| Copyright | (c) Fumiaki Kinoshita 2020 |
|---|---|
| License | BSD3 |
| Maintainer | Fumiaki Kinoshita <fumiexcel@gmail.com> |
| Stability | provisional |
| Portability | non-portable |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Witherable
Contents
Description
Synopsis
- class Functor f => Filterable f where
- (<$?>) :: Filterable f => (a -> Maybe b) -> f a -> f b
- (<&?>) :: Filterable f => f a -> (a -> Maybe b) -> f b
-
class
(
Traversable
t,
Filterable
t) =>
Witherable
t
where
- wither :: Applicative f => (a -> f ( Maybe b)) -> t a -> f (t b)
- witherM :: Monad m => (a -> m ( Maybe b)) -> t a -> m (t b)
- filterA :: Applicative f => (a -> f Bool ) -> t a -> f (t a)
- witherMap :: Applicative m => (t b -> r) -> (a -> m ( Maybe b)) -> t a -> m r
- ordNub :: ( Witherable t, Ord a) => t a -> t a
- ordNubOn :: ( Witherable t, Ord b) => (a -> b) -> t a -> t a
- hashNub :: ( Witherable t, Eq a, Hashable a) => t a -> t a
- hashNubOn :: ( Witherable t, Eq b, Hashable b) => (a -> b) -> t a -> t a
- forMaybe :: ( Witherable t, Applicative f) => t a -> (a -> f ( Maybe b)) -> f (t b)
- class ( FunctorWithIndex i t, Filterable t) => FilterableWithIndex i t | t -> i where
-
class
(
TraversableWithIndex
i t,
Witherable
t) =>
WitherableWithIndex
i t | t -> i
where
- iwither :: Applicative f => (i -> a -> f ( Maybe b)) -> t a -> f (t b)
- iwitherM :: Monad m => (i -> a -> m ( Maybe b)) -> t a -> m (t b)
- ifilterA :: Applicative f => (i -> a -> f Bool ) -> t a -> f (t a)
-
newtype
WrappedFoldable
f a =
WrapFilterable
{
- unwrapFoldable :: f a
Documentation
class Functor f => Filterable f where Source #
Like
Functor
, but you can remove elements instead of updating them.
Formally, the class
Filterable
represents a functor from
Kleisli Maybe
to
Hask
.
A definition of
mapMaybe
must satisfy the following laws:
Methods
mapMaybe :: (a -> Maybe b) -> f a -> f b Source #
Like
mapMaybe
.
Instances
(<$?>) :: Filterable f => (a -> Maybe b) -> f a -> f b infixl 4 Source #
(<&?>) :: Filterable f => f a -> (a -> Maybe b) -> f b infixl 1 Source #
class ( Traversable t, Filterable t) => Witherable t where Source #
An enhancement of
Traversable
with
Filterable
A definition of
wither
must satisfy the following laws:
- identity
-
wither(Identity. Just) ≡Identity - composition
-
Compose.fmap(witherf) .witherg ≡wither(Compose.fmap(witherf) . g)
Parametricity implies the naturality law:
- naturality
-
t .witherf ≡wither(t . f)Where
tis an / applicative transformation / in the sense described in theTraversabledocumentation.
In the relation to superclasses, these should satisfy too:
- conservation
-
wither(fmapJust . f) =traversef - pure filter
-
wither(Identity. f) =Identity.mapMaybef
See the
Properties.md
and
Laws.md
files in the git distribution for more
in-depth explanation about properties of
Witherable
containers.
The laws and restrictions are enough to
constrain
to be uniquely determined as the following default implementation.
wither
wither f = fmapcatMaybes.traversef
If not to provide better-performing implementation,
it's not necessary to implement any one method of
Witherable
. For example, if a type constructor
T
already has instances of
Traversable
and
Filterable
,
the next one line is sufficient to provide the
Witherable T
instance.
instance Witherable T
Minimal complete definition
Nothing
Methods
wither :: Applicative f => (a -> f ( Maybe b)) -> t a -> f (t b) Source #
witherM :: Monad m => (a -> m ( Maybe b)) -> t a -> m (t b) Source #
Monadic variant of wither. This may have more efficient implementation.
