Functional Design: Principles, Patterns, and Practices

3

Recursion and Iteration

In Chapter 1, Immutability, I stated that functional programming makes use of recursion in order to eliminate assignment. In this chapter, we will look at the two different varieties of recursion; one we will call iteration and the other will retain the original name: recursion.

Iteration

TCO is the remedy for the infinite stack depth implied by infinite recursive loops. However, TCO is only applicable if the recursive call is the very last thing to be executed within the function. Such functions are often called tail call functions.

Here is a very traditional implementation of a function to create a list of Fibonacci ...