Wrote a CLDR plural rule parser to replace the eval()-based one from
I58a9cdfe. It converts the infix notation of the XML files to a
sanitized RPN notation, referred to in external interfaces as the
"compiled" form. The RPN notation is cached and then executed by a
fast non-validating evaluator.
Timings for the largest rule in the XML file are ~1.2ms for
compilation and ~200us for execution.
Also:
* Lazy-load the plural rules when recache() requests them, instead of
loading them for every request.
* Language::convertPlural() needs integer keys, and CLDR only gives
string keys. The previous code was not mapping them so it didn't work
at all. I just mapped them in the order they appear in the XML file,
i.e. the first rule becomes MediaWiki's $pluralForm=0, the second
becomes $pluralForm=1, etc. Not sure if there is a more rigorous way
to do it.
Change-Id: I65ee788c1a8e5ee2ede2091990d86eb722749dd3
fceb9bcb49