8ea1c2f · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

Borrow :. from ozataman

See commit cd76bea27a9c1c2c83a32ae11d5882f60836c2d1

commit8ea1c2fcda434784b9ddb3ed95db27ac3549b081 authorLeon P Smith <leon@melding-monads.com> dateFri 4 May 2012, 15:47 (14 years ago) parent9014819

3 files changed+29

compare with master

unifiedsplit

postgresql-simple.cabal+1 src/Database/PostgreSQL/Simple/FromRow.hs+4 src/Database/PostgreSQL/Simple/Types.hs+24

postgresql-simple.cabal+1

@@ -52,6 +52,7 @@ Library

5252 vector

5353

5454 extensions: DoAndIfThenElse, OverloadedStrings, BangPatterns, ViewPatterns

55+ TypeOperators

5556

5657 ghc-options: -Wall -fno-warn-name-shadowing

5758

src/Database/PostgreSQL/Simple/FromRow.hs+4

@@ -33,6 +33,7 @@ import Database.PostgreSQL.Simple.Ok

3333import qualified Database.PostgreSQL.LibPQ as PQ

3434import Database.PostgreSQL.Simple.Internal

3535import Database.PostgreSQL.Simple.FromField

36+import Database.PostgreSQL.Simple.Types

3637

3738import Control.Monad.Trans.State.Strict

3839import Control.Monad.Trans.Reader

@@ -150,3 +151,6 @@ instance FromField a => FromRow [a] where

150151 fromRow = do

151152 n <- numFieldsRemaining

152153 replicateM n field

154+

155+instance (FromRow a, FromRow b) => FromRow (a :. b) where

156+ fromRow = (:.) <$> fromRow <*> fromRow

src/Database/PostgreSQL/Simple/Types.hs+24

@@ -1,5 +1,6 @@

11{-# LANGUAGE DeriveDataTypeable, DeriveFunctor, GeneralizedNewtypeDeriving #-}

3+------------------------------------------------------------------------------

34-- |

45-- Module: Database.PostgreSQL.Simple.Types

@@ -10,6 +11,8 @@

1011-- Portability: portable

1112--

1213-- Basic types.

14+--

15+------------------------------------------------------------------------------

1316

1417module Database.PostgreSQL.Simple.Types

1518 (

@@ -19,6 +22,7 @@ module Database.PostgreSQL.Simple.Types

1922 , Binary(..)

2023 , Query(..)

2124 , Oid(..)

25+ , (:.)(..)

2226 ) where

2327

2428import Blaze.ByteString.Builder (toByteString)

@@ -106,3 +110,23 @@ newtype In a = In a

106110-- | Wrap a mostly-binary string to be escaped in hexadecimal.

107111newtype Binary a = Binary a

108112 deriving (Eq, Ord, Read, Show, Typeable, Functor)

113+

114+-- | A composite type to parse your custom data structures without

115+-- having to define dummy newtype wrappers every time.

116+--

117+--

118+-- > instance FromRow MyData where ...

119+--

120+-- > instance FromRow MyData2 where ...

121+--

122+--

123+-- then I can do the following for free:

124+--

125+-- @

126+-- res <- query' c "..."

127+-- forM res $ \\(MyData{..} :. MyData2{..}) -> do

128+-- ....

129+-- @

130+data h :. t = h :. t deriving (Eq,Ord,Show,Read,Typeable)

131+

132+infixr 3 :.