Hello Pierre,
Thanks for your reply. :-)
----- Original Message -----
From: "Pierre"
Sent: Friday, August 11, 2006
> Hello,
>
> Note that I also answer your previous mail here :)
>
> On Fri, 11 Aug 2006 06:18:13 -0500
> [EMAIL PROTECTED] ("Matt W") wrote:
>
> > Hello again,
> >
> > I discovered a couple more things is_numeric... is causing problems
> > with (leading whitespace). I doubt any of the examples I've given
> > make sense to regular users who don't know what's happening behind
> > the scenes. Add these to the "wrong" list:
> >
> > is_numeric(' .123') // bool(false)
>
> this one should return true.
>
> > ' .123' + 0 // int(0)
>
> ' 0.123' is casted to 0, 0+0. But if the ' .123' is allowed, it should
> then result in 0.123+0, which is the correct behavior.
I may be misunderstanding you, but ' 0.123'+0 results in the correct 0.123.
Just without the leading 0 that it becomes wrong. :-)
> > One more thing I was curious about as far as keeping things
> > consistent is with is_numeric... (and therefore
> > convert_scalar_to_number()), hex strings are allowed/work, but not
> > with convert_to_[long|double]().
>
> I did not check convert_* while fixing/enhancing filters, but I think
> there is a higher risk of breakages if you change these functions. We
> should first have a clear view of what is used where and how the
> changes affect end user scripts and extensions. It sounds like an
> impossible task (except for 6.0).
I was just wondering if convert_to_[long|double] should check for and allow
hex strings like convert_scalar_to_number does (because it uses
is_numeric...).
> I suggest you to take a look at the ext/filter code and what we accept.
> I spend a far amount of times to ask and listen to users to see what
> they expext. I'm quite happy with the current state and for what I
> hear, the users too.
>
> You can check the FILTER_VALIDATE_* mode, they do the same operations
> that we are discussing here. The sanitize mode only checks for
> unexpected chars.
Have to admit that I'm not really familiar with any of the filter stuff. :-/
I'll keep that in mind though.
> > So a few PHP functions properly
> > accept hex strings, but most will convert one to 0. Should anything
> > be done about this difference? I have an idea about allowing hex
> > strings in to_[long|double] using the new is_numeric... functions I
> > will propose.
>
> > Few things about the current is_numeric... and hex strings, which I
> > think I'll change in my proposal unless I hear opinions otherwise:
> > *) Leading whitespace isn't allowed
>
> They should be allowed (leading/ending).
Not sure if you're talking about currently, or agreeing with me. ;-) For
these 3 points, I was only referring to hex strings. Leading space is
allowed with non-hex.
> > *) A sign (±) isn't allowed
>
> It is allowed except for in the hexadecimal notation (see the manual
> page of is_numeric), so if you talk only about is_numeric and the hex
> notation, it is a bug fix.
Again, only referring to hex. Ah yes, I see the manual page for
is_numeric(). Hmm OK, not sure if you'd want that to be changed then...
The internal function would be fine ($n = -0xABC works in the parser), I
guess, but maybe sign & hex returning true with PHP's is_numeric() is
undesired.
> > *) Hex doubles don't work. I think they should (for *whole* numbers
> > only obviously, no "."). So '0xFFFFFFFFFF' + 0 for example, works on
> > a 32-bit system.
>
> They should not, an hexadecimal notation represents an integer (long),
> not a double. A double could be the result of a cast when it is out of
> the integer range.
Well, I think of the hex notation as just a whole number (non-floating) of
whatever range/size. About the cast, yeah, I see that's what is done now in
the parser if the hex number is between LONG_MAX and ULONG_MAX -- results in
a double. hexdec(), etc. will also return a double if needed.
Right now, since hex doubles don't work, you also have (on 32-bit):
is_numeric('0x7FFFFFFF') // bool(true)
is_numeric('0x80000000') // bool(false)
> > If that last one can be changed, it also should be in the language
> > parser of course (you know, for $n = 0xFFFFFFFFFF;).
