
218 | 6 | $const = $class . '::' . $name; |
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219 | 6 | if (!defined($const)) { |
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220 | 1 | throw new InvalidArgumentException($const . ' not defined'); |
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221 | } |
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222 | |||
223 | 5 | return self::$instances[$class][$name] = new $class(constant($const)); |
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224 | } |
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225 | |||
226 | /** |
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227 | * Get an enumeration instance by the given ordinal number |
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228 | * |
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229 | * @param int $ordinal The ordinal number or the enumerator |
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230 | * @return static |
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231 | * @throws InvalidArgumentException On an invalid ordinal number |
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232 | * @throws LogicException On ambiguous values |
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233 | */ |
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234 | 19 | final public static function byOrdinal($ordinal) |
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235 | { |
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236 | 19 | $ordinal = (int) $ordinal; |
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237 | 19 | $class = static::class; |
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238 | 19 | $constants = self::detectConstants($class); |
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239 | 19 | $item = array_slice($constants, $ordinal, 1, true); |
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240 | 19 | if (empty($item)) { |
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241 | 1 | throw new InvalidArgumentException(sprintf( |
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242 | 1 | 'Invalid ordinal number, must between 0 and %s', |
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243 | 1 | count($constants) - 1 |
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244 | 1 | )); |
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245 | } |
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246 | |||
247 | 18 | $name = key($item); |
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248 | 18 | if (isset(self::$instances[$class][$name])) { |
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249 | 17 | return self::$instances[$class][$name]; |
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250 | } |
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251 | |||
252 | 2 | return self::$instances[$class][$name] = new $class(current($item), $ordinal); |
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253 | } |
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254 | |||
255 | /** |
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256 | * Get a list of enumerator instances ordered by ordinal number |
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257 | * |
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258 | * @return static[] |
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259 | */ |
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260 | 12 | final public static function getEnumerators() |
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264 | |||
265 | /** |
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266 | * Get a list of enumerator values ordered by ordinal number |
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267 | * |
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268 | * @return mixed[] |
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269 | */ |
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270 | 1 | final public static function getValues() |
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274 | |||
275 | /** |
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276 | * Get a list of enumerator names ordered by ordinal number |
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277 | * |
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278 | * @return string[] |
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279 | */ |
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280 | 1 | final public static function getNames() |
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284 | /* |
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285 | * Get a list of enumerator ordinal numbers |
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286 | * |
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287 | * @return int[] |
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288 | */ |
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289 | 1 | final public static function getOrdinals() |
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294 | |||
295 | /** |
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296 | * Get all available constants of the called class |
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297 | * |
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298 | * @return array |
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299 | * @throws LogicException On ambiguous constant values |
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300 | */ |
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301 | 60 | final public static function getConstants() |
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305 | |||
306 | /** |
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307 | * Is the given enumerator part of this enumeration |
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308 | * |
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309 | * @param static|null|bool|int|float|string $value |
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310 | * @return bool |
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311 | */ |
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312 | 1 | final public static function has($value) |
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321 | |||
322 | /** |
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323 | * Detect all available constants by the given class |
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324 | * |
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325 | * @param string $class |
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326 | * @return array |
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327 | * @throws LogicException On ambiguous constant values |
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328 | */ |
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329 | 79 | private static function detectConstants($class) |
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375 | |||
376 | /** |
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377 | * Get an enumerator instance by the given name. |
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378 | * |
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379 | * This will be called automatically on calling a method |
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380 | * with the same name of a defined enumerator. |
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381 | * |
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382 | * @param string $method The name of the enumeraotr (called as method) |
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383 | * @param array $args There should be no arguments |
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384 | * @return static |
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385 | * @throws InvalidArgumentException On an invalid or unknown name |
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386 | * @throws LogicException On ambiguous constant values |
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387 | */ |
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388 | 18 | final public static function __callStatic($method, array $args) |
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392 | } |
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393 |