2 files changed, 13 insertions, 6 deletions

diff --git a/src/Network/BitTorrent/PeerWire/Bitfield.hs b/src/Network/BitTorrent/PeerWire/Bitfield.hs
index 2baeb516..9d88e784 100644
--- a/src/Network/BitTorrent/PeerWire/Bitfield.hs
+++ b/src/Network/BitTorrent/PeerWire/Bitfield.hs
@@ -18,6 +18,7 @@ module Network.BitTorrent.PeerWire.Bitfield
 
          -- * Construction
        , empty, full
+       , toList
        , fromByteString, toByteString
 
          -- * Query
@@ -62,6 +63,13 @@ full :: Int -> Bitfield
 full n = MkBitfield $ B.replicate (sizeInBase n 8)  (complement 0)
 {-# INLINE full #-}
 
+toList :: Bitfield -> [Bool]
+toList (MkBitfield bs) = concatMap unpkg (B.unpack bs)
+  where
+    unpkg :: Word8 -> [Bool]
+    unpkg byte = L.map (testBit byte) [0..bitSize (undefined :: Word8) - 1]
+{-# INLINE toList #-}
+
 fromByteString :: ByteString -> Bitfield
 fromByteString = MkBitfield
 {-# INLINE fromByteString #-}
@@ -278,5 +286,5 @@ findMax (MkBitfield b) = do
 
 {-# INLINE findMax #-}
 
-frequencies :: [Bitfield] -> UArray PieceIx Int
-frequencies = undefined
+frequencies :: [Bitfield] -> [Int]
+frequencies xs = foldr1 (zipWith (+)) $ map (map fromEnum . toList) xs
diff --git a/src/Network/BitTorrent/PeerWire/Selection.hs b/src/Network/BitTorrent/PeerWire/Selection.hs
index 2e412e06..92285501 100644
--- a/src/Network/BitTorrent/PeerWire/Selection.hs
+++ b/src/Network/BitTorrent/PeerWire/Selection.hs
@@ -48,11 +48,10 @@ strictLast h a _ = findMax (difference a h)
 
 -- |
 rarestFirst :: Selector
-rarestFirst h a xs = error "rarestFirst"
-    -- rarest (frequencies (map (intersection want) xs))
+rarestFirst h a xs = rarest (frequencies (map (intersection want) xs))
   where
     want = difference h a
-    rarest = undefined
+    rarest = Just . head
 
 -- | In general random first is faster than rarest first strategy but
 --    only if all pieces are available.
@@ -62,7 +61,7 @@ randomFirst = do
   error "randomFirst"
 
 endGame :: Selector
-endGame = undefined
+endGame = strictLast
 
 autoSelector :: Selector
 autoSelector = undefined