anchor.diff:  
   arguments 
       : positionalArguments | namedArguments
  -    ;
  -    
  -specialFunctorArguments 
  -    : specialFunctorArgument+
  -    ;
  -
  -specialFunctorArgument
  -    : parameterName specialFunctor
       ;
         
   namedArgument
  
positive.code:     | 'extension'
      ;
  
  //Let's limit statements to things that make sense, like
  //Java does (we could allow any arbitrary expression if
  //we wanted to, but why?)
  //Even though it looks like this is non-associative
  //assignment, it is actually right associative because
  //assignable can be an assignment
  statement 
      : //assignable ';'
        postfixExpression 
        (assignmentOp assignable | specialFunctorArguments)? ';'
      | controlStructure
      ;
  
  
negative.code:     : regularType
      | memberName
      | literal
      //| (primaryFunctorStart) => primaryFunctor
      | parExpression
      | enumeration
      | 'this' 
  