It is suggested that you use the Lisp interpreter available on the general machine general'asu'edu'

1
Getting Started with Lisp
It is suggested that you use the Lisp interpreter
available on the general machine
(general.asu.edu). You are welcome to use other
interpreters while developing, but your programs
should run on the general for grading purposes.
If you absolutely must use a different version
and find that your version is not compatible with
the version on the general, contact the TA before
you turn in any work and make alternate
arrangements.
2
Lisp on the General

• Allegro Common Lisp 4.3.1 is available on the
  general. The general is the general purpose
  Unix account all ASU students have access to. You
  can access it with telnet or (better) ssh, at
  general.asu.edu. Once you logon to the general,
  you will get a Unix prompt. At the prompt, type
  in the command cl to start Common Lisp.

3
The Lisp Prompt

• Lisp is an interactive, interpreted language. You
  can interact with it by entering commands at its
  command prompt, or by telling it to read in a
  file of commands. Every command entered, either
  at the prompt or read from a file, is immediately
  evaluated and executed by the interpreter.

4
Basic Commands

• (exit) or exit - Exits the Lisp interpreter
• (load file) Loads and evaluates a file.
• CtrlC Breaks execution if you get stuck.
• help Shows list of interpreter commands
• reset Starts the interpreter over
• pop Goes up one level of error breaks

5
Manipulating Lists

• Using Quote-
• e.g. USER(1) (1 2 3)
• (1 2 3)
• Using CAR-
• e.g. USER(2) CAR( 1 2 3 4)
• 1
• Using CDR-
• e.g.- USER(3) CDR( 1 2 3)
• ( 2 3)

6
Using Lists II

• Cons (cons a b) Creates a new list with a
  head of a and a tail of b
• e.g. (cons a (b c)) gives (a b c)
• Append (append a b ) Creates a new list out
  of a set of lists
• e.g. (append '(a b c) '() '(d e f)) gives (a b c
  d e f)

7
RECURSION
LISP supports recursion just like any procedural
language(eg C) E.g. Raise X to the Nth power
(defun raise (x n) (if ( n 0)
1 ( x (
raise x (- n 1) ) ) ) )

8
ITERATION
Using dolist - dolist repeats a set of
operations for as many times as there are entries
in a list. E.g.-USER(1) (dolist (x (a b c))
(print x)) A B C NIL
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Using LOOP E.g.- USER(15)- (loop for x from
1 to 7 collect x) (1 2 3 4 5 6
7)
10
Conditional Expressions- Using CASE. E.g.-
User(10)(defun goose (x)
(case x (1 one) (2 two) (3
three) (4 four) (otherwise
many))) goose
11
Using dotimes - dotimes repeats an evaluation as
many times as it is requested E.g.-
USER(10)-(dotimes (i 5 i) (print i) o
1 2 3 4
5
12
Defining functions using defun
USER(1)(defun funct1 (x) ( x
1)) FUNCT1 USER(2)(funct1(3)) 4
13
Input and Output
gt (progn (format t Please enter your
name ) (read-line)) gt (prin1 hello) gt
(format nil Dear A, Our records indicate
Mr. Malatesta) Note There
are many variants. You need to refer to a CL book.
14
Other Resources

• http//grimpeur.tamu.edu/colin/lp/ is a Lisp
  primer. The Programming Techniques section
  should be checked out.
• http//www.math.uio.no/cltl/cltl2.html has the
  complete text of the 2nd edition of Common Lisp
  the Language.