filterA :: Applicative f => (a -> f Bool ) -> t a -> f (t a) Source #
witherMap :: Applicative m => (t b -> r) -> (a -> m ( Maybe b)) -> t a -> m r Source #
Instances
| Witherable [] Source # |
Methods are good consumers for fusion. |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> [a] -> f [b] Source # witherM :: Monad m => (a -> m ( Maybe b)) -> [a] -> m [b] Source # filterA :: Applicative f => (a -> f Bool ) -> [a] -> f [a] Source # witherMap :: Applicative m => ([b] -> r) -> (a -> m ( Maybe b)) -> [a] -> m r Source # |
|
| Witherable Maybe Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Maybe a -> f ( Maybe b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Maybe a -> m ( Maybe b) Source # filterA :: Applicative f => (a -> f Bool ) -> Maybe a -> f ( Maybe a) Source # witherMap :: Applicative m => ( Maybe b -> r) -> (a -> m ( Maybe b)) -> Maybe a -> m r Source # |
|
| Witherable Option Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Option a -> f ( Option b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Option a -> m ( Option b) Source # filterA :: Applicative f => (a -> f Bool ) -> Option a -> f ( Option a) Source # witherMap :: Applicative m => ( Option b -> r) -> (a -> m ( Maybe b)) -> Option a -> m r Source # |
|
| Witherable ZipList Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> ZipList a -> f ( ZipList b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> ZipList a -> m ( ZipList b) Source # filterA :: Applicative f => (a -> f Bool ) -> ZipList a -> f ( ZipList a) Source # witherMap :: Applicative m => ( ZipList b -> r) -> (a -> m ( Maybe b)) -> ZipList a -> m r Source # |
|
| Witherable IntMap Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> IntMap a -> f ( IntMap b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> IntMap a -> m ( IntMap b) Source # filterA :: Applicative f => (a -> f Bool ) -> IntMap a -> f ( IntMap a) Source # witherMap :: Applicative m => ( IntMap b -> r) -> (a -> m ( Maybe b)) -> IntMap a -> m r Source # |
|
| Witherable Seq Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Seq a -> f ( Seq b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Seq a -> m ( Seq b) Source # filterA :: Applicative f => (a -> f Bool ) -> Seq a -> f ( Seq a) Source # witherMap :: Applicative m => ( Seq b -> r) -> (a -> m ( Maybe b)) -> Seq a -> m r Source # |
|
| Witherable Vector Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Vector a -> f ( Vector b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Vector a -> m ( Vector b) Source # filterA :: Applicative f => (a -> f Bool ) -> Vector a -> f ( Vector a) Source # witherMap :: Applicative m => ( Vector b -> r) -> (a -> m ( Maybe b)) -> Vector a -> m r Source # |
|
| Monoid e => Witherable ( Either e) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Either e a -> f ( Either e b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Either e a -> m ( Either e b) Source # filterA :: Applicative f => (a -> f Bool ) -> Either e a -> f ( Either e a) Source # witherMap :: Applicative m => ( Either e b -> r) -> (a -> m ( Maybe b)) -> Either e a -> m r Source # |
|
| Witherable ( V1 :: Type -> Type ) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> V1 a -> f ( V1 b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> V1 a -> m ( V1 b) Source # filterA :: Applicative f => (a -> f Bool ) -> V1 a -> f ( V1 a) Source # witherMap :: Applicative m => ( V1 b -> r) -> (a -> m ( Maybe b)) -> V1 a -> m r Source # |
|
| Witherable ( U1 :: Type -> Type ) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> U1 a -> f ( U1 b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> U1 a -> m ( U1 b) Source # filterA :: Applicative f => (a -> f Bool ) -> U1 a -> f ( U1 a) Source # witherMap :: Applicative m => ( U1 b -> r) -> (a -> m ( Maybe b)) -> U1 a -> m r Source # |
|
| Witherable ( Proxy :: Type -> Type ) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Proxy a -> f ( Proxy b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Proxy a -> m ( Proxy b) Source # filterA :: Applicative f => (a -> f Bool ) -> Proxy a -> f ( Proxy a) Source # witherMap :: Applicative m => ( Proxy b -> r) -> (a -> m ( Maybe b)) -> Proxy a -> m r Source # |
