| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Data.Label.Base
Contents
Description
Labels for data types in the base package. The lens types are kept abstract to be fully reusable in custom contexts. Build to be imported qualified.
- head :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr [a] a
- tail :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr [a] [a]
- left :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr (Either a b -> Either o b) (a -> o)
- right :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr (Either a b -> Either a o) (b -> o)
- just :: (ArrowChoice cat, ArrowZero cat, ArrowApply cat) => Lens cat (Maybe a -> Maybe b) (a -> b)
- fst :: ArrowApply arr => Lens arr ((a, b) -> (o, b)) (a -> o)
- snd :: ArrowApply arr => Lens arr ((a, b) -> (a, o)) (b -> o)
- swap :: ArrowApply arr => Lens arr ((a, b) -> (c, d)) ((b, a) -> (d, c))
- fst3 :: ArrowApply arr => Lens arr ((a, b, c) -> (o, b, c)) (a -> o)
- snd3 :: ArrowApply arr => Lens arr ((a, b, c) -> (a, o, c)) (b -> o)
- trd3 :: ArrowApply arr => Lens arr ((a, b, c) -> (a, b, o)) (c -> o)
- readShow :: (Read a, Show a) => Iso Partial String a
Lenses for lists.
head :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr [a] a Source #
Lens pointing to the head of a list's cons cell. (Partial and monomorphic)
tail :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr [a] [a] Source #
Lens pointing to the tail of a list's cons cell. (Partial and monomorphic)
Lenses for Either.
left :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr (Either a b -> Either o b) (a -> o) Source #
Lens pointing to the left value in an Either. (Partial and polymorphic)
right :: (ArrowZero arr, ArrowApply arr, ArrowChoice arr) => Lens arr (Either a b -> Either a o) (b -> o) Source #
Lens pointing to the right value in an Either. (Partial and polymorphic)
Lens for Maybe.
just :: (ArrowChoice cat, ArrowZero cat, ArrowApply cat) => Lens cat (Maybe a -> Maybe b) (a -> b) Source #
Lens pointing to the value in a Maybe. (Partial and polymorphic)
Lenses for 2-tuples.
fst :: ArrowApply arr => Lens arr ((a, b) -> (o, b)) (a -> o) Source #
Lens pointing to the first component of a 2-tuple. (Total and polymorphic)
snd :: ArrowApply arr => Lens arr ((a, b) -> (a, o)) (b -> o) Source #
Lens pointing to the second component of a 2-tuple. (Total and polymorphic)
swap :: ArrowApply arr => Lens arr ((a, b) -> (c, d)) ((b, a) -> (d, c)) Source #
Polymorphic lens that swaps the components of a tuple. (Total and polymorphic)
Lenses for 3-tuples.
fst3 :: ArrowApply arr => Lens arr ((a, b, c) -> (o, b, c)) (a -> o) Source #
Lens pointing to the first component of a 3-tuple. (Total and polymorphic)
snd3 :: ArrowApply arr => Lens arr ((a, b, c) -> (a, o, c)) (b -> o) Source #
Lens pointing to the second component of a 3-tuple. (Total and polymorphic)
trd3 :: ArrowApply arr => Lens arr ((a, b, c) -> (a, b, o)) (c -> o) Source #
Lens pointing to the third component of a 3-tuple. (Total and polymorphic)