[antlr-interest] How to resolve the left-recursion problem?

[YiQing Yang]

Hi,

I need to write a parser rule for an extended class attribute namme
expression. It could be simply a single attribute name with the class scope
as option (persion::name) or a series of attribute names chained by "." (ie,
"employer.ceo.name": "ceo" is an attribute of "employer" corresponded class.
"name" is an attribute of "ceo" corresponded class).

I wrote the parser rules as following which contains left-recursion. I do
not know how to resolve this problem without changing the semantic. I would
appreciate if anyone could help.

-----------------------------------------------------
attribute_expression
  : attribute_name
  | dot_operator_exp
  ;

dot_operator_exp
  : attribute_expression DOT attribute_name
  ;

attribute_name
  : n1:NAME (SCOPE n2:NAME)? 
  ;
------------------------------------------------------
    
Yiqing Yang