Is there any documentation of the number format used by the quantity type? Bumped into this and had to implement the BCmath extension to handle the number. The reason why I did it (except it was fun) is to handle some weird unit conversions. By inspection I found there were numbers at Wikidata that clearly could not be implemented as doubles, and testing a little I found that this had to be implemented as some kind of big numbers. Lua does not have big numbers, and using the numbers from quantity as a plain number type is a coming disaster.

So, is there any documentation for the quantity format anywhere? I have not found anything. I posted a task about it, and please add info there if you know where some info can be found. I suspect the format just happen to be the same as BC, and nobody really checked if the format was compatible, or…?

The BCmath extension can be found at
- https://www.mediawiki.org/wiki/Extension:BCmath
https://github.com/jeblad/BCmath

There is a Vagrant role if anyone likes to test it out.