Module

Data.Bitraversable

#Bitraversable 

class (Bifunctor t, Bifoldable t) <= Bitraversable t  where

Bitraversable represents data structures with two type arguments which can be traversed.

A traversal for such a structure requires two functions, one for each type argument. Type class instances should choose the appropriate function based on the type of the element encountered at each point of the traversal.

Default implementations are provided by the following functions:

  • bitraverseDefault
  • bisequenceDefault

Members

Instances

#bitraverseDefault 

bitraverseDefault :: forall t f a b c d. Bitraversable t => Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f (t c d)

A default implementation of bitraverse using bisequence and bimap.

#bisequenceDefault 

bisequenceDefault :: forall t f a b. Bitraversable t => Applicative f => t (f a) (f b) -> f (t a b)

A default implementation of bisequence using bitraverse.

#ltraverse 

ltraverse :: forall t b c a f. Bitraversable t => Applicative f => (a -> f c) -> t a b -> f (t c b)

#rtraverse 

rtraverse :: forall t b c a f. Bitraversable t => Applicative f => (b -> f c) -> t a b -> f (t a c)

#bifor 

bifor :: forall t f a b c d. Bitraversable t => Applicative f => t a b -> (a -> f c) -> (b -> f d) -> f (t c d)

Traverse a data structure, accumulating effects and results using an Applicative functor.

#lfor 

lfor :: forall t b c a f. Bitraversable t => Applicative f => t a b -> (a -> f c) -> f (t c b)

#rfor 

rfor :: forall t b c a f. Bitraversable t => Applicative f => t a b -> (b -> f c) -> f (t a c)

Re-exports from Data.Bifoldable

#Bifoldable 

class Bifoldable p  where

Bifoldable represents data structures with two type arguments which can be folded.

A fold for such a structure requires two step functions, one for each type argument. Type class instances should choose the appropriate step function based on the type of the element encountered at each point of the fold.

Default implementations are provided by the following functions:

  • bifoldrDefault
  • bifoldlDefault
  • bifoldMapDefaultR
  • bifoldMapDefaultL

Note: some combinations of the default implementations are unsafe to use together - causing a non-terminating mutually recursive cycle. These combinations are documented per function.

Members

  • bifoldr :: forall a b c. (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c
  • bifoldl :: forall a b c. (c -> a -> c) -> (c -> b -> c) -> c -> p a b -> c
  • bifoldMap :: forall m a b. Monoid m => (a -> m) -> (b -> m) -> p a b -> m

Instances

#bitraverse_ 

bitraverse_ :: forall t f a b c d. Bifoldable t => Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f Unit

Traverse a data structure, accumulating effects using an Applicative functor, ignoring the final result.

#bisequence_ 

bisequence_ :: forall t f a b. Bifoldable t => Applicative f => t (f a) (f b) -> f Unit

Collapse a data structure, collecting effects using an Applicative functor, ignoring the final result.

#bifor_ 

bifor_ :: forall t f a b c d. Bifoldable t => Applicative f => t a b -> (a -> f c) -> (b -> f d) -> f Unit

A version of bitraverse_ with the data structure as the first argument.

#bifoldrDefault 

bifoldrDefault :: forall p a b c. Bifoldable p => (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c

A default implementation of bifoldr using bifoldMap.

Note: when defining a Bifoldable instance, this function is unsafe to use in combination with bifoldMapDefaultR.

#bifoldlDefault 

bifoldlDefault :: forall p a b c. Bifoldable p => (c -> a -> c) -> (c -> b -> c) -> c -> p a b -> c

A default implementation of bifoldl using bifoldMap.

Note: when defining a Bifoldable instance, this function is unsafe to use in combination with bifoldMapDefaultL.

#bifoldMapDefaultR 

bifoldMapDefaultR :: forall p m a b. Bifoldable p => Monoid m => (a -> m) -> (b -> m) -> p a b -> m

A default implementation of bifoldMap using bifoldr.

Note: when defining a Bifoldable instance, this function is unsafe to use in combination with bifoldrDefault.

#bifoldMapDefaultL 

bifoldMapDefaultL :: forall p m a b. Bifoldable p => Monoid m => (a -> m) -> (b -> m) -> p a b -> m

A default implementation of bifoldMap using bifoldl.

Note: when defining a Bifoldable instance, this function is unsafe to use in combination with bifoldlDefault.

#bifold 

bifold :: forall t m. Bifoldable t => Monoid m => t m m -> m

Fold a data structure, accumulating values in a monoidal type.

#biany 

biany :: forall t a b c. Bifoldable t => BooleanAlgebra c => (a -> c) -> (b -> c) -> t a b -> c

Test whether a predicate holds at any position in a data structure.

#biall 

biall :: forall t a b c. Bifoldable t => BooleanAlgebra c => (a -> c) -> (b -> c) -> t a b -> c

Test whether a predicate holds at all positions in a data structure.

Packages