Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:64591
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain mrclay.org from 50.22.11.19 cause and error)
Message-ID: <50E8D6D0.7030307@mrclay.org>
Date: Sat, 05 Jan 2013 20:43:44 -0500
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/17.0 Thunderbird/17.0
MIME-Version: 1.0
To: internals@lists.php.net
References: <CAF+90c_girfbcPBb8rCV3bPNR2Hsd5gyRPB+VArCfqjPPqG5DQ@mail.gmail.com> <19D80B01-BE88-4119-8A15-B631A96060E5@mrclay.org> <CAF+90c9=HgRLHv4o=5dGkQzZPC5Q0tbPC8GD9AZ13Jwkr0pOcw@mail.gmail.com> <CAHjTTqOwrCfprcw3jCiLU21NygYCjrz+3+zpjdnU_sj-JbQonQ@mail.gmail.com> <50E8AA4D.5090207@sugarcrm.com> <CAAyV7nFW45f5vEUkZXhbgaJe=TL1Tbfp7igbUkQ=ifJc9tAsvQ@mail.gmail.com> <50E8C2BA.9080309@sugarcrm.com> <CAAyV7nHk0yqgsatAo46ThDbYRtNPVmVGCPh1jshpXVY6fXkFSA@mail.gmail.com>
In-Reply-To: <CAAyV7nHk0yqgsatAo46ThDbYRtNPVmVGCPh1jshpXVY6fXkFSA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] [RFC] Alternative typehinting syntax for accessors
From: steve@mrclay.org (Steve Clay)

On 1/5/13 7:25 PM, Anthony Ferrara wrote:
> No, the other initializer that would be useful is `new Foo`. Assigning a
> default value is not an initializer. An initializer is something that's run
> on object construction (and has been discussed in other threads):
>
> class Foo {
>      public DateTime $bar {
>          init: { $bar = new DateTime(); }
>      }
> }

I think property init() would enable two bad practices:
1. putting too much logic in a property (SRP)
2. building dependencies within the object instead of injecting them (the better way is 
what we already do: receive dependencies in the constructor and assign them to the properties)

> null pointers. And if you set the property in the constructor (and it's
> typed), you should never have the chance for it to be non-null, unless you
> explicitly define it that way. Otherwise, you'd have to litter your code
> with is_null checks... Which defeats the point of the syntax in the first

Which is why I think the default setting signature should not have "= null". If someone 
wants to allow setting the property *back* to null, they could easily:

public Foo $foo {
   get;
   set($value = null);
}

I agree with you that, in an ideal world, a property with a declared type would *never not 
have* that type, but I think a property init() would be a bad tradeoff to make that a reality.

The class constructor is the best place to do this, and maybe this is why C# forces 
property storage to be in fields; you can set fields directly from the constructor without 
going through property setters.

Steve Clay
-- 
http://www.mrclay.org/