Re: Converting bytes to an integer

Subject: Re: Converting bytes to an integer
From: Erik Naggum <erik@naggum.no>
Date: 12 Sep 2002 17:32:43 +0000
Newsgroups: comp.lang.lisp
Message-ID: <3240840763579547@naggum.no>

* Frode Vatvedt Fjeld <frodef@acm.org>
| This looks good to me, but I'd prefer something like this:
| 
|  (defun bytes-to-int (bytes start end)
|    "Convert the bits of a little-endian 8-bit byte array to an integer."
|    (reduce (lambda (x y) (+ (* 256 x) y)) bytes :start start :end end))

  I would much prefer

(reduce (lambda (x y) (logior (ash x 8) y)) bytes :start start :end end)

  This is not a job for multiplication and addition.

-- 
Erik Naggum, Oslo, Norway

Act from reason, and failure makes you rethink and study harder.
Act from faith, and failure makes you blame someone and push harder.