Safe Haskell	None
Language	Haskell2010

Optics.Indexed.Core

Contents

Class for optic kinds that can be indexed
Composition of indexed optics
Indexed optic flavours
Functors with index
- Foldable with index
- Traversable with index

Description

This module defines basic functionality for indexed optics. See the "Indexed optics" section of the overview documentation in the Optics module of the main optics package for more details.

Synopsis

class IxOptic k s t a b where
- noIx :: NonEmptyIndices is => Optic k is s t a b -> Optic k NoIx s t a b
conjoined :: is `HasSingleIndex` i => Optic k NoIx s t a b -> Optic k is s t a b -> Optic k is s t a b
(%) :: forall k l m is js ks s t u v a b. (JoinKinds k l m, AppendIndices is js ks) => Optic k is s t u v -> Optic l js u v a b -> Optic m ks s t a b
(<%>) :: (JoinKinds k l m, IxOptic m s t a b, is `HasSingleIndex` i, js `HasSingleIndex` j) => Optic k is s t u v -> Optic l js u v a b -> Optic m (WithIx (i, j)) s t a b
(%>) :: (JoinKinds k l m, IxOptic k s t u v, NonEmptyIndices is) => Optic k is s t u v -> Optic l js u v a b -> Optic m js s t a b
(<%) :: (JoinKinds k l m, IxOptic l u v a b, NonEmptyIndices js) => Optic k is s t u v -> Optic l js u v a b -> Optic m is s t a b
reindexed :: is `HasSingleIndex` i => (i -> j) -> Optic k is s t a b -> Optic k (WithIx j) s t a b
icompose :: (i -> j -> ix) -> Optic k '[i, j] s t a b -> Optic k (WithIx ix) s t a b
icompose3 :: (i1 -> i2 -> i3 -> ix) -> Optic k '[i1, i2, i3] s t a b -> Optic k (WithIx ix) s t a b
icompose4 :: (i1 -> i2 -> i3 -> i4 -> ix) -> Optic k '[i1, i2, i3, i4] s t a b -> Optic k (WithIx ix) s t a b
icompose5 :: (i1 -> i2 -> i3 -> i4 -> i5 -> ix) -> Optic k '[i1, i2, i3, i4, i5] s t a b -> Optic k (WithIx ix) s t a b
icomposeN :: forall k i is s t a b. (CurryCompose is, NonEmptyIndices is) => Curry is i -> Optic k is s t a b -> Optic k (WithIx i) s t a b
module Optics.IxAffineFold
module Optics.IxAffineTraversal
module Optics.IxFold
module Optics.IxGetter
module Optics.IxLens
module Optics.IxSetter
module Optics.IxTraversal
class Functor f => FunctorWithIndex i (f :: Type -> Type) | f -> i where
- imap :: (i -> a -> b) -> f a -> f b
class Foldable f => FoldableWithIndex i (f :: Type -> Type) | f -> i where
- ifoldMap :: Monoid m => (i -> a -> m) -> f a -> m
- ifoldMap' :: Monoid m => (i -> a -> m) -> f a -> m
- ifoldr :: (i -> a -> b -> b) -> b -> f a -> b
- ifoldl :: (i -> b -> a -> b) -> b -> f a -> b
- ifoldr' :: (i -> a -> b -> b) -> b -> f a -> b
- ifoldl' :: (i -> b -> a -> b) -> b -> f a -> b
itraverse_ :: (FoldableWithIndex i t, Applicative f) => (i -> a -> f b) -> t a -> f ()
ifor_ :: (FoldableWithIndex i t, Applicative f) => t a -> (i -> a -> f b) -> f ()
itoList :: FoldableWithIndex i f => f a -> [(i, a)]
class (FunctorWithIndex i t, FoldableWithIndex i t, Traversable t) => TraversableWithIndex i (t :: Type -> Type) | t -> i where
- itraverse :: Applicative f => (i -> a -> f b) -> t a -> f (t b)
ifor :: (TraversableWithIndex i t, Applicative f) => t a -> (i -> a -> f b) -> f (t b)

Class for optic kinds that can be indexed

class IxOptic k s t a b where Source #

Class for optic kinds that can have indices.

Methods

noIx :: NonEmptyIndices is => Optic k is s t a b -> Optic k NoIx s t a b Source #

Convert an indexed optic to its unindexed equivalent.

