RE: [PHP-DEV] idea: implement a Comparable interface
On Tue, May 7, 2013 at 6:17 PM, Thomas Anderson zeln...@gmail.com wrote:
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
[PHP-DEV] 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.
Re: [PHP-DEV] 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.
Re: [PHP-DEV] 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.
Re: [PHP-DEV] idea: implement a Comparable interface
On 7 May 2013 09:17, Thomas Anderson zeln...@gmail.com wrote: It'd be nice if, when doing $objA $objB, that that'd invoke $objA-__compareTo($objB) or something, much like Java's Comparable interface. 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). I ended up withdrawing it because the response at the time was somewhere between meh and outright hostility; I didn't see much point devoting time to something that was going to fail a vote regardless. It could be dusted off and reproposed for 5.6 if there was enough interest, but my guess is that it'd still be an uphill battle (even though some internal classes, most notably DateTime, do exactly this). Adam -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] idea: implement a Comparable interface
On Tue, May 7, 2013 at 6:17 PM, Thomas Anderson zeln...@gmail.com wrote: 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
Re: [PHP-DEV] idea: implement a Comparable interface
Its kinda useless feature for PHP. Daniel Ribeiro Gomes Pereira Twitter https://twitter.com/#!/drgomesp | Facebookhttps://www.facebook.com/profile.php?id=10407054469 | LinkedIn http://www.linkedin.com/pub/daniel-ribeiro-gomes/21/414/39 iPhone: +55 (48) 9111-0931 2013/5/7 Nikita Popov nikita@gmail.com On Tue, May 7, 2013 at 6:17 PM, Thomas Anderson zeln...@gmail.com wrote: 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
Re: [PHP-DEV] idea: implement a Comparable interface
Classes without the ability to overload the comparison operator could be considered kinda useless as well. On Tue, May 7, 2013 at 11:11 AM, Daniel Ribeiro drgom...@gmail.com wrote: Its kinda useless feature for PHP. Daniel Ribeiro Gomes Pereira Twitter https://twitter.com/#!/drgomesp | Facebookhttps://www.facebook.com/profile.php?id=10407054469 | LinkedIn http://www.linkedin.com/pub/daniel-ribeiro-gomes/21/414/39 iPhone: +55 (48) 9111-0931 2013/5/7 Nikita Popov nikita@gmail.com On Tue, May 7, 2013 at 6:17 PM, Thomas Anderson zeln...@gmail.com wrote: 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
Re: [PHP-DEV] idea: implement a Comparable interface
I proposed something similar recently in the PHP-FIG group, but decided that without the language-level ability to overload comparison operators, standardizing comparables ony using methods was not very useful. If PHP could provide a magic method for comparison that involved being able to use comparison operators, I think this feature would be really useful. An example that comes to mind is a Money class: $pesos = new Money(200, Money::PESO); $dollars = new Money(100, Money::US_DOLLAR); var_dump($pesos $dollars); Then, the Money class could take care of normalizing and comparing the values. Food for thought... -- Jake On May 7, 2013, at 1:15 PM, Stuart Langley slang...@google.com wrote: Classes without the ability to overload the comparison operator could be considered kinda useless as well. On Tue, May 7, 2013 at 11:11 AM, Daniel Ribeiro drgom...@gmail.com wrote: Its kinda useless feature for PHP. Daniel Ribeiro Gomes Pereira Twitter https://twitter.com/#!/drgomesp | Facebookhttps://www.facebook.com/profile.php?id=10407054469 | LinkedIn http://www.linkedin.com/pub/daniel-ribeiro-gomes/21/414/39 iPhone: +55 (48) 9111-0931 2013/5/7 Nikita Popov nikita@gmail.com On Tue, May 7, 2013 at 6:17 PM, Thomas Anderson zeln...@gmail.com wrote: 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 -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] idea: implement a Comparable interface
On Tue, May 7, 2013 at 1:05 PM, Nikita Popov nikita@gmail.com wrote: On Tue, May 7, 2013 at 6:17 PM, Thomas Anderson zeln...@gmail.com wrote: 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.
Re: [PHP-DEV] idea: implement a Comparable interface
Hi! Classes without the ability to overload the comparison operator could be considered kinda useless as well. That's demonstrably false - classes are very useful right now in PHP yet no overloading of operators exists. -- Stanislav Malyshev, Software Architect SugarCRM: http://www.sugarcrm.com/ (408)454-6900 ext. 227 -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] idea: implement a Comparable interface
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 -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] idea: implement a Comparable interface
To me, it sounds that those extremely specific cases ask for a extremely specific compareTo(stdClass) method. Daniel Ribeiro Gomes Pereira Twitter https://twitter.com/#!/drgomesp | Facebookhttps://www.facebook.com/profile.php?id=10407054469 | LinkedIn http://www.linkedin.com/pub/daniel-ribeiro-gomes/21/414/39 iPhone: +55 (48) 9111-0931 2013/5/7 Stas Malyshev smalys...@sugarcrm.com 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 -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
