idea: implement a Comparable interface

It'd be nice if, when doing $objA > $objB, that that'd invoke

$objA->__compareTo($objB) or something, much like Java's Comparable
interface.

There is nothing stopping you from creating this in user-land. Also, I
have spent a lot of time writing libraries in PHP and I now believe that
this approach is not the best solution anyway.

Except for the magic that happens on the comparison, I mean. I really
don't think PHP should go down that road at this point, if ever.

Hi!

I wrote https://wiki.php.net/rfc/comparable a couple of years ago —
there's a patch there that would probably still apply without too much
work to master. About the only difference was that I didn't double
underscore the magic method (in line with both Java and PHP interfaces
like Countable).

Overriding < and > isn't the biggest issue, even though BC issues with
conversions may definitely be a surprise. Bug biggest one is ==, which
may have a lot of very non-trivial effects if you make == return
"equals" when other functions (such as searches, hashes, etc.) may treat
them as not equal. It is quite a complex thing which is rife with
unexpected side effects, so I think it would be better if it were explicit.

--
Stanislav Malyshev, Software Architect
SugarCRM: http://www.sugarcrm.com/
(408)454-6900 ext. 227

Its kinda useless feature for PHP.

Daniel Ribeiro Gomes Pereira
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2013/5/7 Nikita Popov nikita.ppv@gmail.com

It'd be nice if, when doing $objA > $objB, that that'd invoke
$objA->__compareTo($objB) or something, much like Java's Comparable
interface.

Do you have examples of what this would be useful for? The two things that
come to mind are DateTime (which can do this anyway as it's an internal
class) and classes for bignums or something like that (which are probably
also better implemented internally). So I'm not sure how much use there is
for this.

Nikita

It'd be nice if, when doing $objA > $objB, that that'd invoke
$objA->__compareTo($objB) or something, much like Java's Comparable
interface.

Do you have examples of what this would be useful for? The two things that
come to mind are DateTime (which can do this anyway as it's an internal
class) and classes for bignums or something like that (which are probably
also better implemented internally). So I'm not sure how much use there is
for this.

bignum PHP class:

http://phpseclib.sourceforge.net/math/intro.html

Per the benchmarks it's internal implementation (without OpenSSL) is faster
than BCMath is in 5.4 lol. Not sure which OS the test was ran on.

That's the only use case I can come up with off the top of my head but
that's more than I can come up with for Iterator atm lol.

It'd be nice if, when doing $objA > $objB, that that'd invoke
$objA->__compareTo($objB) or something, much like Java's Comparable
interface.

Do you have examples of what this would be useful for? The two things that
come to mind are DateTime (which can do this anyway as it's an internal
class) and classes for bignums or something like that (which are probably
also better implemented internally). So I'm not sure how much use there is
for this.

Nikita

I would like to see this feature in PHP! I often thought it would be very helpful. In days of PHP 5.2 I wrote a Date-Class similar to DateTime but with another API which should be the same as in C#. Comparing dates with $date->compareTo($date2) > 0 is always hard to read and error-prone.

Another example: You have one database entity and a collection and you want to check if it is in the collection.

$dbEntity = ...;
$dbCollection = ...;

foreach ($dbCollection as $tmpEntity) {
if ($dbEntity->getId() == $tmpEntity->getId()) {
// ...
}
}

Instead you could write $dbEntity == $tmpEntity. I think this is easier to read.

Of course you can say "just syntetic sugar", but better readability of code helps developers a lot!

Best regards
Christian