[antlr-interest] += in a tree grammar

[André van der Merwe]

Hi,

I'm trying to build a heterogeneous AST from a tree grammar but I can't get a list of nodes using +=.

Firstly I building the AST in the tree grammar for two reasons
 1) Its easier as I'm working with a simplified/normalised tree (i.e. not a parse tree).
 2) My parser code can be reused for other purposes, i.e. I just create a new tree walker and leave the parser as is.


What I'm trying to do is create nodes for each parameter in a method call. Here is my (simplified) parser grammar
   program
      :   IDENTIFIER LPAREN parameters* RPAREN   -> ^(CALL IDENTIFIER parameters?)
      ;
   parameters
      :   INT (COMMA INT)* -> INT+
      ;

And my tree grammar
   program
      :   ^(CALL IDENTIFIER (e+=INT)*)
      {
         object obj1 = $e;
         object obj2 = e;
      };


I've tried everything but I can't get this to work.



Using 3.1 beta 1: I can't even parse this "someMethod( 1, 2 )" as I get an RewriteEarlyExitException. The same parser works in 3.0.1
   root_0 = (CommonTree)adaptor.GetNilNode();
   // 20:21: -> ( INT )+
   {
   if ( !(stream_INT.HasNext()) ) {
     throw new RewriteEarlyExitException();
----


Using 3.0.1 with the tree grammar's output = AST generates the correct code for the '+=' but the rest of the code does not compile as the generated tree is passing CommonTree objects to the adapter's Create() method not ITokens. [I know that 3.0.1 does not support tree to tree grammars so I'm not surprised]
----


Using 3.0.1 with the tree grammar's output = template compiles but then the '+=' is concatenating templates
   if (list_e == null)
      list_e = new ArrayList();

   list_e.Add(e.Template);
----



Any ideas? I don't want to have to move all my code into the parser but it is beginning to look like the only option :( Is there perhaps a later beta available or can I download the latest source somewhere?


Thanks

Andre