I remember the text--and the old course--actually spent a good bit of time talking about proper tail calls and "iteration" vs "recursion". We talked about how t

I remember the text--and the old course--actually spent a good bit of time talking about proper tail calls and "iteration" vs "recursion". We talked about how the code behaves differently--e.g. space usage--and about how to identify the two types. Also, it's the Structure and Interpretation of Computer Programs; naturally, the first bit talks about how programs look (structure), but the second bit (mainly chapters 4 and 5, if I remember correctly) talks about exactly that: how to execute code on the machine. The last chapter, in fact, introduces a register-based language not unlike assembly.