[antlr-interest] assign a derived token to the lexer

[Ric Klaren]

On Tue, May 27, 2003 at 09:22:27AM -0000, thomaskrebs wrote:
> I want to assign a different Token than CommonToken to the lexer. In 
> lexer.html at lexer.html#Token_Attributes it is documented how to do 
> that. But this seems to be wrong:
> 
> ImageToken t = new ImageToken(IMAGE,$getText);
> 
> t.setAttributes(attrs);
>
> $setToken(t);

That's the java syntax.

> I assume t should be a pointer to ImageToken and the parameter to 
> setToken can not be a Token or a pointer to a Token but a RefToken. 
> But I cannot assign a RefCount<ADerivedToken> to the _token inside 
> the parser rule. How to deal with that?

Make sure your token is derived of CommonToken, then make a RefToken of
your new token (not a RefCount<ADerived> or you have to cast static_cast
them :( ). When trying to access your own token you would then have to use
the get() method to access the underlying pointer to the refcounter then
dynamic_cast or if the situation permits static_cast (but be sure not to
cheat too much with this pointer).

HTH,

Ric
-- 
-----+++++*****************************************************+++++++++-------
    ---- Ric Klaren ----- j.klaren at utwente.nl ----- +31 53 4893722  ----
-----+++++*****************************************************+++++++++-------
 "Don't call me stupid." "Oh, right. To call you stupid would be an insult
    to stupid people. I've known sheep that could outwit you! I've worn
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