4 files changed, 31 insertions, 12 deletions

diff --git a/bittorrent.cabal b/bittorrent.cabal
index 49f444e2..65e8208d 100644
--- a/bittorrent.cabal
+++ b/bittorrent.cabal
@@ -41,7 +41,7 @@ library
                      , RecordWildCards
   hs-source-dirs:      src
   exposed-modules:     Data.Torrent
-                     , Data.Torrent.Bitfield
+--                     , Data.Torrent.Bitfield
                      , Data.Torrent.Block
                      , Data.Torrent.InfoHash
                      , Data.Torrent.Layout
diff --git a/src/Data/Torrent/InfoHash.hs b/src/Data/Torrent/InfoHash.hs
index 5ec429b5..ac13aa6c 100644
--- a/src/Data/Torrent/InfoHash.hs
+++ b/src/Data/Torrent/InfoHash.hs
@@ -1,3 +1,12 @@
+-- |
+--   Copyright   :  (c) Sam Truzjan 2013
+--   License     :  BSD3
+--   Maintainer  :  pxqr.sta@gmail.com
+--   Stability   :  experimental
+--   Portability :  portable
+--
+--   Infohash is a unique identifier of torrent.
+--
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 module Data.Torrent.InfoHash
diff --git a/src/Data/Torrent/Layout.hs b/src/Data/Torrent/Layout.hs
index 6f0668f2..ea8fa894 100644
--- a/src/Data/Torrent/Layout.hs
+++ b/src/Data/Torrent/Layout.hs
@@ -5,7 +5,7 @@
 --   Stability   :  experimental
 --   Portability :  portable
 --
---
+--   Layout of files in torrent.
 --
 {-# LANGUAGE BangPatterns               #-}
 {-# LANGUAGE FlexibleInstances          #-}
diff --git a/src/Data/Torrent/Tree.hs b/src/Data/Torrent/Tree.hs
index 8c18041a..cf71c2ec 100644
--- a/src/Data/Torrent/Tree.hs
+++ b/src/Data/Torrent/Tree.hs
@@ -5,21 +5,25 @@
 --   Stability   :  experimental
 --   Portability :  portable
 --
+--   Directory tree can be used to easily manipulate file layout info.
+--
 {-# LANGUAGE FlexibleInstances  #-}
 {-# LANGUAGE TemplateHaskell    #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 module Data.Torrent.Tree
-       ( DirTree (..)
+       ( -- * Directory tree
+         DirTree (..)
+
+         -- * Construction
        , build
 
+         -- * Query
        , Data.Torrent.Tree.lookup
        , lookupDir
-
        , fileNumber
        , dirNumber
        ) where
 
-import Control.Arrow
 import Data.ByteString as BS
 import Data.ByteString.Char8 as BC
 import Data.Foldable
@@ -30,10 +34,12 @@ import Data.Monoid
 import Data.Torrent.Layout
 
 
+-- | 'DirTree' is more convenient form of 'LayoutInfo'.
 data DirTree a = Dir  { children :: Map ByteString (DirTree a) }
                | File { node     :: FileInfo a                 }
                  deriving Show
 
+-- | Build directory tree from a list of files.
 build :: LayoutInfo -> DirTree ()
 build SingleFile {liFile = FileInfo {..}} = Dir
     { children = M.singleton fiName (File fi) }
@@ -46,26 +52,30 @@ build MultiFile {..} = Dir $ M.singleton liDirName files
       where
         ent = File $ FileInfo fiLength fiMD5Sum ()
 
-decompress :: DirTree () -> [FileInfo ()]
-decompress = undefined
+--decompress :: DirTree () -> [FileInfo ()]
+--decompress = undefined
 
+-- | Lookup file by path.
 lookup :: [FilePath] -> DirTree a -> Maybe (DirTree a)
 lookup []        t      = Just t
 lookup (p : ps) (Dir m) | Just subTree <- M.lookup (BC.pack p) m
                         = Data.Torrent.Tree.lookup ps subTree
 lookup _         _      = Nothing
 
+-- | Lookup directory by path.
 lookupDir :: [FilePath] -> DirTree a -> Maybe [(ByteString, DirTree a)]
-lookupDir ps d
-  | Just subTree <- Data.Torrent.Tree.lookup ps d =
-    case subTree of
-      File _  -> Nothing
-      Dir  es -> Just $ M.toList es
+lookupDir ps d = do
+  subTree <- Data.Torrent.Tree.lookup ps d
+  case subTree of
+    File _  -> Nothing
+    Dir  es -> Just $ M.toList es
 
+-- | Get total count of files in directory and subdirectories.
 fileNumber :: DirTree a -> Sum Int
 fileNumber File {..} = Sum 1
 fileNumber Dir  {..} = foldMap fileNumber children
 
+-- | Get total count of directories in the directory and subdirectories.
 dirNumber :: DirTree a -> Sum Int
 dirNumber File {..} = Sum 0
 dirNumber Dir  {..} = Sum 1 <> foldMap dirNumber children