Safe Haskell	None
Language	Haskell2010

Optics.Zoom

Contents

Zoom
Magnify

Synopsis

class (MonadState s m, MonadState t n) => Zoom m n s t | m -> s, n -> t, m t -> n, n s -> m where
- zoom :: Is k A_Lens => Optic' k is t s -> m c -> n c
- zoomMaybe :: Is k An_AffineTraversal => Optic' k is t s -> m c -> n (Maybe c)
- zoomMany :: (Is k A_Traversal, Monoid c) => Optic' k is t s -> m c -> n c
class (MonadReader b m, MonadReader a n) => Magnify m n b a | m -> b, n -> a, m a -> n, n b -> m where
- magnify :: Is k A_Getter => Optic' k is a b -> m c -> n c
- magnifyMaybe :: Is k An_AffineFold => Optic' k is a b -> m c -> n (Maybe c)
class (MonadReader b m, MonadReader a n, Magnify m n b a) => MagnifyMany m n b a | m -> b, n -> a, m a -> n, n b -> m where
- magnifyMany :: (Is k A_Fold, Monoid c) => Optic' k is a b -> m c -> n c

Zoom

class (MonadState s m, MonadState t n) => Zoom m n s t | m -> s, n -> t, m t -> n, n s -> m where Source #

This class allows us to zoom in, changing the State supplied by many different monad transformers, potentially quite deep in a monad transformer stack.

Its functions can be used to run a monadic action in a larger State than it was defined in, using a Lens', an AffineTraversal' or a Traversal'.

This is commonly used to lift actions in a simpler State Monad into a State Monad with a larger State type.

When used with a Traversal' over multiple values, the actions for each target are executed sequentially and the results are aggregated.

This can be used to edit pretty much any Monad transformer stack with a State in it!

>>> flip L.evalState ('a','b') $ zoom _1 $ use equality
'a'

>>> flip S.execState ('a','b') $ zoom _1 $ equality .= 'c'
('c','b')

>>> flip L.execState [(1,2),(3,4)] $ zoomMany traversed $ _2 %= (*10)
[(1,20),(3,40)]

>>> flip S.runState [('a',"b"),('c',"d")] $ zoomMany traversed $ _2 <%= (\x -> x <> x)
("bbdd",[('a',"bb"),('c',"dd")])

>>> flip S.evalState ("a","b") $ zoomMany each (use equality)
"ab"

Methods

zoom :: Is k A_Lens => Optic' k is t s -> m c -> n c infixr 2 Source #

zoomMaybe :: Is k An_AffineTraversal => Optic' k is t s -> m c -> n (Maybe c) infixr 2 Source #

zoomMany :: (Is k A_Traversal, Monoid c) => Optic' k is t s -> m c -> n c infixr 2 Source #

