Advanced R

12

Function operators

In this chapter, you’ll learn about function operators (FOs). A function operator is a function that takes one (or more) functions as input and returns a function as output. In some ways, function operators are similar to functionals: there’s nothing you can’t do without them, but they can make your code more readable and expressive, and they can help you write code faster. The main difference is that functionals extract common patterns of loop use, where function operators extract common patterns of anonymous function use.

The following code shows a simple function operator, chatty(). It wraps a function, making a new function that prints out its first argument. It’s useful because it gives you a window to see how functionals, ...