Fix documentation for access function

CHANGELOG.md

@@ -2,6 +2,11 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Package Versioning Policy](https://wiki.haskell.org/Package_versioning_policy).
 
+## [2.3.0] - unreleased
+
+### Changed
+- Description of access function
+
 ## [2.2.0] - 2017-04-08
 
 ### Added

Database/MongoDB/Query.hs

@@ -116,7 +116,8 @@ type Action = ReaderT MongoContext
 -- ^ A monad on top of m (which must be a MonadIO) that may access the database and may fail with a DB 'Failure'
 
 access :: (MonadIO m) => Pipe -> AccessMode -> Database -> Action m a -> m a
--- ^ Run action against database on server at other end of pipe. Use access mode for any reads and writes. Return Left on connection failure or read/write failure.
+-- ^ Run action against database on server at other end of pipe. Use access mode for any reads and writes.
+-- Throw 'Failure' in case of any error.
 access mongoPipe mongoAccessMode mongoDatabase action = runReaderT action MongoContext{..}
 
 -- | A connection failure, or a read or write exception like cursor expired or inserting a duplicate key.

doc/tutorial.md

@@ -35,7 +35,7 @@ A DB read or write operation is called a DB `Action`. A DB Action is a monad so
 
 	> access pipe master "test" allCollections
 
-`access` return either Left `Failure` or Right result. Failure means there was a connection failure, or a read/write failure like cursor expired or duplicate key insert.
+`access` throw `Failure` if there is any issue. Failure means there was a connection failure, or a read/write failure like cursor expired or duplicate key insert.
 
 `master` is an `AccessMode`. Access mode indicates how reads and writes will be performed. Its three modes are: `ReadStaleOk`, `UnconfirmedWrites`, and `ConfirmWrites GetLastErrorParams`. `master` is just short hand for `ConfirmWrites []`. The first mode may be used against a slave or a master server, the last two must be used against a master server.