Lens.Family2.Stock

This module contains lenses, prisms, grids, grates and traversals for common structures in Haskell. It also contains the combinators for various kinds of optics.

A Function name with ' is a grate variant of a grid, and a function name with _ is a traversal variants of a grid or prism. For example, both' is the grate variant of both while both_ is the traversal variant.

Stock Lenses

_1 :: Lens (a, r) (b, r) a b

Lens on the first element of a pair.

_2 :: Lens (r, a) (r, b) a b

Lens on the second element of a pair.

chosen :: Lens (Either a a) (Either b b) a b

Lens on the Left or Right element of an (Either a a).

ix :: Eq k => k -> Lens' (k -> v) v

Lens on a given point of a function.

at :: Ord k => k -> Lens' (Map k v) (Maybe v)

Lens on a given point of a Map.

intAt :: Int -> Lens' (IntMap v) (Maybe v)

Lens on a given point of a IntMap.

at' :: Ord k => k -> Lens' (Map k v) (Maybe v)

Lens providing strict access to a given point of a Map.

intAt' :: Int -> Lens' (IntMap v) (Maybe v)

Lens providing strict access to a given point of a IntMap.

contains :: Ord k => k -> Lens' (Set k) Bool

Lens on a given point of a Set.

intContains :: Int -> Lens' IntSet Bool

Lens on a given point of a IntSet.

Stock Prisms

left :: Prism (Either a r) (Either b r) a b

A prism on the Left element of an Either.

right :: Prism (Either r a) (Either r b) a b

A prism on the Right element of an Either.

just :: Prism (Maybe a) (Maybe b) a b

A prism on the Just element of a Maybe.

nothing :: Prism' (Maybe a) ()

A prism on the Nothing element of a Maybe.

Stock Grids

both :: Grid (a, a) (b, b) a b

A grid on both elements of a pair (a,a).

bend :: FiniteBits b => Grid' b Bool

A grid from the most significant bit to the least significant bit of a FiniteBits type.

Big endian order.

lend :: FiniteBits b => Grid' b Bool

A grid from the least significant bit to the most significant bit of a FiniteBits type.

Little endian order.

Stock Grates

cod :: Grate (r -> a) (r -> b) a b

A grate accessing the codomain of a function.

both' :: Grate (a, a) (b, b) a b

A grate on both elements of a pair (a,a).

bend' :: FiniteBits b => Grate' b Bool

A grate from the most significant bit to the least significant bit of a FiniteBits type.

Big endian order.

lend' :: FiniteBits b => Grate' b Bool

A grate from the least significant bit to the most significant bit of a FiniteBits type.

Little endian order.

Stock Traversals

both_ :: Traversal (a, a) (b, b) a b

Traversals on both elements of a pair (a,a).

bend_ :: FiniteBits b => Traversal' b Bool

A traversal from the most significant bit to the least significant bit of a FiniteBits type.

Big endian order.

lend_ :: FiniteBits b => Traversal' b Bool

A traversal from the least significant bit to the most significant bit of a FiniteBits type.

Little endian order.

left_ :: Traversal (Either a r) (Either b r) a b

Traversal on the Left element of an Either.

right_ :: Traversal (Either r a) (Either r b) a b

Traversal on the Right element of an Either.

just_ :: Traversal (Maybe a) (Maybe b) a b

Traversal on the Just element of a Maybe.

nothing_ :: Traversal' (Maybe a) ()

Traversal on the Nothing element of a Maybe.

ignored :: Traversal a a b b'

The empty traveral on any type.

Stock SECs

mapped :: Functor f => Setter (f a) (f a') a a'

An SEC referencing the parameter of a functor.

Lens Combinators

alongside :: Functor f => LensLike (AlongsideLeft f b1) s0 t0 a0 b0 -> LensLike (AlongsideRight f t0) s1 t1 a1 b1 -> LensLike f (s0, s1) (t0, t1) (a0, a1) (b0, b1)

alongside :: Lens s0 t0 a0 b0 -> Lens s1 t1 a1 b1 -> Lens (s0, s1) (t0, t1) (a0, a1) (b0, b1)

alongside :: Getter s0 t0 a0 b0 -> Getter s1 t1 a1 b1 -> Getter (s0, s1) (t0, t1) (a0, a1) (b0, b1)

Given two lens/getter families, make a new lens/getter on their product.

backwards :: LensLike (Backwards f) s t a b -> LensLike f s t a b

backwards :: Traversal s t a b -> Traversal s t a b
backwards :: Fold s t a b -> Fold s t a b

Given a traversal or fold, reverse the order that elements are traversed.

backwards :: Lens s t a b -> Lens s t a b
backwards :: Getter s t a b -> Getter s t a b
backwards :: Setter s t a b -> Setter s t a b

