GNU Emacs Lisp Reference Manual

1.3.4: Printing Notation

Many of the examples in this manual print text when they are evaluated. If you execute example code in a Lisp Interaction buffer (such as the buffer `*scratch*'), the printed text is inserted into the buffer. If you execute the example by other means (such as by evaluating the function eval-region), the printed text is displayed in the echo area. You should be aware that text displayed in the echo area is truncated to a single line.

Examples in this manual indicate printed text with `-|', irrespective of where that text goes. The value returned by evaluating the form (here bar) follows on a separate line.

(progn (print 'foo) (print 'bar))
     -| foo
     -| bar
     => bar