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Subject: Re: [PHP-DEV] [RFC] Mixed type
From: bobwei9@hotmail.com (Bob Weinand)

Hey Dan,

this, I consider one of the few concepts which should never make it into PH=
P.

In particular, the main problem with mixed is that it is a very easy "I hav=
e no idea how to type that properly, so just let's use mixed".

And really, in general, except for some debug functions, mixed is just an e=
xcuse to not use proper generics. I cannot think of non-debug scenarios whe=
re we are juggling truly unknown types where the type is unidirectional.
(Uni-directional means: there is no corresponding getting/forwarding functi=
on for an input.)

Mixed is in almost every case just patching the holes in PHPs type system. =
And as such, I'd rather promote RFCs trying to properly fix the gaps in the=
 type system than supporting mixed.

Mixed is a hack, do not use mixed.

Bob

P.s.: If you want to migrate your types and have an overview of what's alre=
ady migrated, maybe just add a comment // type-migrated before or similar? =
But that's seriously not the business of the language.

> Am 20.04.2020 um 13:17 schrieb Dan Ackroyd <danack@basereality.com>:
>=20
> Hi Internals,
>=20
> Here is an RFC for adding a 'mixed' type to the language:
> https://wiki.php.net/rfc/mixed_type_v2
> The RFC builds on an earlier draft by Michael Moravec.
>=20
> Part of the motivation for pursuing this RFC was my recent experience
> in upgrading an application to PHP 7.4.
>=20
> Being able to add types to the application made the code much easier
> to reason about, but there were places where I couldn't add type info
> due to the lack of mixed. That made it hard to see if that piece of
> code had been upgraded (but type info couldn't be added), or if that
> code still needed to be upgraded.
>=20
> cheers
> Dan
> Ack
>=20
> --=20
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: http://www.php.net/unsub.php
>=20