Hi, (I can't remember if this has been suggested or shot down before; I might have a need for something like this soon, so I'd appreciate guidance on it.) How hard would it be, do people think, to provide from Drei something like a regexp-token-syntax class, such that it becomes straightforward for people to define simple tokenizing syntaxes? An example might help; I'd like to be able to do (define-token-syntax chord-ontology () ("(([A-G])(s|ss|b|bb)?):\(([0-9](,[0-9])*)\)" ((root pitch accidental) pitches)) (t error-token)) and have that be essentially all that's necessary to be able to use the syntax in interesting ways, such as: * being able to do (accept 'chord-ontology-token) and have the user input coloured in red unless it's valid, and be given the parse tree on return; * being able to use Chord Ontology syntax in a buffer, where there is no parse per se, but the buffer is lexed according to the token syntax. Is this sensible, worthwhile, possible, easy? I would have thought that we would have essentially all the components already, and it was a matter of gluing them together, but maybe I'm forgetting a snag? Cheers, Christophe [ In my example, the nesting in the symbolic names is intended to correspond to register groups; in that example, "As:(1,3)" is intended to generate the equivalent of (make-instance 'chord-ontology-token 'root (make-instance 'root 'pitch "A" 'accidental "s") 'pitches "1,3") I hope that my intent is reasonably clear. ]