Re: [PHP-DEV] Proposal: change precision for output functions
> 08.01.2019, 00:39, "Legale.legale" : > What proposal? I'm talking about elementary arithmetic. > > Take a look here: > Https://jdoodle.com/embed/v0/Tgu Yes, floating-point arithmetic says: '0.8!=0.1+0.7'. jdoodle.com/a/Thv Will we discuss this now? -- Semen V. Dubina https://sam002.net/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] Inconsistent float to string vs. string to floatcasting
AFAIK, gettext functions do depend on setlocale. I wish so much that it wasn't the case (as you then need to have the locale installed on the system), but it is, so setlocale definetely is quite used in the wild and deprecating it seems a bit far-fetched unless we can actually replace it with something else (better). But gettext has other issues related to being cached in the current process, as you need to restart apache if the compiled .mo files have changed to get the new strings :( Another function that is influenced by setlocale is strftime. This is often the common way to display a date in a different language. So I'm all for deprecating setlocale but before that we would need to have something better for everything that's currently depending on it :) BohwaZ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] Proposal: change precision for output functions
What proposal? I'm talking about elementary arithmetic. Take a look here: Https://jdoodle.com/embed/v0/Tgu On Jan 7, 2019 10:32 PM, Semen Dubina wrote: > > > > 07.01.2019, 22:17, "Legale.legale" : > > I think your solution by changing precision is not good enough because > > float summation is still not working properly. > > > > > var_dump(0.1 + 0.7); > > > > returns: > > > > 0.79 > > > > expected: 0.8 > > > > Hi! > > If you are about the proposal, then '0.1 + 0.7 !== 0.8'. > Why you expected 0.8? > Check, plz: https://3v4l.org/Ughn2 > > -- Semen V. Dubina https://sam002.net/
Re: [PHP-DEV] Proposal: change precision for output functions
> 07.01.2019, 22:17, "Legale.legale" : > I think your solution by changing precision is not good enough because float > summation is still not working properly. > > var_dump(0.1 + 0.7); > > returns: > > 0.79 > > expected: 0.8 > Hi! If you are about the proposal, then '0.1 + 0.7 !== 0.8'. Why you expected 0.8? Check, plz: https://3v4l.org/Ughn2 -- Semen V. Dubina https://sam002.net/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] Proposal: change precision for output functions
I think your solution by changing precision is not good enough because float
summation is still not working properly.
wrote:
>
> > 07.01.2019, 20:24, "Thomas Bley" :
> >
> > Hello,
> >
> > good point, having:
> >
> > echo ini_get('precision') . PHP_EOL;
> > echo ini_get('serialize_precision') . PHP_EOL;
> > echo json_encode(array('price' => round('45.99', 2))) . PHP_EOL;
> > echo (0.1+0.7), json_encode(0.1+0.7) . PHP_EOL;
> >
> > gives (https://3v4l.org/ldgo8):
> >
> > Output for 7.1.0 - 7.3.0
> > 14
> > -1
> > {"price":45.99}
> > 0.80.7999
> >
> > Output for 5.3.6 - 5.6.38, 7.0.0 - 7.0.33
> > 14
> > 17
> > {"price":45.99}
> > 0.80.8
> >
> > what is the preferred way to upgrade from php 5.6 to 7.x in order to get
> > the same results?
> >
> > Regards
> > Thomas
> >
>
> Force 'serialize_precision': https://3v4l.org/coaWm
> But remember - a float is not suitable for output. You need rounded and
> formatted manually.
>
> P.S. Try with JS: `JSON.stringify(0.1+0.7);`
>
> -- Semen V. Dubina https://sam002.net/
>
> --
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: http://www.php.net/unsub.php
>
Re: [PHP-DEV] Proposal: change precision for output functions
> 07.01.2019, 20:24, "Thomas Bley" :
>
> Hello,
>
> good point, having:
>
> echo ini_get('precision') . PHP_EOL;
> echo ini_get('serialize_precision') . PHP_EOL;
> echo json_encode(array('price' => round('45.99', 2))) . PHP_EOL;
> echo (0.1+0.7), json_encode(0.1+0.7) . PHP_EOL;
>
> gives (https://3v4l.org/ldgo8):
>
> Output for 7.1.0 - 7.3.0
> 14
> -1
> {"price":45.99}
> 0.80.7999
>
> Output for 5.3.6 - 5.6.38, 7.0.0 - 7.0.33
> 14
> 17
> {"price":45.99}
> 0.80.8
>
> what is the preferred way to upgrade from php 5.6 to 7.x in order to get the
> same results?
>
> Regards
> Thomas
>
Force 'serialize_precision': https://3v4l.org/coaWm
But remember - a float is not suitable for output. You need rounded and
formatted manually.
P.S. Try with JS: `JSON.stringify(0.1+0.7);`
-- Semen V. Dubina https://sam002.net/
--
PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP-DEV] Proposal: change precision for output functions
Semen Dubina wrote on 07.01.2019 16:38:
> Hi, everyone!
> Original PR and description see: https://github.com/php/php-src/pull/3460.
>
> Because of the accuracy constraint set by the 'precision' variable, debugging
> problems often occur, and many developers consider the limited accuracy to be
> a
> feature of the language.
> For better compatibility with other languages and predictable behavior, I
> suggest changing the default value of the variable 'precision' to -1.
> In the tracker you can find several bugs in which people trusted output of
> 'var_dump' and 'echo':
> https://bugs.php.net/bug.php?id=66866
> https://bugs.php.net/bug.php?id=66959
> https://bugs.php.net/bug.php?id=68551
> https://bugs.php.net/bug.php?id=73358
>
> Examples: https://3v4l.org/Mr4KM
>
> If you know a case when it will violate some task, describe it, please. I
> think
> that the trusting of FLOAT is a very bad practice.
>
> -- Semen V. Dubina https://sam002.net/
>
> --
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: http://www.php.net/unsub.php
>
Hello,
good point, having:
echo ini_get('precision') . PHP_EOL;
echo ini_get('serialize_precision') . PHP_EOL;
echo json_encode(array('price' => round('45.99', 2))) . PHP_EOL;
echo (0.1+0.7), json_encode(0.1+0.7) . PHP_EOL;
gives (https://3v4l.org/ldgo8):
Output for 7.1.0 - 7.3.0
14
-1
{"price":45.99}
0.80.7999
Output for 5.3.6 - 5.6.38, 7.0.0 - 7.0.33
14
17
{"price":45.99}
0.80.8
what is the preferred way to upgrade from php 5.6 to 7.x in order to get the
same results?
Regards
Thomas
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[PHP-DEV] Proposal: change precision for output functions
Hi, everyone! Original PR and description see: https://github.com/php/php-src/pull/3460. Because of the accuracy constraint set by the 'precision' variable, debugging problems often occur, and many developers consider the limited accuracy to be a feature of the language. For better compatibility with other languages and predictable behavior, I suggest changing the default value of the variable 'precision' to -1. In the tracker you can find several bugs in which people trusted output of 'var_dump' and 'echo': https://bugs.php.net/bug.php?id=66866 https://bugs.php.net/bug.php?id=66959 https://bugs.php.net/bug.php?id=68551 https://bugs.php.net/bug.php?id=73358 Examples: https://3v4l.org/Mr4KM If you know a case when it will violate some task, describe it, please. I think that the trusting of FLOAT is a very bad practice. -- Semen V. Dubina https://sam002.net/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
