Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:51020
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain stefan-marr.de from 85.88.12.247 cause and error)
Mime-Version: 1.0 (Apple Message framework v1082)
Content-Type: text/plain; charset=us-ascii
In-Reply-To: <AANLkTi=dz1pu7B+1k-xAbCRPmFx24J=27ABaWLRuPwqK@mail.gmail.com>
Date: Mon, 13 Dec 2010 17:02:13 +0100
Cc: "internals@lists.php.net Development" <internals@lists.php.net>
Content-Transfer-Encoding: quoted-printable
Message-ID: <D9ED43A9-833E-4644-9DFC-DE89CF83656F@stefan-marr.de>
References: <89C52156-CF92-4DDB-8BA4-4ABF6883512C@stefan-marr.de> <AANLkTi=dz1pu7B+1k-xAbCRPmFx24J=27ABaWLRuPwqK@mail.gmail.com>
To: RQuadling@googlemail.com
Subject: Re: [PHP-DEV] Traits and Properties
From: php@stefan-marr.de (Stefan Marr)

Hi Richard:

On 13 Dec 2010, at 14:13, Richard Quadling wrote:

> =46rom the rfc [1], "A Trait is similar to a class, but only intended =
to
> group functionality".
>=20
> I'm guessing that says it all. A trait has no properties.

It is really a practical concern of language consistency for the moment.
I am not talking about any fancy new language feature to handle state.

At the moment, I am just concerned with examples like the following:

trait Foo {
  function bar() {
    $this->baz =3D 'abcd';
  }
}

If that example becomes more complex, I would consider it to be good =
software engineering practice to document the usage of $this->baz and =
its semantic.

For classes this is usually done by explicitly naming the property in =
the class body.

At the moment, there is nothing which hinders you in doing that for a =
trait.

However, since traits do not provide any safety provisioning for state, =
i.e., there is no collision handling for properties, the question is, =
how do we either promote to use explicit accessors or how do we deal =
with the inevitable and certainly justified use of properties in one or =
the other way.

Best regards
Stefan

--=20
Stefan Marr
Software Languages Lab
Vrije Universiteit Brussel
Pleinlaan 2 / B-1050 Brussels / Belgium
http://soft.vub.ac.be/~smarr
Phone: +32 2 629 2974
Fax:   +32 2 629 3525