comonad 0.6.1.2 → 0.6.2

raw patch · 2 files changed

+61/−2 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• Data/Distributive.hs +59/−0
• comonad.cabal +2/−2

@@ -0,0 +1,59 @@+-----------------------------------------------------------------------------+-- |+-- Module      :  Data.Distributive+-- Copyright   :  (C) 2011 Edward Kmett+-- License     :  BSD-style (see the file LICENSE)+--+-- Maintainer  :  Edward Kmett <ekmett@gmail.com>+-- Stability   :  provisional+-- Portability :  portable+--+----------------------------------------------------------------------------+module Data.Distributive +  ( Distributive(..)+  , fmapDefault+  ) where++import Control.Applicative+import Control.Comonad+import Control.Monad.Trans.Identity+import Control.Monad.Instances ()+import Data.Functor.Identity++-- | This is the categorical dual of 'Traversable'+-- +-- Minimal definition: 'mapW' or 'distribute'+--+-- > mapW = fmap f . duplicate+-- > distribute = mapW id+-- +-- To be distributable a container will need to have a way to consistently+-- zip a potentially infinite number of copies of itself. This effectively+-- means that the holes in all values of that type, must have the same +-- cardinality, fixed sized vectors, infinite streams, functions, etc.+-- and no extra information to try to merge together.++class Functor g => Distributive g where+  -- | The dual of 'Data.Traversable.mapM'+  cotraverse :: Comonad w => (w a -> b) -> w (g a) -> g b++  -- | The dual of 'Data.Traversable.sequence'+  distribute :: Comonad w => w (g a) -> g (w a)++  cotraverse f = fmap f . distribute+  distribute = cotraverse id+  +instance Distributive Identity where+  cotraverse f = Identity . f . fmap runIdentity+  distribute = Identity . fmap runIdentity++instance Distributive ((->)e) where+  distribute w e = fmap ($e) w++instance Distributive g => Distributive (IdentityT g) where+  cotraverse f w = IdentityT $ cotraverse f (runIdentityT <$> w)+  distribute w = IdentityT $ distribute (runIdentityT <$> w)++-- | Every 'Distributive' is a 'Functor'. This is a valid default definition.+fmapDefault :: Distributive g => (a -> b) -> g a -> g b+fmapDefault f = cotraverse (f . runIdentity) . Identity

@@ -1,6 +1,6 @@ name:          comonad category:      Control, Comonads-version:       0.6.1.2+version:       0.6.2 license:       BSD3 cabal-version: >= 1.6 license-file:  LICENSE@@ -17,7 +17,6 @@   type: git   location: git://github.com/ekmett/comonad.git - library   build-depends:      base >= 4 && < 4.4,@@ -25,5 +24,6 @@    exposed-modules:     Control.Comonad+    Data.Distributive    ghc-options: -Wall