Re: Converting things to and from binary

20 May 2003

      Glynn Clements  writes:
...
George Russell wrote:
...
...
The general problem to solve is "How to we convert things to and
from a binary format, so they can be efficiently written to and
from disk".  I have solved this (incompletely) twice myself,
...
Possibly the best way to handle this would be to extend the Storable
class, e.g.
...
class Storable a where
          :
[snip]    :
  toByteArray :: a -> Array Int Word8
  fromByteArray :: Array Int Word8 -> a
I wonder if this could be used to address a question (or perhaps
"frustration" is a better term), namely that of efficient packing of
data structures in memory.

Would it be possible to separate binary I/O in two layers, the binary
layer converting to/from (U?)Arrays of Word8, and another, the I/O
layer, reading and writing such arrays?  

Something almost entirely, but not quite, unlike:

        class Binary a where
                toBin :: a -> Array Int Word8
                toBinList :: [a] -> Array Int Word8
                fromBin :: Array Int Word8 -> a  -- perhaps with offset?
                fromBinList :: Array Int Word8 -> [a]

        hPutArray :: Handle -> Array Int Word8 -> IO ()
        hGetArray :: ...
        writeBinaryFile :: FilePath -> Array Int Word8 -> IO ()
        :

-kzm
-- 
If I haven't seen further, it is by standing in the footprints of giants

Re: Converting things to and from binary

ketil＠ii.uib.no