Programming Clojure, 3rd Edition

How to Be Lazy

Before we get to laziness, we first need to delve into recursion as an approach to enumerating sequences of values.

Functional programs make great use of recursive definitions. A recursive definition consists of two parts:

• A basis, which explicitly enumerates some members of the sequence
• An induction, which provides rules for combining members of the sequence to produce additional members

Our challenge in this section is converting a recursive definition into working code. You might do this in several ways:

• A simple recursion, using a function that calls itself in some way to implement the induction step.

• A tail recursion, using a function calling itself only at the tail end of its execution. Tail recursion enables an ...