-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Partial functions from the prelude with a MonadFailure interface
--   
--   Partial functions from the base library, such as <tt>head</tt> and
--   <tt>!!</tt>, modified to fail in a <tt>MonadFailure</tt> monad. These
--   functions can be used to reduce the number of unsafe pattern matches
--   in your code.
@package safe-failure
@version 0.2


-- | A library for safe functions, based on standard functions that may
--   crash.
--   
--   This module reexports versions which produce exceptions in an
--   arbitrary <a>MonadFailure</a> monad.
module Safe.Failure
head :: (MonadFailure HeadFailure m) => [a] -> m a
tail :: (MonadFailure TailFailure m) => [a] -> m [a]
init :: (MonadFailure InitFailure m) => [a] -> m [a]
last :: (MonadFailure LastFailure m) => [a] -> m a
minimum :: (Ord a, MonadFailure MinimumFailure m) => [a] -> m a
maximum :: (Ord a, MonadFailure MaximumFailure m) => [a] -> m a
foldr1 :: (MonadFailure Foldr1Failure m) => (a -> a -> a) -> [a] -> m a
foldl1 :: (MonadFailure Foldl1Failure m) => (a -> a -> a) -> [a] -> m a
at :: (MonadFailure IndexFailure m) => [a] -> Int -> m a

-- | <pre>
--   lookupJust key = fromJust . lookup key
--   </pre>
lookup :: (Eq a, MonadFailure (LookupFailure a) m) => a -> [(a, b)] -> m b
fromJust :: (MonadFailure FromJustFailure m) => Maybe a -> m a
read :: (Read a, MonadFailure ReadFailure m) => String -> m a

-- | <tt>def</tt>, use it to return a default value in the event of an
--   error.
--   
--   E.g. you can define a version of <tt>tail</tt> which returns a default
--   value when the list is empty
--   
--   <pre>
--   tailDef defaultValue = def defaultValue . tail
--   </pre>
def :: a -> Maybe a -> a

-- | <tt>note</tt>, use it to fail with an annotated runtime error
note :: (Exception e) => String -> Either e a -> a

-- | Assert a value to be true. If true, returns the first value as a
--   succss. Otherwise, returns the second value as a failure.
assert :: (MonadFailure e m, Exception e) => Bool -> v -> e -> m v

-- | The standard readFile function with any <a>IOException</a>s returned
--   as a failure instead of a runtime exception.
readFile :: (MonadFailure IOException m, MonadIO m) => FilePath -> m String
data SafeException
SafeException :: e -> SafeException
data HeadFailure
HeadFailure :: HeadFailure
data TailFailure
TailFailure :: TailFailure
data InitFailure
InitFailure :: InitFailure
data LastFailure
LastFailure :: LastFailure
data MaximumFailure
MaximumFailure :: MaximumFailure
data MinimumFailure
MinimumFailure :: MinimumFailure
data Foldl1Failure
Foldl1Failure :: Foldl1Failure
data Foldr1Failure
Foldr1Failure :: Foldr1Failure
data IndexFailure
IndexFailure :: Int -> IndexFailure
data LookupFailure a
LookupFailure :: a -> LookupFailure a
data FromJustFailure
FromJustFailure :: FromJustFailure
data ReadFailure
ReadFailure :: String -> ReadFailure
instance Typeable1 LookupFailure
instance Typeable ReadFailure
instance Typeable IndexFailure
instance Typeable FromJustFailure
instance Typeable Foldl1Failure
instance Typeable Foldr1Failure
instance Typeable MaximumFailure
instance Typeable MinimumFailure
instance Typeable LastFailure
instance Typeable HeadFailure
instance Typeable InitFailure
instance Typeable TailFailure
instance Typeable SafeException
instance (Show a) => Show (LookupFailure a)
instance Show ReadFailure
instance Show IndexFailure
instance Show FromJustFailure
instance Show Foldl1Failure
instance Show Foldr1Failure
instance Show MaximumFailure
instance Show MinimumFailure
instance Show LastFailure
instance Show HeadFailure
instance Show InitFailure
instance Show TailFailure
instance (Typeable a, Show a) => Throws (LookupFailure a) (Caught SafeException l)
instance Throws ReadFailure (Caught SafeException l)
instance Throws IndexFailure (Caught SafeException l)
instance Throws FromJustFailure (Caught SafeException l)
instance Throws Foldl1Failure (Caught SafeException l)
instance Throws Foldr1Failure (Caught SafeException l)
instance Throws MaximumFailure (Caught SafeException l)
instance Throws MinimumFailure (Caught SafeException l)
instance Throws LastFailure (Caught SafeException l)
instance Throws InitFailure (Caught SafeException l)
instance Throws HeadFailure (Caught SafeException l)
instance Throws TailFailure (Caught SafeException l)
instance (Typeable a, Show a) => Exception (LookupFailure a)
instance Exception ReadFailure
instance Exception IndexFailure
instance Exception FromJustFailure
instance Exception Foldl1Failure
instance Exception Foldr1Failure
instance Exception MaximumFailure
instance Exception MinimumFailure
instance Exception LastFailure
instance Exception HeadFailure
instance Exception InitFailure
instance Exception TailFailure
instance Exception SafeException
instance Show SafeException