[plt-scheme] Question about delayed evaluation
I'm studying "Structure and Interpretation of Computer Program" and in
the third chapter are introduced streams. To improve the use of
cpu/memory are introduced streams with delayed evaluation of the tail
that are constructed with the use of a special form 'cons-stream'
(cons-stream head tail) where the head is evaluated at once while the
tail is evaluated only when is accessed. I haven't found such a special
form, does it exist or not?
I know that I can use delay,force,cons, car and cdr to implement streams
with delayed evaluation but in this case the clients of the streams must
pass to the cons operator a cdr argument already delayed (wrapped in a
delay). I would like that clients don't know that streams have a delayed
evaluation.
Giannandrea