recursion-schemes-ext 1.0.0.0 → 1.0.0.1

raw patch · 5 files changed

+38/−32 lines, 5 filesPVP: minor bump suggested

API additions: PVP suggests at least a minor version bump

API changes (from Hackage documentation)

Files

• README.md +0/−4
• recursion-schemes-ext.cabal +3/−4
• src/Data/Functor/Foldable/Exotic.hs +15/−3
• test/Examples.hs +8/−13
• test/Spec.hs +12/−8

@@ -8,7 +8,3 @@  This package provides `cataM`, `anaM`, and `hyloM`. That means you can have (co)algebras that return a monadic value.--## Dendromorphisms etc.--This section of documentation is under construction.

@@ -1,12 +1,12 @@ name:                recursion-schemes-ext-version:             1.0.0.0+version:             1.0.0.1 synopsis:            Amateur addenda to recursion-schemes description:         This package provides some exotic recursion schemes as well monadic versions of some morphisms. homepage:            https://hub.darcs.net/vmchale/recursion-schemes-ext#readme license:             BSD3 license-file:        LICENSE author:              Vanessa McHale-maintainer:          vanessa.mchale@reconfigure.io+maintainer:          vamchale@gmail.com copyright:           Copyright: (c) 2017 Vanessa McHale category:            Control build-type:          Simple@@ -57,9 +57,8 @@   build-depends:       base                      , recursion-schemes-ext                      , criterion-                     , recursion-schemes                      , deepseq-  ghc-options:         -O2+                     , recursion-schemes   default-language:    Haskell2010   if flag(development)     ghc-options:       -Werror

@@ -25,6 +25,8 @@     , mutu     -- * Data type for transformations     , Trans+    -- * Helper functions+    , finish     ) where  import           Control.Arrow@@ -32,8 +34,18 @@ import           Control.Lens import           Data.Functor.Foldable --- margaritari ::+dock :: (Eq a) => [a] -> a+dock [x] = x+dock []  = undefined+dock (x:ys@(y:_))+    | x == y = y+    | otherwise = dock ys +-- | Helper function to force recursion. This can be used alongside 'dendro' to+-- simplify writing a 'Trans'+finish :: (Eq a) => (a -> a) -> a -> a+finish = dock .* iterate+ -- | A map of F-algebras type Trans s a = ∀ f. Functor f => (f a -> a) -> f s -> s @@ -43,7 +55,7 @@  -- | Entangle two hylomorphisms. scolio :: (Functor f, Functor g)-    => ((f b -> b) -> Trans b b) -- ^ A prism parametric in an F-algebra that allows `b` to inspect itself.+    => ((f b -> b) -> Trans b b) -- ^ A pseudoprism parametric in an F-algebra that allows `b` to inspect itself.     -> ((a -> f a) -> Lens' a a) -- ^ A lens parametric in an F-coalgebra that allows `b` to inspect itself.     -> (g b -> b) -- ^ A g-algebra     -> (a -> g a) -- ^ A g-coalgebra@@ -62,7 +74,7 @@  -- | A dendromorphism entangles two catamorphisms dendro :: (Recursive t', Functor f)-    => ((f a -> a) -> Trans b b) -- ^ A prism parametric in an F-algebra that allows `b` to inspect itself.+    => ((f a -> a) -> Trans b b) -- ^ A pseudoprism parametric in an F-algebra that allows `b` to inspect itself.     -> (f a -> a) -- ^ A (Base t)-algebra     -> (Base t' b -> b) -- ^ A (Base t')-algebra     -> t' -> b

