When I got to the first lecture, the instructor kept writing code snippets on the blackboard and asking questions about them. Now I knew a enough FORTRAN to do simple plots for my physics lab courses, but the code on the blackboard had way too many parenthesis to be FORTRAN.

Here’s one example (from memory):

  (DE MEMBER (PIP DECK) (COND
      ((EQ PIP (CAR DECK)) T)
      (T (MEMBER PIP (CDR DECK)))))

(And yes, the layout is accurate. The COND was definitely on the first line. At this point in the class, it was explained as required "magic".)

"What kind of programming language is this?" I thought. It didn’t make any sense for about 3 days. And then I had the "Ah-HA!" experience and everything fell into place. I finally "got it", and fell in love with Lisp and programming in general from that point on.

The instructor for the course was Daniel Friedman, the author of the book "The Little Lisper" (which was one of the required books for the course). The Little Lisper emulated, in print, Professor Friedman’s style of teaching, revealing a little bit of information through a question and answer session until the reader/student gains enough understanding to put all together.

Brian Marick has started a book where he emulates that Q&A style, but targets the book at Object Orientation and Ruby instead of Lisp. You can find the first three chapters of A Little Ruby, A Lot of Objects at www.visibleworkings.com/little-ruby. In those three short chapters he introduces objects, messages, protocols, inheritance, classes and meta-classes to a beginning programmer in a whimsical manner, similar to the original Lisp book. It was a delight to read the step by step approach used in the book.

The only downside is that Brian seems to have stopped after three chapters. Nevertheless, if you are looking for a gentle introduction to object orientation in general and Ruby in particular, take a look at A Little Ruby, A Lot of Objects.