Alan Crowe <email@example.com> wrote:
| firstname.lastname@example.org writes:
| > Is it fair to say that eval is the opposite of quote?
| > Is there another function considered the opposite of quote?
| Type 2<RET>
| The lisp interpreter looks at 2 and evaluates it. It
| recognises it as a number, and applies the rule that numbers
| evaluatie to themselves, so the answer is 2.
| Type: (+ 2 2)<RET>
| The computer sees the opening parenthesis and realises it is
| being given a list. When it reaches the closing parenthesis
| it is able to work out that it has seen a list of three items.
| The first is the + sign, so it knows to add together the values
| of the remaining items on the list. So it evaluates them, the
| number 2 having the value 2 as before. Answer: 4
CLHS "126.96.36.199 Form Evaluation" is sometimes useful at this point:
Forms fall into three categories: symbols, conses, and
self-evaluating objects. The following sections explain these
188.8.131.52.1 Symbols as Forms
184.108.40.206.2 Conses as Forms
220.127.116.11.3 Self-Evaluating Objects
Rob Warnock <email@example.com>
627 26th Avenue <URL:http://rpw3.org/>
San Mateo, CA 94403 (650)572-2607