Re: Comparison chain

Andrea Faulds wrote on 05/12/2014 14:47:

On 5 Dec 2014, at 14:36, Дмитрий <freax@pop3.ru> wrote: Hi! I followed by https://wiki.php.net/rfc/howto and I would like to propose a concept "comparison chain" to implementing to future PHP versions. It would be very usable if PHP can do that in python-style. Thank for your attension!

Are you saying to allow (1 < x < 2) etc.? That would be nice, although it’s a backwards-compatibility break as currently (1 < x < 2) would do something different, as would, say, ($x == $y == $z).

For those of us that don't know Python, an explanation might be handy. From a quick search, this StackOverflow answer sums it up quite nicely, assuming it's correct: http://stackoverflow.com/a/25753528/157957 So, "$a < $b < $c" would be short-hand for "$a < $b && $b < $c". It would short-circuit in exactly the same way, and be extended to any number of comparison operators. The obvious use case is for maths style "is between" notation, e.g. if ( 10 < $total <= 100 ) Is this correct, a) for Python, and b) for what is suggested for PHP? As Andrea notes, it would be a backwards compatibility, although the chances of anyone deliberately using a boolean as operand to a < or > are unlikely, and that's what's currently implied by $x < $y < $z. Perhaps if == was left out of the mix, so that $x == $y == true would evaluate the same way it does now, that might be a working compromise? Regards, -- Rowan Collins [IMSoP]