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 Str 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 Str, and based on these observations, apply Extract Interface, too.
| 1 | <?php | ||
| 8 | class Str | ||
|  | |||
| 9 | { | ||
| 10 | /** | ||
| 11 | * The cache of snake-cased words. | ||
| 12 | * | ||
| 13 | * @var array | ||
| 14 | */ | ||
| 15 | protected static $snakeCache = []; | ||
| 16 | |||
| 17 | /** | ||
| 18 | * The cache of camel-cased words. | ||
| 19 | * | ||
| 20 | * @var array | ||
| 21 | */ | ||
| 22 | protected static $camelCache = []; | ||
| 23 | |||
| 24 | /** | ||
| 25 | * The cache of studly-cased words. | ||
| 26 | * | ||
| 27 | * @var array | ||
| 28 | */ | ||
| 29 | protected static $studlyCache = []; | ||
| 30 | |||
| 31 | /** | ||
| 32 | * Transliterate a UTF-8 value to ASCII. | ||
| 33 | * | ||
| 34 | * @param string $value | ||
| 35 | * | ||
| 36 | * @return string | ||
| 37 | */ | ||
| 38 | public static function ascii($value) | ||
| 46 | |||
| 47 | /** | ||
| 48 | * Convert a value to camel case. | ||
| 49 | * | ||
| 50 | * @param string $value | ||
| 51 | * | ||
| 52 | * @return string | ||
| 53 | */ | ||
| 54 | public static function camel($value) | ||
| 62 | |||
| 63 | /** | ||
| 64 | * Determine if a given string contains a given substring. | ||
| 65 | * | ||
| 66 | * @param string $haystack | ||
| 67 | * @param string|array $needles | ||
| 68 | * | ||
| 69 | * @return bool | ||
| 70 | */ | ||
| 71 | View Code Duplication | public static function contains($haystack, $needles) | |
| 81 | |||
| 82 | /** | ||
| 83 | * Determine if a given string ends with a given substring. | ||
| 84 | * | ||
| 85 | * @param string $haystack | ||
| 86 | * @param string|array $needles | ||
| 87 | * | ||
| 88 | * @return bool | ||
| 89 | */ | ||
| 90 | View Code Duplication | public static function endsWith($haystack, $needles) | |
| 100 | |||
| 101 | /** | ||
| 102 | * Cap a string with a single instance of a given value. | ||
| 103 | * | ||
| 104 | * @param string $value | ||
| 105 | * @param string $cap | ||
| 106 | * | ||
| 107 | * @return string | ||
| 108 | */ | ||
| 109 | public static function finish($value, $cap) | ||
| 115 | |||
| 116 | /** | ||
| 117 | * Determine if a given string matches a given pattern. | ||
| 118 | * | ||
| 119 | * @param string $pattern | ||
| 120 | * @param string $value | ||
| 121 | * | ||
| 122 | * @return bool | ||
| 123 | */ | ||
| 124 | public static function is($pattern, $value) | ||
| 139 | |||
| 140 | /** | ||
| 141 | * Return the length of the given string. | ||
| 142 | * | ||
| 143 | * @param string $value | ||
| 144 | * | ||
| 145 | * @return int | ||
| 146 | */ | ||
| 147 | public static function length($value) | ||
| 151 | |||
| 152 | /** | ||
| 153 | * Limit the number of characters in a string. | ||
| 154 | * | ||
| 155 | * @param string $value | ||
| 156 | * @param int $limit | ||
| 157 | * @param string $end | ||
| 158 | * | ||
| 159 | * @return string | ||
| 160 | */ | ||
| 161 | public static function limit($value, $limit = 100, $end = '...') | ||
| 169 | |||
| 170 | /** | ||
| 171 | * Convert the given string to lower-case. | ||
| 172 | * | ||
| 173 | * @param string $value | ||
| 174 | * | ||
| 175 | * @return string | ||
| 176 | */ | ||
| 177 | public static function lower($value) | ||
| 181 | |||
| 182 | /** | ||
| 183 | * Limit the number of words in a string. | ||
| 184 | * | ||
| 185 | * @param string $value | ||
| 186 | * @param int $words | ||
| 187 | * @param string $end | ||
| 188 | * | ||
| 189 | * @return string | ||
| 190 | */ | ||
| 191 | public static function words($value, $words = 100, $end = '...') | ||
| 201 | |||
| 202 | /** | ||
| 203 | * Parse a Class@method style callback into class and method. | ||
| 204 | * | ||
| 205 | * @param string $callback | ||
| 206 | * @param string $default | ||
| 207 | * | ||
| 208 | * @return array | ||
| 209 | */ | ||
| 210 | public static function parseCallback($callback, $default) | ||
| 214 | |||
| 215 | /** | ||
| 216 | * Generate a more truly "random" alpha-numeric string. | ||
| 217 | * | ||
| 218 | * @param int $length | ||
| 219 | * | ||
| 220 | * @throws \RuntimeException | ||
| 221 | * | ||
| 222 | * @return string | ||
| 223 | */ | ||
| 224 | public static function random($length = 16) | ||
| 238 | |||
| 239 | /** | ||
| 240 | * Generate a more truly "random" bytes. | ||
| 241 | * | ||
| 242 | * @param int $length | ||
| 243 | * | ||
| 244 | * @throws \RuntimeException | ||
| 245 | * | ||
| 246 | * @return string | ||
| 247 | * | ||
| 248 | * @deprecated since version 5.2. Use random_bytes instead. | ||
