On Mon, 04 Oct 2010 00:18:36 +0100, Stas Malyshev <smalys...@sugarcrm.com>
wrote:
* The current behavior for>,<, etc. is completely useless. It's
unpredictable and it doesn't even establish a total order:
$a = new stdclass;
$a->prop = null;
$b = new stdclass;
$b->prop2 = null;
var_dump($a> $b); //false
var_dump($a == $b); //false
var_dump($b> $a); //false
That's because there's no total ordering of generic objects that can
make sense. Only very specific objects - such as ones representing
numeric qualities or having numeric properties - can be ordered, most of
objects are unordered. And comparing objects with scalars automagically
might bring a lot of surprises as nobody really expects $a == $b and $b
== $a to be different now.
I never defended comparison of objects against scalars (though this is
already possible, in a limited sense). Perhaps I ought to have changed the
subject.
I'm just saying that the current comparisons for user classes is either
very limited (==) or completely useless (<, >, >=, <=). Given that, we
could implement a *limited* mechanism for overloading those operators in
user-land. If limited to objects of the same class (or with one operand of
a subclass of the other), this could actually make the comparison
operators useful with little potential for damage. It would also not be
unprecedented since it's already allowed for internal classes.
--
Gustavo Lopes
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