|
| Witherable ( Map k) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Map k a -> f ( Map k b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Map k a -> m ( Map k b) Source # filterA :: Applicative f => (a -> f Bool ) -> Map k a -> f ( Map k a) Source # witherMap :: Applicative m => ( Map k b -> r) -> (a -> m ( Maybe b)) -> Map k a -> m r Source # |
|
| Traversable t => Witherable ( MaybeT t) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> MaybeT t a -> f ( MaybeT t b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> MaybeT t a -> m ( MaybeT t b) Source # filterA :: Applicative f => (a -> f Bool ) -> MaybeT t a -> f ( MaybeT t a) Source # witherMap :: Applicative m => ( MaybeT t b -> r) -> (a -> m ( Maybe b)) -> MaybeT t a -> m r Source # |
|
| ( Eq k, Hashable k) => Witherable ( HashMap k) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> HashMap k a -> f ( HashMap k b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> HashMap k a -> m ( HashMap k b) Source # filterA :: Applicative f => (a -> f Bool ) -> HashMap k a -> f ( HashMap k a) Source # witherMap :: Applicative m => ( HashMap k b -> r) -> (a -> m ( Maybe b)) -> HashMap k a -> m r Source # |
|
| ( Alternative f, Traversable f) => Witherable ( WrappedFoldable f) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> WrappedFoldable f a -> f0 ( WrappedFoldable f b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> WrappedFoldable f a -> m ( WrappedFoldable f b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> WrappedFoldable f a -> f0 ( WrappedFoldable f a) Source # witherMap :: Applicative m => ( WrappedFoldable f b -> r) -> (a -> m ( Maybe b)) -> WrappedFoldable f a -> m r Source # |
|
| Witherable f => Witherable ( Rec1 f) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> Rec1 f a -> f0 ( Rec1 f b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Rec1 f a -> m ( Rec1 f b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> Rec1 f a -> f0 ( Rec1 f a) Source # witherMap :: Applicative m => ( Rec1 f b -> r) -> (a -> m ( Maybe b)) -> Rec1 f a -> m r Source # |
|
| Witherable ( Const r :: Type -> Type ) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Const r a -> f ( Const r b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Const r a -> m ( Const r b) Source # filterA :: Applicative f => (a -> f Bool ) -> Const r a -> f ( Const r a) Source # witherMap :: Applicative m => ( Const r b -> r0) -> (a -> m ( Maybe b)) -> Const r a -> m r0 Source # |
|
| Witherable t => Witherable ( Reverse t) Source # |
Wither from right to left. |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Reverse t a -> f ( Reverse t b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Reverse t a -> m ( Reverse t b) Source # filterA :: Applicative f => (a -> f Bool ) -> Reverse t a -> f ( Reverse t a) Source # witherMap :: Applicative m => ( Reverse t b -> r) -> (a -> m ( Maybe b)) -> Reverse t a -> m r Source # |
|
| Witherable f => Witherable ( IdentityT f) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> IdentityT f a -> f0 ( IdentityT f b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> IdentityT f a -> m ( IdentityT f b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> IdentityT f a -> f0 ( IdentityT f a) Source # witherMap :: Applicative m => ( IdentityT f b -> r) -> (a -> m ( Maybe b)) -> IdentityT f a -> m r Source # |
|
| Witherable t => Witherable ( Backwards t) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> Backwards t a -> f ( Backwards t b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Backwards t a -> m ( Backwards t b) Source # filterA :: Applicative f => (a -> f Bool ) -> Backwards t a -> f ( Backwards t a) Source # witherMap :: Applicative m => ( Backwards t b -> r) -> (a -> m ( Maybe b)) -> Backwards t a -> m r Source # |
|
| Witherable ( K1 i c :: Type -> Type ) Source # | |
|
Defined in Witherable Methods wither :: Applicative f => (a -> f ( Maybe b)) -> K1 i c a -> f ( K1 i c b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> K1 i c a -> m ( K1 i c b) Source # filterA :: Applicative f => (a -> f Bool ) -> K1 i c a -> f ( K1 i c a) Source # witherMap :: Applicative m => ( K1 i c b -> r) -> (a -> m ( Maybe b)) -> K1 i c a -> m r Source # |
