This is perhaps really a problem with forward-sexp, not so much a slime issue, but I'll bring it up here anyway:
I recently played around with creating a reader macro for the #; combination. But then I found that trying for example
(foo #;bar)
then I would only get [input not complete] in the minibuffer. Perhaps forward-sexp should be taught that a semicolon after a sharpsign doesn't start a comment? This can get tricky if someone were to write #1#; of course. ...
- Harald