Safe Haskell | Safe |
---|---|

Language | Haskell2010 |

A strict version of the `Maybe`

type.

Import qualified, as in
```
import qualified Agda.Utils.Maybe.Strict as Strict
```

Copyright : (c) 2006-2007 Roman Leshchinskiy (c) 2013 Simon Meier License : BSD-style (see the file LICENSE)

Copyright : (c) 2014 Andreas Abel

## Synopsis

- maybe :: b -> (a -> b) -> Maybe a -> b
- fromMaybe :: a -> Maybe a -> a
- fromJust :: Maybe a -> a
- isNothing :: Maybe a -> Bool
- isJust :: Maybe a -> Bool
- data Maybe a
- toStrict :: Maybe a -> Maybe a
- toLazy :: Maybe a -> Maybe a
- listToMaybe :: [a] -> Maybe a
- maybeToList :: Maybe a -> [a]
- catMaybes :: [Maybe a] -> [a]
- mapMaybe :: (a -> Maybe b) -> [a] -> [b]
- unionMaybeWith :: (a -> a -> a) -> Maybe a -> Maybe a -> Maybe a
- unzipMaybe :: Maybe (a, b) -> (Maybe a, Maybe b)
- filterMaybe :: (a -> Bool) -> a -> Maybe a
- forMaybe :: [a] -> (a -> Maybe b) -> [b]
- caseMaybe :: Maybe a -> b -> (a -> b) -> b
- maybeM :: Monad m => m b -> (a -> m b) -> m (Maybe a) -> m b
- fromMaybeM :: Monad m => m a -> m (Maybe a) -> m a
- caseMaybeM :: Monad m => m (Maybe a) -> m b -> (a -> m b) -> m b
- ifJustM :: Monad m => m (Maybe a) -> (a -> m b) -> m b -> m b
- whenJust :: Monad m => Maybe a -> (a -> m ()) -> m ()
- whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()

# Documentation

The type of strict optional values.

## Instances

listToMaybe :: [a] -> Maybe a Source #

Analogous to `listToMaybe`

in Data.Maybe.

maybeToList :: Maybe a -> [a] Source #

Analogous to `maybeToList`

in Data.Maybe.

unionMaybeWith :: (a -> a -> a) -> Maybe a -> Maybe a -> Maybe a Source #

`unionWith`

for collections of size <= 1.

filterMaybe :: (a -> Bool) -> a -> Maybe a Source #

Filtering a singleton list.

filterMaybe p a =`listToMaybe`

(`filter`

p [a])

forMaybe :: [a] -> (a -> Maybe b) -> [b] Source #

Version of `mapMaybe`

with different argument ordering.

caseMaybeM :: Monad m => m (Maybe a) -> m b -> (a -> m b) -> m b Source #

ifJustM :: Monad m => m (Maybe a) -> (a -> m b) -> m b -> m b Source #

`caseMaybeM`

with flipped branches.

whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m () Source #

`caseMaybeM`

without the `Nothing`

case.

# Orphan instances

Applicative Maybe Source # | Note that strict Maybe is an |

Foldable Maybe Source # | |

fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |

Traversable Maybe Source # | |

Data a => Data (Maybe a) Source # | |

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Maybe a -> c (Maybe a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Maybe a) # toConstr :: Maybe a -> Constr # dataTypeOf :: Maybe a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe0 (c (Maybe a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe0 (c (Maybe a)) # gmapT :: (forall b. Data b => b -> b) -> Maybe a -> Maybe a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r # gmapQ :: (forall d. Data d => d -> u) -> Maybe a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Maybe a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # | |

Generic (Maybe a) Source # | |

Semigroup a => Semigroup (Maybe a) Source # | |

Semigroup a => Monoid (Maybe a) Source # | |

Binary a => Binary (Maybe a) Source # | |

NFData a => NFData (Maybe a) Source # | |

Null (Maybe a) Source # | |