I was trying to get some of the examples out of The Seasoned
Schemer going this evening with absolutely no luck what-so-ever. Very
strange errors were resulting from my macro to implement let-cc, the
books short-hand for call-with-current-continuation. Seemingly impossible
errors. Eventually it dawned on me: I was dragging in the examples
from their previous book, The Little Schemer, for all the
not-quite-standard-scheme utility functions. This included chapter
10. In chapter 10 they re-implemented the scheme evaluator. It isn’t
quite as complete as the real thing, but I got through 80% of the
Seasoned Schemer before I noticed. Scheme is just a little too
powerful for its own good at times.
By the way, I thoroughly recommend both books. An unorthodox, but
very effective, way to learn about scheme.