|
| ( Witherable f, Witherable g) => Witherable (f :+: g) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> (f :+: g) a -> f0 ((f :+: g) b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> (f :+: g) a -> m ((f :+: g) b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> (f :+: g) a -> f0 ((f :+: g) a) Source # witherMap :: Applicative m => ((f :+: g) b -> r) -> (a -> m ( Maybe b)) -> (f :+: g) a -> m r Source # |
|
| ( Witherable f, Witherable g) => Witherable (f :*: g) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> (f :*: g) a -> f0 ((f :*: g) b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> (f :*: g) a -> m ((f :*: g) b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> (f :*: g) a -> f0 ((f :*: g) a) Source # witherMap :: Applicative m => ((f :*: g) b -> r) -> (a -> m ( Maybe b)) -> (f :*: g) a -> m r Source # |
|
| ( Witherable f, Witherable g) => Witherable ( Product f g) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> Product f g a -> f0 ( Product f g b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Product f g a -> m ( Product f g b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> Product f g a -> f0 ( Product f g a) Source # witherMap :: Applicative m => ( Product f g b -> r) -> (a -> m ( Maybe b)) -> Product f g a -> m r Source # |
|
| ( Witherable f, Witherable g) => Witherable ( Sum f g) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> Sum f g a -> f0 ( Sum f g b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Sum f g a -> m ( Sum f g b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> Sum f g a -> f0 ( Sum f g a) Source # witherMap :: Applicative m => ( Sum f g b -> r) -> (a -> m ( Maybe b)) -> Sum f g a -> m r Source # |
|
| Witherable f => Witherable ( M1 i c f) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> M1 i c f a -> f0 ( M1 i c f b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> M1 i c f a -> m ( M1 i c f b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> M1 i c f a -> f0 ( M1 i c f a) Source # witherMap :: Applicative m => ( M1 i c f b -> r) -> (a -> m ( Maybe b)) -> M1 i c f a -> m r Source # |
|
| ( Traversable f, Witherable g) => Witherable (f :.: g) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> (f :.: g) a -> f0 ((f :.: g) b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> (f :.: g) a -> m ((f :.: g) b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> (f :.: g) a -> f0 ((f :.: g) a) Source # witherMap :: Applicative m => ((f :.: g) b -> r) -> (a -> m ( Maybe b)) -> (f :.: g) a -> m r Source # |
|
| ( Traversable f, Witherable g) => Witherable ( Compose f g) Source # | |
|
Defined in Witherable Methods wither :: Applicative f0 => (a -> f0 ( Maybe b)) -> Compose f g a -> f0 ( Compose f g b) Source # witherM :: Monad m => (a -> m ( Maybe b)) -> Compose f g a -> m ( Compose f g b) Source # filterA :: Applicative f0 => (a -> f0 Bool ) -> Compose f g a -> f0 ( Compose f g a) Source # witherMap :: Applicative m => ( Compose f g b -> r) -> (a -> m ( Maybe b)) -> Compose f g a -> m r Source # |
|
ordNub :: ( Witherable t, Ord a) => t a -> t a Source #
ordNubOn :: ( Witherable t, Ord b) => (a -> b) -> t a -> t a Source #
forMaybe :: ( Witherable t, Applicative f) => t a -> (a -> f ( Maybe b)) -> f (t b) Source #
Indexed variants
class ( FunctorWithIndex i t, Filterable t) => FilterableWithIndex i t | t -> i where Source #
Indexed variant of
Filterable
.
Minimal complete definition
Nothing
Instances
class ( TraversableWithIndex i t, Witherable t) => WitherableWithIndex i t | t -> i where Source #
Indexed variant of
Witherable
.
Minimal complete definition
Nothing
Methods
iwither :: Applicative f => (i -> a -> f ( Maybe b)) -> t a -> f (t b) Source #
iwitherM :: Monad m => (i -> a -> m ( Maybe b)) -> t a -> m (t b) Source #
Monadic variant of wither. This may have more efficient implementation.
ifilterA :: Applicative f => (i -> a -> f Bool ) -> t a -> f (t a) Source #
Instances
Wrapper
newtype WrappedFoldable f a Source #
Constructors
| WrapFilterable | |
|
Fields
|
|