Instances

Instances details

Zoom m n s t => Zoom (ListT m) (ListT n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> ListT m c -> ListT n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> ListT m c -> ListT n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> ListT m c -> ListT n c Source #
Zoom m n s t => Zoom (MaybeT m) (MaybeT n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> MaybeT m c -> MaybeT n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> MaybeT m c -> MaybeT n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> MaybeT m c -> MaybeT n c Source #
Zoom m n s t => Zoom (IdentityT m) (IdentityT n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> IdentityT m c -> IdentityT n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> IdentityT m c -> IdentityT n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> IdentityT m c -> IdentityT n c Source #
(Error e, Zoom m n s t) => Zoom (ErrorT e m) (ErrorT e n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> ErrorT e m c -> ErrorT e n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> ErrorT e m c -> ErrorT e n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> ErrorT e m c -> ErrorT e n c Source #
Zoom m n s t => Zoom (ExceptT e m) (ExceptT e n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> ExceptT e m c -> ExceptT e n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> ExceptT e m c -> ExceptT e n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> ExceptT e m c -> ExceptT e n c Source #
Zoom m n s t => Zoom (ReaderT e m) (ReaderT e n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> ReaderT e m c -> ReaderT e n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> ReaderT e m c -> ReaderT e n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> ReaderT e m c -> ReaderT e n c Source #
Monad m => Zoom (StateT s m) (StateT t m) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> StateT s m c -> StateT t m c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> StateT s m c -> StateT t m (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> StateT s m c -> StateT t m c Source #
Monad m => Zoom (StateT s m) (StateT t m) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> StateT s m c -> StateT t m c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> StateT s m c -> StateT t m (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> StateT s m c -> StateT t m c Source #
(Monoid w, Zoom m n s t) => Zoom (WriterT w m) (WriterT w n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> WriterT w m c -> WriterT w n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> WriterT w m c -> WriterT w n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> WriterT w m c -> WriterT w n c Source #
(Monoid w, Zoom m n s t) => Zoom (WriterT w m) (WriterT w n) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> WriterT w m c -> WriterT w n c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> WriterT w m c -> WriterT w n (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> WriterT w m c -> WriterT w n c Source #
(Monoid w, Monad m) => Zoom (RWST r w s m) (RWST r w t m) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> RWST r w s m c -> RWST r w t m c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> RWST r w s m c -> RWST r w t m (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> RWST r w s m c -> RWST r w t m c Source #
(Monoid w, Monad m) => Zoom (RWST r w s m) (RWST r w t m) s t Source #
Instance details Defined in Optics.Zoom Methods zoom :: forall k (is :: IxList) c. Is k A_Lens => Optic' k is t s -> RWST r w s m c -> RWST r w t m c Source # zoomMaybe :: forall k (is :: IxList) c. Is k An_AffineTraversal => Optic' k is t s -> RWST r w s m c -> RWST r w t m (Maybe c) Source # zoomMany :: forall k c (is :: IxList). (Is k A_Traversal, Monoid c) => Optic' k is t s -> RWST r w s m c -> RWST r w t m c Source #

Magnify

class (MonadReader b m, MonadReader a n) => Magnify m n b a | m -> b, n -> a, m a -> n, n b -> m where Source #

This class allows us to magnify part of the environment, changing the environment supplied by many different Monad transformers. Unlike zoom this can change the environment of a deeply nested Monad transformer.

Its functions can be used to run a monadic action in a larger environment than it was defined in, using a Getter or an AffineFold.

They act like local, but can in many cases change the type of the environment as well.

They're commonly used to lift actions in a simpler Reader Monad into a Monad with a larger environment type.

They can be used to edit pretty much any Monad transformer stack with an environment in it:

>>> (1,2) & magnify _2 (+1)
3

>>> flip runReader (1,2) $ magnify _1 ask
1

>>> flip runReader (1,2,[10..20]) $ magnifyMaybe (_3 % _tail) ask
Just [11,12,13,14,15,16,17,18,19,20]

Methods

magnify :: Is k A_Getter => Optic' k is a b -> m c -> n c infixr 2 Source #

magnifyMaybe :: Is k An_AffineFold => Optic' k is a b -> m c -> n (Maybe c) infixr 2 Source #

