Copyright | (c) Ross Paterson 2010 |
---|---|

License | BSD-style (see the file LICENSE) |

Maintainer | [email protected] |

Stability | experimental |

Portability | portable |

Safe Haskell | Safe |

Language | Haskell98 |

Adding a new kind of pure computation to an applicative functor.

Applicative functor formed by adding pure computations to a given applicative functor.

Functor f => Functor (Lift f) | |

Applicative f => Applicative (Lift f) | A combination is |

Foldable f => Foldable (Lift f) | |

Defined in Control.Applicative.Lift ## Methodsfold :: Monoid m => Lift f m -> m Source foldMap :: Monoid m => (a -> m) -> Lift f a -> m Source foldMap' :: Monoid m => (a -> m) -> Lift f a -> m Source foldr :: (a -> b -> b) -> b -> Lift f a -> b Source foldr' :: (a -> b -> b) -> b -> Lift f a -> b Source foldl :: (b -> a -> b) -> b -> Lift f a -> b Source foldl' :: (b -> a -> b) -> b -> Lift f a -> b Source foldr1 :: (a -> a -> a) -> Lift f a -> a Source foldl1 :: (a -> a -> a) -> Lift f a -> a Source toList :: Lift f a -> [a] Source null :: Lift f a -> Bool Source length :: Lift f a -> Int Source elem :: Eq a => a -> Lift f a -> Bool Source maximum :: Ord a => Lift f a -> a Source minimum :: Ord a => Lift f a -> a Source | |

Traversable f => Traversable (Lift f) | |

Defined in Control.Applicative.Lift | |

Eq1 f => Eq1 (Lift f) | |

Ord1 f => Ord1 (Lift f) | |

Defined in Control.Applicative.Lift | |

Read1 f => Read1 (Lift f) | |

Defined in Control.Applicative.Lift ## MethodsliftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Lift f a) Source liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Lift f a] Source liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Lift f a) Source liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Lift f a] Source | |

Show1 f => Show1 (Lift f) | |

Alternative f => Alternative (Lift f) | A combination is |

(Eq1 f, Eq a) => Eq (Lift f a) | |

(Ord1 f, Ord a) => Ord (Lift f a) | |

Defined in Control.Applicative.Lift | |

(Read1 f, Read a) => Read (Lift f a) | |

(Show1 f, Show a) => Show (Lift f a) | |

unLift :: Applicative f => Lift f a -> f a Source

Projection to the other functor.

mapLift :: (f a -> g a) -> Lift f a -> Lift g a Source

Apply a transformation to the other computation.

elimLift :: (a -> r) -> (f a -> r) -> Lift f a -> r Source

Eliminator for `Lift`

.

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.

pure f <*> pure x = pure (f x)

pure f <*> failure e = failure e

failure e <*> pure x = failure e

failure e1 <*> failure e2 = failure (e1 <> e2)

runErrors :: Errors e a -> Either e a Source

Extractor for computations with accumulating errors.

failure :: e -> Errors e a Source

Report an error.

eitherToErrors :: Either e a -> Errors e a Source

© The University of Glasgow and others

Licensed under a BSD-style license (see top of the page).

https://downloads.haskell.org/~ghc/8.8.3/docs/html/libraries/transformers-0.5.6.2/Control-Applicative-Lift.html