3a639f2 · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

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Implement the Monad of No Return proposal

3a639f2Leon P Smith11 years ago

src/Database/PostgreSQL/Simple/Internal.hs+4−2

compare with master

unifiedsplit

@@ -4,7 +4,7 @@

4------------------------------------------------------------------------------

5-- |

6-- Module: Database.PostgreSQL.Simple.Internal

8-- License: BSD3

9-- Maintainer: Leon P Smith <leon@melding-monads.com>

10-- Stability: experimental

@@ -476,7 +476,9 @@ instance Alternative Conversion where

476 Errors _ -> (oka <|>) <$> runConversion mb conn

477

478instance Monad Conversion where

479− return a = Conversion $ \_conn -> return (return a)

479+#if !(MIN_VERSION_base(4,8,0))

480+ return = pure

481+#endif

480 m >>= f = Conversion $ \conn -> do

482 m >>= f = Conversion $ \conn -> do

481 oka <- runConversion m conn

483 oka <- runConversion m conn

482 case oka of

484 case oka of

src/Database/PostgreSQL/Simple/Ok.hs+5−2

@@ -1,10 +1,11 @@

1{-# LANGUAGE DeriveDataTypeable #-}

2{-# LANGUAGE DeriveFunctor #-}

3+{-# LANGUAGE CPP #-}

4------------------------------------------------------------------------------

5------------------------------------------------------------------------------

5-- |

6-- |

6-- Module : Database.PostgreSQL.Simple.Ok

7-- Module : Database.PostgreSQL.Simple.Ok

8-- License : BSD3

9-- License : BSD3

9--

10--

10-- Maintainer : leon@melding-monads.com

11-- Maintainer : leon@melding-monads.com

@@ -69,7 +70,9 @@ instance MonadPlus Ok where

69 mplus = (<|>)

70 mplus = (<|>)

71instance Monad Ok where

72instance Monad Ok where

73+#if !(MIN_VERSION_base(4,8,0))

72− return = Ok

74+ return = pure

75+#endif

74 Errors es >>= _ = Errors es

77 Errors es >>= _ = Errors es

75 Ok a >>= f = f a

78 Ok a >>= f = f a