No effect on lenses, getters or setters.

beside :: (Applicative f, Functor g) => AdapterLike f g s0 t0 a b -> AdapterLike f g s1 t1 a b -> AdapterLike f g (s0, s1) (t0, t1) a b

beside :: Grid s1 t1 a b -> Grid s2 t2 a b -> Grid (s1, s2) (t1, t2) a b

Given two grids referencing a type c, create a grid on the pair referencing c.

beside' :: Functor g => GrateLike g s0 t0 a b -> GrateLike g s1 t1 a b -> GrateLike g (s0, s1) (t0, t1) a b

beside' :: Grate s0 t0 a b -> Grate s1 t1 a b -> Grate (s0, s1) (t0, t1) a b

beside' :: Resetter s0 t0 a b -> Resetter s1 t1 a b -> Resetter (s0, s1) (t0, t1) a b

Given two grates/resetters referencing a type c, create a grate/resetter on the pair referencing c.

beside_ :: Applicative f => LensLike f s0 t0 a b -> LensLike f s1 t1 a b -> LensLike f (s0, s1) (t0, t1) a b

beside_ :: Traversal s0 t0 a b -> Traversal s1 t1 a b -> Traversal (s0, s1) (t0, t1) a b

beside_ :: Fold s0 t0 a b -> Fold s1 t1 a b -> Fold (s0, s1) (t0, t1) a b

beside_ :: Setter s0 t0 a b -> Setter s1 t1 a b -> Setter (s0, s1) (t0, t1) a b

Given two traversals/folds/setters referencing a type c, create a traversal/fold/setter on the pair referencing c.

choosing :: Functor f => LensLike f s0 t0 a b -> LensLike f s1 t1 a b -> LensLike f (Either s0 s1) (Either t0 t1) a b

choosing :: Lens s0 t0 a b -> Lens s1 t1 a b -> Lens (Either s0 s1) (Either t0 t1) a b

choosing :: Traversal s0 t0 a b -> Traversal s1 t1 a b -> Traversal (Either s0 s1) (Either t0 t1) a b

choosing :: Getter s0 t0 a b -> Getter s1 t1 a b -> Getter (Either s0 s1) (Either t0 t1) a b

choosing :: Fold s0 t0 a b -> Fold s1 t1 a b -> Fold (Either s0 s1) (Either t0 t1) a b

choosing :: Setter s0 t0 a b -> Setter s1 t1 a b -> Setter (Either s0 s1) (Either t0 t1) a b

Given two lens/traversal/getter/fold/setter families with the same substructure, make a new lens/traversal/getter/fold/setter on Either.

from :: (Functor f, Functor g) => AdapterLike (FromF (g s -> f t) (f b) g) (FromG (f b) f) b a t s -> AdapterLike f g s t a b

from :: Adapter b a t s -> Adapter s t a b

Reverses the direction of an adapter.

from :: Getter b a t s -> Reviewer s t a b
from :: Reviewer b a t s -> Getter s t a b

Changes a Getter into a Reviewer and vice versa.

Types

data AlongsideLeft (f :: Type -> Type) b a

Instances

Functor f => Functor (AlongsideLeft f a)

Defined in Lens.Family.Stock

Methods

fmap :: (a0 -> b) -> AlongsideLeft f a a0 -> AlongsideLeft f a b

(<$) :: a0 -> AlongsideLeft f a b -> AlongsideLeft f a a0

Phantom f => Phantom (AlongsideLeft f a)

Defined in Lens.Family.Stock

Methods

coerce :: AlongsideLeft f a a0 -> AlongsideLeft f a b

data AlongsideRight (f :: Type -> Type) a b

Instances

Functor f => Functor (AlongsideRight f a)

Defined in Lens.Family.Stock

Methods

fmap :: (a0 -> b) -> AlongsideRight f a a0 -> AlongsideRight f a b

(<$) :: a0 -> AlongsideRight f a b -> AlongsideRight f a a0

Phantom f => Phantom (AlongsideRight f a)

Defined in Lens.Family.Stock

Methods

coerce :: AlongsideRight f a a0 -> AlongsideRight f a b

data FromF i j (g :: Type -> Type) x

Instances

Functor g => Functor (FromF i j g)

Defined in Lens.Family.Stock

Methods

fmap :: (a -> b) -> FromF i j g a -> FromF i j g b

(<$) :: a -> FromF i j g b -> FromF i j g a

Phantom g => Phantom (FromF i j g)

Defined in Lens.Family.Stock

Methods

coerce :: FromF i j g a -> FromF i j g b

data FromG e (f :: Type -> Type) x

Instances

Functor f => Functor (FromG e f)

Defined in Lens.Family.Stock

Methods

fmap :: (a -> b) -> FromG e f a -> FromG e f b

(<$) :: a -> FromG e f b -> FromG e f a

Phantom g => Phantom (FromG e g)

