Re: How to use our own token ?

[Hans Aberg]

On 29 Jan 2010, at 03:11, Aurelien Tran wrote:

> > Use 'bison --defines' - see manual or 'bison --help', which then
> > writes a header .tab.h, which contains stuff like:
> >   enum yytokentype {
> >      token_error = 258,
> >      help_key = 259,
> >      quit_key = 260,
> >      ...
> >   }
> >
> > Include this header in the lexer file, and use those names.

> I know that this is the general way to do this but the lexer is in  
> fact an
> external module that I cant modify. I would like to avoid rewriting  
> all the
> token and their value in another file. If need to I will but I would  
> to
> avoid it in order to have more maintainable source code.
>
> I just want to be sure that Bison do not support this kind of  
> feature (Which
> is actually the real purpose of my post here).

As you see from the numbers above, Bison just numbers the tokens  
sequentially, and it is used shifted in parser lookup tables as  
indices, for speed simply. So Bison does not support that, I feel  
sure, and it would not be easy to fit with the implementation model.

So you need some translation table of sort, I think.

  Hans