semigroups 0.2.0 → 0.3.0

raw patch · 2 files changed

+54/−15 lines, 2 files

Files

• Data/Semigroup.hs +53/−14
• semigroups.cabal +1/−1

@@ -1,3 +1,4 @@+{-# LANGUAGE DeriveDataTypeable #-} ----------------------------------------------------------------------------- -- | -- Module      :  Data.Semigroup@@ -11,24 +12,34 @@ ---------------------------------------------------------------------------- module Data.Semigroup (      Semigroup(..)+  -- * Semigroups   , Min(..)   , Max(..)-  , Option(..)+  , First(..)+  , Last(..)   , WrappedMonoid(..)+  -- * Monoids from Data.Monoid +  , Dual(..)+  , Endo(..)+  , All(..)+  , Any(..)+  , Sum(..)+  , Product(..)+  -- * New Monoids+  , Option(..)+  , option   ) where  import Prelude hiding (foldr1)-import Data.Monoid-import Data.Foldable+import Data.Monoid hiding (First(..), Last(..))+import qualified Data.Monoid as Monoid+import Data.Data  infixl 4 <>   class Semigroup a where   (<>) :: a -> a -> a -  fold1 :: Foldable f => f a -> a-  fold1 = foldr1 (<>) - -- Semigroups from Data.Monoid  instance Semigroup a => Semigroup (Dual a) where@@ -49,28 +60,54 @@ instance Num a => Semigroup (Product a) where   Product a <> Product b = Product (a * b) -instance Semigroup (First a) where-  First Nothing <> b = b+instance Semigroup (Monoid.First a) where+  Monoid.First Nothing <> b = b   a             <> _ = a -instance Semigroup (Last a) where-  a <> Last Nothing = a+instance Semigroup (Monoid.Last a) where+  a <> Monoid.Last Nothing = a   _ <> b            = b +-- * Other Semigroups  newtype Min a = Min { getMin :: a } +  deriving (Eq,Ord,Bounded,Show,Read,Data,Typeable)+ instance Ord a => Semigroup (Min a) where   Min a <> Min b = Min (a `min` b) +instance (Ord a, Bounded a) => Monoid (Min a) where+  mempty = maxBound+  mappend = (<>) + newtype Max a = Max { getMax :: a } +  deriving (Eq,Ord,Bounded,Show,Read,Data,Typeable)+ instance Ord a => Semigroup (Max a) where   Max a <> Max b = Max (a `min` b) --- (==)/XNOR on Bool forms a Semigroup, but has no good name+instance (Ord a, Bounded a) => Monoid (Max a) where+  mempty = minBound+  mappend = (<>)  +-- | Use Option (First a) -- to get the behavior of Data.Monoid.First+newtype First a = First { getFirst :: a }+  deriving (Eq,Ord,Bounded,Show,Read,Data,Typeable) +instance Semigroup (First a) where+  a <> _ = a++-- | Use Option (Last a) -- to get the behavior of Data.Monoid.Last+newtype Last a = Last { getLast :: a }+  deriving (Eq,Ord,Bounded,Show,Read,Data,Typeable)++instance Semigroup (Last a) where+  _ <> b = b++-- (==)/XNOR on Bool forms a Semigroup, but has no good name+ newtype WrappedMonoid m = WrapMonoid { unwrapMonoid :: m } -  deriving (Show, Read, Eq, Ord)+  deriving (Data, Typeable, Show, Read, Eq, Ord)  instance Monoid m => Semigroup (WrappedMonoid m) where   WrapMonoid a <> WrapMonoid b = WrapMonoid (a `mappend` b)@@ -79,9 +116,11 @@   mempty = WrapMonoid mempty   WrapMonoid a `mappend` WrapMonoid b = WrapMonoid (a `mappend` b) - newtype Option a = Option { getOption :: Maybe a } -  deriving (Show, Read, Eq, Ord)+  deriving (Data, Typeable, Show, Read, Eq, Ord)++option :: b -> (a -> b) -> Option a -> b+option n j (Option m) = maybe n j m  instance Semigroup a => Semigroup (Option a) where   Option Nothing <> b = b

@@ -1,6 +1,6 @@ name:          semigroups category:      Control, Comonads-version:       0.2.0+version:       0.3.0 license:       BSD3 cabal-version: >= 1.2 license-file:  LICENSE