X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=Data%2FMaybe.hs;h=981d028d42443c95fec1bb053b9e8c3215a4c2d1;hb=487b9d4571a847ee0273b4627aaa135c46a51b8d;hp=0e8bef572ea0f17cf4317719fd49f472d6b2c3b1;hpb=fde71f72181bed62ed528e789d6cb0366e478b0b;p=ghc-base.git diff --git a/Data/Maybe.hs b/Data/Maybe.hs index 0e8bef5..981d028 100644 --- a/Data/Maybe.hs +++ b/Data/Maybe.hs @@ -1,4 +1,4 @@ -{-# OPTIONS_GHC -fno-implicit-prelude #-} +{-# OPTIONS_GHC -XNoImplicitPrelude #-} ----------------------------------------------------------------------------- -- | -- Module : Data.Maybe @@ -16,22 +16,21 @@ module Data.Maybe ( Maybe(Nothing,Just)-- instance of: Eq, Ord, Show, Read, - -- Functor, Monad, MonadPlus + -- Functor, Monad, MonadPlus - , maybe -- :: b -> (a -> b) -> Maybe a -> b + , maybe -- :: b -> (a -> b) -> Maybe a -> b - , isJust -- :: Maybe a -> Bool - , isNothing -- :: Maybe a -> Bool - , fromJust -- :: Maybe a -> a - , fromMaybe -- :: a -> Maybe a -> a + , isJust -- :: Maybe a -> Bool + , isNothing -- :: Maybe a -> Bool + , fromJust -- :: Maybe a -> a + , fromMaybe -- :: a -> Maybe a -> a , listToMaybe -- :: [a] -> Maybe a - , maybeToList -- :: Maybe a -> [a] - , catMaybes -- :: [Maybe a] -> [a] - , mapMaybe -- :: (a -> Maybe b) -> [a] -> [b] + , maybeToList -- :: Maybe a -> [a] + , catMaybes -- :: [Maybe a] -> [a] + , mapMaybe -- :: (a -> Maybe b) -> [a] -> [b] ) where #ifdef __GLASGOW_HASKELL__ -import {-# SOURCE #-} GHC.Err ( error ) import GHC.Base #endif @@ -44,7 +43,7 @@ import Maybe , fromJust , fromMaybe , listToMaybe - , maybeToList + , maybeToList , catMaybes , mapMaybe ) @@ -64,7 +63,7 @@ import Maybe -- monad, where all errors are represented by 'Nothing'. A richer -- error monad can be built using the 'Data.Either.Either' type. -data Maybe a = Nothing | Just a +data Maybe a = Nothing | Just a deriving (Eq, Ord) instance Functor Maybe where @@ -79,7 +78,7 @@ instance Monad Maybe where Nothing >> _ = Nothing return = Just - fail _ = Nothing + fail _ = Nothing -- --------------------------------------------------------------------------- -- Functions over Maybe