Safe Haskell | None |
---|---|
Language | Haskell2010 |
Optional values
- data OptionT m a
- type Option = OptionT Identity
- none :: String -> OptionT m a
- some :: Monad m => a -> OptionT m a
- guardO :: String -> Data Bool -> OptionT m ()
- guarded :: Monad m => String -> Data Bool -> a -> OptionT m a
- rebuildOption :: Monad m => Option a -> OptionT m a
- option :: Syntax b => (String -> b) -> (a -> b) -> Option a -> b
- caseOption :: Syntax b => Option a -> (String -> b) -> (a -> b) -> b
- fromSome :: Syntax a => Option a -> a
- optionM :: MonadComp m => (String -> m ()) -> (a -> m ()) -> Option a -> m ()
- caseOptionM :: MonadComp m => Option a -> (String -> m ()) -> (a -> m ()) -> m ()
- fromSomeM :: (Syntax a, MonadComp m) => Option a -> m a
- optionT :: MonadComp m => (String -> m ()) -> (a -> m ()) -> OptionT m a -> m ()
- caseOptionT :: MonadComp m => OptionT m a -> (String -> m ()) -> (a -> m ()) -> m ()
- fromSomeT :: (Syntax a, MonadComp m) => OptionT m a -> m a
Documentation
Transformer version of Option
MonadTrans OptionT Source # | |
Monad m => Monad (OptionT m) Source # | |
Monad m => Functor (OptionT m) Source # | |
Monad m => Applicative (OptionT m) Source # | |
Syntax a => Syntactic (Option a) Source # | |
MonadComp m => MonadComp (OptionT m) Source # | |
(Storable a, Syntax a, (~) * (StoreSize a) ()) => Storable (Option a) Source # | |
Syntax a => Forcible (Option a) Source # | |
type Internal (Option a) Source # | |
type Domain (Option a) Source # | |
type StoreRep (Option a) Source # | |
type StoreSize (Option a) Source # | |
type ValueRep (Option a) Source # | |
guarded :: Monad m => String -> Data Bool -> a -> OptionT m a Source #
Construct an Option
from a guard and a value. The value will not be
evaluated if the guard is false.
Deconstruct an Option
value
fromSome :: Syntax a => Option a -> a Source #
Extract the value of an Option
that is assumed to be present
Deconstruct an Option
value
fromSomeM :: (Syntax a, MonadComp m) => Option a -> m a Source #
Extract the value of an Option
that is assumed to be present
Deconstruct an OptionT
value
Deconstruct an OptionT
value