Control.Lens.Setter

Setter s a b is the fmap summary of Functor. You can map content to a structure and modify the content, but it is not strong enough to enumerate the content. Start with fmap :: Functor. f => (a -> b) -> f a -> f b Unify the type to (a -> b) -> s -> t and decorate it using Identity.

With Functor, you can do everything, you can use Setter. There are several combiners that can summarize fmap and (<$).

Using Prelude's (.) You can write a setter using Lens or Traversal.

This is a convenient alias when defining highly polymorphic code that uses both ASetter and AnIndexedSetter. If the function takes this function, one of these two will be expected depending on the context.

Another way to display the collection is to convert it to a Setter using the Semantic Editor Combiner.

Temporary crazy functors until GHC 10 becomes a super class of monads, you may have to use it instead of mapping.

Note: Attempting to set fold or getter will fail at compile time and will display a relatively good error message.

Use user-supplied features to change all targets of lens target or setter or traversal

Make a numeric lens, setter, or traverse target an integral multiple of nonnegative

Replace target of all targets of lens, setter and traversal with monad state and use new value regardless of old value.

Replace target of all targets of lens, setter and traversal with monad state and use new value regardless of old value.

Make a numeric lens, setter, or traverse target an integral multiple of nonnegative

If you do not need a copy of intermediate results, use l. = d avoids unused binding warnings

To replace the targets of all targets in lenses, setters, and traversal with our monad state, only new values ​​are needed, regardless of the old value.

If you do not need a copy of intermediate results, use l. = d avoids unused binding warnings

As a reasonable mnemonic, this allows you to store the result of a unary action in a shot instead of a local variable.

Replace lens target, setter or traversal target with fixed value without changing type

Note: Attempting to adjust set'a Fold or Getter will fail at compile time and will display a relatively good error message.

Another way to display isets is to require a "semantic editor combiner" modified to carry the index and convert it to IndexedSetter.

Access the index and adjust each target in the current state of IndexedSetter, IndexedLens, or IndexedTraversal.

Replace each target in the current state of IndexedSetter, IndexedLens, or IndexedTraversal with an index.

Run the command and use its output to set all targets of lens, setter, or traversal to the result.

assignA can be used in a way very similar to (<~), except that you can change the type of object being changed. For example:

Gfoldl:: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g.g -> c g) -> identity a -> c (identity) #

Gun battle:: (forall b r. Data b => c (b -> r) -> c r) -> (forall r.r -> c r) -> Constr -> c (flag a) #

If the runIdentity field is deleted, this instance is equivalent to a derived instance of Identity newtype.