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Function LOGAND, LOGANDC1, LOGANDC2, LOGEQV, LOGIOR, LOGNAND, LOGNOR, LOGNOT, LOGORC1, LOGORC2, LOGXOR

Syntax

logand &rest integersresult-integer logandc1 integer-1 integer-2result-integer logandc2 integer-1 integer-2result-integer logeqv &rest integersresult-integer logior &rest integersresult-integer lognand integer-1 integer-2result-integer lognor integer-1 integer-2result-integer lognot integerresult-integer logorc1 integer-1 integer-2result-integer logorc2 integer-1 integer-2result-integer logxor &rest integersresult-integer

Arguments and Values

Description

The functions logandc1, arguments, that are treated as if they were binary. The table below lists the meaning of each of the functions. Where an `identity' is shown, it indicates the value yielded by the function when no arguments are supplied. ^ Function ^ Identity ^ Operation performed ^ | logandc1 | --- | and complement of integer-1 with integer-2 | | logandc2 | --- | and integer-1 with complement of integer-2 | | logand | -1 | and | | logeqv | -1 | equivalence (exclusive nor) | | logior | 0 | inclusive or | | lognand | --- | complement of integer-1 and integer-2 | | lognor | --- | complement of integer-1 or integer-2 | | lognot | --- | complement | | logorc1 | --- | or complement of integer-1 with integer-2 | | logorc2 | --- | or integer-1 with complement of integer-2 | | logxor | 0 | exclusive or | Negative integers are treated as if they were in two's-complement notation. ====Examples==== <blockquote> (logior 1 2 4 8) <r>15 </r> (logxor 1 3 7 15) <r>10 </r> (logeqv) <r>-1 </r> (logand 16 31) <r>16 </r> (lognot 0) <r>-1 </r> (lognot 1) <r>-2 </r> (lognot -1) <r>0 </r> (lognot (1+ (lognot 1000))) <r>999</r> </blockquote> In the following example, m is a mask. For each bit in the mask that is a 1, the corresponding bits in x and y are exchanged. For each bit in the mask that is a 0, the corresponding bits of x and y are left unchanged. <blockquote> (flet ((show (m x y) (format t "~%m = #o~6,'0O~%x = #o~6,'0O~%y = #o~6,'0O~%" m x y))) (let ((m #o007750) (x #o452576) (y #o317407)) (show m x y) (let ((z (logand (logxor x y) m))) (setf x (logxor z x)) (setf y (logxor z y)) (show m x y)))) <o>m = #o007750 x = #o452576 y = #o317407 m = #o007750 x = #o457426 y = #o312557 </o> <r>NIL </r> </blockquote> ====Side Effects==== None. ====Affected By==== None. ====Exceptional Situations==== Should signal type-error if any argument is not an integer. ====See Also==== * Function BOOLE ====Notes==== (logbitp k -1) returns true for all values of k. Because the following functions are not associative, they take exactly two arguments rather than any number of arguments. <blockquote> (lognand n1 n2) ≡ (lognot (logand n1 n2)) (lognor n1 n2) ≡ (lognot (logior n1 n2)) (logandc1 n1 n2) ≡ (logand (lognot n1) n2) (logandc2 n1 n2) ≡ (logand n1 (lognot n2)) (logiorc1 n1 n2) ≡ (logior (lognot n1) n2) (logiorc2 n1 n2) ≡ (logior n1 (lognot n2)) (logbitp j (lognot x)) ≡ (not (logbitp j x)) </blockquote>