LLVM provides a lot, but it’s still only a small part of the runtime a functional language needs. And C FFI calls are uncomplicated because LLVM leaves memory management to be handled by someone else. Interacting the Garbage Collector is what makes FFI calls difficult in languages such as Scheme. You might be interested in … Read more
The Haskell definition is not uniform. In Racket, the function to both folds have the same order of inputs, and therefore you can just replace foldl by foldr and get the same result. If you do that with the Haskell version you’d get a different result (usually) — and you can see this in the … Read more
For a beginner, I would highly recommend DrRacket (formerly Dr. Scheme), since it gives you a really nice environment to work in, supports many dialects of Scheme, and gives very good failure and debugging information. I believe most implementations of Scheme are interpreters, although it is possible that there is a compiler out there. If … Read more
Lazy evaluation makes macros redundant This is pure nonsense (not your fault; I’ve heard it before). It’s true that you can use macros to change the order, context, etc. of expression evaluation, but that’s the most basic use of macros, and it’s really not convenient to simulate a lazy language using ad-hoc macros instead of … Read more
You have several answers here, but none is really comprehensive (and I’m not talking about having enough details or being long enough). First of all, the bottom line: you should not use Common Lisp if you want to have a good experience with SICP. If you don’t know much Common Lisp, then just take it … Read more
Your confusion is reasonable: ‘let’ and ‘define’ both create new bindings. One advantage to ‘let’ is that its meaning is extraordinarily well-defined; there’s absolutely no disagreement between various Scheme systems (incl. Racket) about what plain-old ‘let’ means. The ‘define’ form is a different kettle of fish. Unlike ‘let’, it doesn’t surround the body (region where … Read more
Not a lot of people use it that I know, but it is definitely worth a peek (if even just to try programming in another paradigm, so that you learn to think differently). You’re lucky to be able to take a class that uses Scheme, as most universities these days now teach Java. Here’s a … Read more
I think @Vijay’s answer is the best one so far and I just intend to Erlangify it. Pairs (cons cells) in Erlang are written as [Head|Tail] and nil is written as []. There is no restriction as to what the head and tail are but if you use the tail to chain more cons cells … Read more
A good summary is available in Implementation Strategies for First-Class Continuations, an article by Clinger, Hartheimer, and Ost. I recommend looking at Chez Scheme’s implementation in particular. Stack copying isn’t that complex and there are a number of well-understood techniques available to improve performance. Using heap-allocated frames is also fairly simple, but you make a … Read more
The Little Schemer teaches recursion really well, and it’s fun and simple to read. I also liked The Scheme Programming Language for a broader introduction into the language.