| Portability | portable |
|---|---|
| Stability | experimental |
| Maintainer | ross@soi.city.ac.uk |
| Safe Haskell | Safe-Inferred |
Control.Applicative.Lift
Contents
Description
Adding a new kind of pure computation to an applicative functor.
Documentation
Applicative functor formed by adding pure computations to a given applicative functor.
Instances
| Functor f => Functor (Lift f) | |
| Applicative f => Applicative (Lift f) | A combination is |
| Foldable f => Foldable (Lift f) | |
| Traversable f => Traversable (Lift f) | |
| Alternative f => Alternative (Lift f) | A combination is |
| Show1 f => Show1 (Lift f) | |
| Read1 f => Read1 (Lift f) | |
| Ord1 f => Ord1 (Lift f) | |
| Eq1 f => Eq1 (Lift f) | |
| (Eq1 f, Eq a) => Eq (Lift f a) | |
| (Ord1 f, Ord a) => Ord (Lift f a) | |
| (Read1 f, Read a) => Read (Lift f a) | |
| (Show1 f, Show a) => Show (Lift f a) |
unLift :: Applicative f => Lift f a -> f aSource
Projection to the other functor.
Collecting errors
type Errors e = Lift (Constant e)Source
An applicative functor that collects a monoid (e.g. lists) of errors.
A sequence of computations fails if any of its components do, but
unlike monads made with ExceptT from Control.Monad.Trans.Except,
these computations continue after an error, collecting all the errors.