| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Control.Reference.Predefined
Contents
Description
Predefined references.
_Naming convention_: If there is a reference foo and a reference foo' then
foo' is the restricted version of foo. If foo is generic in it's writer monad
foo' has the simplest writer monad that suffices.
- simple :: Monad w => Lens' w a b a b
- simple' :: Lens a b a b
- emptyRef :: (Monad w, Monad r, MonadPlus r) => SimpleRef w r s a
- emptyRef' :: Monad w => SimpleRef w Maybe s a
- traverse :: (Monad w, Traversable t) => Traversal' w (t a) (t b) a b
- traverse' :: Traversable t => Traversal (t a) (t b) a b
- lens :: Monad w => (s -> a) -> (b -> s -> t) -> Lens' w s t a b
- lens' :: (s -> a) -> (b -> s -> t) -> Lens s t a b
- partial :: Monad w => (s -> Maybe a) -> (a -> s -> s) -> Simple' w LensPart' s a
- partial' :: (s -> Maybe a) -> (a -> s -> s) -> Simple LensPart s a
- polyPartial :: Monad w => (s -> Either (w t) (a, b -> w t)) -> LensPart' w s t a b
- polyPartial' :: (s -> Either t (a, b -> t)) -> LensPart s t a b
- fromLens :: (Functor w, Monad w) => Lens s s a a -> Lens s t a b -> Lens' w s t a b
- fromTraversal :: (Applicative w, Monad w) => Traversal s s a a -> Traversal s t a b -> Traversal' w s t a b
- filtered :: (Applicative w, Monad w, MonadPlus r) => (a -> Bool) -> SimpleRef w r a a
- filteredTrav :: (Applicative w, Monad w) => (a -> Bool) -> Simple' w Traversal' a a
- filteredPartial :: (Applicative w, Monad w) => (a -> Bool) -> Simple' w LensPart' a a
- iso :: Monad w => (a -> b) -> (b -> a) -> Simple' w Lens' a b
- iso' :: (a -> b) -> (b -> a) -> Simple Lens a b
- just :: Monad w => LensPart' w (Maybe a) (Maybe b) a b
- just' :: LensPart (Maybe a) (Maybe b) a b
- right :: Monad w => LensPart' w (Either a b) (Either a c) b c
- right' :: LensPart (Either a b) (Either a c) b c
- left :: Monad w => LensPart' w (Either a c) (Either b c) a b
- left' :: LensPart (Either a c) (Either b c) a b
- anyway :: Monad w => Lens' w (Either a a) (Either b b) a b
- anyway' :: Lens (Either a a) (Either b b) a b
- both :: Monad w => Traversal' w (a, a) (b, b) a b
- both' :: Traversal (a, a) (b, b) a b
- _head :: Monad w => Simple' w LensPart' [a] a
- _head' :: Simple LensPart [a] a
- _tail :: Monad w => Simple' w LensPart' [a] [a]
- _tail' :: Simple LensPart [a] [a]
- class Association e where
- type AssocIndex e :: *
- type AssocElem e :: *
- element :: Monad w => AssocIndex e -> Simple' w LensPart' e (AssocElem e)
- element' :: AssocIndex e -> Simple LensPart e (AssocElem e)
- mvar :: SimpleRef IO IO (MVar a) a
- mvarNow :: SimpleRef IO (MaybeT IO) (MVar a) a
- ioref :: SimpleRef IO IO (IORef a) a
- state :: SimpleRef (State s) (State s) a s
Trivial references
emptyRef :: (Monad w, Monad r, MonadPlus r) => SimpleRef w r s a Source
An empty reference that do not traverse anything
Reference generators
traverse :: (Monad w, Traversable t) => Traversal' w (t a) (t b) a b Source
Generates a traversal on any traversable
traverse' :: Traversable t => Traversal (t a) (t b) a b Source
lens :: Monad w => (s -> a) -> (b -> s -> t) -> Lens' w s t a b Source
Generates a lens from a getter and a setter
partial :: Monad w => (s -> Maybe a) -> (a -> s -> s) -> Simple' w LensPart' s a Source
Creates a monomorphic partial lens
polyPartial :: Monad w => (s -> Either (w t) (a, b -> w t)) -> LensPart' w s t a b Source
Creates a polymorphic partial lense
polyPartial' :: (s -> Either t (a, b -> t)) -> LensPart s t a b Source
fromLens :: (Functor w, Monad w) => Lens s s a a -> Lens s t a b -> Lens' w s t a b Source
Generate a reference from a simple lens from Lens
fromTraversal :: (Applicative w, Monad w) => Traversal s s a a -> Traversal s t a b -> Traversal' w s t a b Source
Generate a reference from a simple lens from Lens
filtered :: (Applicative w, Monad w, MonadPlus r) => (a -> Bool) -> SimpleRef w r a a Source
Filters the traversed elements with a given predicate. Has specific versions for traversals and partial lenses.
filteredTrav :: (Applicative w, Monad w) => (a -> Bool) -> Simple' w Traversal' a a Source
Filters a traversal
filteredPartial :: (Applicative w, Monad w) => (a -> Bool) -> Simple' w LensPart' a a Source
Filters a partial lens
iso :: Monad w => (a -> b) -> (b -> a) -> Simple' w Lens' a b Source
Generate a lens from a pair of inverse functions
References for simple data structures
just :: Monad w => LensPart' w (Maybe a) (Maybe b) a b Source
A partial lens to access the value that may not exist
right :: Monad w => LensPart' w (Either a b) (Either a c) b c Source
A partial lens to access the right option of an Either
left :: Monad w => LensPart' w (Either a c) (Either b c) a b Source
A partial lens to access the left option of an Either
anyway :: Monad w => Lens' w (Either a a) (Either b b) a b Source
Access the value that is in the left or right state of an Either
both :: Monad w => Traversal' w (a, a) (b, b) a b Source
References both elements of a tuple
class Association e where Source
Lenses for given values in a data structure that is indexed by keys.
Minimal complete definition
Methods
element :: Monad w => AssocIndex e -> Simple' w LensPart' e (AssocElem e) Source
element' :: AssocIndex e -> Simple LensPart e (AssocElem e) Source
Instances
| Association [a] | |
| Ord k => Association (Map k v) |
Stateful references
mvar :: SimpleRef IO IO (MVar a) a Source
Access a value inside an MVar. Writing should only be used for initial assignment or parts of the program will block infinitely. Reads and updates are done in sequence, always using consistent data.