Instances

Instances details

(s ~ t, a ~ b) => IxOptic A_Fold s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic A_Fold is s t a b -> Optic A_Fold NoIx s t a b Source #
(s ~ t, a ~ b) => IxOptic An_AffineFold s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic An_AffineFold is s t a b -> Optic An_AffineFold NoIx s t a b Source #
(s ~ t, a ~ b) => IxOptic A_Getter s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic A_Getter is s t a b -> Optic A_Getter NoIx s t a b Source #
IxOptic A_Setter s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic A_Setter is s t a b -> Optic A_Setter NoIx s t a b Source #
IxOptic A_Traversal s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic A_Traversal is s t a b -> Optic A_Traversal NoIx s t a b Source #
IxOptic An_AffineTraversal s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic An_AffineTraversal is s t a b -> Optic An_AffineTraversal NoIx s t a b Source #
IxOptic A_Lens s t a b Source #
Instance details Defined in Optics.Indexed.Core Methods noIx :: forall (is :: IxList). NonEmptyIndices is => Optic A_Lens is s t a b -> Optic A_Lens NoIx s t a b Source #

conjoined :: is `HasSingleIndex` i => Optic k NoIx s t a b -> Optic k is s t a b -> Optic k is s t a b Source #

Construct a conjoined indexed optic that provides a separate code path when used without indices. Useful for defining indexed optics that are as efficient as their unindexed equivalents when used without indices.

Note: conjoined f g is well-defined if and only if f ≡ noIx g.

Composition of indexed optics

(%) :: forall k l m is js ks s t u v a b. (JoinKinds k l m, AppendIndices is js ks) => Optic k is s t u v -> Optic l js u v a b -> Optic m ks s t a b infixl 9 Source #

Compose two optics of compatible flavours.

Returns an optic of the appropriate supertype. If either or both optics are indexed, the composition preserves all the indices.

(<%>) :: (JoinKinds k l m, IxOptic m s t a b, is `HasSingleIndex` i, js `HasSingleIndex` j) => Optic k is s t u v -> Optic l js u v a b -> Optic m (WithIx (i, j)) s t a b infixl 9 Source #

Compose two indexed optics. Their indices are composed as a pair.

>>> itoListOf (ifolded <%> ifolded) ["foo", "bar"]
[((0,0),'f'),((0,1),'o'),((0,2),'o'),((1,0),'b'),((1,1),'a'),((1,2),'r')]

(%>) :: (JoinKinds k l m, IxOptic k s t u v, NonEmptyIndices is) => Optic k is s t u v -> Optic l js u v a b -> Optic m js s t a b infixl 9 Source #

Compose two indexed optics and drop indices of the left one. (If you want to compose a non-indexed and an indexed optic, you can just use (%).)

>>> itoListOf (ifolded %> ifolded) ["foo", "bar"]
[(0,'f'),(1,'o'),(2,'o'),(0,'b'),(1,'a'),(2,'r')]

(<%) :: (JoinKinds k l m, IxOptic l u v a b, NonEmptyIndices js) => Optic k is s t u v -> Optic l js u v a b -> Optic m is s t a b infixl 9 Source #

Compose two indexed optics and drop indices of the right one. (If you want to compose an indexed and a non-indexed optic, you can just use (%).)

>>> itoListOf (ifolded <% ifolded) ["foo", "bar"]
[(0,'f'),(0,'o'),(0,'o'),(1,'b'),(1,'a'),(1,'r')]

reindexed :: is `HasSingleIndex` i => (i -> j) -> Optic k is s t a b -> Optic k (WithIx j) s t a b Source #

Remap the index.

>>> itoListOf (reindexed succ ifolded) "foo"
[(1,'f'),(2,'o'),(3,'o')]

>>> itoListOf (ifolded %& reindexed succ) "foo"
[(1,'f'),(2,'o'),(3,'o')]

icompose :: (i -> j -> ix) -> Optic k '[i, j] s t a b -> Optic k (WithIx ix) s t a b Source #

Flatten indices obtained from two indexed optics.

