Moduleerrors-2.3.0Haskell98

Control.Error.Safe

This module extends the safe library's functions with corresponding versions compatible with Either and ExceptT, and also provides a few Maybe-compatible functions missing from safe.

I suffix the Either-compatible functions with Err and prefix the ExceptT-compatible functions with try.

Note that this library re-exports the Maybe compatible functions from safe in the Control.Error module, so they are not provided here.

The 'Z'-suffixed functions generalize the Maybe functions to also work with anything that implements MonadPlus, including:

Lists
Most parsers
ExceptT (if the left value is a Monoid)

Contents

Maybe-compatible functions
Either-compatible functions
ExceptT-compatible functions
MonadPlus-compatible functions

Synopsis

value assertMay
value rightMay
value tailErr
value initErr
value headErr
value lastErr
value minimumErr
value maximumErr
value foldr1Err
value foldl1Err
value foldl1Err'
value atErr
value readErr
value assertErr
value justErr
value tryTail
value tryInit
value tryHead
value tryLast
value tryMinimum
value tryMaximum
value tryFoldr1
value tryFoldl1
value tryFoldl1'
value tryAt
value tryRead
value tryAssert
value tryJust
value tryRight
value tailZ
value initZ
value headZ
value lastZ
value minimumZ
value maximumZ
value foldr1Z
value foldl1Z
value foldl1Z'
value atZ
value readZ
value assertZ
value justZ
value rightZ

Packageerrors-2.3.0
Exports43
LanguageHaskell98
LicenceBSD-3-Clause
SourceSafe.hs

Maybe-compatible functions

valueassertMay :: Bool -> Maybe ()

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An assertion that fails in the Maybe monad

valuerightMay :: Either e a -> Maybe a

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A fromRight that fails in the Maybe monad

Either-compatible functions

valuetailErr :: e -> [a] -> Either e [a]

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A tail that fails in the Either monad

valueinitErr :: e -> [a] -> Either e [a]

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An init that fails in the Either monad

valueheadErr :: e -> [a] -> Either e a

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A head that fails in the Either monad

valuelastErr :: e -> [a] -> Either e a

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A last that fails in the Either monad

valueminimumErr :: Ord a => e -> [a] -> Either e a

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A minimum that fails in the Either monad

valuemaximumErr :: Ord a => e -> [a] -> Either e a

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A maximum that fails in the Either monad

valuefoldr1Err :: e -> (a -> a -> a) -> [a] -> Either e a

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A foldr1 that fails in the Either monad

valuefoldl1Err :: e -> (a -> a -> a) -> [a] -> Either e a

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A foldl1 that fails in the Either monad

valuefoldl1Err' :: e -> (a -> a -> a) -> [a] -> Either e a

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A foldl1' that fails in the Either monad

valueatErr :: e -> [a] -> Int -> Either e a

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A (!!) that fails in the Either monad

valuereadErr :: Read a => e -> String -> Either e a

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A read that fails in the Either monad

valueassertErr :: e -> Bool -> Either e ()

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An assertion that fails in the Either monad

valuejustErr :: e -> Maybe a -> Either e a

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A fromJust that fails in the Either monad

ExceptT-compatible functions

valuetryTail :: Monad m => e -> [a] -> ExceptT e m [a]

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A tail that fails in the ExceptT monad

valuetryInit :: Monad m => e -> [a] -> ExceptT e m [a]

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An init that fails in the ExceptT monad

valuetryHead :: Monad m => e -> [a] -> ExceptT e m a

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A head that fails in the ExceptT monad

valuetryLast :: Monad m => e -> [a] -> ExceptT e m a

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A last that fails in the ExceptT monad

valuetryMinimum :: (Monad m, Ord a) => e -> [a] -> ExceptT e m a

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A minimum that fails in the ExceptT monad

valuetryMaximum :: (Monad m, Ord a) => e -> [a] -> ExceptT e m a

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A maximum that fails in the ExceptT monad

valuetryFoldr1 :: Monad m => e -> (a -> a -> a) -> [a] -> ExceptT e m a

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A foldr1 that fails in the ExceptT monad

valuetryFoldl1 :: Monad m => e -> (a -> a -> a) -> [a] -> ExceptT e m a

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A foldl1 that fails in the ExceptT monad

valuetryFoldl1' :: Monad m => e -> (a -> a -> a) -> [a] -> ExceptT e m a

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A foldl1' that fails in the ExceptT monad

valuetryAt :: Monad m => e -> [a] -> Int -> ExceptT e m a

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A (!!) that fails in the ExceptT monad

valuetryRead :: (Monad m, Read a) => e -> String -> ExceptT e m a

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A read that fails in the ExceptT monad

valuetryAssert :: Monad m => e -> Bool -> ExceptT e m ()

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An assertion that fails in the ExceptT monad

valuetryJust :: Monad m => e -> Maybe a -> ExceptT e m a

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A fromJust that fails in the ExceptT monad

valuetryRight :: Monad m => Either e a -> ExceptT e m a

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A fromRight that fails in the ExceptT monad

MonadPlus-compatible functions

valuetailZ :: MonadPlus m => [a] -> m [a]

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A tail that fails using mzero

valueinitZ :: MonadPlus m => [a] -> m [a]

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An init that fails using mzero

valueheadZ :: MonadPlus m => [a] -> m a

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A head that fails using mzero

valuelastZ :: MonadPlus m => [a] -> m a

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A last that fails using mzero

valueminimumZ :: (MonadPlus m, Ord a) => [a] -> m a

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A minimum that fails using mzero

valuemaximumZ :: (MonadPlus m, Ord a) => [a] -> m a

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A maximum that fails using mzero

valuefoldr1Z :: MonadPlus m => (a -> a -> a) -> [a] -> m a

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A foldr1 that fails using mzero

valuefoldl1Z :: MonadPlus m => (a -> a -> a) -> [a] -> m a

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A foldl1 that fails using mzero

valuefoldl1Z' :: MonadPlus m => (a -> a -> a) -> [a] -> m a

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A foldl1' that fails using mzero

valueatZ :: MonadPlus m => [a] -> Int -> m a

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A (!!) that fails using mzero

valuereadZ :: (MonadPlus m, Read a) => String -> m a

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A read that fails using mzero

valueassertZ :: MonadPlus m => Bool -> m ()

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An assertion that fails using mzero

valuejustZ :: MonadPlus m => Maybe a -> m a

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A fromJust that fails using mzero

valuerightZ :: MonadPlus m => Either e a -> m a

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A fromRight that fails using mzero