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Date: Thu, 3 Feb 2005 17:23:30 +0100
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Subject: Re: [PHP-DEV] PHP 5.1
From: tslettebo@broadpark.no (=?iso-8859-1?Q?Terje_Sletteb=F8?=)

> Derick Rethans wrote:
> > On Thu, 3 Feb 2005, Sebastian Bergmann wrote:
> >
> >>Derick Rethans wrote:
> >>>This adds operator overloading to user classes?
> >> Yes, have a look at Johannes' Complex example [1].
> >
> > Okay, mega Yuck then. Although it looks cool, I consider it as a bad
> > practise. It confuses the hell out of people that they can add two
> > objects. Use C++/Java if you want this...
>
> I couldn't agree more. I like PHP not because it is the most compact or
> flexible of all languages but because the syntax is quite simple.
>
> Try explaining someone who just learned PHP and doesn't know your code
> where to find the implementation of
> $c = $a + $b;
> as opposed to
> $c= $a->add($b);
> or
> $c = Complex::add($a, $b);

If $a is an object of a class, then they would both be in the class
definition. One is called "add", and the other is called "operator+". What's
the problem with that?

> Another little thought how confusion can easily happen with operator
> overloading: $b = $a + 42; works but $b = 42 + $a; doesn't, i.e. the
> overloaded addition isn't commutative.

It would if operator overloading was allowed on free functions (as it is in
C++). E..g:

function operator+(complex $a, complex $b)
{
  return new complex($a.real + $b.real, $a.imag + $b.imag);
}

The binary operators are recommended to to free functions, for this reason,
in C++.

Regards,

Terje