(rdb-field bsp i) is analogous to Common Lisp's (mask-field bytespec integer).
(rdb-field bsp i) → nat
Function: rdb-field
(defun rdb-field (bsp i) (declare (xargs :guard (and (bspp bsp) (integerp i)))) (let ((__function__ 'rdb-field)) (declare (ignorable __function__)) (logand i (wrb -1 bsp 0))))