From bd3bbbf8d778b79b0eabba04c7b9ae83a643ca65 Mon Sep 17 00:00:00 2001
From: Sam T <pxqr.sta@gmail.com>
Date: Mon, 26 Aug 2013 22:21:18 +0400
Subject: + Document generics.

---
 src/Data/BEncode.hs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'src/Data/BEncode.hs')

diff --git a/src/Data/BEncode.hs b/src/Data/BEncode.hs
index f41e4b8..d18d787 100644
--- a/src/Data/BEncode.hs
+++ b/src/Data/BEncode.hs
@@ -158,6 +158,28 @@ type Result = Either String
 
 -- | This class is used to define new datatypes that could be easily
 -- serialized using bencode format.
+--
+--   By default 'BEncodable' have a generic implementation; suppose
+--   the following datatype:
+--
+-- > data List a = Cons { _head  :: a
+-- >                    , __tail :: (List a) }
+-- >             | Nil
+-- >               deriving Generic
+--
+--   If we don't need to obey any particular specification or
+--   standard, the default instance could be derived automatically
+--   from the 'Generic' instance:
+--
+-- > instance BEncodable a => BEncodable (List a)
+--
+--   Example of derived 'toBEncode' result:
+--
+-- > > toBEncode (Cons 123 $ Cons 1 Nil)
+-- > BDict (fromList [("head",BInteger 123),("tail",BList [])])
+--
+--  Note that '_' prefixes are omitted.
+--
 class BEncodable a where
   -- | See an example of implementation here 'Assoc'
   toBEncode   :: a -> BEncode
-- 
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