boole op integer-1 integer-2 => result-integer
Op---a bit-wise logical operation specifier.
integer-1---an integer.
integer-2---an integer.
result-integer---an integer.
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 Figure 12--16.
{
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
Figure 12--16: Bit-Wise Logical Operations
}
(boole boole-ior 1 16) => 17
(boole boole-and -2 5) => 4
(boole boole-eqv 17 15) => -31
;;; These 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 <op> #b0011 #b0101) ...~
~
(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 <op> #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
=> NIL
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.
@xref{logand; logandc1; logandc2; logeqv; logior; lognand; lognor; lognot; logorc1; logorc2; logxor}
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
(proclaim '(inline boole-n))
=> implementation-dependent
(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)
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