>>> itoListOf (ifolded % ifolded %& icompose (,)) ["foo","bar"]
[((0,0),'f'),((0,1),'o'),((0,2),'o'),((1,0),'b'),((1,1),'a'),((1,2),'r')]

icompose3 :: (i1 -> i2 -> i3 -> ix) -> Optic k '[i1, i2, i3] s t a b -> Optic k (WithIx ix) s t a b Source #

Flatten indices obtained from three indexed optics.

>>> itoListOf (ifolded % ifolded % ifolded %& icompose3 (,,)) [["foo","bar"],["xyz"]]
[((0,0,0),'f'),((0,0,1),'o'),((0,0,2),'o'),((0,1,0),'b'),((0,1,1),'a'),((0,1,2),'r'),((1,0,0),'x'),((1,0,1),'y'),((1,0,2),'z')]

icompose4 :: (i1 -> i2 -> i3 -> i4 -> ix) -> Optic k '[i1, i2, i3, i4] s t a b -> Optic k (WithIx ix) s t a b Source #

Flatten indices obtained from four indexed optics.

icompose5 :: (i1 -> i2 -> i3 -> i4 -> i5 -> ix) -> Optic k '[i1, i2, i3, i4, i5] s t a b -> Optic k (WithIx ix) s t a b Source #

Flatten indices obtained from five indexed optics.

icomposeN :: forall k i is s t a b. (CurryCompose is, NonEmptyIndices is) => Curry is i -> Optic k is s t a b -> Optic k (WithIx i) s t a b Source #

Flatten indices obtained from arbitrary number of indexed optics.

Indexed optic flavours

module Optics.IxAffineFold

module Optics.IxAffineTraversal

module Optics.IxFold

module Optics.IxGetter

module Optics.IxLens

module Optics.IxSetter

module Optics.IxTraversal

Functors with index

class Functor f => FunctorWithIndex i (f :: Type -> Type) | f -> i where #

A Functor with an additional index.

Instances must satisfy a modified form of the Functor laws:

imap f . imap g ≡ imap (\i -> f i . g i)
imap (\_ a -> a) ≡ id

Minimal complete definition

Nothing

Methods

imap :: (i -> a -> b) -> f a -> f b #

Map with access to the index.

