yaya 0.6.1.0 → 0.6.2.0

raw patch · 4 files changed

+36/−18 lines, 4 files

Files

• src/Yaya/Fold.hs +3/−3
• src/Yaya/Fold/Common.hs +4/−3
• src/Yaya/Zoo.hs +28/−11
• yaya.cabal +1/−1

@@ -328,9 +328,9 @@  -- | A fixed-point operator for inductive / finite data structures. -----  *NB*: This is only guaranteed to be finite when @f a@ is strict in @a@---       (having strict functors won't prevent `Nu` from being lazy). Using---       @-XStrictData@ can help with this a lot.+--  __NB__: This is only guaranteed to be finite when @f a@ is strict in @a@+--         (having strict functors won't prevent `Nu` from being lazy). Using+--          @-XStrictData@ can help with this a lot. newtype Mu f = Mu (forall a. Algebra (->) f a -> a)  instance (Functor f) => Projectable (->) (Mu f) f where

@@ -122,9 +122,10 @@ -- | When folded, returns the number of nodes in the data structure. -- --  __NB__: This is /not/ the same as the length when applied to a list. I.e.,---          @`length` xs + 1 == `cata` `size` xs@, because this is counting the---          nodes of the structure (how many `Neither`s and `Both`s), not how---          many elements (which would be equivalent to only counting `Both`s).+--          @`Data.List.length` xs `+` 1 `==` `Yaya.Fold.cata` `size` xs@,+--          because this is counting the nodes of the structure (how many+--         `Neither`s and `Both`s), not how many elements (which would be+--          equivalent to only counting `Both`s). size :: (Foldable f) => f Natural -> Natural size = foldr (+) 1 

@@ -17,6 +17,7 @@     comap,     comutu,     contramap,+    gapo,     gmutu,     histo,     insidePartial,@@ -45,6 +46,7 @@ import "this" Yaya.Fold   ( Algebra,     AlgebraM,+    Coalgebra,     Corecursive (ana),     DistributiveLaw,     GAlgebra,@@ -75,6 +77,18 @@     uncurry,   ) +-- | A generalized form of `apo`, where, rather than returning a complete+--   branch, you can return a value of another type, provided there is a+--   corresponding `Coalgebra` to expand the value into the same fixed-point+--   result type.+gapo ::+  (Corecursive (->) t f, Functor f) =>+  Coalgebra (->) f b ->+  GCoalgebra (->) (Either b) f a ->+  a ->+  t+gapo ψ = gana $ seqEither ψ+ -- | A recursion scheme that allows you to return a complete branch when --   unfolding. apo ::@@ -82,7 +96,7 @@   GCoalgebra (->) (Either t) f a ->   a ->   t-apo = gana (seqEither project)+apo = gapo project  -- | If you have a monadic algebra, you can fold it by distributing the monad --   over the algebra.@@ -91,7 +105,7 @@   AlgebraM (->) m f a ->   t ->   m a-cataM φ = cata (φ <=< sequenceA)+cataM = cata . (<=< sequenceA)  -- | A recursion scheme that allows two algebras to see each others’ results. (A --   generalization of `zygo`.) This is an example that falls outside the scope@@ -122,7 +136,9 @@       let a = fst p        in fmap (a :!:) (snd p) --- | This could use a better name.+-- | As the name implies, this is the dual of `mutu`, and thus generalizes+--  `gapo`. Each coalgebra can return a value of an alternative type, which+--   causes expansion to continue with the other coalgebra. comutu ::   (Corecursive (->) t f, Functor f) =>   GCoalgebra (->) (Either a) f b ->@@ -162,8 +178,9 @@   m a mutuM φ' φ = fmap snd . cataM (bisequence . bimap (φ' . fmap swap) φ . diagonal) -histo :: (Recursive (->) t f, Functor f) => GAlgebra (->) (Cofree f) f a -> t -> a-histo = gcata (distCofreeT id)+histo ::+  (Recursive (->) t f, Functor f) => GAlgebra (->) (Cofree f) f a -> t -> a+histo = gcata $ distCofreeT id  -- | A recursion scheme that gives you access to the original structure as you --   fold. (A specialization of `zygo`.)@@ -172,7 +189,7 @@   GAlgebra (->) (Pair t) f a ->   t ->   a-para = gcata (distTuple embed)+para = zygo embed  -- | A recursion scheme that uses a “helper algebra” to provide additional --   information when folding. (A generalization of `para`, and specialization@@ -183,18 +200,18 @@   GAlgebra (->) (Pair b) f a ->   t ->   a-zygo φ = gcata (distTuple φ)+zygo φ = gcata $ distTuple φ --- | This definition is different from the one given by `gcataM (distTuple φ')`---   because it has a monadic “helper” algebra. But at least it gives us the---   opportunity to show how `zygo` is a specialization of `mutu`.+-- | This definition is different from the one given by @`gcataM` `.`+--  `distTuple`@ because it has a monadic “helper” algebra. But at least it+--   gives us the opportunity to show how `zygo` is a specialization of `mutu`. zygoM ::   (Monad m, Recursive (->) t f, Traversable f) =>   AlgebraM (->) m f b ->   GAlgebraM (->) m (Pair b) f a ->   t ->   m a-zygoM φ' = mutuM (φ' . fmap snd)+zygoM = mutuM . (. fmap snd)  -- | Potentially-infinite lists, like `[]`. type Colist a = Nu (XNor a)

@@ -1,7 +1,7 @@ cabal-version:  3.0  name:        yaya-version:     0.6.1.0+version:     0.6.2.0 synopsis:    Total recursion schemes. description: Recursion schemes allow you to separate recursion from your              business logic – making your own operations simpler, more modular,