From cef52ebf124dc85565e167b9b3b9dbd8d90b813e Mon Sep 17 00:00:00 2001
From: "Scott R. Parish" <sparish@peak6.com>
Date: Mon, 18 Jan 2010 15:03:25 -0600
Subject: [PATCH] BSON.lookup

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

diff --git a/Database/MongoDB/BSON.hs b/Database/MongoDB/BSON.hs
index fbcaa4a..105cb1b 100644
--- a/Database/MongoDB/BSON.hs
+++ b/Database/MongoDB/BSON.hs
@@ -30,10 +30,14 @@ module Database.MongoDB.BSON
      BsonDoc(..),
      toBsonDoc,
      BinarySubType(..),
+     -- * BsonDoc Operations
+     lookup,
      -- * Conversion
      fromBson, toBson
     )
 where
+import Prelude hiding (lookup)
+
 import Control.Monad
 import Data.Binary
 import Data.Binary.Get
@@ -88,6 +92,10 @@ newtype BsonDoc = BsonDoc {
 toBsonDoc :: [(L8.ByteString, BsonValue)] -> BsonDoc
 toBsonDoc = BsonDoc . Map.fromList
 
+-- | Return the BsonValue for given key, if any.
+lookup :: L8.ByteString -> BsonDoc -> Maybe BsonValue
+lookup k = Map.lookup k . fromBsonDoc
+
 data DataType =
     Data_min_key        | -- -1
     Data_number         | -- 1