anchor.diff:      | selfReference
       | nonstringLiteral
       | prefixOperatorStart
  +    | STRING_LITERAL
       ;
   
   prefixOperatorStart
  
positive.code:         { fa.addParameterList($p2.parameterList); }
        )*
        COMPUTE?
        e1=expression
        { fa.setExpression($e1.expression); 
          $expression = new Expression(null); 
          $expression.setTerm(fa); }
  
negative.code: //that distinguish declarations from
  //expressions
  declarationStart
      : VALUE_MODIFIER
      | FUNCTION_MODIFIER LIDENTIFIER //to disambiguate anon functions
      | ASSIGN
      | VOID_MODIFIER
      | INTERFACE_DEFINITION
      | CLASS_DEFINITION
      | OBJECT_DEFINITION
      | ALIAS 
      | type ELLIPSIS? LIDENTIFIER
      ;
  
  statement returns [Statement statement]
  