Aww come on, I admit that it's not a book to skim, but by the end of chapter 5 you understand one of the crown jewels of CS: the kernel of scheme. It's like a perfect piece of clockwork (not my sloppy implementation, I mean the core idea.) It's a kind of transcendental experience to hold in your head the internals of a complete programming language, and only Scheme is simple enough to do that with. That has to be worth a little extra effort? :-)
Bill H
perl -e 'print sub { "Hello @{[shift->()]}!\n" }->(sub{"World"})'
