Conventions

Typography

Key Entry

We use the angle bracket convention to indicate typing actual key on the keyboard. For instance, when the reader sees <ENTER> they should interpret this as an actual key they should type. Note that all keys are given in upper-case. If the reader is expected to use an upper-case "C" instead of a lower-case "c", they will be presented with the key combination <SHIFT><C>.

Code

Color syntax highlighting is used in this text to display blocks of code. The formatting of this display is done in such a way as to invoke in the mind of the reader the feeling of a terminal, thus making an obvious visual distinction in the text. For instance:

(defun fib
  ((0) 0)
  ((1) 1)
  ((n)
    (+ (fib (- n 1))
       (fib (- n 2)))))

Examples such as this one are readily copied and may be pasted without edit into a file or even the LFE REPL itself.

For interactive code, we display the default LFE prompt the reader will see when in the REPL:

lfe> (integer_to_list 42 2)
;; "101010"

We also distinguish the output from the entered LFE code using code comments displayed afer the command.

For shell commands, the commands to enter at the prompt are prefixed by a $ for the prompt. Input and any relevant output are provided as comment strings:

$ echo "I am excited to learn LFE"
# I am excited to learn LFE

LiffyBot

This is a severly hoopy frood. With an attitude. He pops up from time to time, generally with good advice. Or simply as a marker for something the authors hope you will pay special note.

Messages of Note

From time to time you will see call-out boxes, aimed at drawing your attention to something of note. There are four differnt types of these:

• ones that share useful info (blue)
• ones that highlight something of a momentus nature (green)
• ones that offer warnings to tred carefully (orange)
• ones that beg you not to follow a particular path (red)

These messages will take the following forms: