[lisper]

Well, it can't be straight out of SICP because SICP uses Scheme and this code is in Haskell. And, in fact, if you did a straightforward translation of the Haskell code back into Scheme it wouldn't work. Figuring out why it doesn't work in Scheme but it does in Haskell is left as an exercise.

[dmunoz]

Of course, in later chapters SICP covers both streams [0] and lazy evaluation in the interpreter [1]. It's a really great book! I'm completely jealous of anyone who was introduced to CS via a serious studying of SICP.

[0] https://mitpress.mit.edu/sicp/full-text/book/book-Z-H-24.htm...

[1] https://mitpress.mit.edu/sicp/full-text/book/book-Z-H-27.htm...

[obblekk]

scheme lists aren't lazily generated?

[davexunit]

You use streams a la SRFI-41 for this.

[brudgers]

Or Lazy Racket [in so far as Racket is a Scheme].

http://docs.racket-lang.org/lazy/