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)