[antlr-interest] Doubt About rewrite rulse

[Junkman]

Hi Victor,

Victor Giordano wrote:
> Hi, i am a newbie. Trying to figure out how to work with AST tree and 
>
> ...
>
> butttttttt if i want to use rewrite rules... how do i thread the 
> repetion EBNF operator like * or +.
> 
> expr : term (('+'|'-') term)* -> term ^(('+'|'-') term)* ;
> 

try this:

expr: ( term -> term )
      ( ( '+' | '-' ) term -> ^( ( '+' | '-' ) $expr term ) )* ;


Not sure if the terms need to be distinguished with labels.

The Antlr reference book describes the use of rewrite rule inside
subrule in more detail.

J