the comment filter example

["Uwe Hoffmann" <uhoffmann@imosnet.de>]

Etienne's thesis has an example in the lexer part that shows how to make a
subclass of the lexer that overwrites filter().

One small remark: the signature of filter() has changed since then: it
throws exceptions.

Question:

setText in all the generated tokens throws RuntimeExceptions. So the example
that does comment.setText() wouldn't even work anymore. What's the
alternative if I want to change token text in filter() ?

thanks,

uwe