rfc:abstract_final_class

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rfc:abstract_final_class [2014/12/12 15:41]
guilhermeblanco
rfc:abstract_final_class [2017/09/22 13:28] (current)
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   * Date: 2014-11-26   * Date: 2014-11-26
   * Author: Guilherme Blanco, guilhermeblanco@php.net   * Author: Guilherme Blanco, guilhermeblanco@php.net
-  * Status: ​Under Discussion+  * Status: ​Declined
   * First Published at: http://​wiki.php.net/​rfc/​abstract_final_class   * First Published at: http://​wiki.php.net/​rfc/​abstract_final_class
  
 ===== Introduction ===== ===== Introduction =====
 +
 +Please understand only one of the following proposals can be accepted, not both.
 +They'​re explained together because the address the same issue.
 +
 +==== As Static classes ====
 +
  
 Static classes are helpful in the case you are wrapping common functions that are static, but the common class itself cannot be instantiated. Static classes are helpful in the case you are wrapping common functions that are static, but the common class itself cannot be instantiated.
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   * Could also be used with combination of "​final",​ meaning it cannot be extended (such as more permissive visibility, behavior change, etc)   * Could also be used with combination of "​final",​ meaning it cannot be extended (such as more permissive visibility, behavior change, etc)
   * There'​s no way of adding static variables to a namespace. This would address this issue too.   * There'​s no way of adding static variables to a namespace. This would address this issue too.
 +
 +==== As abstract final ====
 +
 +
 +
 +Abstract final classes are helpful in the case you are wrapping common functions that are static, but the common class itself cannot be instantiated. Currently, PHP developers'​ only resource is to create a final class with a private constructor,​ leading to untestable and error prone code.
 +
 +For such, here is motivation:
 +
 +    As “abstract”,​ it cannot be instantiated
 +    As “final”,​ it cannot be extended (such as visibility increase, behavior change, etc)
 +    There'​s no way of adding variables to a namespace. This would address this issue too
  
 ===== Proposal ===== ===== Proposal =====
  
-Change language scanner to accept static class construction,​ and subsequently enforcing the existence of only static members.+Change language scanner to accept static class or abstract final construction,​ and subsequently enforcing the existence of only static members.
  
 ===== Proposed PHP Version(s) ===== ===== Proposed PHP Version(s) =====
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 ===== Example ===== ===== Example =====
  
-  final static class Environment+==== As static class ==== 
 + 
 +  ​static class Environment
   {   {
       private static $rootDirectory = '/​var/​www/​project';​       private static $rootDirectory = '/​var/​www/​project';​
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   echo Environment::​getRootDirectory();​   echo Environment::​getRootDirectory();​
 +
 +==== As abstract final ====
 +
 +  abstract final class StringUtil
 +  {
 +      public static function isNotNullOrSpace($str)
 +      {
 +          return !($str === null || strlen($str) < 1 || strlen(trim($str)) < 1);
 +      }
 +  }
 +
 +  echo StringUtil::​isNotNullOrSpace(''​)
 +    ? 'Empty string'​
 +    : '​Non-empty string';​
 +
  
 ===== Vote ===== ===== Vote =====
-<doodle title="​Static classes"​ auth="​guilhermeblanco"​ voteType="​single"​ closed="​false">​ +<doodle title="​Static classes"​ auth="​guilhermeblanco"​ voteType="​single"​ closed="​true">​ 
-   * Yes+   * Yes, as "​static class"​ 
 +   * Yes, as "​abstract final class"
    * No    * No
 </​doodle>​ </​doodle>​
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 ===== Implementation ===== ===== Implementation =====
  
-Most recent suggested implementation available at https://​github.com/​php/​php-src/​pull/​929 +  * Most recent suggested implementation available at https://​github.com/​php/​php-src/​pull/​929 
-Originally suggested as abstract class at https://​github.com/​php/​php-src/​pull/​923+  ​* ​Originally suggested as abstract class at https://​github.com/​php/​php-src/​pull/​923
rfc/abstract_final_class.1418398876.txt.gz · Last modified: 2017/09/22 13:28 (external edit)