Instances

Instances details

Magnify m n b a => Magnify (ListT m) (ListT n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> ListT m c -> ListT n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> ListT m c -> ListT n (Maybe c) Source #
Magnify m n b a => Magnify (MaybeT m) (MaybeT n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> MaybeT m c -> MaybeT n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> MaybeT m c -> MaybeT n (Maybe c) Source #
Magnify m n b a => Magnify (IdentityT m) (IdentityT n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> IdentityT m c -> IdentityT n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> IdentityT m c -> IdentityT n (Maybe c) Source #
(Error e, Magnify m n b a) => Magnify (ErrorT e m) (ErrorT e n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> ErrorT e m c -> ErrorT e n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> ErrorT e m c -> ErrorT e n (Maybe c) Source #
Magnify m n b a => Magnify (ExceptT e m) (ExceptT e n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> ExceptT e m c -> ExceptT e n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> ExceptT e m c -> ExceptT e n (Maybe c) Source #
Monad m => Magnify (ReaderT b m) (ReaderT a m) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> ReaderT b m c -> ReaderT a m c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> ReaderT b m c -> ReaderT a m (Maybe c) Source #
Magnify m n b a => Magnify (StateT s m) (StateT s n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> StateT s m c -> StateT s n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> StateT s m c -> StateT s n (Maybe c) Source #
Magnify m n b a => Magnify (StateT s m) (StateT s n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> StateT s m c -> StateT s n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> StateT s m c -> StateT s n (Maybe c) Source #
(Monoid w, Magnify m n b a) => Magnify (WriterT w m) (WriterT w n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> WriterT w m c -> WriterT w n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> WriterT w m c -> WriterT w n (Maybe c) Source #
(Monoid w, Magnify m n b a) => Magnify (WriterT w m) (WriterT w n) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> WriterT w m c -> WriterT w n c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> WriterT w m c -> WriterT w n (Maybe c) Source #
Magnify ((->) b :: Type -> Type) ((->) a :: Type -> Type) b a Source #	`magnify` = `views` `magnifyMaybe` = `previews`
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> (b -> c) -> a -> c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> (b -> c) -> a -> Maybe c Source #
(Monad m, Monoid w) => Magnify (RWST b w s m) (RWST a w s m) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> RWST b w s m c -> RWST a w s m c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> RWST b w s m c -> RWST a w s m (Maybe c) Source #
(Monad m, Monoid w) => Magnify (RWST b w s m) (RWST a w s m) b a Source #
Instance details Defined in Optics.Zoom Methods magnify :: forall k (is :: IxList) c. Is k A_Getter => Optic' k is a b -> RWST b w s m c -> RWST a w s m c Source # magnifyMaybe :: forall k (is :: IxList) c. Is k An_AffineFold => Optic' k is a b -> RWST b w s m c -> RWST a w s m (Maybe c) Source #

class (MonadReader b m, MonadReader a n, Magnify m n b a) => MagnifyMany m n b a | m -> b, n -> a, m a -> n, n b -> m where Source #

Extends Magnify with an ability to magnify using a Fold over multiple targets so that actions for each one are executed sequentially and the results are aggregated.

There is however no sensible instance of MagnifyMany for StateT.

Methods

magnifyMany :: (Is k A_Fold, Monoid c) => Optic' k is a b -> m c -> n c infixr 2 Source #

Instances

Instances details

MagnifyMany m n b a => MagnifyMany (ListT m) (ListT n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> ListT m c -> ListT n c Source #
MagnifyMany m n b a => MagnifyMany (MaybeT m) (MaybeT n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> MaybeT m c -> MaybeT n c Source #
MagnifyMany m n b a => MagnifyMany (IdentityT m) (IdentityT n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> IdentityT m c -> IdentityT n c Source #
(Error e, MagnifyMany m n b a) => MagnifyMany (ErrorT e m) (ErrorT e n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> ErrorT e m c -> ErrorT e n c Source #
MagnifyMany m n b a => MagnifyMany (ExceptT e m) (ExceptT e n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> ExceptT e m c -> ExceptT e n c Source #
Monad m => MagnifyMany (ReaderT b m) (ReaderT a m) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> ReaderT b m c -> ReaderT a m c Source #
(Monoid w, MagnifyMany m n b a) => MagnifyMany (WriterT w m) (WriterT w n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> WriterT w m c -> WriterT w n c Source #
(Monoid w, MagnifyMany m n b a) => MagnifyMany (WriterT w m) (WriterT w n) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> WriterT w m c -> WriterT w n c Source #
MagnifyMany ((->) b :: Type -> Type) ((->) a :: Type -> Type) b a Source #	`magnifyMany` = `foldMapOf`
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> (b -> c) -> a -> c Source #
(Monad m, Monoid w) => MagnifyMany (RWST b w s m) (RWST a w s m) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> RWST b w s m c -> RWST a w s m c Source #
(Monad m, Monoid w) => MagnifyMany (RWST b w s m) (RWST a w s m) b a Source #
Instance details Defined in Optics.Zoom Methods magnifyMany :: forall k c (is :: IxList). (Is k A_Fold, Monoid c) => Optic' k is a b -> RWST b w s m c -> RWST a w s m c Source #