[antlr-interest] error in tree grammar syntax...

[Pady Srinivasan]

I have a parser grammar as...

statement
 : assignment
 | 'if' boolExpression ( assignment | '{' s1+=statement* '}')
     (options {k=1;}:'else' ( s2=statement | '{' s3=statement '}' ) )?
   -> ^('if' boolExpression assignment? $s1* ^('else' ($s2)? ($s3)? )? )
 ;



When I try something like this in my tree grammar, I get an error:

statement
 : assignment
 | ^('if' boolExpression assignment? statement* ^('else' (statement)? 
(statement)? )? )
 ;


error(100): GwfWalker.g:32:85: syntax error: antlr: GwfWalker.g:32:85: 
expecting RPAREN, found '?'
error(100): GwfWalker.g:32:87: syntax error: antlr: GwfWalker.g:32:87: 
expecting SEMI, found ')'
error(106): GwfWalker.g:26:4: reference to undefined rule: statement


Thx

-- pady