;; Bitvector in protocol byte order (little endian) → integer in host byte order
(define (ptoh octet-size bv)
  ;; Procedures to convert bytevector index to shift value for LE and BE.
  (define (shle idx) (* idx 8))                       ;; INDEX * 8
  (define (shbe idx) (- octet-size (+ 1 (* idx 8))))  ;; BYTE-SIZE - ((INDEX + 1) * 8)

  (let ((shift-proc
          (if (memq 'little-endian (features))
            shle shbe))) ;; Use shle on LE and shbe on BE platforms
    (apply bitwise-ior
           (map (lambda (index)
                   (arithmetic-shift
                     (bytevector-u8-ref bv index) ;; Get nth byte from vector
                     (shift-proc index)))         ;; Shift according to byte order
                (range octet-size)))))