Instances

Instances details

FunctorWithIndex Int []	The position in the list is available as the index.
Instance details Defined in WithIndex Methods imap :: (Int -> a -> b) -> [a] -> [b] #
FunctorWithIndex Int ZipList	Same instance as for `[]`.
Instance details Defined in WithIndex Methods imap :: (Int -> a -> b) -> ZipList a -> ZipList b #
FunctorWithIndex Int NonEmpty
Instance details Defined in WithIndex Methods imap :: (Int -> a -> b) -> NonEmpty a -> NonEmpty b #
FunctorWithIndex Int IntMap
Instance details Defined in WithIndex Methods imap :: (Int -> a -> b) -> IntMap a -> IntMap b #
FunctorWithIndex Int Seq	The position in the `Seq` is available as the index.
Instance details Defined in WithIndex Methods imap :: (Int -> a -> b) -> Seq a -> Seq b #
FunctorWithIndex () Maybe
Instance details Defined in WithIndex Methods imap :: (() -> a -> b) -> Maybe a -> Maybe b #
FunctorWithIndex () Par1
Instance details Defined in WithIndex Methods imap :: (() -> a -> b) -> Par1 a -> Par1 b #
FunctorWithIndex () Identity
Instance details Defined in WithIndex Methods imap :: (() -> a -> b) -> Identity a -> Identity b #
FunctorWithIndex k (Map k)
Instance details Defined in WithIndex Methods imap :: (k -> a -> b) -> Map k a -> Map k b #
FunctorWithIndex k ((,) k)
Instance details Defined in WithIndex Methods imap :: (k -> a -> b) -> (k, a) -> (k, b) #
Ix i => FunctorWithIndex i (Array i)
Instance details Defined in WithIndex Methods imap :: (i -> a -> b) -> Array i a -> Array i b #
FunctorWithIndex Void (V1 :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (Void -> a -> b) -> V1 a -> V1 b #
FunctorWithIndex Void (U1 :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (Void -> a -> b) -> U1 a -> U1 b #
FunctorWithIndex Void (Proxy :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (Void -> a -> b) -> Proxy a -> Proxy b #
FunctorWithIndex i f => FunctorWithIndex i (Reverse f)
Instance details Defined in WithIndex Methods imap :: (i -> a -> b) -> Reverse f a -> Reverse f b #
FunctorWithIndex i f => FunctorWithIndex i (Rec1 f)
Instance details Defined in WithIndex Methods imap :: (i -> a -> b) -> Rec1 f a -> Rec1 f b #
FunctorWithIndex i m => FunctorWithIndex i (IdentityT m)
Instance details Defined in WithIndex Methods imap :: (i -> a -> b) -> IdentityT m a -> IdentityT m b #
FunctorWithIndex i f => FunctorWithIndex i (Backwards f)
Instance details Defined in WithIndex Methods imap :: (i -> a -> b) -> Backwards f a -> Backwards f b #
FunctorWithIndex Void (Const e :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (Void -> a -> b) -> Const e a -> Const e b #
FunctorWithIndex Void (Constant e :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (Void -> a -> b) -> Constant e a -> Constant e b #
FunctorWithIndex r ((->) r :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (r -> a -> b) -> (r -> a) -> r -> b #
FunctorWithIndex Void (K1 i c :: Type -> Type)
Instance details Defined in WithIndex Methods imap :: (Void -> a -> b) -> K1 i c a -> K1 i c b #
FunctorWithIndex [Int] Tree
Instance details Defined in WithIndex Methods imap :: ([Int] -> a -> b) -> Tree a -> Tree b #
FunctorWithIndex i m => FunctorWithIndex (e, i) (ReaderT e m)
Instance details Defined in WithIndex Methods imap :: ((e, i) -> a -> b) -> ReaderT e m a -> ReaderT e m b #
(FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (Sum f g)
Instance details Defined in WithIndex Methods imap :: (Either i j -> a -> b) -> Sum f g a -> Sum f g b #
(FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (Product f g)
Instance details Defined in WithIndex Methods imap :: (Either i j -> a -> b) -> Product f g a -> Product f g b #
(FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (f :+: g)
Instance details Defined in WithIndex Methods imap :: (Either i j -> a -> b) -> (f :+: g) a -> (f :+: g) b #
(FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (f :*: g)
Instance details Defined in WithIndex Methods imap :: (Either i j -> a -> b) -> (f :: g) a -> (f :: g) b #
(FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (i, j) (Compose f g)
Instance details Defined in WithIndex Methods imap :: ((i, j) -> a -> b) -> Compose f g a -> Compose f g b #
(FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (i, j) (f :.: g)
Instance details Defined in WithIndex Methods imap :: ((i, j) -> a -> b) -> (f :.: g) a -> (f :.: g) b #

Foldable with index

class Foldable f => FoldableWithIndex i (f :: Type -> Type) | f -> i where #

A container that supports folding with an additional index.

Minimal complete definition

Nothing

Methods

ifoldMap :: Monoid m => (i -> a -> m) -> f a -> m #

Fold a container by mapping value to an arbitrary Monoid with access to the index i.

When you don't need access to the index then foldMap is more flexible in what it accepts.

foldMap ≡ ifoldMap . const

ifoldMap' :: Monoid m => (i -> a -> m) -> f a -> m #

A variant of ifoldMap that is strict in the accumulator.

ifoldr :: (i -> a -> b -> b) -> b -> f a -> b #

Right-associative fold of an indexed container with access to the index i.

When you don't need access to the index then foldr is more flexible in what it accepts.

foldr ≡ ifoldr . const

ifoldl :: (i -> b -> a -> b) -> b -> f a -> b #

Left-associative fold of an indexed container with access to the index i.

When you don't need access to the index then foldl is more flexible in what it accepts.

foldl ≡ ifoldl . const

ifoldr' :: (i -> a -> b -> b) -> b -> f a -> b #

Strictly fold right over the elements of a structure with access to the index i.

When you don't need access to the index then foldr' is more flexible in what it accepts.

foldr' ≡ ifoldr' . const

ifoldl' :: (i -> b -> a -> b) -> b -> f a -> b #

Fold over the elements of a structure with an index, associating to the left, but strictly.

