LISP - Symbols

Lisp - Bitwise Operators

Quiz

Bitwise operators work on bits and perform bit-by-bit operation. The truth tables for bitwise and, or, and xor operations are as follows −

p	q	p and q	p or q	p xor q
0	0	0	0	0
0	1	0	1	1
1	1	1	1	0
1	0	0	1	1

Assume if A = 60; and B = 13; now in binary format they will be as follows:
A = 0011 1100
B = 0000 1101
-----------------
A and B = 0000 1100
A or B = 0011 1101
A xor B = 0011 0001
not A  = 1100 0011

The Bitwise operators supported by LISP are listed in the following table. Assume variable A holds 60 and variable B holds 13, then −

Operator	Description	Example
logand	This returns the bit-wise logical AND of its arguments. If no argument is given, then the result is -1, which is an identity for this operation.	(logand a b)) will give 12
logior	This returns the bit-wise logical INCLUSIVE OR of its arguments. If no argument is given, then the result is zero, which is an identity for this operation.	(logior a b) will give 61
logxor	This returns the bit-wise logical EXCLUSIVE OR of its arguments. If no argument is given, then the result is zero, which is an identity for this operation.	(logxor a b) will give 49
lognor	This returns the bit-wise NOT of its arguments. If no argument is given, then the result is -1, which is an identity for this operation.	(lognor a b) will give -62,
logeqv	This returns the bit-wise logical EQUIVALENCE (also known as exclusive nor) of its arguments. If no argument is given, then the result is -1, which is an identity for this operation.	(logeqv a b) will give -50

Example - logand, logior Operator

Create a new source code file named main.lisp and type the following code in it. Here we're using logand, logior operators to check various scenarios.

main.lisp

; set a as 60
(setq a 60)
; set b as 13
(setq b 13)

; print logand of a and b
(format t "~% BITWISE AND of a and b is ~a" (logand a b))
; print logand of a or b
(format t "~% BITWISE INCLUSIVE OR of a and b is ~a" (logior a b))

; terminate printing to print in new line
(terpri)

; assign variables new values
(setq a 10)
(setq b 0)
(setq c 30)
(setq d 40)

; print logand of all four variables
(format t "~% Result of bitwise and operation on 10, 0, 30, 40 is ~a" (logand a b c d))
; print logor of all four variables
(format t "~% Result of bitwise or operation on 10, 0, 30, 40 is ~a" (logior a b c d))

When you click the Execute button, or type Ctrl+E, LISP executes it immediately and the result returned is −

BITWISE AND of a and b is 12
 BITWISE INCLUSIVE OR of a and b is 61

 Result of bitwise and operation on 10, 0, 30, 40 is 0
 Result of bitwise or operation on 10, 0, 30, 40 is 62

Example - logxor, lognor Operator

Update the source code file named main.lisp and type the following code in it. Here we're using logxor, lognor operators to check various scenarios.

main.lisp

; set a as 60
(setq a 60)
; set b as 13
(setq b 13)

; print logxor of a and b
(format t "~% BITWISE EXCLUSIVE OR of a and b is ~a" (logxor a b))
; print lognor of a and b
(format t "~% A NOT B is ~a" (lognor a b))

; terminate printing to print in new line
(terpri)

; assign variables new values
(setq a 10)
(setq b 0)
(setq c 30)
(setq d 40)

; print logxor of all four variables
(format t "~% Result of bitwise xor operation on 10, 0, 30, 40 is ~a" (logxor a b c d))
; print logeqv of all four variables
(format t "~% Result of bitwise eqivalance operation on 10, 0, 30, 40 is ~a" (logeqv a b c d))

When you click the Execute button, or type Ctrl+E, LISP executes it immediately and the result returned is −

BITWISE EXCLUSIVE OR of a and b is 49A NOT B is -62
Result of bitwise xor operation on 10, 0, 30, 40 is 60
 Result of bitwise eqivalance operation on 10, 0, 30, 40 is -61

Example - logeqv Operator

Update the source code file named main.lisp and type the following code in it. Here we're using logeqv operator to check the scenario.

main.lisp

; set a as 60
(setq a 60)
; set b as 13
(setq b 13)

; print logeqv of a and b
(format t "~% A EQUIVALANCE B is ~a" (logeqv a b))

; terminate printing to print in new line
(terpri)

; assign variables new values
(setq a 10)
(setq b 0)
(setq c 30)
(setq d 40)

; print logeqv of all four variables
(format t "~% Result of bitwise eqivalance operation on 10, 0, 30, 40 is ~a" (logeqv a b c d))

When you click the Execute button, or type Ctrl+E, LISP executes it immediately and the result returned is −

A EQUIVALANCE B is -50
Result of bitwise eqivalance operation on 10, 0, 30, 40 is -61

lisp_operators.htm

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