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Date: Wed, 22 Feb 2012 19:45:40 +1100
To: Sebastian Krebs <krebs.seb@googlemail.com>
Cc: internals@lists.php.net
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Subject: Re: [PHP-DEV] [RFC] Enum proposal (yet another)
From: charlie@charliesomerville.com (Charlie Somerville)

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My point is that *although* it's certainly possible to do almost everythi=
ng I want already, I should not have to write all that boilerplate for ea=
ch enum.

I would much prefer to write something like 'enum =7B A, B, C =7D' rather=
 than write a full class for the enum, duplicate each enum value multiple=
 times (your example repeats 'foo' and 'bar' three times each), overload =
the =5F=5FtoString() magic method, do manual error handling in the constr=
uctor, etc.

Since PHP provides no way to overload the equality operator, any solution=
 that tries to emulate enums as Samuel or I have written about will be fl=
awed. =20


On Wednesday, 22 =46ebruary 2012 at 7:37 PM, Sebastian Krebs wrote:

> 2012/2/22 Charlie Somerville <charlie=40charliesomerville.com (mailto:c=
harlie=40charliesomerville.com)>
> =20
> > Right, but enums could possibly be a lot richer than class constants =
are
> > now.
> > =20
> > They could be a type where the only values are what's defined in the =
enum.
> > This could be used with type hinting:
> > =20
> > enum =46oo =7B
> > A,
> > B,
> > C
> > =7D
> > =20
> > function bar(=46oo =24x) =7B
> > // ...
> > =7D
> > =20
> =20
> =20
> =20
> class MyEnum =7B
> const =46OO =3D 'foo';
> const BAR =3D 'bar';
> private =24value;
> public function =5F=5Fconstruct (=24value) =7B
> if (=21in=5Farray(=24value, array(self::=46OO, self::BAR)) throw new
> UnexpectedValueException;
> =24this->value =3D =24value;
> =7D
> public function =5F=5FtoString () =7B return =24this->value; =7D
> =7D
> =20
> =20
> function doSomething (MyEnum =24foo) =7B /* code */ =7D
> =20
> =20
> What I wanted to say: I don't see, what is not possible already=3F
> =20
> =20
> =20
> > =20
> > There'd be no need to do any manual checking that =24x is a valid val=
ue.
> > =20
> > Perhaps enum values could also be casted back to strings:
> > =20
> > (string)=46oo::B; // =22B=22
> > =20
> > Sure, this is the kind of stuff that's possible in other ways already=
, but
> > first class support always helps.
> > On =46eb 22, 2012 4:14 PM, =22Laruence=22 <laruence=40php.net (mailto=
:laruence=40php.net)> wrote:
> > =20
> > > On Wed, =46eb 22, 2012 at 12:45 PM, Samuel Deal <samuel.deal=40gmai=
l.com (mailto:samuel.deal=40gmail.com)>
> > > wrote:
> > > > Hi all,
> > > > =20
> > > > I really missed enums in PHP,
> > > Why=3F we have class constant.
> > > =20
> > > thanks
> > > > So after reading I tryed to synthetise the various views.
> > > > =20
> > > > You can find a draft here :
> > > > https://github.com/SamNrique/php-src/wiki/R=46C-draft
> > > > (I can't write on the wiki, and perhaps it's better to finish the=

> > > > discussion first)
> > > > =20
> > > > There's an implementation with this draft.
> > > > I'd love to have feedbacks because it's my first php-core hack.
> > > > =20
> > > > Thanks
> > > > --
> > > > Samuel D=C3=A9al
> > > > samuel.deal=40gmail.com (mailto:samuel.deal=40gmail.com)
> > > > =20
> > > =20
> > > =20
> > > =20
> > > =20
> > > --
> > > Laruence Xinchen Hui
> > > http://www.laruence.com/
> > > =20
> > > --
> > > PHP Internals - PHP Runtime Development Mailing List
> > > To unsubscribe, visit: http://www.php.net/unsub.php
> > > =20
> > =20
> > =20
> =20
> =20
> =20



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