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Function BYTE, BYTE-SIZE, BYTE-POSITION

Syntax

  • byte size positionbytespec
  • byte-size bytespecsize byte-position bytespecposition

Arguments and Values

Description

byte returns a byte specifier that indicates a byte of width size and whose bits have weights 2^(position + size - 1) through 2^position, and whose representation is implementation-dependent.

byte-size returns the number of bits specified by bytespec.

byte-position returns the position specified by bytespec.

Examples

(defparameter *b* (byte 100 200))

*B*

*b*

#<BYTE-SPECIFIER size 100 position 200>

(byte-size *b*)

100

(byte-position *b*)

200

Affected By

None.

Exceptional Situations

None.

See Also

Notes

(byte-size (byte j k)) ≡ j (byte-position (byte j k)) ≡ k

A byte of size of 0 is permissible; it refers to a byte of width zero. For example:

(ldb (byte 0 3) #o7777) → 0 (dpb #o7777 (byte 0 3) 0) → 0