When you don't need access to the index then foldlOf' is more flexible in what it accepts.

foldlOf' l ≡ ifoldlOf' l . const

Instances

Instances details

FoldableWithIndex Int []
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Int -> a -> m) -> [a] -> m # ifoldMap' :: Monoid m => (Int -> a -> m) -> [a] -> m # ifoldr :: (Int -> a -> b -> b) -> b -> [a] -> b # ifoldl :: (Int -> b -> a -> b) -> b -> [a] -> b # ifoldr' :: (Int -> a -> b -> b) -> b -> [a] -> b # ifoldl' :: (Int -> b -> a -> b) -> b -> [a] -> b #
FoldableWithIndex Int ZipList
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Int -> a -> m) -> ZipList a -> m # ifoldMap' :: Monoid m => (Int -> a -> m) -> ZipList a -> m # ifoldr :: (Int -> a -> b -> b) -> b -> ZipList a -> b # ifoldl :: (Int -> b -> a -> b) -> b -> ZipList a -> b # ifoldr' :: (Int -> a -> b -> b) -> b -> ZipList a -> b # ifoldl' :: (Int -> b -> a -> b) -> b -> ZipList a -> b #
FoldableWithIndex Int NonEmpty
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Int -> a -> m) -> NonEmpty a -> m # ifoldMap' :: Monoid m => (Int -> a -> m) -> NonEmpty a -> m # ifoldr :: (Int -> a -> b -> b) -> b -> NonEmpty a -> b # ifoldl :: (Int -> b -> a -> b) -> b -> NonEmpty a -> b # ifoldr' :: (Int -> a -> b -> b) -> b -> NonEmpty a -> b # ifoldl' :: (Int -> b -> a -> b) -> b -> NonEmpty a -> b #
FoldableWithIndex Int IntMap
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Int -> a -> m) -> IntMap a -> m # ifoldMap' :: Monoid m => (Int -> a -> m) -> IntMap a -> m # ifoldr :: (Int -> a -> b -> b) -> b -> IntMap a -> b # ifoldl :: (Int -> b -> a -> b) -> b -> IntMap a -> b # ifoldr' :: (Int -> a -> b -> b) -> b -> IntMap a -> b # ifoldl' :: (Int -> b -> a -> b) -> b -> IntMap a -> b #
FoldableWithIndex Int Seq
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Int -> a -> m) -> Seq a -> m # ifoldMap' :: Monoid m => (Int -> a -> m) -> Seq a -> m # ifoldr :: (Int -> a -> b -> b) -> b -> Seq a -> b # ifoldl :: (Int -> b -> a -> b) -> b -> Seq a -> b # ifoldr' :: (Int -> a -> b -> b) -> b -> Seq a -> b # ifoldl' :: (Int -> b -> a -> b) -> b -> Seq a -> b #
FoldableWithIndex () Maybe
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (() -> a -> m) -> Maybe a -> m # ifoldMap' :: Monoid m => (() -> a -> m) -> Maybe a -> m # ifoldr :: (() -> a -> b -> b) -> b -> Maybe a -> b # ifoldl :: (() -> b -> a -> b) -> b -> Maybe a -> b # ifoldr' :: (() -> a -> b -> b) -> b -> Maybe a -> b # ifoldl' :: (() -> b -> a -> b) -> b -> Maybe a -> b #
FoldableWithIndex () Par1
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (() -> a -> m) -> Par1 a -> m # ifoldMap' :: Monoid m => (() -> a -> m) -> Par1 a -> m # ifoldr :: (() -> a -> b -> b) -> b -> Par1 a -> b # ifoldl :: (() -> b -> a -> b) -> b -> Par1 a -> b # ifoldr' :: (() -> a -> b -> b) -> b -> Par1 a -> b # ifoldl' :: (() -> b -> a -> b) -> b -> Par1 a -> b #
FoldableWithIndex () Identity
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (() -> a -> m) -> Identity a -> m # ifoldMap' :: Monoid m => (() -> a -> m) -> Identity a -> m # ifoldr :: (() -> a -> b -> b) -> b -> Identity a -> b # ifoldl :: (() -> b -> a -> b) -> b -> Identity a -> b # ifoldr' :: (() -> a -> b -> b) -> b -> Identity a -> b # ifoldl' :: (() -> b -> a -> b) -> b -> Identity a -> b #
FoldableWithIndex k (Map k)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (k -> a -> m) -> Map k a -> m # ifoldMap' :: Monoid m => (k -> a -> m) -> Map k a -> m # ifoldr :: (k -> a -> b -> b) -> b -> Map k a -> b # ifoldl :: (k -> b -> a -> b) -> b -> Map k a -> b # ifoldr' :: (k -> a -> b -> b) -> b -> Map k a -> b # ifoldl' :: (k -> b -> a -> b) -> b -> Map k a -> b #
FoldableWithIndex k ((,) k)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (k -> a -> m) -> (k, a) -> m # ifoldMap' :: Monoid m => (k -> a -> m) -> (k, a) -> m # ifoldr :: (k -> a -> b -> b) -> b -> (k, a) -> b # ifoldl :: (k -> b -> a -> b) -> b -> (k, a) -> b # ifoldr' :: (k -> a -> b -> b) -> b -> (k, a) -> b # ifoldl' :: (k -> b -> a -> b) -> b -> (k, a) -> b #
