Hi,

> If the lexer to use can be determined by only one token
> (BEGIN_VERB), I think you can change the state in the lexer
> like this:

Unfortunately the language features some verbatim-like environments
where choosing the right scanner entails knowing more about the
context than what is available to the lexer.  As an example, in
the command \link{url}{text}, the "url" should be interpreted
verbatim, whereas the "text" portion uses the general scanner.
The parser is fully aware of the context, of course, which is
why the "dummy action" solution worked fine.

(And yes, I thought of having different delimiters for different
scanning contexts, but in many ways it would make the language
more cumbersome for the user).

Cheers,
Dario Teixeira