[gambit-list] Promises & lazy thunks

Promises as specified in the Scheme spec are not terribly useful... but I was thinking that I could make a much cleaner implementation of lazy sequences and other things given a Scheme runtime which automatically forced promises when the promise is operated on as a value.

I was wondering if anyone's thought about doing this. Also, if it's really as hard as making every primitive (except, course, promise?, promise-forced? and friends) check and force every parameter, or if there are any neat implementation tricks, especially if there's something which can be used in gambit (like error-handler, but that seems gross. Also, incomplete and messy).

-Jason