Starting to Get it, Understanding Computer Programming

I just discovered Structure and Interpretation of Computer Programs, by Abelson, Sussman, and Sussman aka SICP aka The Wizard Book. It’s a computer science text book that introduces computer programing. It uses Scheme, a dialect of LISP, as the example and basis with which to teach.

I’ve been on the hunt for a computer science book I can click with. I’ve read/skimmed a lot of them. I mean A LOT. Both in print form and on-line. For some reason my mind has a real hard time staying focused while reading about functions, lists, arrays, operators, etc. But this book feels different.

Maybe it’s the magic analogy at the beginning of the first chapter that inspires me.

We are about to study the idea of a computational process. Computational processes are abstract beings that inhabit computers. As they evolve, processes manipulate other abstract things called data. The evolution of a process is directed by a pattern of rules called a program. People create programs to direct processes. In effect, we conjure the spirits of the computer with our spells.

A computational process is indeed much like a sorcerer’s idea of a spirit. It cannot be seen or touched. It is not composed of matter at all. However, it is very real. It can perform intellectual work. It can answer questions. It can affect the world by disbursing money at a bank or by controlling a robot arm in a factory. The programs we use to conjure processes are like a sorcerer’s spells. They are carefully composed from symbolic expressions in arcane and esoteric programming languages that prescribe the tasks we want our processes to perform.

Or possibly the call from Alan J. Perlis, the first recipient of the Turing Award, to keep computing fun. (Whom the book is dedicated.)

“I think that it’s extraordinarily important that we in computer science keep fun in computing. When it started out, it was an awful lot of fun. Of course, the paying customers got shafted every now and then, and after a while we began to take their complaints seriously. We began to feel as if we really were responsible for the successful, error-free perfect use of these machines. I don’t think we are. I think we’re responsible for stretching them, setting them off in new directions, and keeping fun in the house. I hope the field of computer science never loses its sense of fun. Above all, I hope we don’t become missionaries. Don’t feel as if you’re Bible salesmen. The world has too many of those already. What you know about computing other people will learn. Don’t feel as if the key to successful computing is only in your hands. What’s in your hands, I think and hope, is intelligence: the ability to see the machine as more than when you were first led up to it, that you can make it more.”

Alan J. Perlis (April 1, 1922-February 7, 1990)

What ever the reason I am some how starting to feel as if I get it. Get computer programing that is. I bet that the decade plus of reading a little bit here and a little bit there is adding up. But I have to thank MIT and this awesome free book for helping out. Getting a real foundation of knowledge is making a difference!

Now to leap over the wall my brain has built and release some code I’m proud of.

(Full free text of SICP is here http://mitpress.mit.edu/sicp/)