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Date: Thu, 17 Jul 2014 08:34:09 +0100
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To: Zeev Suraski <zeev@zend.com>
Subject: Re: [PHP-DEV] [RFC] intdiv()
From: ajf@ajf.me (Andrea Faulds)


On 17 Jul 2014, at 08:19, Zeev Suraski <zeev@zend.com> wrote:

> PHP's not Perl.  Let's keep it that way please=85

> I don't think it makes sense to add a
> specialized integer division operator when we do have a different =
division
> operator, and I don't think other dynamic languages have such an =
operator
> - so unlike **, there's no established precedent=85

True, but PHP clearly drew inspiration from Perl, and C, which also has =
integer division.

Many of these languages don=92t have an integer division operator simply =
because they don=92t need one. In most C-like languages and plenty of =
non C-like, an integer divided by an integer is always an integer, and =
you only get a float result if one or more operands are a float. =
However, in languages like PHP, Python, Visual Basic and Pascal, the =
division operator is unusually (though I=92d say more intuitively) =
defined as sometimes giving a float for integer operands. In the case of =
PHP and Python, this is only when the the second operand isn=92t a =
factor, while in the case of VB and Pascal, / always results in a float. =
It is in these languages that we find the much rarer integer division =
operator (Python has //, Visual Basic has \, Pascal has div) because you =
can=92t do it the =93normal=94 way. In this respect, it=92s rather =
unusual that PHP lacks an integer division operator, or even some =
built-in way to do integer division at all, given that all its peers do =
support it.

There are also languages which don=92t have integers, like JavaScript. =
In JS there=92s no need for such an operator as, since it doesn=92t have =
integers anyway, Math.floor(x / y) isn=92t going to lose any accuracy.

Makes me wonder why we don=92t have one after all these years. I assume =
either the division operator hasn=92t always done what id does now (I=92m =
not a historian, so I couldn=92t tell you that), or that people have =
tended to just go for floor(x / y). After all, that works perfectly on =
32-bit platforms. ;)
--
Andrea Faulds
http://ajf.me/