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.