Moduleoptics-extra-0.4.2.1Haskell2010

Optics.State.Operators

Defines infix operators for the operations in Optics.State. These operators are not exposed by the main Optics module, but must be imported explicitly.

1 class
10 values

Packageoptics-extra-0.4.2.1
Exports11
LanguageHaskell2010
LicenceBSD-3-Clause
SourceOperators.hs

State modifying optics

3 declarations

value(.=) :: (Is k A_Setter, MonadState s m) => Optic k is s s a b -> b -> m ()

Replace the target(s) of an Optic in our monadic state with a new value, irrespective of the old.

This is an infix version of assign.

value(?=)

:: (Is k A_Setter, MonadState s m)
=> Optic k is s s (Maybe a) (Maybe b)
-> b
-> m ()

Replace the target(s) of an Optic in our monadic state with Just a new value, irrespective of the old.

value(%=)

:: (Is k A_Setter, MonadState s m)
=> Optic k is s s a b
-> a -> b
-> m ()

Map over the target(s) of an Optic in our monadic state.

This is an infix version of modifying.

State modifying optics with passthrough

1 declaration

value(%%=)

:: (PermeableOptic k r, MonadState s m)
=> Optic k is s s a b
-> a -> (r, b)
-> m (ViewResult k r)

Modify the target of an PermeableOptic in the current state returning some extra information of type depending on the optic (r, Maybe r or monoidal summary).

Returning new value

3 declarations

value(<.=)

:: (PermeableOptic k b, MonadState s m)
=> Optic k is s s a b
-> b
-> m (ViewResult k b)

Set with pass-through.

This is useful for chaining assignment without round-tripping through your Monad stack.

value(<?=)

:: (PermeableOptic k (Maybe b), MonadState s m)
=> Optic k is s s (Maybe a) (Maybe b)
-> b
-> m (ViewResult k (Maybe b))

Set Just a value with pass-through.

This is useful for chaining assignment without round-tripping through your Monad stack.

value(<%=)

:: (PermeableOptic k b, MonadState s m)
=> Optic k is s s a b
-> a -> b
-> m (ViewResult k b)

Modify the target of a PermeableOptic into your Monad's state by a user supplied function and return the result.

Returning old value

3 declarations

value(<<.=)

:: (PermeableOptic k a, MonadState s m)
=> Optic k is s s a b
-> b
-> m (ViewResult k a)

Replace the target of a PermeableOptic into your Monad's state with a user supplied value and return the old value that was replaced.

value(<<?=)

:: (PermeableOptic k (Maybe a), MonadState s m)
=> Optic k is s s (Maybe a) (Maybe b)
-> b
-> m (ViewResult k (Maybe a))

Replace the target of a PermeableOptic into your Monad's state with Just a user supplied value and return the old value that was replaced.

value(<<%=)

:: (PermeableOptic k a, MonadState s m)
=> Optic k is s s a b
-> a -> b
-> m (ViewResult k a)

Modify the target of a PermeableOptic into your Monad's state by a user supplied function and return the old value that was replaced.

Passthrough

1 declaration

classclass (Is k A_Traversal, ViewableOptic k r) => PermeableOptic (k :: OpticKind) r where

Methods

passthrough :: Optic k is s t a b -> (a -> (r, b)) -> s -> (ViewResult k r, t)
Modify the target of an Optic returning extra information of type r.

Instances5PermeableOptic

Monoid r => PermeableOptic A_Traversal rDefined in optics-extra-0.4.2.1 · Optics.Passthrough
PermeableOptic A_Lens rDefined in optics-extra-0.4.2.1 · Optics.Passthrough
PermeableOptic A_Prism rDefined in optics-extra-0.4.2.1 · Optics.Passthrough
PermeableOptic An_AffineTraversal rDefined in optics-extra-0.4.2.1 · Optics.Passthrough
PermeableOptic An_Iso rDefined in optics-extra-0.4.2.1 · Optics.Passthrough