Defined in Lens.Family.Stock

Methods

coerce :: FromG e g a -> FromG e g b

Re-exports

type Lens s t a b = forall f. Functor f => LensLike f s t a b

type Lens' s a = forall f. Functor f => LensLike' f s a

type Grate s t a b = forall g. Functor g => GrateLike g s t a b

type Grate' s a = forall g. Functor g => GrateLike' g s a

type Traversal s t a b = forall f. Applicative f => LensLike f s t a b

type Traversal' s a = forall f. Applicative f => LensLike' f s a

type Setter s t a b = forall f. Identical f => LensLike f s t a b

type AdapterLike (f :: Type -> Type) (g :: Type -> Type) s t a b = (g a -> f b) -> g s -> f t

type AdapterLike' (f :: Type -> Type) (g :: Type -> Type) s a = (g a -> f a) -> g s -> f s

type LensLike (f :: Type -> Type) s t a b = (a -> f b) -> s -> f t

type LensLike' (f :: Type -> Type) s a = (a -> f a) -> s -> f s

class (Traversable f, Applicative f) => Identical (f :: Type -> Type)

Minimal complete definition

extract

Instances

Identical Identity

Defined in Lens.Family.Identical

Methods

extract :: Identity a -> a

Identical f => Identical (Backwards f)

Defined in Lens.Family.Identical

Methods

extract :: Backwards f a -> a

(Identical f, Identical g) => Identical (Compose f g)

Defined in Lens.Family.Identical

Methods

extract :: Compose f g a -> a

data Backwards (f :: k -> Type) (a :: k)

The same functor, but with an Applicative instance that performs actions in the reverse order.

Instances

Functor f => Functor (Backwards f)

Derived instance.

Defined in Control.Applicative.Backwards

Methods

fmap :: (a -> b) -> Backwards f a -> Backwards f b

(<$) :: a -> Backwards f b -> Backwards f a

Applicative f => Applicative (Backwards f)

Apply f-actions in the reverse order.

Defined in Control.Applicative.Backwards

Methods

pure :: a -> Backwards f a

(<*>) :: Backwards f (a -> b) -> Backwards f a -> Backwards f b

liftA2 :: (a -> b -> c) -> Backwards f a -> Backwards f b -> Backwards f c

(*>) :: Backwards f a -> Backwards f b -> Backwards f b

(<*) :: Backwards f a -> Backwards f b -> Backwards f a

Foldable f => Foldable (Backwards f)

Derived instance.

Defined in Control.Applicative.Backwards

Methods

fold :: Monoid m => Backwards f m -> m

foldMap :: Monoid m => (a -> m) -> Backwards f a -> m

foldMap' :: Monoid m => (a -> m) -> Backwards f a -> m

foldr :: (a -> b -> b) -> b -> Backwards f a -> b

foldr' :: (a -> b -> b) -> b -> Backwards f a -> b

foldl :: (b -> a -> b) -> b -> Backwards f a -> b

foldl' :: (b -> a -> b) -> b -> Backwards f a -> b

foldr1 :: (a -> a -> a) -> Backwards f a -> a

foldl1 :: (a -> a -> a) -> Backwards f a -> a

toList :: Backwards f a -> [a]

null :: Backwards f a -> Bool

length :: Backwards f a -> Int

elem :: Eq a => a -> Backwards f a -> Bool

maximum :: Ord a => Backwards f a -> a

minimum :: Ord a => Backwards f a -> a

sum :: Num a => Backwards f a -> a

product :: Num a => Backwards f a -> a

Traversable f => Traversable (Backwards f)

Derived instance.

Defined in Control.Applicative.Backwards

Methods

traverse :: Applicative f0 => (a -> f0 b) -> Backwards f a -> f0 (Backwards f b)

sequenceA :: Applicative f0 => Backwards f (f0 a) -> f0 (Backwards f a)

mapM :: Monad m => (a -> m b) -> Backwards f a -> m (Backwards f b)

sequence :: Monad m => Backwards f (m a) -> m (Backwards f a)

Contravariant f => Contravariant (Backwards f)

Derived instance.

Defined in Control.Applicative.Backwards

Methods

contramap :: (a -> b) -> Backwards f b -> Backwards f a

(>$) :: b -> Backwards f b -> Backwards f a

Eq1 f => Eq1 (Backwards f)

Defined in Control.Applicative.Backwards

Methods

liftEq :: (a -> b -> Bool) -> Backwards f a -> Backwards f b -> Bool

Ord1 f => Ord1 (Backwards f)

Defined in Control.Applicative.Backwards

Methods

liftCompare :: (a -> b -> Ordering) -> Backwards f a -> Backwards f b -> Ordering

Read1 f => Read1 (Backwards f)

Defined in Control.Applicative.Backwards

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Backwards f a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Backwards f a]

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Backwards f a)

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Backwards f a]

Show1 f => Show1 (Backwards f)

Defined in Control.Applicative.Backwards

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Backwards f a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Backwards f a] -> ShowS

Alternative f => Alternative (Backwards f)

Try alternatives in the same order as f.

