(5) foo : bar "string" -- means pass foo as
                          first argument followed by "string" (and only
                          these two) to bar, and call.
                        
                        (6) foo : bar {table} -- means pass foo as
                          first argument followed by {table} (and only
                          these two) to bar, and call.
                          
                        
                        This way (5) and (6) are particular cases
                          of (4). We can also interpret (5) and (6)
                          notation as a generic binary operator [1],
                          with arguments foo and "string", or foo and
                          {table}, and bar operator.
                        
                        
                        
                        PROPOSAL
                          
                        
                        We also have a third, particular and common
                          case of (generic) unary operators [2]. At the
                          time this is more easily accomplished by the
                          notation
                          
                        
                        (7) foo : bar ()
                          
                        
                        where the *suffix* () pass nothing to bar,
                          it is only redundant. In this case the
                          *preffix* function call
                          
                        
                        (8) foo : bar 
                          
                        
                        is completely defined, means pass foo
                          (only) to bar, and call. Very simply indeed,
                          and completely compatible with the Lua *look*
                          just implemented capabilities. Compare with
                          the comments of (2) and (3) above, and [2].
                        
                        
                        
                        If you do not feel confortable with (8)
                          then use (7), since it is only syntactic
                          sugar! If you really want to be (not so)
                          expressive in the Lua way use
                          
                        
                        (9) foo.bar(foo)
                        
                        
                        
                        it is only convenience, as well as (2),
                          (3), (5) and (6), but the expressiveness
                          increases a lot.
                        
                        
                        
                        [1] example: we can think of 5 : + (6) as
                          simply as 5 + 6 .
                          [2] real(imaginay number) as z : Re, as well
                          as Re (z), the *prefix* and *suffix* versions.