rfc:closures

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rfc:closures [2008/09/19 12:02] – Add example of using a lambda inline. rquadlingrfc:closures [2009/12/15 22:40] – Fix list numbering rquadling
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   * Date: 2008-07-01   * Date: 2008-07-01
   * Author: Christian Seiler <chris_se@gmx.net>, Dmitry Stogov <dmitry@zend.com>   * Author: Christian Seiler <chris_se@gmx.net>, Dmitry Stogov <dmitry@zend.com>
-  * Status: Accepted+  * Status: Implemented
  
 This RFC discusses the introduction of compile-time lambda functions and closures in PHP. This RFC discusses the introduction of compile-time lambda functions and closures in PHP.
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 Closures and lambda functions can make programming much easier in several ways: Closures and lambda functions can make programming much easier in several ways:
- 
 ==== Lambda Functions ==== ==== Lambda Functions ====
  
 Lambda functions allow the quick definition of throw-away functions that are not used elsewhere. Imagine for example a piece of code that needs to call preg_replace_callback(). Currently, there are three possibilities to achieve this: Lambda functions allow the quick definition of throw-away functions that are not used elsewhere. Imagine for example a piece of code that needs to call preg_replace_callback(). Currently, there are three possibilities to achieve this:
- +  - Define the callback function elsewhere. This distributes code that belongs together throughout the file and decreases readability. 
-   - Define the callback function elsewhere. This distributes code that belongs together throughout the file and decreases readability. +  - Define the callback function in-place (but with a name). In that case one has to use function_exists() to make sure the function is only defined once. Here, the additional if() around the function definition makes the source code difficult to read. Example code:<code php>
- +
-   - Define the callback function in-place (but with a name). In that case one has to use function_exists() to make sure the function is only defined once. Here, the additional if() around the function definition makes the source code difficult to read. Example code: +
- +
-<code php>+
    function replace_spaces ($text) {    function replace_spaces ($text) {
      if (!function_exists ('replace_spaces_helper')) {      if (!function_exists ('replace_spaces_helper')) {
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    }    }
 </code> </code>
- +  - Use the present create_function() in order to create a function at runtime. This approach has several disadvantages: First of all, syntax highlighting does not work because a string is passed to the function. It also compiles the function at run time and not at compile time so opcode caches can't cache the function.
-   - Use the present create_function() in order to create a function at runtime. This approach has several disadvantages: First of all, syntax highlighting does not work because a string is passed to the function. It also compiles the function at run time and not at compile time so opcode caches can't cache the function.+
  
 ==== Closures ==== ==== Closures ====
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 === Interaction with OOP === === Interaction with OOP ===
 +
 +$this support has been removed, see [[rfc/closures/removal-of-this|removal of this]]
  
 If a closure is defined inside an object, the closure has full access to the current object through $this (without the need to import it explicitly) and all private and protected methods of that class. This also applies to nested closures. Example: If a closure is defined inside an object, the closure has full access to the current object through $this (without the need to import it explicitly) and all private and protected methods of that class. This also applies to nested closures. Example:
rfc/closures.txt · Last modified: 2017/09/22 13:28 by 127.0.0.1

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