ri doesn't know about __FILE__

I was trying to produce an informative error message for a script
and wanted to find out what line number information I could pick up.
ISTR there is a __LINE__ or __line__ variable, but have not found it
looking quickly.  So I tried ri.  It doesn't know about itns hgs 209

brains hgs 209 %> ri __LINE__
Nothing known about __LINE__
brains hgs 210 %> ri __FILE__
Nothing known about __FILE__
brains hgs 211 %> ri '$0'
Nothing known about $0
brains hgs 212 %> ri 'ARGV'
Nothing known about ARGV
brains hgs 213 %>

but my ri works (lots of classes turn up information.)..

Should this information make it into ri? Else, why not?

I'm not sure what is happening with ri given that Rdoc maintnance
is to be adopted by someone, so I'm sending this here rather than to
Dave Thomas.

        Thank you,
        Hugh