church-pair (empty) → 0.1.0.0

raw patch · 5 files changed

+160/−0 lines, 5 filesdep +basesetup-changed

Dependencies added: base

Files

• CHANGELOG.md +5/−0
• Data/Church/Pair.hs +97/−0
• LICENSE +30/−0
• Setup.hs +2/−0
• church-pair.cabal +26/−0

@@ -0,0 +1,5 @@+# Revision history for church-pair++## 0.1.0.0++* First version. Released on an unsuspecting world.

@@ -0,0 +1,97 @@+{-# LANGUAGE Rank2Types #-}+{-# LANGUAGE Safe #-}++-----------------------------------------------------------------------------+-- |+-- Module      : Data.Church.Pair+-- Copyright   : Matthew Harm Bekkema 2017+-- License     : BSD3+-- Maintainer  : mbekkema97@gmail.com+-- Stability   : experimental+-- Portability : portable+--+-- The church encoded pair type and associated operations.+--+-----------------------------------------------------------------------------++module Data.Church.Pair+( Pair(Pair)+, mkPair+, pair+) where++import Data.Bifunctor (Bifunctor (bimap), second)+import Data.Semigroup (Semigroup ((<>), stimes))+import Data.Functor.Classes (Eq2 (liftEq2), Eq1 (liftEq), Ord2 (liftCompare2),+                             Ord1 (liftCompare), eq2, compare2)+++-- | The church encoded pair+newtype Pair a b = Pair { runPair :: forall r. (a -> b -> r) -> r }++instance Bifunctor Pair where+    bimap fx fy (Pair p) = Pair $ \r -> p $ \x y -> r (fx x) (fy y)++instance Functor (Pair a) where+    fmap = second++instance Eq2 Pair where+    liftEq2 f1 f2 (Pair px) (Pair py) = px $ \x1 x2 -> py $ \y1 y2 ->+        f1 x1 y1 && f2 x2 y2++instance Ord2 Pair where+    liftCompare2 f1 f2 (Pair px) (Pair py) = px $ \x1 x2 -> py $ \y1 y2 ->+        case f1 x1 y1 of+            EQ -> f2 x2 y2+            oo -> oo++instance Eq a => Eq1 (Pair a) where+    liftEq = liftEq2 (==)++instance Ord a => Ord1 (Pair a) where+    liftCompare = liftCompare2 compare++instance (Eq a, Eq b) => Eq (Pair a b) where+    (==) = eq2++instance (Ord a, Ord b) => Ord (Pair a b) where+    compare = compare2++instance (Semigroup a, Semigroup b) => Semigroup (Pair a b) where+    (<>) = liftMappend2 (<>) (<>)+    stimes n (Pair p) = Pair $ \r -> p $ \x y -> r (stimes n x) (stimes n y)++instance (Monoid a, Monoid b) => Monoid (Pair a b) where+    mempty = mkPair mempty mempty+    mappend = liftMappend2 mappend mappend++instance Monoid a => Applicative (Pair a) where+    pure = mkPair mempty+    Pair pf <*> Pair px = Pair $ \r -> pf $ \u f -> px $ \v x ->+        r (mappend u v) (f x)++instance Foldable (Pair a) where+    foldr f z (Pair p) = p $ \_ y -> f y z+    foldMap f (Pair p) = p $ \_ y -> f y++instance Traversable (Pair a) where+    traverse f (Pair p) = p $ \x y -> mkPair x <$> f y++instance Monoid a => Monad (Pair a) where+    return = pure+    (Pair p) >>= k = Pair $ \r -> p $ \u a -> runPair (k a) $ r . mappend u+++liftMappend2 :: (a -> a -> a)+             -> (b -> b -> b)+             -> (Pair a b -> Pair a b -> Pair a b)+liftMappend2 f1 f2 (Pair px) (Pair py) = Pair $ \r -> px $ \x1 x2 -> py $ \y1 y2 ->+    r (f1 x1 y1) (f2 x2 y2)++-- | Case analysis on `Pair`+pair :: (a -> b -> r) -> Pair a b -> r+pair = flip runPair++-- | Construct a `Pair` from two values+mkPair :: a -> b -> Pair a b+mkPair x y = Pair $ \r -> r x y

@@ -0,0 +1,30 @@+Copyright (c) 2017, Matthew Harm Bekkema++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.++    * Redistributions in binary form must reproduce the above+      copyright notice, this list of conditions and the following+      disclaimer in the documentation and/or other materials provided+      with the distribution.++    * Neither the name of Matthew Harm Bekkema nor the names of other+      contributors may be used to endorse or promote products derived+      from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

@@ -0,0 +1,26 @@+name:                church-pair+version:             0.1.0.0+license:             BSD3+license-file:        LICENSE+author:              Matthew Harm Bekkema+maintainer:          mbekkema97@gmail.com+synopsis:            Church encoded pair+category:            Data+description:+    This package contains a Church encoded 'Pair' type along with appropriate+    instances for typeclasses in 'base'.+cabal-version:       >=1.10+build-type:          Simple++extra-source-files:  CHANGELOG.md+++library+  default-language:    Haskell98++  other-extensions:    Rank2Types+                       Safe++  build-depends:       base >= 4.9 && < 5+  exposed-modules:     Data.Church.Pair+  ghc-options:         -Wall