byte; byte-size; byte-position

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byte, byte-size, byte-position (Function)

Syntax:

— Function: byte size position → bytespec

— Function: byte-size bytespec → size

— Function: byte-position bytespec → position

Arguments and Values:

size, position—a non-negative integer.

bytespec—a byte specifier.

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:

 (setq b (byte 100 200)) → #<BYTE-SPECIFIER size 100 position 200>
 (byte-size b) → 100
 (byte-position b) → 200

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