bug 6455 to enable the string parsing capabilities of ParserFunctions (ex-StringFunctions) was closed with a comment saying they are a horrible mess and the Lua extension is a saner alternative. If that is the case, please enable it on WMF wikis. Reasons for why string processing would be useful can be found in the discussion for that bug.
Version: unspecified
Severity: enhancement
URL: http://www.mediawiki.org/wiki/Extension:Lua