Function ldb-test

Syntax:

ldb-test bytespec integer generalized-boolean

Arguments and Values:

bytespec—a byte specifier.

integer—an integer.

generalized-boolean—a generalized boolean.

Description:

12.8.0 8Returns true if any of the bits of the byte in integer specified by bytespec is non-zero; otherwise returns false.

Examples:

 (ldb-test (byte 4 1) 16) → true
 (ldb-test (byte 3 1) 16) → false
 (ldb-test (byte 3 2) 16) → true

Side Effects:

None.

Affected By:

None.

Exceptional Situations:

None.

See Also:

byte, ldb, zerop

Notes:

 (ldb-test bytespec n) ≡
 (not (zerop (ldb bytespec n))) ≡
 (logtest (ldb bytespec -1) n)
Item 3 of that equivalence contributed by Barmar. -kmp 16-Jul-91