byte size position → bytespec

byte-size bytespec → size

byte-position bytespec → position

size, position — a non-negative integer.

bytespec — a byte specifier.

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.

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

ldb, dpb

(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