PHP 8.2 proposal: "match", allow "default" as conditional_expression,e.g. 'en_US', 'en_GB', default => loadDefaults()

  116479
November 22, 2021 18:18 syntheme@gmx.de (Andreas)
Hi internals,

This is a proposal to allow to append the `default` pattern by comma to
the end of the last match branch. (Like a conditional_expression)

This allows to re-use the return_expression if required and avoids code
duplication.

PROPOSAL: PHP 8.2

 loadGermanLanguageSettings(),
     'en_US', 'en_GB', default => loadDefaultLanguageSettings(),
};
?>

// PHP 8.1 (Current implementation works like before)

 loadGermanLanguageSettings(),
     'en_US', 'en_GB' => loadDefaultLanguageSettings(),
     default => loadDefaultLanguageSettings(),
};
?>

The `default` pattern must be the last item in the last expression branch.

Thanks,
Andreas
  116480
November 22, 2021 21:06 nikita.ppv@gmail.com (Nikita Popov)
On Mon, Nov 22, 2021 at 7:18 PM Andreas <syntheme@gmx.de> wrote:

> Hi internals, > > This is a proposal to allow to append the `default` pattern by comma to > the end of the last match branch. (Like a conditional_expression) > > This allows to re-use the return_expression if required and avoids code > duplication. > > PROPOSAL: PHP 8.2 > > return match ($locale) { > 'de_DE', 'de_CH', 'de_AT' => loadGermanLanguageSettings(), > 'en_US', 'en_GB', default => loadDefaultLanguageSettings(), > }; > ?> >
Isn't this equivalent to just this? loadGermanLanguageSettings(), default => loadDefaultLanguageSettings(), }; 'en_US' and 'en_GB' will already go to the default branch if they're not listed explicitly. Regards, Nikita
  116482
November 22, 2021 22:04 syntheme@gmx.de (Andreas)
On 22.11.21 22:06, Nikita Popov wrote:
> On Mon, Nov 22, 2021 at 7:18 PM Andreas <syntheme@gmx.de> wrote: > > Hi internals, > > This is a proposal to allow to append the `default` pattern by > comma to > the end of the last match branch. (Like a conditional_expression) > > This allows to re-use the return_expression if required and avoids > code > duplication. > > PROPOSAL: PHP 8.2 > > return match ($locale) { >      'de_DE', 'de_CH', 'de_AT' => loadGermanLanguageSettings(), >      'en_US', 'en_GB', default => loadDefaultLanguageSettings(), > }; > ?> > > > Isn't this equivalent to just this? > > return match ($locale) { >      'de_DE', 'de_CH', 'de_AT' => loadGermanLanguageSettings(), >      default => loadDefaultLanguageSettings(), > }; > > 'en_US' and 'en_GB' will already go to the default branch if they're > not listed explicitly. > > Regards, > Nikita
Hi Nikita, nice to meet you. Yes, that's indeed possible. But I personally like to list all handled conditional_expressions (here the $locales) in the match in order to directly see in the code for later reference, which of them are explicit handled (and which are handled by the default pattern). This proposal is mainly syntactic sugar to avoid code duplication, in this case the duplicate return_expression loadDefaultLanguageSettings(). Just as a side note: PHPStorm's inspection suggests "Merge with default arm" every time because of this code duplication. Regards, Andreas