rfc:argument_unpacking
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rfc:argument_unpacking [2013/12/29 11:30] nikic |
rfc:argument_unpacking [2017/09/22 13:28] (current) |
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| * Date: 2013-08-30 | * Date: 2013-08-30 | ||
| * Author: Nikita Popov <nikic@php.net> | * Author: Nikita Popov <nikic@php.net> | ||
| - | * Status: In Voting | + | * Status: Implemented (in PHP 5.6) |
| - | * Proposed for: PHP 5.6 | + | |
| * Patch: https://github.com/php/php-src/pull/477 | * Patch: https://github.com/php/php-src/pull/477 | ||
| * Mailing list discussion: http://markmail.org/message/dxae5ybjldg6pftp | * Mailing list discussion: http://markmail.org/message/dxae5ybjldg6pftp | ||
| Line 40: | Line 39: | ||
| </code> | </code> | ||
| - | It's possible to use ''%%...%%'' multiple times in a call and it is possible to mix it with normal arguments: | + | It's possible to use ''%%...%%'' multiple times in a call and it is possible to use normal arguments before argument unpacking: |
| <code php> | <code php> | ||
| Line 47: | Line 46: | ||
| test(...$args1, ...$args2); // [1, 2, 3, 4, 5, 6] | test(...$args1, ...$args2); // [1, 2, 3, 4, 5, 6] | ||
| test(1, 2, 3, ...$args2); // [1, 2, 3, 4, 5, 6] | test(1, 2, 3, ...$args2); // [1, 2, 3, 4, 5, 6] | ||
| - | test(...$args1, 4, 5, 6); // [1, 2, 3, 4, 5, 6] | + | </code> |
| + | |||
| + | However, it is not possible to use normal arguments after argument unpacking was used. Both of the following are invalid: | ||
| + | |||
| + | <code php> | ||
| + | test(...$args1, 4, 5, 6); | ||
| + | test(...$args1, 4, 5, 6, ...$args2); | ||
| </code> | </code> | ||
| Line 75: | Line 80: | ||
| <code php> | <code php> | ||
| - | var_dump(1, 2, ...null, 3, 4); | + | var_dump(1, 2, ...null, ...[3, 4]); |
| // Warning: Only arrays and Traversables can be unpacked | // Warning: Only arrays and Traversables can be unpacked | ||
| // int(1) int(2) int(3) int(4) | // int(1) int(2) int(3) int(4) | ||
| Line 214: | Line 219: | ||
| } | } | ||
| } | } | ||
| - | </code> | ||
| - | |||
| - | ==== Normal arguments after unpacked arguments ==== | ||
| - | |||
| - | Some people also had doubts regarding the usefulness of allowing ''%%foo(...$args, $arg)%%'' calls, where a normal argument follows after an unpacked argument. | ||
| - | |||
| - | One use-case for this pattern are the variants of ''array_diff'' and ''array_intersect'' which accept callback functions as the **last** one or two arguments: | ||
| - | |||
| - | <code php> | ||
| - | array_udiff(...$arrays, $valueCmpFunction); | ||
| - | array_udiff_uassoc(...$arrays, $valueCmpFunction, $keyCmpFunction); | ||
| - | </code> | ||
| - | |||
| - | While this kind of API was undoubtedly a bad choice in the first place, I see little reason not to support calls to them. | ||
| - | |||
| - | Another use case is appending one additional argument to a variadic argument list. For example, the following snippet adds an additional ''LIMIT'' parameter to an existing query: | ||
| - | |||
| - | <code php> | ||
| - | $this->query($query . ' LIMIT ?', ...$params, $limit); | ||
| </code> | </code> | ||
| Line 243: | Line 229: | ||
| As this is a language change a two third majority is required. | As this is a language change a two third majority is required. | ||
| - | Voting started 2013-12-21 and closes 2014-01-11. | + | Voting started 2013-12-21 and ended 2014-01-11. |
| - | <doodle title="Implement argument unpacking in PHP 5.6?" auth="nikic" voteType="single" closed="false"> | + | <doodle title="Implement argument unpacking in PHP 5.6?" auth="nikic" voteType="single" closed="true"> |
| * Yes | * Yes | ||
| * No | * No | ||
rfc/argument_unpacking.1388316606.txt.gz · Last modified: 2017/09/22 13:28 (external edit)