> 
> It indeed works much better, thanks!
> 
> I found a bug and a way to replicate it (you'll need to update your Bison grammar):
> - Open the file "treesit-bug-highlighting-demo";
> - Enable bison-ts-mode;
> - At the beginning of the second line (the part managed by the embedded C parser, with "static void ..."), add a space;
> 
> => The whole line loses its highlighting.
> 
> If you add a space again, the highlighting works correctly again.
> Not a big issue, but pretty weird.

Thanks. Weird indeed. I found the bug and fixed it. Latest master should work fine now.

> 
> Also, I have one (last?) question:
> 
> Since the C code uses its own indentation, it's entirely independent of Bison's nodes positions.
> Is it possible to add an offset to the indentation of the embedded parts, relative to its container node?
> 
> For instance, rather than:
> 
> %%
> grammar_declaration:
>      grammar_rule
>    {
> int myvar;
>    }
>    ;
> %%
> 
> 
> 
> I would like to get
> 
> 
> 
> %%
> grammar_declaration:
>      grammar_rule
>    {
>      int myvar;
>    }
>    ;
> %%
> 
> 
> ("int myvar;" is managed by a C parser).

Makes sense. You can use a custom matcher to indent the top level nodes in the C code. I modified your mode for a POC. The modified parts are marked with "!!!".

Yuan