rfc:short_list_syntax

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rfc:short_list_syntax [2016/04/05 14:02] – ] ajfrfc:short_list_syntax [2016/05/20 00:03] – Implemented ajf
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 ====== PHP RFC: Square bracket syntax for array destructuring assignment ====== ====== PHP RFC: Square bracket syntax for array destructuring assignment ======
   * Version: 1.0   * Version: 1.0
-  * Date: 2016-04-03+  * Date: 2016-04-07
   * Authors: Andrea Faulds <ajf@ajf.me>, Bob Weinand <bwoebi@php.net>   * Authors: Andrea Faulds <ajf@ajf.me>, Bob Weinand <bwoebi@php.net>
-  * Status: Draft+  * Status: Implemented (PHP 7.1)
   * First Published at: http://wiki.php.net/rfc/short_list_syntax   * First Published at: http://wiki.php.net/rfc/short_list_syntax
  
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 This syntax is more concise, and like the <php>[]</php> alternative to <php>array()</php>, this new syntax does not resemble a function call. This syntax is more concise, and like the <php>[]</php> alternative to <php>array()</php>, this new syntax does not resemble a function call.
  
-Importantly, this syntax for destructuring an array means there is now symmetry between array construction and destructuring, which should make the purpose more obvious:+Importantly, this syntax for destructuring an array means there is now symmetry between array construction and destructuring, which should make it clearer what the function of the syntax is:
  
 <code php> <code php>
 <?php <?php
  
-// These two statements are equivalent:+// The two lines in each of the following pairs are equivalent to each other 
 list($a, $b, $c) = array(1, 2, 3); list($a, $b, $c) = array(1, 2, 3);
 [$a, $b, $c] = [1, 2, 3]; [$a, $b, $c] = [1, 2, 3];
  
-// These two statements are also equivalent: 
 list("a" => $a, "b" => $b, "c" => $c) = array("a" => 1, "b" => 2, "c" => 3); list("a" => $a, "b" => $b, "c" => $c) = array("a" => 1, "b" => 2, "c" => 3);
 ["a" => $a, "b" => $b, "c" => $c] = ["a" => 1, "b" => 2, "c" => 3]; ["a" => $a, "b" => $b, "c" => $c] = ["a" => 1, "b" => 2, "c" => 3];
 +
 +list($a, $b) = array($b, $a);
 +[$a, $b] = [$b, $a];
 </code> </code>
  
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 ===== Details ===== ===== Details =====
  
-The <php>list()</php> syntax is not only permitted on the left-hand side of an assignment operation, but also as variable in a <php>foreach</php> loop. The new <php>[]</php> syntax for destructuring would work the same here:+The <php>list()</php> syntax is not only permitted on the left-hand side of an assignment operation, but also as variable in a <php>foreach</php> loop. The new <php>[]</php> syntax for destructuring would likewise be permitted here:
  
 <code php> <code php>
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 // This is also not allowed: // This is also not allowed:
 [list($a, $b), list($c, $d)] = [[1, 2], [3, 4]]; [list($a, $b), list($c, $d)] = [[1, 2], [3, 4]];
 +
 +// This, however, is allowed:
 +[[$a, $b], [$c, $d]] = [[1, 2], [3, 4]];
 </code> </code>
 +
 +Aside from this restriction, assignment with <php>[]</php> on the left-hand side behaves identically to <php>list()</php> in all respects.
  
 ===== Backward Incompatible Changes ===== ===== Backward Incompatible Changes =====
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 ===== Open Issues ===== ===== Open Issues =====
  
-Currently, the patch permits nesting the <php>[]</php> syntax form within <php>list()</php>. This will need to be fixed.+None.
  
 ===== Unaffected PHP Functionality ===== ===== Unaffected PHP Functionality =====
  
-The existing <php>list()</php> syntax will not be removed, nor deprecated, as a result of this RFC.+This RFC does not remove nor deprecate the existing <php>list()</php> syntax, and it continues to function identically.
  
 ===== Future Scope ===== ===== Future Scope =====
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 We may wish to introduce destructuring assignment syntax for objects in future. We may wish to introduce destructuring assignment syntax for objects in future.
  
-===== Proposed Voting Choices =====+===== Vote =====
  
 Because this proposal affects the language syntax (and also therefore the specification), it is a language change and requires at least a 2/3 majority to be accepted when put to a vote. Because this proposal affects the language syntax (and also therefore the specification), it is a language change and requires at least a 2/3 majority to be accepted when put to a vote.
  
 The vote will be a simple Yes/No vote on whether or not to accept the RFC for PHP 7.1 and merge the patch into master. The vote will be a simple Yes/No vote on whether or not to accept the RFC for PHP 7.1 and merge the patch into master.
 +
 +Voting started on 2016-04-27 and ended on 2016-05-08.
 +
 +<doodle title="Accept the RFC Square bracket syntax for array destructuring assignment for PHP 7.1?" auth="ajf" voteType="single" closed="true">
 +   * Yes
 +   * No
 +</doodle>
  
 ===== Patches and Tests ===== ===== Patches and Tests =====
  
-TODO php-src+There is a pull request, with tests, for the PHP interpreter (''php-src'') here: https://github.com/php/php-src/pull/1849
  
-TODO php-langspec+There is not yet a patch or pull request for the language specification (''php-langspec'').
  
 ===== Implementation ===== ===== Implementation =====
 +Merged into master for PHP 7.1: http://git.php.net/?p=php-src.git;a=commitdiff;h=4f077aee836ad7d8335cf62629a8364bdf939db9
 +
 +Not yet in the language specification.
 +
 After the project is implemented, this section should contain  After the project is implemented, this section should contain 
-  - the version(s) it was merged to 
-  - a link to the git commit(s) 
   - a link to the PHP manual entry for the feature   - a link to the PHP manual entry for the feature
  
rfc/short_list_syntax.txt · Last modified: 2017/09/22 13:28 by 127.0.0.1

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