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Function BOOLE
Syntax
- boole op integer-1 integer-2 → result-integer
Arguments and Values
Description
boole performs bit-wise logical operations on integer-1 and integer-2, which are treated as if they were binary and in two's complement representation.
The operation to be performed and the return value are determined by op.
boole returns the values specified for any op in the following table.
| Op | Result |
|---|---|
| boole-1 | integer-1 |
| boole-2 | integer-2 |
| boole-andc1 | and complement of integer-1 with integer-2 |
| boole-andc2 | and integer-1 with complement of integer-2 |
| boole-and | and |
| boole-c1 | complement of integer-1 |
| boole-c2 | complement of integer-2 |
| boole-clr | always 0 (all zero bits) |
| boole-eqv | equivalence (exclusive nor) |
| boole-ior | inclusive or |
| boole-nand | not-and |
| boole-nor | not-or |
| boole-orc1 | or complement of integer-1 with integer-2 |
| boole-orc2 | or integer-1 with complement of integer-2 |
| boole-set | always -1 (all one bits) |
| boole-xor | exclusive or |
Examples
(boole boole-ior 1 16)
17
(boole boole-and -2 5)
4
(boole boole-eqv 17 15)
-31
The below examples illustrate the result of applying BOOLE and each of the possible values of OP to each possible combination of bits.
(progn (format t "~&Results of (BOOLE
#b0011 #b0101) ...~ ~%---Op-------Decimal-----Binary----Bits---~%") (dolist (symbol '(boole-1 boole-2 boole-and boole-andc1 boole-andc2 boole-c1 boole-c2 boole-clr boole-eqv boole-ior boole-nand boole-nor boole-orc1 boole-orc2 boole-set boole-xor)) (let ((result (boole (symbol-value symbol) #b0011 #b0101))) (format t "~& ~A~13T~3,' D~23T~:*~5,' B~31T ...~4,'0B~%" symbol result (logand result #b1111)))))
Results of (BOOLE
#b0011 #b0101) ... ---Op-------Decimal-----Binary----Bits--- BOOLE-1 3 11 ...0011 BOOLE-2 5 101 ...0101 BOOLE-AND 1 1 ...0001 BOOLE-ANDC1 4 100 ...0100 BOOLE-ANDC2 2 10 ...0010 BOOLE-C1 -4 -100 ...1100 BOOLE-C2 -6 -110 ...1010 BOOLE-CLR 0 0 ...0000 BOOLE-EQV -7 -111 ...1001 BOOLE-IOR 7 111 ...0111 BOOLE-NAND -2 -10 ...1110 BOOLE-NOR -8 -1000 ...1000 BOOLE-ORC1 -3 -11 ...1101 BOOLE-ORC2 -5 -101 ...1011 BOOLE-SET -1 -1 ...1111 BOOLE-XOR 6 110 ...0110
</blockquote>
====Affected By==== None.
====Exceptional Situations==== Should signal type-error if its first argument is not a bit-wise logical operation specifier or if any subsequent argument is not an integer.
====See Also====
====Notes==== In general:
(boole boole-and x y) ≡ (logand x y)
Programmers who would prefer to use numeric indices rather than bit-wise logical operation specifiers can get an equivalent effect by a technique such as the following.
The order of the values in this "table" are such that
(logand (boole (elt boole-n-vector n) #b0101 #b0011) #b1111) → n.(defconstant boole-n-vector (vector boole-clr boole-and boole-andc1 boole-2 boole-andc2 boole-1 boole-xor boole-ior boole-nor boole-eqv boole-c1 boole-orc1 boole-c2 boole-orc2 boole-nand boole-set))
BOOLE-N-VECTOR
(defun boole-n (n integer &rest more-integers) (apply #'boole (elt boole-n-vector n) integer more-integers))
BOOLE-N
(boole-n #b0111 5 3)
7
(boole-n #b0001 5 3)
1
(boole-n #b1101 5 3)
-3
(loop for n from #b0000 to #b1111 collect (boole-n n 5 3))
(0 1 2 3 4 5 6 7 -8 -7 -6 -5 -4 -3 -2 -1)
