[RFC][DISCUSSION] - Disallow Multiple Constructor Calls

Hi Nikita,

thank you for your feedback. Would you suggest to convert RFC into prohibition of explicit __construct calls except parent::__construct?

Regards,
Tim

Dear internals,

me and Richard Fussenegger came up with a RFC draft disallowing multiple constructor calls - https://wiki.php.net/rfc/disallow-multiple-constructor-calls https://wiki.php.net/rfc/disallow-multiple-constructor-calls <https://wiki.php.net/rfc/disallow-multiple-constructor-calls https://wiki.php.net/rfc/disallow-multiple-constructor-calls>

Here is a Reddit discussion thread - https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/ https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/ <https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/ https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/>

Any suggestions are highly welcome. Thank you.

Regards,
Tim

Without putting a lot of though into this, the restriction sounds reasonable.

However, it is not immediately clear to me how this can be implemented without adding a disproportionate amount of overhead for something which I would consider a rather minor feature. If an object only had a single constructor this would be a simple flag, but if you want to allow one call per each constructor in the hierarchy (i.e. you can call the constructor and each parent constructor once), this information needs to be stored somehow. The obvious way would be a hashset containing the constructors (or CEs) that have been called on the object, but I don't think this would be acceptable.

Regards,
Nikita

Without putting a lot of though into this, the restriction sounds
reasonable.

However, it is not immediately clear to me how this can be implemented
without adding a disproportionate amount of overhead for something which I
would consider a rather minor feature. If an object only had a single
constructor this would be a simple flag, but if you want to allow one call
per each constructor in the hierarchy (i.e. you can call the constructor
and each parent constructor once), this information needs to be stored
somehow. The obvious way would be a hashset containing the constructors (or
CEs) that have been called on the object, but I don't think this would be
acceptable.

Regards,
Nikita

Hey Nikic!

Thanks for skimming over it. I also though about implementation already.
My initial though was -- especially to keep it simple -- to simply
delete the method from the object's table.

Not sure if this is possible or just introduced more problems than it
solves. Also considering that we think reflection should continue to
allow calling it multiple times, though this is obviously still debatable.

--
Richard "Fleshgrinder" Fussenegger

Hi Marcio,

there is no deprecation because nothing is deprecated. This is a behavioural constrain.

Regarding parent() this is just one possible future RFC. Our intention was just to depict that the RFC in hand opens such possibilities. There is no obligation.

Regards,
Tim

Hi Tim,

I'm ok with the idea. But could you elaborate why not propose a deprecation before the error on PHP 8?

Also, one point about the future scope "Add shorthand parent() as alternative to parent::__construct().":
Do we really need to introduce more language constructs that look like valid user space code https://3v4l.org/CE2q8 https://3v4l.org/CE2q8 ?

Thanks.
Márcio.

2017-01-17 16:17 GMT-04:00 Tim Bezhashvyly <tim.bezhashvyly@gmail.com mailto:tim.bezhashvyly@gmail.com>:
Dear internals,

me and Richard Fussenegger came up with a RFC draft disallowing multiple constructor calls - https://wiki.php.net/rfc/disallow-multiple-constructor-calls https://wiki.php.net/rfc/disallow-multiple-constructor-calls <https://wiki.php.net/rfc/disallow-multiple-constructor-calls https://wiki.php.net/rfc/disallow-multiple-constructor-calls>

Here is a Reddit discussion thread - https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/ https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/ <https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/ https://www.reddit.com/r/PHP/comments/5okdac/php_rfc_disallow_multiple_constructor_calls/>

Any suggestions are highly welcome. Thank you.

Regards,
Tim