This 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)
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.