@@ -29,7 +29,7 @@ import           Data.Functor.Foldable.TH import           GHC.Generics                 (Generic) --- | We call our co-dependent data types 'Ernie' and 'Bert'. They represent mutually recursive+-- | We call our co-dependent data types 'Ernie' and 'Bert'. data Bert = Bert Ernie           | Num Integer           | String String@@ -38,28 +38,23 @@  data Ernie = Ernie Bert            | Multiply Ernie Ernie-           | List [Ernie]            deriving (Show, Eq, Generic, NFData)  makeBaseFunctor ''Ernie makeBaseFunctor ''Bert --- TODO bifunctor ?? ernieHelper :: (BertF Bert -> Bert) -> Trans Ernie Ernie-ernieHelper alg = (mapErnie g .) -- . (. fmap (mapErnie g))+ernieHelper alg = (mapErnie g .)     where g (Ernie b) = Ernie $ dendro bertHelper ernieAlgebra alg b           g x         = x           mapErnie f (Ernie (Bert e)) = mapErnie f e-          mapErnie f (Multiply e e') = Multiply (mapErnie f e) (mapErnie f e')-          mapErnie f (List es) = List (mapErnie f <$> es)-          mapErnie f e = f e+          mapErnie f e                = f e -bertHelper :: (ErnieF Ernie -> Ernie) -> Trans Bert Bert -- TODO more flexible data type that allows us to use BertF or whatever-bertHelper alg = (mapBert g .) . (. fmap (mapBert g))-    where g (Bert e) = Bert $ dendro ernieHelper bertAlgebra alg e -- FIXME cata alg e?+bertHelper :: (ErnieF Ernie -> Ernie) -> Trans Bert Bert+bertHelper alg = (mapBert g .)+    where g (Bert e) = Bert $ dendro ernieHelper bertAlgebra alg e           g x        = x           mapBert f (Bert (Ernie b)) = mapBert f b-          mapBert f (Add b b')       = Add (mapBert f b) (mapBert f b')           mapBert f x                = f x  -- | BertF-algebra@@ -75,12 +70,12 @@ -- | Dendromorphism collapsing the tree. Note that we can use the same -- F-algebras here as we would in a normal catamorphism. collapseErnieSyntaxTree :: (Recursive Ernie, Recursive Bert) => Ernie -> Ernie-collapseErnieSyntaxTree = dendro ernieHelper bertAlgebra ernieAlgebra+collapseErnieSyntaxTree = finish $ dendro ernieHelper bertAlgebra ernieAlgebra  -- | We can generate two functions by swapping the F-algebras and the dummy -- type. collapseBertSyntaxTree :: (Recursive Bert, Recursive Ernie) => Bert -> Bert-collapseBertSyntaxTree = dendro bertHelper ernieAlgebra bertAlgebra+collapseBertSyntaxTree = finish $ dendro bertHelper ernieAlgebra bertAlgebra  -- | Catamorphism, which collapses the tree the usual way. collapseErnieSyntaxTree' :: (Recursive Ernie) => Ernie -> Ernie

@@ -23,16 +23,20 @@  main :: IO () main = hspec $-    describe "dendro" $ do-        parallel $ it "collapses a simple syntax tree" $+    describe "dendro" $ parallel $ do+        it "collapses a simple syntax tree" $             collapseBertSyntaxTree bertSum `shouldBe` Num 5-        parallel $ it "collapses both parts of a syntax tree" $+        it "collapses both parts of a syntax tree" $             collapseErnieSyntaxTree ernieMult `shouldBe` resultErnie-        parallel $ it "matches solution via catamorphism" $+        it "matches solution via catamorphism" $             collapseErnieSyntaxTree' ernieMult `shouldBe` collapseErnieSyntaxTree ernieMult-        parallel $ it "collapses complex syntax trees" $+        it "collapses complex syntax trees" $             collapseBertSyntaxTree bertComplex `shouldBe` Num 18-        parallel $ it "should work would when triply wrapped (1/2)" $+        it "should work would when triply wrapped (1/2)" $             collapseErnieSyntaxTree (Ernie (Bert (Ernie (Num 15)))) `shouldBe` resultErnie-        parallel $ it "should work would when triply wrapped (2/2)" $-            collapseErnieSyntaxTree (Ernie (Bert ernieComplex)) `shouldBe` resultErnie+        it "should work would when doubly wrapped" $+            collapseBertSyntaxTree (Bert (Ernie (Num 15))) `shouldBe` (Num 15)+        it "should work would when triply wrapped (2/3)" $+            collapseBertSyntaxTree (Bert (Ernie bertComplex)) `shouldBe` (Num 18)+        it "should work would when triply wrapped (3/3)" $+            collapseBertSyntaxTree (Bert ernieComplex) `shouldBe` (Num 15)