Cover by Conrad Barski M.D.

Safari, the world’s most comprehensive technology and business learning platform.

Find the exact information you need to solve a problem on the fly, or go deeper to master the technologies and skills you need to succeed

Start Free Trial

No credit card required

O'Reilly logo

Chapter 4. Making Decisions with Conditions

In the previous chapters, you learned some basic Lisp commands, as well as some of the philosophy behind Lisp. In this chapter, we’ll be looking in detail at commands for handling conditions. The elegance of these commands shows that the unusual philosophy and design of Lisp has real practical benefits.

The Symmetry of nil and ()

One thing is particularly striking when we look at how Lisp commands and data structures work: They are imbued with symmetry in every conceivable way. This symmetry can give your Lisp code a certain elegance that other languages cannot have, and Lisp’s simple syntax is an important factor in making this symmetry possible.

Empty Equals False

Since the Lisp philosophy strongly emphasizes ...

Find the exact information you need to solve a problem on the fly, or go deeper to master the technologies and skills you need to succeed

Start Free Trial

No credit card required