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	"'Nikita Popov'" <nikita.ppv@gmail.com>,
	"'Rasmus Lerdorf'" <rasmus@lerdorf.com>
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Date: Wed, 18 Feb 2015 12:14:29 +0100
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Subject: AW: [PHP-DEV] Scalar Type Hints v0.4
From: php@tutteli.ch ("Robert Stoll")

> -----Urspr=C3=BCngliche Nachricht-----
> Von: Zeev Suraski [mailto:zeev@zend.com]
> Gesendet: Mittwoch, 18. Februar 2015 08:00
> An: Nikita Popov; Rasmus Lerdorf
> Cc: Sara Golemon; PHP internals
> Betreff: RE: [PHP-DEV] Scalar Type Hints v0.4
>=20
> > -----Original Message-----
> > From: Nikita Popov [mailto:nikita.ppv@gmail.com]
> > Sent: Wednesday, February 18, 2015 3:06 AM
> > To: Rasmus Lerdorf
> > Cc: Sara Golemon; PHP internals
> > Subject: Re: [PHP-DEV] Scalar Type Hints v0.4
> >
> > The inability to implicitly cast "123" to int is pretty much the KEY
> > distinction between weak and strict scalar typehints (those pesky
> > value-dependent type checks). If the strict typing mode doesn't =
offer
> > this, what's the point at all?
>=20
> I am wondering what the point is indeed with preventing "123" to 123.  =
So far, all the concrete use cases people brought up
> had to do with "Apple" or
> "100 dogs", but nobody ever seems to be able to explain why converting =
"123"
> to 123 is likely to be a problem real world.  Is it really just static =
analyzers?
>=20

Strict mode is useful in the sense that it prevents unnecessary implicit =
conversions (which are costly) and it improves readability.=20
Following an example:

function foo(string $x, int $y){
  bar(1);=20
  return strstr($x,"hello", $y);
}

function bar(float $a){}

After adding the implicit conversions the code would look as follows:

function foo(string $x, int $y){
  bar((float) 1);
  return strstr($x, "hello", (bool) $y);
}

function bar(float $a){}

In strict mode the original code would not be valid (rightly so IMO). =
Just from reading the original code I would suspect that strstr expects =
some kind of an offset (hence the int), therefore strict mode probably =
revealed a bug.=20
And if not, then one can add the conversion manually. However, this is =
not as trivial as it sounds. Personally I think it would only make sense =
to have strict mode in PHP if the user had more strict conversion =
functions at hand. What is the benefit of the following? if the =
conversion to int is as sloppy as today then one does not gain anything =
from the strict mode IMO:

function foo(int $x){}
foo( (int)$_GET["bla"]);