semigroupoids 1.3.3 → 1.3.4

raw patch · 2 files changed

+17/−21 lines, 2 files

Files

• Data/Functor/Alt.hs +16/−20
• semigroupoids.cabal +1/−1

@@ -1,4 +1,3 @@-{-# LANGUAGE CPP, FlexibleContexts, ScopedTypeVariables #-} ----------------------------------------------------------------------------- -- | -- Module      :  Data.Functor.Alt@@ -20,7 +19,6 @@ import Control.Exception (catch, SomeException) import Control.Monad import Control.Monad.Trans.Identity--- import Control.Monad.Trans.Cont import Control.Monad.Trans.Error import Control.Monad.Trans.List import Control.Monad.Trans.Maybe@@ -40,34 +38,30 @@ import Data.Sequence (Seq) import qualified Data.Map as Map import Data.Map (Map)-import Prelude hiding (id,-#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 705-                       catch,-#endif-                       (.))+import Prelude (($),Either(..),Maybe(..),const,IO,Ord,(++)) -infixl 3 <!> +infixl 3 <!>  -- | Laws:--- +-- -- > <!> is associative:             (a <!> b) <!> c = a <!> (b <!> c) -- > <$> left-distributes over <!>:  f <$> (a <!> b) = (f <$> a) <!> (f <$> b) -- -- If extended to an 'Alternative' then '<!>' should equal '<|>'. ----- Ideally, an instance of 'Alt' also satisfies the \"left distributon\" law of +-- Ideally, an instance of 'Alt' also satisfies the \"left distributon\" law of -- MonadPlus with respect to <.>: -- -- > <.> right-distributes over <!>: (a <!> b) <.> c = (a <.> c) <!> (b <.> c)--- --- But 'Maybe', 'IO', @'Either' a@, @'ErrorT' e m@, and 'STM' satisfy the alternative +--+-- But 'Maybe', 'IO', @'Either' a@, @'ErrorT' e m@, and 'STM' satisfy the alternative -- \"left catch\" law instead:--- +-- -- > pure a <!> b = pure a -- -- However, this variation cannot be stated purely in terms of the dependencies of 'Alt'. ----- When and if MonadPlus is successfully refactored, this class should also +-- When and if MonadPlus is successfully refactored, this class should also -- be refactored to remove these instances. -- -- The right distributive law should extend in the cases where the a 'Bind' or 'Monad' is@@ -98,7 +92,9 @@ -- | This instance does not actually satisfy the (<.>) right distributive law -- It instead satisfies the "Left-Catch" law instance Alt IO where-  m <!> n = m `catch` \(_ :: SomeException) -> n+  m <!> n = catch m (go n) where+    go :: x -> SomeException -> x+    go = const  instance Alt [] where   (<!>) = (++)@@ -114,7 +110,7 @@   (<!>) = (<|>)  instance ArrowPlus a => Alt (WrappedArrow a b) where-  (<!>) = (<|>) +  (<!>) = (<|>)  instance Ord k => Alt (Map k) where   (<!>) = Map.union@@ -143,7 +139,7 @@     case v of       Nothing -> b       Just _ -> return v-  + instance (Bind f, Monad f) => Alt (ErrorT e f) where   ErrorT m <!> ErrorT n = ErrorT $ do     a <- m@@ -156,16 +152,16 @@  instance Alt f => Alt (Strict.StateT e f) where   Strict.StateT m <!> Strict.StateT n = Strict.StateT $ \s -> m s <!> n s-  + instance Alt f => Alt (Lazy.StateT e f) where   Lazy.StateT m <!> Lazy.StateT n = Lazy.StateT $ \s -> m s <!> n s  instance Alt f => Alt (Strict.WriterT w f) where   Strict.WriterT m <!> Strict.WriterT n = Strict.WriterT $ m <!> n-  + instance Alt f => Alt (Lazy.WriterT w f) where   Lazy.WriterT m <!> Lazy.WriterT n = Lazy.WriterT $ m <!> n-  + instance Alt f => Alt (Strict.RWST r w s f) where   Strict.RWST m <!> Strict.RWST n = Strict.RWST $ \r s -> m r s <!> n r s 

@@ -1,6 +1,6 @@ name:          semigroupoids category:      Control, Comonads-version:       1.3.3+version:       1.3.4 license:       BSD3 cabal-version: >= 1.6 license-file:  LICENSE