ldb-test (Function)

Syntax:

Arguments and Values:

bytespec—a byte specifier.

integer—an integer.

generalized-boolean—a generalized boolean.

Description:

Returns 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

See Also:

byte, ldb, zerop

Notes:

 (ldb-test bytespec n) ≡
 (not (zerop (ldb bytespec n))) ≡
 (logtest (ldb bytespec -1) n)