Re: What controls the decimal delimiter?

[Marc Balmer <marc@...>]

> Am 23.01.2023 um 11:22 schrieb Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br>:
> 
>> When I output a number value, e.g. 42.0, it is normally output with a decimal point.
> 
> The locale controls that.
> 
> % lua
>> tonumber("42,0")
> nil
>> os.setlocale"de_DE"
> de_DE
>> tonumber("42,0")
> 42,0
>> tonumber("42.0")
> 42,0

Well, that is converting a string to a number.  I had the problem when Lua converts a number to a string, i.e. the other way round.

Lua uses *(localconv())->decimal_point to get a localized decimal point and insert it into the string.  Most Linux distributions return a point when the LANG environment variable is not set. But openSUSE Leap returns a comma if LANG is not set.  As soon as you set LANG, it will return whatever is configured in that locale.  So it uses a different default decimal limiter than most other Linux distributions, it seems.

The reason was actually a funny one (but took me quite some time to find out):

I store some numbers (representing coins of a certain currency) in a number array in PostgreSQL.  The syntax to do so in SQL is „{5.0, 2.0, 1.0}“. Now, when Lua gives you commas instead of points, you get „{5,0, 2,0, 1,0}“, so it will insert six numbers instead of three.