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Date: Wed, 4 Sep 2019 11:09:01 -0500
In-Reply-To: <CAH0Uv3EuC+okBDzWyi_4WL3LvjhMgLqWVVCyfLj2Yrd=huRtTw@mail.gmail.com>
Cc: Lynn <kjarli@gmail.com>,
 =?utf-8?Q?Micha=C5=82_Brzuchalski?= <michal.brzuchalski@gmail.com>,
 Fwentish Aelondes <fwentish@gmail.com>,
 PHP Internals List <internals@lists.php.net>
To: Andreas Hennings <andreas@dqxtech.net>
References: <CAJVEVObtRNX_1VWtd35bKKYm_Z9RY=kgx78VY3T3cuFhWMR=5g@mail.gmail.com>
 <CABdc3WpzBP7uYvsHPGeuW7+W+KSZpw7QCGwm706jz2LBS59hpw@mail.gmail.com>
 <CANS-=pco95mG_6AmZhFYJ-ig8UEagZoR-MZ65AVEAm9foDZdhg@mail.gmail.com>
 <CAH0Uv3EuC+okBDzWyi_4WL3LvjhMgLqWVVCyfLj2Yrd=huRtTw@mail.gmail.com>
Subject: Re: [PHP-DEV] Silent Types
From: ben@benramsey.com (Ben Ramsey)

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> Andreas Hennings wrote:
>=20
> In some other languages the mixed type is called "variant".
> https://en.m.wikipedia.org/wiki/Variant_type
> I mostly remember it from VisualBasic.

Union types are probably better than specifying a variant or mixed type. =
At present, parameters and properties with no type specified are mixed =
by default. Nikita has just opened discussion on a new union types =
proposal in another thread.


> Fwentish Aelondes wrote:
>=20
> Hello internals,
>=20
> Zeev's idea to bring peace to the galaxy seems like a good idea, but
> impossible to implement in practice.
>=20
> But it got me thinking about how one might introduce static typing
> into a dynamically typed language w/out breaking BC.
>=20
> And then I had this crazy idea:
>=20
> //int
> $i =3D 0;
>=20
> //string
> $c =3D 'c';
>=20
> //float
> $pi =3D 3.14;
>=20
> If static typing in php was *only* an opt-in kind-of-thing, would this
> work? Could the parser be built to identify 3 or 4 different keywords
> in comments and give warnings or fatal errors for type conversions of
> variables that have the type specified in the immediately preceding
> comment?

Static analyzers (like PHPStan) already honor types specified in =
comments above variables.

/* @param int */
$i =3D 0;


> Micha=C5=82 Brzuchalski wrote:
>=20
> IMO it's crazy idea and we should not change the way comments work
> especially inline comments which even aren't kept in opcache.
>=20
> I think better approach would be to put type in front of first =
variable
> declaration like:
>=20
> [type] $variable =3D $value;

I think specifying the type in front of the variable is the best option, =
and we have precedence for this with typed properties in PHP 7.4.


Cheers,
Ben

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