Executable RLP decoding of a scalar.
(rlp-decodex-scalar encoding) → (mv error? scalar)
This has the same form as the alternative definition rule of rlp-decode-scalar in terms of rlp-decode-bytes. As such, it is immediate to prove equal (i.e. correct with respect) to rlp-decode-scalar, using the correctness theorem of rlp-decodex-bytes.
Function:
(defun rlp-decodex-scalar (encoding) (declare (xargs :guard (byte-listp encoding))) (let ((__function__ 'rlp-decodex-scalar)) (declare (ignorable __function__)) (b* (((mv error? bytes) (rlp-decodex-bytes encoding)) ((when error?) (mv error? 0)) ((unless (equal (trim-bendian* bytes) bytes)) (mv (rlp-error-leading-zeros-in-scalar bytes) 0)) (scalar (bebytes=>nat bytes))) (mv nil scalar))))
Theorem:
(defthm maybe-rlp-error-p-of-rlp-decodex-scalar.error? (b* (((mv ?error? ?scalar) (rlp-decodex-scalar encoding))) (maybe-rlp-error-p error?)) :rule-classes :rewrite)
Theorem:
(defthm natp-of-rlp-decodex-scalar.scalar (b* (((mv ?error? ?scalar) (rlp-decodex-scalar encoding))) (natp scalar)) :rule-classes :rewrite)
Theorem:
(defthm rlp-decode-scalar-is-rlp-decodex-scalar (and (iff (mv-nth 0 (rlp-decode-scalar encoding)) (mv-nth 0 (rlp-decodex-scalar encoding))) (equal (mv-nth 1 (rlp-decode-scalar encoding)) (mv-nth 1 (rlp-decodex-scalar encoding)))))
Theorem:
(defthm rlp-decodex-scalar-of-byte-list-fix-encoding (equal (rlp-decodex-scalar (byte-list-fix encoding)) (rlp-decodex-scalar encoding)))
Theorem:
(defthm rlp-decodex-scalar-byte-list-equiv-congruence-on-encoding (implies (byte-list-equiv encoding encoding-equiv) (equal (rlp-decodex-scalar encoding) (rlp-decodex-scalar encoding-equiv))) :rule-classes :congruence)