More complete std.optparse example?

[Dan Christian <danchristian65@...>]

I'm trying to use std.optparse for the first time.  The example shows
me how to get a parse arg and opt, but I don't know how to test
individual options from there.

   local parser = OptionParser (help)
   local arg, opts = parser:parse (_G.arg)
   ...

What should ... be?

Thanks,
Dan