Portability | MTPCs, FDs, Rank2 |
---|---|
Stability | experimental |
Maintainer | Edward Kmett <ekmett@gmail.com> |
Safe Haskell | Safe-Infered |
Control.Lens.Action
Description
- type Action m a c = forall f r. Effective m r f => (c -> f c) -> a -> f a
- act :: Monad m => (a -> m c) -> Action m a c
- acts :: Action m (m a) a
- perform :: Monad m => Acting m c a c -> a -> m c
- liftAct :: (MonadTrans t, Monad m) => Acting m c a c -> Action (t m) a c
- (^!) :: Monad m => a -> Acting m c a c -> m c
- type MonadicFold m a c = forall f r. (Effective m r f, Applicative f) => (c -> f c) -> a -> f a
- type Acting m r a c = (c -> Effect m r c) -> a -> Effect m r a
- class (Monad m, Gettable f) => Effective m r f | f -> m r where
- effective :: Isomorphic k => k (m r) (f a)
- ineffective :: Effective m r f => Isomorphic k => k (f a) (m r)
- newtype Effect m r a = Effect {
- getEffect :: m r
Composable Actions
Folds with Effecs
type MonadicFold m a c = forall f r. (Effective m r f, Applicative f) => (c -> f c) -> a -> f aSource
A MonadicFold
is a Fold
enriched with access to a Monad
for side-effects.
Every Fold
can be used as a MonadicFold
, that simply ignores the access to the Monad
.
You can compose a MonadicFold
with another MonadicFold
using (.
) from the Prelude
.
Implementation Details
class (Monad m, Gettable f) => Effective m r f | f -> m r whereSource
An Effective
Functor
ignores its argument and is isomorphic to a monad wrapped around a value.
That said, the monad is possibly rather unrelated to any Applicative
structure.
Methods
effective :: Isomorphic k => k (m r) (f a)Source
ineffective :: Effective m r f => Isomorphic k => k (f a) (m r)Source
A convenient antonym that is used internally.
Wrap a monadic effect with a phantom type argument.