Exercise 1.4.19

Quoting

Another way to construct tree structure is using the quote or '.

* (quote (1 2 3))
(1 2 3)

* '(1 2 3)
(1 2 3)

* (list 1 2 3)
(1 2 3)

The structures you create this way are equivalent.

* (equal (quote (1 2 3)) '(1 2 3))
T

* (equal '(1 2 3) (list 1 2 3))
T

The difference is that, while list essentially means "Return the list of these arguments", quote/' means "Return this argument without evaluating it".

* (defparameter *test* 2)
*test*

* (list 1 *test* 3)
(1 2 3)

* '(1 *test* 3)
(1 *test* 3)

* (list (+ 3 4) (+ 5 6) (+ 7 8))
(7 11 15)

* '((+ 3 4) (+ 5 6) (+ 7 8))
((+ 3 4) (+ 5 6) (+ 7 8))