Indexed Functor, Foldable, and Traversable typeclasses
This Haskell package provides three useful generalizations:
class Functor f => FunctorWithIndex i f | f -> i where imap :: (i -> a -> b) -> f a -> f b
class Foldable f => FoldableWithIndex i f | f -> i where ifoldMap :: Monoid m => (i -> a -> m) -> f a -> m
class (FunctorWithIndex i t, FoldableWithIndex i t, Traversable t) => TraversableWithIndex i t | t -> i where itraverse :: Applicative f => (i -> a -> f b) -> t a -> f (t b)
The ghc-keys
package provides similar functionality, but uses associated TypeFamilies
instead of FunctionalDependencies
.
Linter | Message | Location |
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formatting Look for formatting issues in the source | line 14866 is way too long (91 characters) |