Adding support for environments that have a system locales with different decimal separator

[manowark]

Q	A
Branch?	master
Bug fix?	yes
New feature?	no
BC breaks?	no
Tests pass?	yes

STR:

1. environment must have locale with decimal separator different from . (for example de_DE.UTF-8) or locale set by terminal variable like export LC_ALL=de_DE.UTF-8
2. run any code which do calculations with float values and try to convert value to brick/math type

For example:

$decimal = \Brick\Math\BigDecimal::of(5/2);

It will not give an error if locale is equal to eu_US. But if locale is equal to de_DE then there will be an error Brick\Math\Exception\NumberFormatException : The given value "2,5" does not represent a valid number..
It happened because in this environment PHP will use , as decimal separator and ::of() method must be sensitive to it.

It can also happen when using Doctrine and convert float values from DB to brick/math type.

[BenMorel]

Hi, thanks for your PR. TBH I had no idea that float to string conversion was affected by the current locale (I personally try to stay away from using setlocale()).

One thing that bothers me with your approach, is that you're changing the current behaviour to also parse strings using the current locale; while I agree that parsing a float, e.g. BigDecimal::of(5/2) must work whatever the current locale, I don't think that string parsing should be affected by the locale (we could add another locale-aware method to parse those, though, if that's useful).

I'd rather change this line, when $value is a float, to convert it to a string using a dot character prior to running the current regexp.

The problem is that apart from temporarily reverting setlocale() to 'C', I don't think there is a way to replicate PHP's variable-precision float to string conversion: sprintf's %F could have been a good candidate as it always outputs a dot, but it's fixed width.

[BenMorel]

Actually, this approach breaks a lot of tests:
https://travis-ci.org/brick/math/jobs/491765751

This is because strings that were using dots are not parsed correctly after a global setlocale() has been applied, as mentioned above.

[manowark]

@BenMorel, I added normalizing of string after conversion to it form float. Now I don't change regexp to valid format from locale configuration, just convert string to valid format.

[BenMorel]

@manowark With the suggested changes it should be good to go! 👍

[manowark]

@BenMorel, done.

[BenMorel]

Nice and clean. Thanks!

[manowark]

@BenMorel, Thanks for the quick response and constructive comments.
When can I download the package with this fix? I mean tag 0.8.5.

[BenMorel]

I'm going to release 0.8.5 as soon as I get the confirmation from Travis CI that master is OK! It should not take more than a few minutes.

[BenMorel]

0.8.5 is released!