fclabels-0.2.0: First class record labels Source code Contents Index

Data.Record.Label

Contents Getter, setter and modifier types. Label type. Bidirectional composition. State monadic label operations. Convenient label for list indexing. Derive labels using Template Haskell.

Synopsis

type Getter a b = a -> b type Setter a b = b -> a -> a type Modifier a b = (b -> b) -> a -> a data a :-> b = Label { lget :: Getter a b lset :: Setter a b lmod :: Modifier a b } mkModifier :: Getter a b -> Setter a b -> Modifier a b mkLabel :: Getter a b -> Setter a b -> a :-> b (%) :: (g :-> a) -> (f :-> g) -> f :-> a class Lens f where lmap :: (a -> b, b -> a) -> f a -> f b getM :: MonadState s m => (s :-> b) -> m b setM :: MonadState s m => (s :-> b) -> b -> m () modM :: MonadState s m => (s :-> b) -> (b -> b) -> m () (=:) :: MonadState s m => (s :-> b) -> b -> m () enterM :: MonadState s m => (s :-> b) -> State b b1 -> m b1 enterMT :: (MonadState s (t m), MonadTrans t, Monad m) => (s :-> b) -> StateT b m a -> t m a bothM :: MonadState s m => (s :-> b) -> State b b1 -> m (b, b1) localM :: MonadState s m => (s :-> b) -> m b1 -> m b1 withM :: MonadState s m => (s :-> b) -> State b a -> m b1 -> m b1 list :: Int -> [a] :-> a mkLabels :: [Name] -> Q [Dec]

Getter, setter and modifier types.

type Getter a b = a -> b Source

type Setter a b = b -> a -> a Source

type Modifier a b = (b -> b) -> a -> a Source

Label type.

data a :-> b Source

Constructors Label lget :: Getter a b lset :: Setter a b lmod :: Modifier a b Instances Lens (:-> f)

mkModifier :: Getter a b -> Setter a b -> Modifier a b Source

Create a modifier function out of a getter and a setter.

mkLabel :: Getter a b -> Setter a b -> a :-> b Source

Smart constructor for Labels, the modifier will be computed based on getter and setter.

Bidirectional composition.

(%) :: (g :-> a) -> (f :-> g) -> f :-> a Source

class Lens f where Source

Methods lmap :: (a -> b, b -> a) -> f a -> f b Source Instances Lens (:-> f)

State monadic label operations.

getM :: MonadState s m => (s :-> b) -> m b Source

Get a value out of state pointed to by the specified label.

setM :: MonadState s m => (s :-> b) -> b -> m () Source

Set a value somewhere in state pointed to by the specified label.

modM :: MonadState s m => (s :-> b) -> (b -> b) -> m () Source

Modify a value with a function somewhere in state pointed to by the specified label.

(=:) :: MonadState s m => (s :-> b) -> b -> m () Source

Alias for setM that reads like an assignment.

enterM :: MonadState s m => (s :-> b) -> State b b1 -> m b1 Source

enterMT :: (MonadState s (t m), MonadTrans t, Monad m) => (s :-> b) -> StateT b m a -> t m a Source

bothM :: MonadState s m => (s :-> b) -> State b b1 -> m (b, b1) Source

localM :: MonadState s m => (s :-> b) -> m b1 -> m b1 Source

withM :: MonadState s m => (s :-> b) -> State b a -> m b1 -> m b1 Source

Convenient label for list indexing.

list :: Int -> [a] :-> a Source

Derive labels using Template Haskell.

mkLabels :: [Name] -> Q [Dec] Source

Produced by Haddock version 2.4.2