darcs patch: Implementation of aton and ntoa outside the IO monad

[Bulat Ziganshin]

Hello Robert,

Monday, September 25, 2006, 12:09:13 PM, you wrote:

> data ByteOrder = BigEndian | LittleEndian
>                  deriving ( Eq, Show, Read )

jfyi: there are (very rare) computers that are not LE nor BE. afaik,
VAX was one - it has smth like 1032 byte order, mixing BE in 2-byte
words and LE of 2-byte words in 4-byte word (or vice versa, i'm not
sure)


> flipEndian :: Integral a => a -> a
> flipEndian = wordConcat . reverse . toWord8s

a bit faster:

flipEndian n = let w1 = (n       ) .&. 0xff
                   w2 = (n >>#  8) .&. 0xff
                   w3 = (n >># 16) .&. 0xff
                   w4 = (n >># 24)
                   in (w1 <<# 24) .|. (w2 <<# 16) .|. (w3 <<# 8) .|. w4

#ifdef __GLASGOW_HASKELL__

(I# a) <<# (I# b) = (I# (a `iShiftL#` b))
(I# a) >># (I# b) = (I# (a `uncheckedIShiftRL#` b))

#else /* ! __GLASGOW_HASKELL__ */

a <<# b = a `shiftL` b
a >># b = a `shiftR` b

#endif /* ! __GLASGOW_HASKELL__ */




-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com