---------- Forwarded message ---------- From: szergling <senatorzergling@gmail.com> Date: Thu, Feb 26, 2009 at 6:41 PM Subject: Re: More interesting stuff To: Marco Antoniotti <marcoxa@gmail.com> [[...]] After thinking more, I still regard let as being different from letrec (saying this as a Lisper, Haskeller might very well have different expectations). I have a better example to show my confusion. Assuming full laziness, I expect the following -- (let ((x 1)) (let ((x (cons 1 x))) x)) => (1 . 1) (let ((x 1)) (letrec ((x (cons 1 x))) x)) => (1 1 1 1 1 ...) That's why I think we need to be able to differentiate between let and letrec.
Finally, I took some decisions w.r.t. your suggestions. I made two block-like blocks, called LAZILY (and SLACKING: I kind of like this one) in lieu of WITH-LAZINESS. So now you can do (lazily (print 42) (cons (loop) 42)) and CONS *will* be called lazily. You code-walking solution was the right one.
Code-walking is hard... my example was only a hack. It's completely buggy at the moment, but even if it works, it will fail on "confusing names" in "confusing positions", for example, (let ((car 2)) ...) or (lambda (car ...) ...) Might have to bring in Arnesi...