Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:63791
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain m.gmane.org designates 80.91.229.3 as permitted sender)
To: internals@lists.php.net
Date: Fri, 09 Nov 2012 02:50:51 -0700
Lines: 50
Message-ID: <k7ijlq$gml$1@ger.gmane.org>
References: <CAESVnVrZz1jMGX2PQPFY48zoCBijvUq3nXtEE=KmLmz6_7jREw@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0
In-Reply-To: <CAESVnVrZz1jMGX2PQPFY48zoCBijvUq3nXtEE=KmLmz6_7jREw@mail.gmail.com>
Subject: Re: [PHP-DEV] Object comparison
From: fullmoon@newsguy.com (crankypuss)

On 11/08/2012 05:07 PM, Sara Golemon wrote:
> From: http://php.net/manual/en/language.operators.comparison.php
>
> An object compared to anything which is not a bool, null, or object
> should result in the object appearing to be greater than the other
> operand.  For example:
>
> $a = new stdClass();
> $b = new stdClass();
>
> var_dump(null < $a);
> var_dump(false < $a);
> var_dump(true == $a);
> var_dump($a == $b);
> var_dump(0 < $a);
> var_dump(1 < $a); // false
> var_dump(2 < $a); // false
> var_dump("foo" < $a);
> var_dump("2" < $a);
> var_dump(tmpfile() < $a);
>
> Based on docs, I expect all nine of these to yield true, however in
> practice, the two marked "false" come out as false because the RHS
> object is converted to an integer (1), contrary to the docs.
>
> Doc bug? Or code bug?  I'm inclined to call it a code bug, but wanted
> others' thoughts.
>
> -Sara
>

You seem to be reporting a bug ("contrary to the docs"), but you might 
be suggesting that the doc be corrected (since doc and behaviour should 
always match).

I would suggest being very careful about implementing something as 
central as a change to how comparisons are made, that ought to be 
approached with great caution because it has the potential for breaking 
a huge amount of existing code.

[It does occur to me however, simply as a point of interest, that 
objects traditionally have both a constructor and a destructor, and the 
idea of objects also having a comparator makes a certain amount of 
sense; a default object comparator might implement the currently defined 
comparisons while allowing derived classes to override the default 
behaviour and leaving comparisons not involving objects undisturbed.]

Comparing objects to scalars is really an apples/oranges comparision to 
begin with.