Fixed locale floating point character

[kyl3n]

When running this code in locales that do not use a period for floating point integers, an error would occur. This is now resolved.

[kyl3n]

A bit of clarification. json.lua does not work on locales that use a decimal comma instead of a decimal point for floating point numbers, causing a Lua exception. There are about 80 countries who use decimal comma's.

https://en.wikipedia.org/wiki/Decimal_separator

[rxi]

My understanding of the JSON specification is that only the . decimal separator should be supported:

https://tools.ietf.org/html/rfc7159#page-7

[kyl3n]

You are correct that it's in the JSON spec. However, this is a situation where the spec shouldn't come into play because of how Lua handles changing the locale.

1. When you change the locale in Lua to a comma decimal region it changes all period decimals to comma decimals. Lua does not care if you haven't had time to process them yet.

2. Decoding JSON format to Lua is not the same as Encoding to the proper JSON spec. What I'm saying here is that it is okay to decode from comma decimals in this instance. But when you encode it should still enforce the point decimal system.

The way you check if a JSON key with an integer is valid is a good way to check for valid numbers. But it still should adapt to Lua no matter what locale is being used.