[antlr-interest] Transforming input

[Terence Parr]

On May 5, 2007, at 4:41 PM, Miguel Ping wrote:

> Hi all,
>
> It seems that I can parse a reasonable subset of sql selects now,  
> and my problem now is finding a nice way of generating output. I  
> thought of string template, but I think it would be a bit overkill  
> since the difference between the input and output is small, and I  
> do not want to target multiple languages, which I believe one of ST  
> strong point. Because I need to retain original formatting  
> including whitespaces, what is the best way of storing and  
> outputing the result?

option rewrite=true and optionally output=ST

> I tried setting the token text within a visitor class, and after  
> that using a custom token stream to output token texts +  
> whitespaces. It didn't work, I guess antlr internally copies/clones  
> the tokens when creating the the AST tree. Can anyone give me a  
> good hint on this?
>

It only keeps a poitner to it.  You need to use rewrite mode...nice  
description in book about doing these kind of translations ;)
Ter