Defined in Control.Applicative.Backwards

Methods

empty :: Backwards f a

(<|>) :: Backwards f a -> Backwards f a -> Backwards f a

some :: Backwards f a -> Backwards f [a]

many :: Backwards f a -> Backwards f [a]

Phantom f => Phantom (Backwards f)

Defined in Lens.Family.Phantom

Methods

coerce :: Backwards f a -> Backwards f b

Identical f => Identical (Backwards f)

Defined in Lens.Family.Identical

Methods

extract :: Backwards f a -> a

(Eq1 f, Eq a) => Eq (Backwards f a)

Defined in Control.Applicative.Backwards

Methods

(==) :: Backwards f a -> Backwards f a -> Bool

(/=) :: Backwards f a -> Backwards f a -> Bool

(Ord1 f, Ord a) => Ord (Backwards f a)

Defined in Control.Applicative.Backwards

Methods

compare :: Backwards f a -> Backwards f a -> Ordering

(<) :: Backwards f a -> Backwards f a -> Bool

(<=) :: Backwards f a -> Backwards f a -> Bool

(>) :: Backwards f a -> Backwards f a -> Bool

(>=) :: Backwards f a -> Backwards f a -> Bool

max :: Backwards f a -> Backwards f a -> Backwards f a

min :: Backwards f a -> Backwards f a -> Backwards f a

(Read1 f, Read a) => Read (Backwards f a)

Defined in Control.Applicative.Backwards

Methods

readsPrec :: Int -> ReadS (Backwards f a)

readList :: ReadS [Backwards f a]

readPrec :: ReadPrec (Backwards f a)

readListPrec :: ReadPrec [Backwards f a]

(Show1 f, Show a) => Show (Backwards f a)

Defined in Control.Applicative.Backwards

Methods

showsPrec :: Int -> Backwards f a -> ShowS

show :: Backwards f a -> String

showList :: [Backwards f a] -> ShowS

class Bits b => FiniteBits b

The FiniteBits class denotes types with a finite, fixed number of bits.

Since: base-4.7.0.0

Minimal complete definition

finiteBitSize

Instances

FiniteBits Bool

Since: base-4.7.0.0

Defined in Data.Bits

Methods

finiteBitSize :: Bool -> Int

countLeadingZeros :: Bool -> Int

countTrailingZeros :: Bool -> Int

FiniteBits Int

Since: base-4.6.0.0

Defined in Data.Bits

Methods

finiteBitSize :: Int -> Int

countLeadingZeros :: Int -> Int

countTrailingZeros :: Int -> Int

FiniteBits Word

Since: base-4.6.0.0

Defined in Data.Bits

Methods

finiteBitSize :: Word -> Int

countLeadingZeros :: Word -> Int

countTrailingZeros :: Word -> Int

FiniteBits a => FiniteBits (Identity a)

Since: base-4.9.0.0

Defined in Data.Functor.Identity

Methods

finiteBitSize :: Identity a -> Int

countLeadingZeros :: Identity a -> Int

countTrailingZeros :: Identity a -> Int

FiniteBits a => FiniteBits (Down a)

Since: base-4.14.0.0

Defined in Data.Ord

Methods

finiteBitSize :: Down a -> Int

countLeadingZeros :: Down a -> Int

countTrailingZeros :: Down a -> Int

FiniteBits a => FiniteBits (Const a b)

Since: base-4.9.0.0

Defined in Data.Functor.Const

Methods

finiteBitSize :: Const a b -> Int

countLeadingZeros :: Const a b -> Int

countTrailingZeros :: Const a b -> Int

Deprecated names

lft :: Prism (Either a r) (Either b r) a b

Deprecated: Renamed as left.

rgt :: Prism (Either r a) (Either r b) a b

Deprecated: Renamed as right.

some :: Prism (Maybe a) (Maybe b) a b

Deprecated: Renamed as just.

none :: Prism' (Maybe a) ()

Deprecated: Renamed as nothing.

lft_ :: Traversal (Either a r) (Either b r) a b

Deprecated: Renamed as left_.

rgt_ :: Traversal (Either r a) (Either r b) a b

Deprecated: Renamed as right_.

some_ :: Traversal (Maybe a) (Maybe b) a b

Deprecated: Renamed as just_.

none_ :: Traversal' (Maybe a) ()

Deprecated: Renamed as nothing_.