Admittedly, while I'm interested to look at this book, it really looks to me like you should come in with at least a basic knowledge of C. The book appears to hold your hand through most of what goes on to create a basic Lisp-like language, but it really jumps fairly quickly over the basic C stuff at the beginning so you can get to the coding. That may actually be fine for you if you already have a basic C knowledge though.
> it really jumps fairly quickly over the basic C stuff at the beginning
In fact, for me it seems to be the best thing about this book. It mentions everything you need to hear once to be able to use search engine and clarify anything you don't understand. So help yourself! You don't know syntax of "switch" statement? Google it (or duckduckgo, or whatever)! You don't know how to use printf? You've been shown the way to cplusplus.com already, take your time and find out everything you want to know about that function. Then come back for a new piece of information to think about.
The only two things I guess are missing is "make" (I'd mention it from the start to help everybody save some time, with gdb and valgrind) and a little bit more information about pointers from the very beginning, because searching for help about "free" function will be no good if you don't know about stack/heap allocations.