>
> It is the endless problem about 32/64bits issues, also I don't think
> you are considering to use double in a for loop? :)
In a for loop of a script? No :-), but someone may want to specify a number
in hex larger than ULONG_MAX (and it may work if they're 64-bit, then break
on 32-bit). I've not had a need for it (in parser), but I would like the
larger hex strings to work as I have code like ('0x' . $hexstr) + 0 where
$hexstr comes from a packed/binary number (after bin2hex()) that may be any
size. I don't want to use hexdec() because it's slower (and this is
speed-critical, in a loop) and usually the value WILL fit in a long.
That reminds me, a "(number)" typecast would be nice to have. :-)
> > > Since I've been looking at is_numeric_[string|unicode], I found a
> > > weird thing it causes; probably doesn't make sense to users; bug?
> > > Look:
>
>
> > > abs(-1e500) // float(INF)
> > > abs('-1e500') // int(1) WRONG
>
> Agreed, it should float(INF)
>
> > > abs('-1e100') // float(1.0E+100)
> > > is_finite(1e500) // bool(false)
>
> > > is_finite('1e500') // bool(true) WRONG
>
> Agreed, should float(INF)
You mean bool(false) ;-)
> > > is_finite('1e100') // bool(true)
> > > is_numeric(1e500) // bool(true)
> > > is_numeric('1e500') // bool(false) WRONG
>
> Agreed, float(INF) as before
... and bool(true)
> > > is_numeric('1e100') // bool(true)
> > > 1e500 + 123 // float(INF)
> > > '1e500' + 123 // int(124) WRONG
>
> I get the feeling that the E notation has one bug, solving it should
> most of these issues. ext/filter pass all these tests successfully. But
> it had the same problems in its early days.
>
> > > You get the idea. That's because is_numeric_string() *ignores* the
> > > value from zend_strtod() if errno==ERANGE. I don't think that's
> > > right, and it doesn't happen when convert_to_double() uses
> > > zend_strtod():
>
> I have to check the sources :)
Yes, it ignores the INF/ERANGE, for whatever reason. :-)
> > > Just wondering if others think is_numeric_string() should be
> > > changed in that respect? I was going to rewrite the function to
> > > improve/optimize it (and submit it of course), so I can easily
> > > change its behavior while I'm at it...
>
> It would be nice to bring consistency between functions. But changing
> the behaviors at this level can have a very large impact. It has to be
> done really carefully and will _many_ tests. I can help if you like,
> both for the tests and the implementation.
I will send a new example function to the list in a few days, after doing
some tests, etc. Its behavior should be the same, except for these bugs.
And currently, strto[l|d] is sometimes called unnecessarily -- for example,
I think '123 foo' would result in zend_strtod() after strtol() -- pretty
sure that can be avoided. You'll see soon...
> > > Also, is this the desired behavior of array_count_values() (manual
> > > doesn't say; it also uses is_numeric...)?
> > >
> > > print_r(array_count_values(array(1, ' 1', ' 1 ')))
> > > Array
> > > (
> > > [1] => 2
> > > [ 1 ] => 1
> > > )
>
> This is typically an example of why we cannot not change the behaviors
> in php5, but I definitively like to do it for php 6.x.
I e-mailed Andrei about array_count_values() since I think it's incorrect.
If so, it should be very simple to fix -- just eliminate the use of
is_numeric_string.
> Cheers,
> -- Pierre
Thanks again,
Matt
P.S. I forgot to add before that I noticed a comment Derick added a few
days ago for is_numeric_string -- only in 5.2
(http://cvs.php.net/viewvc.cgi/ZendEngine2/zend_operators.h?r1=1.94.2.4.2.2&;
r2=1.94.2.4.2.3&view=patch). It says it returns IS_DOUBLE if the number
didn't fit in the integer range, but that's wrong if it's INF. :-)
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