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  ANSI Common Lisp   15 Arrays   15.2 Dictionary of Arrays

15.2.34 bit-and, bit-andc1, bit-andc2, bit-eqv, bit-ior, bit-nand, bit-nor, bit-not, bit-orc1, bit-orc2, bit-xor Function

Syntax:
bit-and bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-andc1 bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-andc2 bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-eqv bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-ior bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-nand bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-nor bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-orc1 bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-orc2 bit-array1 bit-array2 &optional opt-arg resulting-bit-array
bit-xor bit-array1 bit-array2 &optional opt-arg resulting-bit-array

bit-not bit-array &optional opt-arg    resulting-bit-array

Arguments and Values:
bit-array, bit-array1, bit-array2 - a bit array.

Opt-arg - a bit array, or t, or nil. The default is nil.

Bit-array, bit-array1, bit-array2, and opt-arg (if an array) must all be of the same rank and dimensions.

resulting-bit-array - a bit array.

Description:
These functions perform bit-wise logical operations on bit-array1 and bit-array2 and return an array of matching rank and dimensions, such that any given bit of the result is produced by operating on corresponding bits from each of the arguments.

In the case of bit-not, an array of rank and dimensions matching bit-array is returned that contains a copy of bit-array with all the bits inverted.

If opt-arg is of type (array bit) the contents of the result are destructively placed into opt-arg. If opt-arg is the symbol t, bit-array or bit-array1 is replaced with the result; if opt-arg is nil or omitted, a new array is created to contain the result.

The next figure indicates the logical operation performed by each of the functions.

Bit-wise Logical Operation
Function Operation
bit-andand
bit-eqvequivalence (exclusive nor)
bit-notcomplement
bit-iorinclusive or
bit-xorexclusive or
bit-nandcomplement of bit-array1 and bit-array2
bit-norcomplement of bit-array1 or bit-array2
bit-andc1and complement of bit-array1 with bit-array2
bit-andc2and bit-array1 with complement of bit-array2
bit-orc1or complement of bit-array1 with bit-array2
bit-orc2or bit-array1 with complement of bit-array2

Examples:
 (bit-and (setq ba #*11101010) #*01101011)  #*01101010
 (bit-and #*1100 #*1010)  #*1000      
 (bit-andc1 #*1100 #*1010)  #*0010
 (setq rba (bit-andc2 ba #*00110011 t))  #*11001000
 (eq rba ba)  true
 (bit-not (setq ba #*11101010))  #*00010101
 (setq rba (bit-not ba 
                     (setq tba (make-array 8 
                                           :element-type 'bit))))
 #*00010101
 (equal rba tba)  true
 (bit-xor #*1100 #*1010)  #*0110

See Also:
lognot, logand

Allegro CL Implementation Details:
None.

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