Re: [PHP-DEV] [Strawpoll] Promoting redefining constant to exception
On Tue, Jan 25, 2022 at 5:11 PM Rowan Tommins
wrote:
> On 25/01/2022 19:44, Chase Peeler wrote:
> > If we start throwing exceptions, which can't be suppressed, it will make
> > this much more difficult to read since the constants.php will have to be
> > updated:
> >
> > if(!defined('dbserver')){
> >define('dbserver','productiondb.example.com');
> > }
> > if(!defined('otherconstant')){
> > define('otherconstants','foobar');
> > }
>
>
> A wrapper function for this use case is entirely trivial:
>
> function define_if_not_defined($name, $value) {
> if ( ! defined($name) ) {
> define($name, $value);
> }
> }
>
> Give it a short name like 'def', and your config file actually becomes
> shorter:
>
> def('dbserver', 'productiondb.example.com');
> def('otherconstants', 'foobar');
>
> "define" itself is just a function name, not a reserved word, so you
> could even declare the above as "define" in a namespace, then add "use
> function SomeNamespace\define;" and leave the rest of the file alone.
>
>
Bruce and Rowan - thanks for the suggestions. I like both of those and I
think they'll work in our situation. Appreciate you taking the time to
recommend some solutions instead of just telling me I'm doing it the wrong
way.
> Regards,
>
> --
> Rowan Tommins
> [IMSoP]
>
> --
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: https://www.php.net/unsub.php
>
>
--
Chase Peeler
chasepee...@gmail.com
Re: [PHP-DEV] [Strawpoll] Promoting redefining constant to exception
On 25/01/2022 19:44, Chase Peeler wrote:
If we start throwing exceptions, which can't be suppressed, it will make
this much more difficult to read since the constants.php will have to be
updated:
if(!defined('dbserver')){
define('dbserver','productiondb.example.com');
}
if(!defined('otherconstant')){
define('otherconstants','foobar');
}
A wrapper function for this use case is entirely trivial:
function define_if_not_defined($name, $value) {
if ( ! defined($name) ) {
define($name, $value);
}
}
Give it a short name like 'def', and your config file actually becomes
shorter:
def('dbserver', 'productiondb.example.com');
def('otherconstants', 'foobar');
"define" itself is just a function name, not a reserved word, so you
could even declare the above as "define" in a namespace, then add "use
function SomeNamespace\define;" and leave the rest of the file alone.
Regards,
--
Rowan Tommins
[IMSoP]
--
PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: https://www.php.net/unsub.php
Re: [PHP-DEV] [Strawpoll] Promoting redefining constant to exception
On Tue, Jan 25, 2022 at 9:45 PM Chase Peeler wrote:
> it will make this much more difficult to read since the constants.php will
> have to be
> updated:
>
> if(!defined('dbserver')){
> define('dbserver','productiondb.example.com');
> }
> if(!defined('otherconstant')){
>define('otherconstants','foobar');
> }
You could use this form for conciseness:
```
defined('dbserver') or define('dbserver', 'productiondb.example.com');
defined('otherconstant') or define('otherconstant', 'foobar');
```
IMHO it's clearer than `@define()` as it makes it explicit where you
expect a possible previous definition and where you don't.
--
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Re: [PHP-DEV] [Strawpoll] Promoting redefining constant to exception
On Tue, Jan 25, 2022 at 3:08 PM Kamil Tekiela wrote: > A constant is a value that, unlike a variable, cannot be reassociated with > a different value. A properly written software should never redefine > constants. The possibility of redefining constants in PHP should be > considered a bug rather than a feature. > Constants are not good for configuration values that can be changed. A > proper data structure should be used instead. Constants should never have > to be redefined, either by the software itself, its tests or its > extensions. Constant values must remain the same under all circumstances > otherwise they are no longer constants. > > Regardless of whether it's a proper use of constants or not, it's something that was in place long before I started and not something we can easily change now. Also, I'm not suggesting that we allow constants to be redefined. My setup actually works because you can't redefine them. The idea is that the local configuration file is processed first. > +1 to remove it in PHP 9.0 > -- Chase Peeler chasepee...@gmail.com
Re: [PHP-DEV] [Strawpoll] Promoting redefining constant to exception
A constant is a value that, unlike a variable, cannot be reassociated with a different value. A properly written software should never redefine constants. The possibility of redefining constants in PHP should be considered a bug rather than a feature. Constants are not good for configuration values that can be changed. A proper data structure should be used instead. Constants should never have to be redefined, either by the software itself, its tests or its extensions. Constant values must remain the same under all circumstances otherwise they are no longer constants. +1 to remove it in PHP 9.0
Re: [PHP-DEV] [Strawpoll] Promoting redefining constant to exception
We have a main "constants.php" file that resides in git. The first line of
constants.php includes local_constants.php, which is kept out of git. The
idea is that we can "override" any of the constants on a per server basis.
constants.php:
@define('dbserver','productiondb.example.com');
local_constants.php
@define('dbserver','devdb.example.com');
If we start throwing exceptions, which can't be suppressed, it will make
this much more difficult to read since the constants.php will have to be
updated:
if(!defined('dbserver')){
define('dbserver','productiondb.example.com');
}
if(!defined('otherconstant')){
define('otherconstants','foobar');
}
On Sat, Jan 22, 2022 at 10:29 PM Mark Randall wrote:
> Internals,
>
> While cleaning up some PRs I was prompted to re-visit one I had
> outstanding about exception-throwing behaviour when redefining
> constants, this applies to functions like define and language syntax
> constructs such as const.
>
> There have been a few discussions in the past about the topic.
>
> Here is one from 2016 from Dmitry:
> https://wiki.php.net/rfc/constant_redefinition
>
> Discussion:
> https://externals.io/message/93885
>
> My own PR:
> https://github.com/php/php-src/pull/5265
>
> Since Dmitry's RFC was made in 2016, and my PR a while ago, attempted
> redeclaration was promoted from a notice to a warning, but I still think
> it's sensible to go one step further.
>
> There was mention on github that there was some resistence to promotion
> to exception in the past, but I think there is a strong possibility that
> the mood may be different many years later, with PHPs positive moves
> towards throwing on poorly defined or illogical behaviour.
>
> To gauge this, I'm throwing out a non-binding strawpoll to get the lay
> of the land before doing anything else with it. If there is general
> favour I'll fix up my patch and do a proper RFC.
>
> https://wiki.php.net/redefine_constants_exception_strawpoll
>
> Mark Randall
>
> --
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: https://www.php.net/unsub.php
>
>
--
Chase Peeler
chasepee...@gmail.com
[PHP-DEV] [Strawpoll] Promoting redefining constant to exception
Internals, While cleaning up some PRs I was prompted to re-visit one I had outstanding about exception-throwing behaviour when redefining constants, this applies to functions like define and language syntax constructs such as const. There have been a few discussions in the past about the topic. Here is one from 2016 from Dmitry: https://wiki.php.net/rfc/constant_redefinition Discussion: https://externals.io/message/93885 My own PR: https://github.com/php/php-src/pull/5265 Since Dmitry's RFC was made in 2016, and my PR a while ago, attempted redeclaration was promoted from a notice to a warning, but I still think it's sensible to go one step further. There was mention on github that there was some resistence to promotion to exception in the past, but I think there is a strong possibility that the mood may be different many years later, with PHPs positive moves towards throwing on poorly defined or illogical behaviour. To gauge this, I'm throwing out a non-binding strawpoll to get the lay of the land before doing anything else with it. If there is general favour I'll fix up my patch and do a proper RFC. https://wiki.php.net/redefine_constants_exception_strawpoll Mark Randall -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
