[plt-scheme] should `map' reuse cons cells?

Bradd W. Szonye writes:
 > That won't minimize garbage; indeed, it'll /create/ garbage. This MAP
 > would need to create the results, compare them to the original list, and
 > then throw them away if they match.

You're the third person to say this...  What am I missing?  My
implementation (see previous post) creates no more cons cells than a
naive implementation of `map', as far as I can tell.

--dougo at place.org