At Wed, 13 Sep 2006 15:24:39 +0400,
Bulat Ziganshin wrote:
> because REAL code is somewhat larger than examples. try to rewrite the
> following:
>
> directory_blocks <- (`mapM` splitBy (opt_group_dir command)
> files_to_archive)
> ( \filesInOneDirectory -> do
> datablocks <- (`mapM` splitToSolidBlocks filesInOneDirectory)
> ( \filesInOneDataBlock -> do
> let compressor = map (freearcLimitDictionary$ clipToMaxInt
> totalBytes)
> (data_compressor filesInOneDataBlock)
> totalBytes = sum$ map (fiSize.cfFileInfo) filesInOneDataBlock
> copy_solid_block = isWholeSolidBlock filesInOneDataBlock
> writeBlock pipe DATA_BLOCK compressor copy_solid_block $ do
> dir <- if copy_solid_block then do
> sendP pipe (CopySolidBlock filesInOneDataBlock)
> return$ map fileWithCRC filesInOneDataBlock
> else if (compressor==[aFAKE_COMPRESSION]) then do
> sendP pipe (FakeFiles filesInOneDataBlock)
> return$ map (FileWithCRC 0 . cfFileInfo)
> filesInOneDataBlock
> else do
> mapMaybeM (read_file command bufOps decompress_pipe)
> filesInOneDataBlock
> processDir dir
> return dir
> )
> blocks_info <- replicateM (length datablocks) (getP backdoor)
> arcpos <- archiveGetPos archive
>
> writeControlBlock DIR_BLOCK dir_compressor $ do
> archiveWriteDir blocks_info arcpos receiveBuf sendBuf
> )
One transformation might be to get rid of the, if..then..else if..
like this:
do dir <- case () of
_ | copy_solid_block ->
do sendP pipe (CopySolidBlock
filesInOneDataBlock)
return$ map fileWithCRC filesInOneDataBlock
| (compressor==[aFAKE_COMPRESSION]) ->
do sendP pipe (FakeFiles filesInOneDataBlock)
return$ map (FileWithCRC 0 . cfFileInfo)
filesInOneDataBlock
| otherwise ->
mapMaybeM (read_file command bufOps
decompress_pipe) filesInOneDataBlock
Not sure if that is actually better or not :)
j.
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