Node:Numbers Lists, Next:Lisp Atoms, Previous:Lisp Lists, Up:Lisp Lists
Lists can also have numbers in them, as in this list: (+ 2 2).
This list has a plus-sign, +, followed by two 2s, each
separated by whitespace.
In Lisp, both data and programs are represented the same way; that is,
they are both lists of words, numbers, or other lists, separated by
whitespace and surrounded by parentheses. (Since a program looks like
data, one program may easily serve as data for another; this is a very
powerful feature of Lisp.) (Incidentally, these two parenthetical
remarks are not Lisp lists, because they contain ; and
. as punctuation marks.)
Here is another list, this time with a list inside of it:
'(this list has (a list inside of it))
The components of this list are the words this, list,
has, and the list (a list inside of it). The interior
list is made up of the words a, list, inside,
of, it.