I like very much Charles' idea:
Modify "end" so that it takes optional arguments:
   end if
   end do
   end class Food
   end def eat
Advantages:
- it's optional,
- it doesn't break any older code
- I suppose it's easy to implement
- I suppose it's easy to write an emacs routine that
  automatically inserts (or deletes) theses arguments

Regards, Joachim