Ix i => FoldableWithIndex i (Array i)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (i -> a -> m) -> Array i a -> m # ifoldMap' :: Monoid m => (i -> a -> m) -> Array i a -> m # ifoldr :: (i -> a -> b -> b) -> b -> Array i a -> b # ifoldl :: (i -> b -> a -> b) -> b -> Array i a -> b # ifoldr' :: (i -> a -> b -> b) -> b -> Array i a -> b # ifoldl' :: (i -> b -> a -> b) -> b -> Array i a -> b #
FoldableWithIndex Void (V1 :: Type -> Type)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> V1 a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> V1 a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> V1 a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> V1 a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> V1 a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> V1 a -> b #
FoldableWithIndex Void (U1 :: Type -> Type)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> U1 a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> U1 a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> U1 a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> U1 a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> U1 a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> U1 a -> b #
FoldableWithIndex Void (Proxy :: Type -> Type)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> Proxy a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> Proxy a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> Proxy a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> Proxy a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> Proxy a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> Proxy a -> b #
FoldableWithIndex i f => FoldableWithIndex i (Reverse f)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (i -> a -> m) -> Reverse f a -> m # ifoldMap' :: Monoid m => (i -> a -> m) -> Reverse f a -> m # ifoldr :: (i -> a -> b -> b) -> b -> Reverse f a -> b # ifoldl :: (i -> b -> a -> b) -> b -> Reverse f a -> b # ifoldr' :: (i -> a -> b -> b) -> b -> Reverse f a -> b # ifoldl' :: (i -> b -> a -> b) -> b -> Reverse f a -> b #
FoldableWithIndex i f => FoldableWithIndex i (Rec1 f)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (i -> a -> m) -> Rec1 f a -> m # ifoldMap' :: Monoid m => (i -> a -> m) -> Rec1 f a -> m # ifoldr :: (i -> a -> b -> b) -> b -> Rec1 f a -> b # ifoldl :: (i -> b -> a -> b) -> b -> Rec1 f a -> b # ifoldr' :: (i -> a -> b -> b) -> b -> Rec1 f a -> b # ifoldl' :: (i -> b -> a -> b) -> b -> Rec1 f a -> b #
FoldableWithIndex i m => FoldableWithIndex i (IdentityT m)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m0 => (i -> a -> m0) -> IdentityT m a -> m0 # ifoldMap' :: Monoid m0 => (i -> a -> m0) -> IdentityT m a -> m0 # ifoldr :: (i -> a -> b -> b) -> b -> IdentityT m a -> b # ifoldl :: (i -> b -> a -> b) -> b -> IdentityT m a -> b # ifoldr' :: (i -> a -> b -> b) -> b -> IdentityT m a -> b # ifoldl' :: (i -> b -> a -> b) -> b -> IdentityT m a -> b #
FoldableWithIndex i f => FoldableWithIndex i (Backwards f)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (i -> a -> m) -> Backwards f a -> m # ifoldMap' :: Monoid m => (i -> a -> m) -> Backwards f a -> m # ifoldr :: (i -> a -> b -> b) -> b -> Backwards f a -> b # ifoldl :: (i -> b -> a -> b) -> b -> Backwards f a -> b # ifoldr' :: (i -> a -> b -> b) -> b -> Backwards f a -> b # ifoldl' :: (i -> b -> a -> b) -> b -> Backwards f a -> b #
FoldableWithIndex Void (Const e :: Type -> Type)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> Const e a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> Const e a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> Const e a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> Const e a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> Const e a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> Const e a -> b #
