rfc:variadic_empty
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rfc:variadic_empty [2015/02/21 00:31] tpunt |
rfc:variadic_empty [2015/03/28 15:54] tpunt |
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| * Date: 2015-02-20 | * Date: 2015-02-20 | ||
| * Author: Thomas Punt, tpunt@hotmail.co.uk | * Author: Thomas Punt, tpunt@hotmail.co.uk | ||
| - | * Status: Draft | + | * Status: Declined |
| * First Published at: http://wiki.php.net/rfc/variadic_empty | * First Published at: http://wiki.php.net/rfc/variadic_empty | ||
| ===== Introduction ===== | ===== Introduction ===== | ||
| - | This RFC aims to make the ''empty'' language construct accept any number of arguments. | + | This RFC aims make ''empty()'' have a variable arity. |
| <code php> | <code php> | ||
| Line 16: | Line 16: | ||
| if (!empty($a) && !empty($b) && !empty($c)) {} | if (!empty($a) && !empty($b) && !empty($c)) {} | ||
| - | // new example usage #1: | + | // new proposed usage #1: |
| if (empty($a, $b, $c)) {} | if (empty($a, $b, $c)) {} | ||
| - | // new example usage #2: | + | // new proposed usage #2: |
| if (!empty($a, $b, $c)) {} | if (!empty($a, $b, $c)) {} | ||
| </code> | </code> | ||
| ===== Proposal ===== | ===== Proposal ===== | ||
| - | By changing ''empty()'' to have a variable arity, we can write more compact code when checking for the emptiness of multiple expressions. This seems like a common scenario for web applications... | + | The proposal is to change ''empty()'' so that it can accept multiple arguments. This will enable developers to write more compact code when checking for the emptiness of multiple expressions. |
| - | ===== Backward Incompatible Changes ===== | + | As the above snippet demonstrates, the semantics of a variadic ''empty()'' should be the equivalent to logically OR'ing together multiple ''empty()'' invocations. Thus, if //any// arguments passed into ''empty()'' are considered falsy, then **true** will be returned; if //no// arguments are considered empty, then **false** is returned. This behaviour is the most logical (given ''empty()'''s falsy semantics) and seems to be the most prevalent usage of multiple empty checks in user-land code (therefore being the most beneficial behaviour). |
| - | No BC breakages. | + | |
| - | ===== Proposed PHP Version(s) ===== | + | ===== Justification ===== |
| - | PHP 7.0 | + | |
| - | ===== RFC Impact ===== | + | In PHP, it is not uncommon to see conditionals consisting of multiple ''empty()'' invocations. This is evident by simply browsing through some popular open source projects: |
| - | ==== To SAPIs ==== | + | |
| - | None. | + | |
| - | ==== To Existing Extensions ==== | + | WordPress (( https://github.com/WordPress/WordPress/blob/master/wp-admin/includes/template.php#L2007 )): |
| - | None. | + | <code php> |
| + | if ( empty( $pointer_id ) || empty( $selector ) || empty( $args ) || empty( $args['content'] ) ) | ||
| + | </code> | ||
| + | OpenCart (( https://github.com/opencart/opencart/blob/45fc863fa068d82b5280890e6466a198faa54bff/upload/admin/controller/openbay/ebay_profile.php#L128 )): | ||
| + | <code php> | ||
| + | if (empty($setting['dispatch_times']) || empty($setting['countries']) || empty($setting['returns'])){ | ||
| + | </code> | ||
| + | phpBB (( https://github.com/phpbb/phpbb/blob/040d451dcca9ae54d8f4b7bdd2f231033765a8f2/phpBB/phpbb/notification/method/jabber.php#L48 )): | ||
| + | <code php> | ||
| + | return !( | ||
| + | empty($this->config['jab_enable']) || | ||
| + | empty($this->config['jab_host']) || | ||
| + | empty($this->config['jab_username']) || | ||
| + | empty($this->config['jab_password']) || | ||
| + | !@extension_loaded('xml') | ||
| + | ); | ||
| + | </code> | ||
| - | ==== To Opcache ==== | + | And so on... |
| - | None. | + | |
| - | ==== New Constants ==== | + | So this seems like quite a common need for users, and one that cannot be emulated in user-land code because of ''empty()'''s behaviour of suppressing undefined variable errors. |
| - | None. | + | |
| - | ==== php.ini Defaults ==== | + | This change will also make ''empty()'' more inline with the not-too-dissimilar ''isset()'', which is good for [[http://en.wikipedia.org/wiki/Principle_of_least_astonishment|POLA]]. |
| - | None. | + | |
| - | ===== Open Issues ===== | + | ===== Backward Incompatible Changes ===== |
| - | None. | + | No BC breakages. |
| + | |||
| + | ===== Proposed PHP Version(s) ===== | ||
| + | PHP 7.0 | ||
| ===== Unaffected PHP Functionality ===== | ===== Unaffected PHP Functionality ===== | ||
| The current functionality of ''empty()'' will be completely preserved. | The current functionality of ''empty()'' will be completely preserved. | ||
| - | ===== Future Scope ===== | + | ===== Vote ===== |
| - | This sections details areas where the feature might be improved in future, but that are not currently proposed in this RFC. | + | Because this is a language change, a 2/3 majority is required. It is a simple yes/no vote on whether ''empty()'' should be made a variadic. |
| - | ===== Proposed Voting Choices ===== | + | <doodle title="Make empty() a Variadic" auth="tpunt" voteType="single" closed="true"> |
| - | Include these so readers know where you are heading and can discuss the proposed voting options. | + | * Yes |
| + | * No | ||
| + | </doodle> | ||
| - | State whether this project requires a 2/3 or 50%+1 majority (see [[voting]]) | + | Voting starts on 2015-03-07 and ends on 2015-03-21. |
| ===== Patches and Tests ===== | ===== Patches and Tests ===== | ||
| - | Links to any external patches and tests go here. | ||
| - | |||
| - | If there is no patch, make it clear who will create a patch, or whether a volunteer to help with implementation is needed. | ||
| - | |||
| - | Make it clear if the patch is intended to be the final patch, or is just a prototype. | ||
| - | |||
| - | ===== Implementation ===== | ||
| - | 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 | ||
| - | |||
| - | ===== References ===== | ||
| - | Links to external references, discussions or RFCs | ||
| - | ===== Rejected Features ===== | + | PR: https://github.com/php/php-src/pull/1109 |
| - | Keep this updated with features that were discussed on the mail lists. | + | |
rfc/variadic_empty.txt · Last modified: 2017/09/22 13:28 (external edit)