logbitp

(logbitp index integer)

Tests bit index (0 = least significant bit) of the two's-complement integer, returning t when it is set and nil otherwise. A negative integer has infinitely many high one-bits, so (logbitp index -1) is t for every index. On the interpreter and JVM integer may be any magnitude; on WASM bits are read within the 31-bit i31 range only.