FoldableWithIndex Void (Constant e :: Type -> Type)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> Constant e a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> Constant e a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> Constant e a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> Constant e a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> Constant e a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> Constant e a -> b #
FoldableWithIndex Void (K1 i c :: Type -> Type)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> K1 i c a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> K1 i c a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> K1 i c a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> K1 i c a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> K1 i c a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> K1 i c a -> b #
FoldableWithIndex [Int] Tree
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => ([Int] -> a -> m) -> Tree a -> m # ifoldMap' :: Monoid m => ([Int] -> a -> m) -> Tree a -> m # ifoldr :: ([Int] -> a -> b -> b) -> b -> Tree a -> b # ifoldl :: ([Int] -> b -> a -> b) -> b -> Tree a -> b # ifoldr' :: ([Int] -> a -> b -> b) -> b -> Tree a -> b # ifoldl' :: ([Int] -> b -> a -> b) -> b -> Tree a -> b #
(FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (Sum f g)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> Sum f g a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> Sum f g a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> Sum f g a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> Sum f g a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> Sum f g a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> Sum f g a -> b #
(FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (Product f g)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> Product f g a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> Product f g a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> Product f g a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> Product f g a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> Product f g a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> Product f g a -> b #
(FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (f :+: g)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> (f :+: g) a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> (f :+: g) a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> (f :+: g) a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> (f :+: g) a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> (f :+: g) a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> (f :+: g) a -> b #
(FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (f :*: g)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> (f :: g) a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> (f :: g) a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> (f :: g) a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> (f :: g) a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> (f :: g) a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> (f :: g) a -> b #
(FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (i, j) (Compose f g)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => ((i, j) -> a -> m) -> Compose f g a -> m # ifoldMap' :: Monoid m => ((i, j) -> a -> m) -> Compose f g a -> m # ifoldr :: ((i, j) -> a -> b -> b) -> b -> Compose f g a -> b # ifoldl :: ((i, j) -> b -> a -> b) -> b -> Compose f g a -> b # ifoldr' :: ((i, j) -> a -> b -> b) -> b -> Compose f g a -> b # ifoldl' :: ((i, j) -> b -> a -> b) -> b -> Compose f g a -> b #
(FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (i, j) (f :.: g)
Instance details Defined in WithIndex Methods ifoldMap :: Monoid m => ((i, j) -> a -> m) -> (f :.: g) a -> m # ifoldMap' :: Monoid m => ((i, j) -> a -> m) -> (f :.: g) a -> m # ifoldr :: ((i, j) -> a -> b -> b) -> b -> (f :.: g) a -> b # ifoldl :: ((i, j) -> b -> a -> b) -> b -> (f :.: g) a -> b # ifoldr' :: ((i, j) -> a -> b -> b) -> b -> (f :.: g) a -> b # ifoldl' :: ((i, j) -> b -> a -> b) -> b -> (f :.: g) a -> b #

