On Jan 29, 2007, at 16:38 , Ross Paterson wrote:
On Fri, Jan 26, 2007 at 01:51:01PM +1100, Donald Bruce Stewart wrote:
Binary: high performance, pure binary serialisation for
Haskell
---------------------------------------------------------------------
-
The Binary Strike Team is pleased to announce the release of a new,
pure, efficient binary serialisation library for Haskell, now
available
from Hackage:
tarball: http://hackage.haskell.org/cgi-bin/hackage-scripts/
package/binary/0.2
darcs: darcs get http://darcs.haskell.org/binary
haddocks: http://www.cse.unsw.edu.au/~dons/binary/Data-Binary.html
Remind me again: why do you need a Put monad, which always seems to
have
the argument type ()? Monoids really are underappreciated.
I don't know if that's the main reason, but monads give you do-
notation, which can be very nice when you are doing a long sequence
of puts. Here's an example from the tar package [1]:
putHeaderNoChkSum :: TarHeader -> Put
putHeaderNoChkSum hdr =
do let (filePrefix, fileSuffix) = splitLongPath 100 (tarFileName
hdr)
putString 100 $ fileSuffix
putOct 8 $ tarFileMode hdr
putOct 8 $ tarOwnerID hdr
putOct 8 $ tarGroupID hdr
putOct 12 $ tarFileSize hdr
putOct 12 $ let TOD s _ = tarModTime hdr in s
fill 8 $ ' ' -- dummy checksum
putTarFileType $ tarFileType hdr
putString 100 $ tarLinkTarget hdr -- FIXME: take suffix
split at / if too long
putString 6 $ "ustar "
putString 2 $ " " -- strange ustar version
putString 32 $ tarOwnerName hdr
putString 32 $ tarGroupName hdr
putOct 8 $ tarDeviceMajor hdr
putOct 8 $ tarDeviceMinor hdr
putString 155 $ filePrefix
fill 12 $ '\NUL'
I guess mconcat [putX, putY, ... ] would work too, but the syntax is
not quite as nice.
/Björn
[1]
http://www.cs.chalmers.se/~bringert/darcs/tar/_______________________________________________
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