Recursion

Abstract

You will have noticed that I have not yet attempted to write a piece of code containing a loop. The reason for this is that it is often convenient not to use conventional iteration structures at all in Lisp. Such structures are implemented, but they aren’t actually necessary. So I’m going to be somewhat puritanical and do without them entirely for the moment.

“Well, just then I was inventing a new way of getting over a gate—would you like to hear it?”

“Very much indeed,” Alice said politely.

“I’ll tell you how I came to think of it,” said the Knight.

“You see, I said to myself ‘The only difficulty is with the feet: the head is high enough already’. Now first I put my head on top of the gate—then the head’s high enough—then I stand on my head—then the feet are high enough, you see—then I’m over you see.”

Through the Looking-Glass