@@ -12,7 +12,10 @@
12-- returned by a SQL query into a more useful Haskell representation.
12-- returned by a SQL query into a more useful Haskell representation.
14-- Predefined instances are provided for tuples containing up to ten
14-- Predefined instances are provided for tuples containing up to ten
15−-- elements.
15+-- elements. The instances for 'Maybe' types return 'Nothing' if all
16+-- the columns that would have been otherwise consumed are null, otherwise
17+-- it attempts a regular conversion.
16------------------------------------------------------------------------------
19------------------------------------------------------------------------------
18module Database.PostgreSQL.Simple.FromRow
21module Database.PostgreSQL.Simple.FromRow
@@ -26,11 +29,14 @@ module Database.PostgreSQL.Simple.FromRow
26import Prelude hiding (null)
29import Prelude hiding (null)
27import Control.Applicative (Applicative(..), (<$>), (<|>), (*>))
30import Control.Applicative (Applicative(..), (<$>), (<|>), (*>))
28import Control.Monad (replicateM, replicateM_)
31import Control.Monad (replicateM, replicateM_)
32+import Control.Monad.Trans.State.Strict
33+import Control.Monad.Trans.Reader
34+import Control.Monad.Trans.Class
29import Data.ByteString (ByteString)
35import Data.ByteString (ByteString)
30import qualified Data.ByteString.Char8 as B
36import qualified Data.ByteString.Char8 as B
31import Data.Vector (Vector)
37import Data.Vector (Vector)
32import qualified Data.Vector as V
38import qualified Data.Vector as V
33−import Database.PostgreSQL.Simple.Types (Only(..))
39+import Database.PostgreSQL.Simple.Types (Only(..))
34import qualified Database.PostgreSQL.LibPQ as PQ
40import qualified Database.PostgreSQL.LibPQ as PQ
35import Database.PostgreSQL.Simple.Internal
41import Database.PostgreSQL.Simple.Internal
36import Database.PostgreSQL.Simple.Compat
42import Database.PostgreSQL.Simple.Compat
@@ -39,10 +45,6 @@ import Database.PostgreSQL.Simple.Ok
39import Database.PostgreSQL.Simple.Types ((:.)(..), Null)
45import Database.PostgreSQL.Simple.Types ((:.)(..), Null)
40import Database.PostgreSQL.Simple.TypeInfo
46import Database.PostgreSQL.Simple.TypeInfo
42−import Control.Monad.Trans.State.Strict
43−import Control.Monad.Trans.Reader
44−import Control.Monad.Trans.Class
46-- | A collection type that can be converted from a sequence of fields.
48-- | A collection type that can be converted from a sequence of fields.
47-- Instances are provided for tuples up to 10 elements and lists of any length.
49-- Instances are provided for tuples up to 10 elements and lists of any length.