itraverse_ :: (FoldableWithIndex i t, Applicative f) => (i -> a -> f b) -> t a -> f () #

Traverse elements with access to the index i, discarding the results.

When you don't need access to the index then traverse_ is more flexible in what it accepts.

traverse_ l = itraverse . const

ifor_ :: (FoldableWithIndex i t, Applicative f) => t a -> (i -> a -> f b) -> f () #

Traverse elements with access to the index i, discarding the results (with the arguments flipped).

ifor_ ≡ flip itraverse_

When you don't need access to the index then for_ is more flexible in what it accepts.

for_ a ≡ ifor_ a . const

itoList :: FoldableWithIndex i f => f a -> [(i, a)] #

Extract the key-value pairs from a structure.

When you don't need access to the indices in the result, then toList is more flexible in what it accepts.

toList ≡ map snd . itoList

Traversable with index

class (FunctorWithIndex i t, FoldableWithIndex i t, Traversable t) => TraversableWithIndex i (t :: Type -> Type) | t -> i where #

A Traversable with an additional index.

An instance must satisfy a (modified) form of the Traversable laws:

itraverse (const Identity) ≡ Identity
fmap (itraverse f) . itraverse g ≡ getCompose . itraverse (\i -> Compose . fmap (f i) . g i)

Minimal complete definition

Nothing

Methods

itraverse :: Applicative f => (i -> a -> f b) -> t a -> f (t b) #

Traverse an indexed container.

itraverse ≡ itraverseOf itraversed

Instances

Instances details

TraversableWithIndex Int []
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Int -> a -> f b) -> [a] -> f [b] #
TraversableWithIndex Int ZipList
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Int -> a -> f b) -> ZipList a -> f (ZipList b) #
TraversableWithIndex Int NonEmpty
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Int -> a -> f b) -> NonEmpty a -> f (NonEmpty b) #
TraversableWithIndex Int IntMap
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Int -> a -> f b) -> IntMap a -> f (IntMap b) #
TraversableWithIndex Int Seq
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Int -> a -> f b) -> Seq a -> f (Seq b) #
TraversableWithIndex () Maybe
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (() -> a -> f b) -> Maybe a -> f (Maybe b) #
TraversableWithIndex () Par1
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (() -> a -> f b) -> Par1 a -> f (Par1 b) #
TraversableWithIndex () Identity
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (() -> a -> f b) -> Identity a -> f (Identity b) #
TraversableWithIndex k (Map k)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (k -> a -> f b) -> Map k a -> f (Map k b) #
TraversableWithIndex k ((,) k)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (k -> a -> f b) -> (k, a) -> f (k, b) #
Ix i => TraversableWithIndex i (Array i)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (i -> a -> f b) -> Array i a -> f (Array i b) #
TraversableWithIndex Void (V1 :: Type -> Type)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Void -> a -> f b) -> V1 a -> f (V1 b) #
TraversableWithIndex Void (U1 :: Type -> Type)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Void -> a -> f b) -> U1 a -> f (U1 b) #
TraversableWithIndex Void (Proxy :: Type -> Type)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Void -> a -> f b) -> Proxy a -> f (Proxy b) #
TraversableWithIndex i f => TraversableWithIndex i (Reverse f)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (i -> a -> f0 b) -> Reverse f a -> f0 (Reverse f b) #
TraversableWithIndex i f => TraversableWithIndex i (Rec1 f)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (i -> a -> f0 b) -> Rec1 f a -> f0 (Rec1 f b) #
TraversableWithIndex i m => TraversableWithIndex i (IdentityT m)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (i -> a -> f b) -> IdentityT m a -> f (IdentityT m b) #
TraversableWithIndex i f => TraversableWithIndex i (Backwards f)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (i -> a -> f0 b) -> Backwards f a -> f0 (Backwards f b) #
TraversableWithIndex Void (Const e :: Type -> Type)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Void -> a -> f b) -> Const e a -> f (Const e b) #
TraversableWithIndex Void (Constant e :: Type -> Type)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Void -> a -> f b) -> Constant e a -> f (Constant e b) #
TraversableWithIndex Void (K1 i c :: Type -> Type)
Instance details Defined in WithIndex Methods itraverse :: Applicative f => (Void -> a -> f b) -> K1 i c a -> f (K1 i c b) #
TraversableWithIndex [Int] Tree
Instance details Defined in WithIndex Methods itraverse :: Applicative f => ([Int] -> a -> f b) -> Tree a -> f (Tree b) #
(TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (Sum f g)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (Either i j -> a -> f0 b) -> Sum f g a -> f0 (Sum f g b) #
(TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (Product f g)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (Either i j -> a -> f0 b) -> Product f g a -> f0 (Product f g b) #
(TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (f :+: g)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (Either i j -> a -> f0 b) -> (f :+: g) a -> f0 ((f :+: g) b) #
(TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (f :*: g)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => (Either i j -> a -> f0 b) -> (f :: g) a -> f0 ((f :: g) b) #
(TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (i, j) (Compose f g)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => ((i, j) -> a -> f0 b) -> Compose f g a -> f0 (Compose f g b) #
(TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (i, j) (f :.: g)
Instance details Defined in WithIndex Methods itraverse :: Applicative f0 => ((i, j) -> a -> f0 b) -> (f :.: g) a -> f0 ((f :.: g) b) #

ifor :: (TraversableWithIndex i t, Applicative f) => t a -> (i -> a -> f b) -> f (t b) #

Traverse with an index (and the arguments flipped).

for a ≡ ifor a . const
ifor ≡ flip itraverse