deposit-field (Function)

Syntax:

Arguments and Values:

newbyte—an integer.

bytespec—a byte specifier.

integer—an integer.

result-integer—an integer.

Description:

Replaces a field of bits within integer; specifically, returns an integer that contains the bits of newbyte within the byte specified by bytespec, and elsewhere contains the bits of integer.

Examples:

 (deposit-field 7 (byte 2 1) 0) → 6
 (deposit-field -1 (byte 4 0) 0) → 15
 (deposit-field 0 (byte 2 1) -3) → -7

See Also:

byte, dpb

Notes:

 (logbitp j (deposit-field m (byte s p) n))
 ≡ (if (and (>= j p) (< j (+ p s)))
        (logbitp j m)
        (logbitp j n))

deposit-field is to mask-field as dpb is to ldb.