Conventions 

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "The following function f has a side effect, though."

A block of code is set as follows:

user=> (def v [7 11 19 52 42 72]) 
#'user/v 
user=> (def v1 (conj v 52)) 
#'user/v1 

If there is a line (or lines) of code that needs to be highlighted, it is set as follows:

scala> def pop(queue: Fifo): (Int, Fifo) = { 
     |   queue.out match { 
     |     case Nil => throw new IllegalArgumentException("Empty queue"); 
     |     case x :: Nil => (x, queue.copy(out = queue.in.reverse, Nil)) 
     |     case y :: ys => (y, queue.copy(out = ys)) 
     |   } 
     | } 
pop: (queue: Fifo)(Int, Fifo)

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Clicking the Next button moves you to the next screen."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.