(defun bytes-to-int (array)
  (let ((arr-len (length array)))
    (when (< 4 (length array))
      (error "can't make a 32bit integer from more than 4 8bit bytes"))
    (cond ((= arr-len 1)
	   (aref array 0))
	  ((= arr-len 2)
	   (logior (ash (aref array 0) 8) (aref array 1)))
	  ((= arr-len 3)
	   (logior (ash (aref array 0) 16) (ash (aref array 1) 8) (aref array 2)))
	  ((= arr-len 4)
	   (logior (ash (aref array 0) 24) (ash (aref array 1) 16)
		   (ash (aref array 2) 8) (aref array 3))))))
(defun strip-trailing-0s (array)
  "Removes only 0's on the end of a sequence, it will skip 0's in the middle and 
returns a new sequence"
  (loop :for x :across (reverse array)
	:for i :downfrom (length array) :to 0
	:unless (zerop x)
	  :return (subseq array 0 i))))

;;;;;
NET-CONSTRUCT> (bytes-to-int #(1 0 0 0))
16777216 (25 bits, #x1000000)
NET-CONSTRUCT> (bytes-to-int (strip-trailing-0s #(1 0 0 0)))
1 (1 bit, #x1, #o1, #b1) ;value I want
NET-CONSTRUCT> (bytes-to-int (strip-trailing-0s #(48 57 0 0)))
12345 (14 bits, #x3039) ;value I want
NET-CONSTRUCT> (bytes-to-int #(48 57 0 0))
809041920 (30 bits, #x30390000)