Iterating in Scheme

Let's say that I have a list of lists in Scheme, like so:

 (define a-list  (list (list a b) (list c d) (list e f) (list g h) (list i j)))

How would I go about def开发者_JS百科ining a function that would consume this list such that I could use another function to consume each letter in the list?

For instance, I had another function

(define (smorg a)
  (...))

So, how do I go about doing smorg a, smorg b, smorg c... ?

What textbook are you using?

If the answer is How to Design Programs, then follow the design recipe. In particular, you need a data definition; the data definition is used to generate a template, which tells you exactly how to get the recursion right.

If you're not using HtDP, I highly suggest you give it a read. The book is available online, here: http://www.htdp.org/. Then follow the design recipe. In particular, you need a data definition etc etc etc.

In either case, here's a hint: Never, ever use the list function before you've mastered recursion. Not in your functions, not even in your examples. It gets in your way. Build your lists with cons and empty.

Be sure you understand what list?, map, car and cdr do. They might be of use.