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Date: Mon, 30 Mar 2015 09:07:40 +0900
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To: Jakub Zelenka <bukka@php.net>
Cc: PHP internals list <internals@lists.php.net>
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Subject: Re: [PHP-DEV] JSON float number as string
From: yohgaki@ohgaki.net (Yasuo Ohgaki)

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Hi Jakub,

On Mon, Mar 30, 2015 at 4:33 AM, Jakub Zelenka <bukka@php.net> wrote:

> I would like to add a new option to JSON for dealing with large floats. The
> use case is mainly for decoder but can be used for encoder as well.
>
> JSON_FLOAT_AS_STRING
> decode: all float values will be decoded as string
> - It's often an issue for very large float values with many fractional
> digits that are coming from platforms that support larger float
> representation than double. In that case the conversion is lost and there
> is no way how to get it back (see http://bugs.php.net/68456 [pls ignore my
> initial dump comments when I didn't get the issue :)] and an example of the
> lost precision here http://3v4l.org/80iCh ). Converting the value to
> string
> keep the precision and resolves the problem.
>
> encode: all float values will be encoded as string
> - re-using the constant for encoder makes sense if PHP creates JSON for
> platform that support lower float type (e.g. C float) and the precision
> loss is not acceptable
>
>
> I think that this is more a bugfix as the precision is lost without any way
> how to get it back (except pre-processing json string with regular
> expression). I would like to add it to 5.6.x if there are no objections?
>

Converting int/float to PHP native type is obvious bug.
We must consider compatibility for released versions, so
+1 for adding JSON_FLOAT_AS_STRING option.

"int" should be fixed also.
http://3v4l.org/95dHM

So option may be JSON_SCALAR_AS_STRING or
additional JSON_INT_AS_STRING.

PHP7 should have string scalars by default. IMHO.

Regards,

--
Yasuo Ohgaki
yohgaki@ohgaki.net

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