CLHS: Function BIT-AND, BIT-ANDC1, BIT-ANDC2...

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Function BIT-AND, BIT-ANDC1, BIT-ANDC2, BIT-EQV, BIT-IOR, BIT-NAND, BIT-NOR, BIT-NOT, BIT-ORC1, BIT-ORC2, BIT-XOR

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.

    Function                                                 Operation
    ----------

    bit-and                                                  and
    bit-eqv                                                  equivalence (exclusive nor)
    bit-not                                                  complement
    bit-ior                                                  inclusive or
    bit-xor                                                  exclusive or
    bit-nand                                                 complement of bit-array1 and bit-array2
    bit-nor                                                  complement of bit-array1 or bit-array2
    bit-andc1                                                and complement of bit-array1 with bit-array2
    bit-andc2                                                and bit-array1 with complement of bit-array2
    bit-orc1                                                 or complement of bit-array1 with bit-array2
    bit-orc2                                                 or bit-array1 with complement of bit-array2

    Figure 15-4.  Bit-wise Logical Operations on Bit Arrays

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

Affected By: None.

Exceptional Situations: None.

See Also:

lognot, logand

Notes: None.

Copyright 1996-2005, LispWorks Ltd. All rights reserved.