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Subject: Re: [PHP-DEV] [RFC] Combined Comparison Operator
From: ivan.enderlin@hoa-project.net ("Ivan Enderlin @ Hoa")

On 13/02/2014 04:58, Davey Shafik wrote:
> Hey folks,
Hello Davey :-),

Thanks for the proposal.


> I've written up an RFC/Patch to gauge interest and get feedback on the =

> addition of a combined comparison (aka: spaceship) operator.
>
> You can see the RFC at:=20
> https://wiki.php.net/rfc/combined-comparison-operator
>
> This adds a new operator "(expr) <=3D> (expr)" that returns 0 if both=20
> operands are equal, 1 if the left is greater, and -1 if the right is=20
> greater.
>
> It works with all types (just as well as <, <=3D, >=3D, > work) and is =

> great for usort() callbacks for example.
Am I the only one who think that `<=3D>` is already a Mathematical=20
operator standing for the =E2=80=9Cequivalence=E2=80=9D?
PHP already uses `=3D>` as a key/value matching operator for pairs in an =

array, whereas in Math., it is the =E2=80=9Cimplies=E2=80=9D operator. Ri=
ght, we may=20
still introduce the `=3D=3D>` later. But I can't see `<=3D>` becoming `<=3D=
=3D>`=20
or even `<=3D=3D=3D>`.

Moreover, as Jordi and others have suggested, a simple PHP function will =

do the job, and much better. A -1/0/1 result depends on the compared=20
values and the interpretation of these latters: do we compare the number =

of pairs in an array, just the keys, just the values, do we also compare =

the type=E2=80=A6? To much context for a single unambiguous operator. One=
 or=20
more dedicated functions (one per type maybe) is a more realistic way in =

my opinion.

Thoughts?

Cheers :-).

--=20
Ivan Enderlin
Developer of Hoa
http://hoa-project.net/

PhD. student at DISC/Femto-ST (Vesontio) and INRIA (Cassis)
http://disc.univ-fcomte.fr/ and http://www.inria.fr/

Member of HTML and WebApps Working Group of W3C
http://w3.org/