| 249 | */ | ||
| 250 | public static function randomBytes($length = 16) | ||
| 266 | |||
| 267 | /** | ||
| 268 | * Generate a "random" alpha-numeric string. | ||
| 269 | * | ||
| 270 | * Should not be considered sufficient for cryptography, etc. | ||
| 271 | * | ||
| 272 | * @param int $length | ||
| 273 | * | ||
| 274 | * @return string | ||
| 275 | */ | ||
| 276 | public static function quickRandom($length = 16) | ||
| 282 | |||
| 283 | /** | ||
| 284 | * Compares two strings using a constant-time algorithm. | ||
| 285 | * | ||
| 286 | * Note: This method will leak length information. | ||
| 287 | * | ||
| 288 | * Note: Adapted from Symfony\Component\Security\Core\Util\StringUtils. | ||
| 289 | * | ||
| 290 | * @param string $knownString | ||
| 291 | * @param string $userInput | ||
| 292 | * | ||
| 293 | * @return bool | ||
| 294 | * | ||
| 295 | * @deprecated since version 5.2. Use hash_equals instead. | ||
| 296 | */ | ||
| 297 | public static function equals($knownString, $userInput) | ||
| 301 | |||
| 302 | /** | ||
| 303 | * Replace the first occurrence of a given value in the string. | ||
| 304 | * | ||
| 305 | * @param string $search | ||
| 306 | * @param string $replace | ||
| 307 | * @param string $subject | ||
| 308 | * | ||
| 309 | * @return string | ||
| 310 | */ | ||
| 311 | View Code Duplication | public static function replaceFirst($search, $replace, $subject) | |
| 321 | |||
| 322 | /** | ||
| 323 | * Replace the last occurrence of a given value in the string. | ||
| 324 | * | ||
| 325 | * @param string $search | ||
| 326 | * @param string $replace | ||
| 327 | * @param string $subject | ||
| 328 | * | ||
| 329 | * @return string | ||
| 330 | */ | ||
| 331 | View Code Duplication | public static function replaceLast($search, $replace, $subject) | |
| 341 | |||
| 342 | /** | ||
| 343 | * Convert the given string to upper-case. | ||
| 344 | * | ||
| 345 | * @param string $value | ||
| 346 | * | ||
| 347 | * @return string | ||
| 348 | */ | ||
| 349 | public static function upper($value) | ||
| 353 | |||
| 354 | /** | ||
| 355 | * Convert the given string to title case. | ||
| 356 | * | ||
| 357 | * @param string $value | ||
| 358 | * | ||
| 359 | * @return string | ||
| 360 | */ | ||
| 361 | public static function title($value) | ||
| 365 | |||
| 366 | /** | ||
| 367 | * Generate a URL friendly "slug" from a given string. | ||
| 368 | * | ||
| 369 | * @param string $title | ||
| 370 | * @param string $separator | ||
| 371 | * | ||
| 372 | * @return string | ||
| 373 | */ | ||
| 374 | public static function slug($title, $separator = '-') | ||
| 391 | |||
| 392 | /** | ||
| 393 | * Convert a string to snake case. | ||
| 394 | * | ||
| 395 | * @param string $value | ||
| 396 | * @param string $delimiter | ||
| 397 | * | ||
| 398 | * @return string | ||
| 399 | */ | ||
| 400 | public static function snake($value, $delimiter = '_') | ||
| 416 | |||
| 417 | /** | ||
| 418 | * Determine if a given string starts with a given substring. | ||
| 419 | * | ||
| 420 | * @param string $haystack | ||
| 421 | * @param string|array $needles | ||
| 422 | * | ||
| 423 | * @return bool | ||
| 424 | */ | ||
| 425 | View Code Duplication | public static function startsWith($haystack, $needles) | |
| 435 | |||
| 436 | /** | ||
| 437 | * Convert a value to studly caps case. | ||
| 438 | * | ||
| 439 | * @param string $value | ||
| 440 | * | ||
| 441 | * @return string | ||
| 442 | */ | ||
| 443 | public static function studly($value) | ||
| 455 | |||
| 456 | /** | ||
| 457 | * Returns the portion of string specified by the start and length parameters. | ||
| 458 | * | ||
| 459 | * @param string $string | ||
| 460 | * @param int $start | ||
| 461 | * @param int|null $length | ||
| 462 | * | ||
| 463 | * @return string | ||
| 464 | */ | ||
| 465 | public static function substr($string, $start, $length = null) | ||
| 469 | |||
| 470 | /** | ||
| 471 | * Make a string's first character uppercase. | ||
| 472 | * | ||
| 473 | * @param string $string | ||
| 474 | * | ||
| 475 | * @return string | ||
| 476 | */ | ||
| 477 | public static function ucfirst($string) | ||
| 481 | |||
| 482 | /** | ||
| 483 | * Returns the replacements for the ascii method. | ||
| 484 | * | ||
| 485 | * Note: Adapted from Stringy\Stringy. | ||
| 486 | * | ||
| 487 | * @see https://github.com/danielstjules/Stringy/blob/2.2.0/LICENSE.txt | ||
| 488 | * | ||
| 489 | * @return array | ||
| 490 | */ | ||
| 491 | protected static function charsArray() | ||
| 615 | } | ||
| 616 | 
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.