Alexy Khrabrov wrote:
Reflecting why it's harder to pick up Haskell than say Ruby or Python, here's what I found -- those languages deal with a typical domain available to any programmer -- his own computer/system/shell. The artifacts are files, directories, timestamps, etc. The stuff every programmer understands in their sleep. APIs. So I loved the shell-script beautification thread.
Note that there is an inherent difficulty with files, directories, pipes: they are not purely functional in style. While it's unavoidable that writeFile :: FilePath -> String -> IO () is in IO, I think that readFile :: FilePath -> IO String would not need to be in IO if the file system would be persistent (not ephemeral). Pipes are an ugly way to implement lazy evaluation. For instance, take the pipe "ls -l | grep '*.hs'". To achieve the effect that "grep" immediately feeds on the data "ls -l" spits out, both programs are run concurrently and blocking keeps in line. This does not generalize so well to multiple data sources, something lazy evaluation has no problems with. And one of the main problems is that current OS see programs as things of type "String -> IO String". Of course, pure and strongly typed programs would be preferred. So, instead of calling system ("ghc -O2 -c " ++ show filepath) we want GHC.desugar :: GHC.Haskell' -> GHC.Core GHC.optimize :: GHC.Core -> GHC.Core GHC.assemble :: GHC.Core -> OS.Program In a sense, current OS are not ready for Haskell yet. Regards, apfelmus