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To: Sara Golemon <pollita@php.net>
CC: PHP Developers Mailing List <internals@lists.php.net>
Thread-Topic: [PHP-DEV] Putting the match expression in constant expressions
 in PHP 8.0 or 8.1
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Date: Sat, 8 Aug 2020 20:41:56 +0000
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Subject: Re: [PHP-DEV] Putting the match expression in constant expressions in
 PHP 8.0 or 8.1
From: tysonandre775@hotmail.com (tyson andre)

Hi internals,=0A=
=0A=
For unrelated reasons detailed in https://github.com/php/php-src/pull/5951#=
issuecomment-670969676 ,=0A=
I'm not planning on continuing work on this due to issues I found thinking =
about the proposal.=0A=
I initially started work on this because the intended behavior seemed under=
specified.=0A=
=0A=
"[No objections] from me, though I don't think I'd use it personally." sums=
 up my current stance on that.=0A=
=0A=
> Such a construct would be compile-time evaluated, so not having a match s=
hould result in a compile error.=0A=
=0A=
Constants in PHP are lazily evaluated under some circumstances, e.g. class =
constants in constant expressions defer evaluation if they refer to other c=
lass constants so that classes aren't unnecessarily autoloaded.=0A=
https://github.com/php/php-src/pull/5951/files#diff-96ef697f12a482e3f2a7cb0=
966a6c5beR46 is an example of UnhandledMatchError in function default param=
s, which are also deliberately not permanently cached by C.=0A=
=0A=
Compile-time evaluation was something left out of that implementation, but =
is something that would get added in `zend_const_expr_to_zval`, like it alr=
eady is for AST_CONDITIONAL.=0A=
=0A=
- Tyson=