From 2c6905b45fc9c59bd4c39d92f7defb47dff13e3b Mon Sep 17 00:00:00 2001
From: "Scott R. Parish" <sparish@peak6.com>
Date: Mon, 18 Jan 2010 18:32:44 -0600
Subject: [PATCH] BSON.empty

---
 Database/MongoDB/BSON.hs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Database/MongoDB/BSON.hs b/Database/MongoDB/BSON.hs
index ed51d13..d7907d5 100644
--- a/Database/MongoDB/BSON.hs
+++ b/Database/MongoDB/BSON.hs
@@ -31,7 +31,7 @@ module Database.MongoDB.BSON
      toBsonDoc,
      BinarySubType(..),
      -- * BsonDoc Operations
-     lookup,
+     empty, lookup,
      -- * Conversion
      fromBson, toBson
     )
@@ -43,7 +43,7 @@ import Data.Binary
 import Data.Binary.Get
 import Data.Binary.IEEE754
 import Data.Binary.Put
-import Data.ByteString.Char8 as C8
+import Data.ByteString.Char8 as C8 hiding (empty)
 import qualified Data.ByteString.Lazy as L
 import qualified Data.ByteString.Lazy.UTF8 as L8
 import qualified Data.ByteString.UTF8 as S8
@@ -96,6 +96,10 @@ class BsonDocOps a where
     -- | Return the BsonValue for given key, if any.
     lookup :: a -> BsonDoc -> Maybe BsonValue
 
+-- | An empty BsonDoc
+empty :: BsonDoc
+empty = BsonDoc Map.empty
+
 instance BsonDocOps L8.ByteString where
     toBsonDoc = BsonDoc . Map.fromList
     fromBsonDoc = bdFromBsonDoc