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Date: Sun, 5 Jun 2016 06:22:05 -0600
Message-ID: <CAObuZdtRDvKGRsHKuOt9RLP40u4aQ9LUPuEO2xV1YotZPCQL-Q@mail.gmail.com>
To: Robert Stoll <php@tutteli.ch>
Cc: Bob Weinand <bobwei9@hotmail.com>, Andrea Faulds <ajf@ajf.me>, 
	"internals@lists.php.net" <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=001a113d1c260feadd0534870112
Subject: Re: [PHP-DEV] Re: [RFC] [PRE-VOTE] Union types
From: derokorian@gmail.com (Ryan Pallas)

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On Sun, Jun 5, 2016 at 6:09 AM, Robert Stoll <php@tutteli.ch> wrote:

> Hi Andrea, Bob
>
> > -----Urspr=C3=BCngliche Nachricht-----
> > Von: Bob Weinand [mailto:bobwei9@hotmail.com]
> > Gesendet: Sonntag, 5. Juni 2016 01:00
> > An: Andrea Faulds
> > Cc: internals@lists.php.net
> > Betreff: Re: [PHP-DEV] Re: [RFC] [PRE-VOTE] Union types
> >
> >
> > > Am 05.06.2016 um 00:55 schrieb Andrea Faulds <ajf@ajf.me>:
> > >
> > > Hi again,
> > >
> > > In an attempt to be constructive, I have implemented an alternative
> approach to weak scalar type selection here:
> > >
> > >
> https://github.com/krakjoe/php-src/compare/multi-types...TazeTSchnitzel:m=
ulti-types-roulette
> > >
> > > Where there is no exact scalar type match, this patch uses an
> algorithm originally suggested by Nikita, wherein we
> use
> > rand() to pick which type to cast to.
> > >
> > > This is much simpler than having a type precedence matrix, and thus i=
s
> easier to remember and reason about. The
> choice
> > of selection function means that no particular use-case is privileged.
> Given PHP's scalar types are roughly equivalent
> (after
> > all, PHP juggles them freely), this apparently unorthodox selection
> process should nonetheless produce sensible
> results in
> > most cases.
> > >
> > > Please tell me your thoughts!
> > >
> > > --
> > > Andrea Faulds
> > > https://ajf.me/ <https://ajf.me/>
> > This is the holy grail I was hunting for so long!
> >
> > All my computational problems can be solved by a simple rand()!
> >
> > In case nobody objects I'm going to merge that straight ahead into
> php-src 7.0 (no need for master-only, after all
> it's no real
> > BC break!).
> >
> > Thanks a very much!!!
> >
> > Bob
>
> Not sure if this is a clever idea. I haven't read all emails so bear with
> me if this is more than clear. What happens
> with the following?
>
> function foo(int | string $a) {
>   if ($a =3D=3D "") {
>     //a
>   } else {
>     //b
>   }
> }
>
> foo(false);
>
> What branch is taken? Is it taken randomly?
>

In this case, A will always be taken, because of the loose comparison (=3D=
=3D).
Basically:

var_dump("" =3D=3D ""); // bool(true)
var_dump(0 =3D=3D ""); // bool(true)
var_dump(false =3D=3D ""); // bool(true)

>
>
>
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>

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