-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Zipping folds
--   
--   ZipFold is a small package zipping folds, as described in a collection
--   of blog posts, <a>http://conal.net/blog/tag/zip</a>, inspired by a
--   post by Max Rabkin
--   <a>http://squing.blogspot.com/2008/11/beautiful-folding.html</a>.
--   
--   Project wiki page: <a>http://haskell.org/haskellwiki/ZipFold</a>
--   
--   The module documentation pages have links to colorized source code and
--   to wiki pages where you can read and contribute user comments. Enjoy!
--   
--   © 2008 by Conal Elliott; BSD3 license.
@package ZipFold
@version 0.0


-- | Zipping of non-strict left folds.
--   
--   Based on <a>Beautiful Folds</a> by Max Rabkin
--   <a>http://squing.blogspot.com/2008/11/beautiful-folding.html</a>
--   
--   See also
--   <a>http://conal.net/blog/posts/more-beautiful-fold-zipping</a>
module Data.Zip.FoldL

-- | Data representation of a left fold
data Fold b a
F :: (a -> b -> a) -> a -> Fold b a

-- | Interpretation of a <a>Fold</a> as non-strict
cfoldl :: Fold b a -> [b] -> a

-- | Interpretation of a <a>Fold</a> as non-strict
cfoldl' :: Fold b a -> [b] -> a

-- | Add a continuation.
data WithCont h b c

-- | Non-strict left fold with continuation.
type FoldC = WithCont Fold

-- | Interpretation of a <a>FoldC</a>
cfoldlc :: FoldC b a -> [b] -> a

-- | Like <a>WithCont</a> but with pair-strict '(<a>*</a>)'
data WithCont' h b c

-- | Strict left fold with continuation.
type FoldC' = WithCont' Fold

-- | Interpretation of a <a>FoldC</a>
cfoldlc' :: FoldC' b a -> [b] -> a

-- | Strict generalized pair
class Pair' f
pair' :: (Pair' f) => f a -> f b -> f (P a b)

-- | Strict pairs
data P c c'
instance Pair' IO
instance Pair' ((->) u)
instance (Monoid u) => Pair' ((,) u)
instance Pair' []
instance (Pair' (h b)) => Applicative (WithCont' h b)
instance Functor (WithCont' h b)
instance (Pair (h b)) => Applicative (WithCont h b)
instance Functor (WithCont h b)
instance Pair' (Fold b)
instance Pair (Fold b)