Tighten chatty() example

[dkahle]

I may be missing a deeper point here, but it seems simpler for chatty() to use message() instead of cat() and call it before the processing begins?

[hadley]

Hmmm, that is weird. Is chatty() used later in the chapter?

[dkahle]

No, grep's only showing three instances of chatty, two in that first code chunk, and one in the preceding paragraph:

~/Dropbox/dev/adv-r/adv-r(master*) » grep 'chatty' Function-operators.Rmd
In this chapter, you'll learn about function operators. A __function operator__ is a function that takes one (or more) functions as input and returns a function as output. The following code shows a simple function operator, `chatty()`. It wraps a function, making a new function that prints out its first argument. You might create a function like this because it gives you a window to see how functionals, like `map_int()`, work.
chatty <- function(f) {
purrr::map_dbl(s, chatty(f))

[hadley]

Thanks!