[antlr-interest] AST generation in a recursive rule

[Jeff Vincent]

Ah!  I didn't notice initially that the statment ## = #(#CATCH_BLOCK,
##); was *outside* the ( ... )+ expression.
 
Also, it seems that AST.toStringList() and AST.toStringTree() output
the exact same thing.  Why is that? 
 
Thanks for the input.

>>> arnarb at oddi.is 10/24/2003 2:44:02 AM >>>

Hi there

> - Is ## shorthand for #<rulename>?  

Yup..

- Won't using the imaginary token build a tree like:

> CATCH_BLOCK-->CATCH_BLOCK-->(another CATCH_BLOCK, etc.)
>    |
> CATCH
>    |
>    v
> Exception1--(right)-->e1--(right)-->block--(right)-->null
> 
> Is there any way to use the CATCH token in the same manner as the
CATCH_BLOCK imaginary token and in effect, remove the extra node?  

Monty's solution builds a tree like this:

CATCH_BLOCK
  |
CATCH ----> CATCH ----> CATCH ----> ...
  |
Exception1 -> e1 -> block -> null

The CATCH_BLOCK pseudo-token is just a handle to the multiple
catch-nodes, so that your try-catch-finally tree will have constant
size:

try
|
block - CATCH_BLOCK - finally_block

Arnar




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