declare
class EventManager
   attr
      handlers
   meth init handlers:=nil end
   meth event(E)
      handlers:=
         {Map @handlers fun {$ Id#F#S} Id#F#{F E S} end}
   end
   meth add(F S ?Id)
      Id={NewName}
      handlers:=Id#F#S|@handlers
   end
   meth delete(DId ?DS)
      handlers:={List.partition
         @handlers fun {$ Id#F#S} DId==Id end [_#_#DS]}
   end
end