If you want to open an already existing file select

1
Lisp File Basics

• If you want to open an already existing file
  select
• file-gtopen on the menu and then choose the
  program you want to modify. If you want to
  open a new file select file-gtnew on the menu and
  start typing your program on the editor.
• You have to save by clicking file-gtsave after you
  type.
• Be sure your filename has an extension .lisp
• Then you have to compile and load by using
• file-gtcompile and load from the menu
• Open the listener by clicking tools-gtlistener on
  the menu. And check to see if the functions
  defined in your program are correctly working.

2

• At the LISP prompt one can type the command or
  source code(programs) and retrieve the results
  just like at the DOS or UNIX prompt.
• In the solaris based LISP as you type
  /usr/acl5.0.1/lisp at the prompt you get the
  LISP prompt USER.
• In the windows based LISP you acces the LISP by
  clicking START menu--gtHarlequin
  lispworks--gtlispworks .
• Then you select tools-gtlistener from the menu bar
  to invoke the LISP prompt.

3
Defining functions using defun
USER(1)(defun funct1 (x) ( x
1)) FUNCT1 USER(2)(funct1(3)) 4
4
Manipulating Lists

• Using Quote-
• eg USER(1) (1 2 3)
• (1 2 3)
• Using CAR-
• eg USER(2) CAR( 1 2 3 4)
• 1
• Using CDR-
• eg- USER(3) CDR( 1 2 3)
• ( 2 3)

5
RECURSION
LISP supports recursion just like any procedural
language(eg C) Eg Raise X to the Nth power
(defun raise (x n) (if ( n 0)
1 ( x (
raise x (- n 1) ) ) ) )

6
ITERATION
Using dolist - dolist repeats a set of
operations for as many times as there are entries
in a list. Eg-USER(1) (dolist (x (a b c))
(print x)) A B C NIL
7
Using LOOP Eg- USER(15)- (loop for x from 1
to 7 collect x) (1 2 3 4 5 6 7)
8
Using dotimes - dotimes repeats an evaluation as
many times as it is requested Eg-
USER(10)-(dotimes (i 5 i) (print i) o
1 2 3 4
5
9
Conditional Expressions- Using CASE. Eg-
User(10)(defun goose (x)
(case x (1 one) (2 two) (3
three) (4 four) (otherwise
many))) goose
10
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.