fclabels 0.2.0 → 0.3.0

raw patch · 2 files changed

+48/−65 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• Data/Record/Label.hs +27/−47
• fclabels.cabal +21/−18

@@ -11,28 +11,30 @@   , mkModifier   , mkLabel -  -- * Bidirectional composition.-+  -- * Identity and composition.+  , idL   , (%)++  -- * Bidirectional functor.+   , Lens (..)+  , (%%)    -- * State monadic label operations.    , getM, setM, modM, (=:)-  , enterM-  , enterMT-  , bothM-  , localM-  , withM -  -- * Convenient label for list indexing.+  -- * Useful example labels.   , list+  , maybeNull    -- * Derive labels using Template Haskell.   , module Data.Record.Label.TH    ) where +import Prelude hiding ((.), id)+import Control.Category import Control.Monad.State import Data.Record.Label.TH @@ -57,10 +59,17 @@ mkLabel :: Getter a b -> Setter a b -> a :-> b mkLabel g s = Label g s (mkModifier g s) +idL :: a :-> a+idL = mkLabel id const+ infixr 8 % (%) :: (g :-> a) -> (f :-> g) -> (f :-> a) a % b = Label (lget a . lget b) (lmod b . lset a) (lmod b . lmod a) +instance Category (:->) where+  id = idL+  (.) = (%)+ -- Apply custom `parser' and 'printer' function. This can be seen as a -- bidirectional functorial map. @@ -70,8 +79,12 @@ instance Lens ((:->) f) where   lmap (f, g) (Label a b c) = Label (f . a) (b . g) (c . (g.) . (.f)) --- Extend the state monad with support for labels.+-- | Apply label to lifted value and join afterwards. +infixr 8 %%+(%%) :: Functor f => a :-> b -> g :-> f a -> g :-> f b+(%%) a b = let (Label g s _) = a in (fmap g, fmap (\k -> s k (error "unused"))) `lmap` b+ -- | Get a value out of state pointed to by the specified label.  getM :: MonadState s m => s :-> b -> m b@@ -94,46 +107,13 @@ modM :: MonadState s m => s :-> b -> (b -> b) -> m () modM l = modify . lmod l ------- Run a state computation for a sub element updating this part of the state afterwards.--enterM :: MonadState s m => s :-> b -> State b b1 -> m b1-enterM l c = do-  b <- getM l-  let (a, s) = runState c b-  setM l s-  return a--enterMT-  :: (MonadState s (t m), MonadTrans t, Monad m)-  => s :-> b -> StateT b m a -> t m a-enterMT l c = do-  b <- getM l-  (a, s) <- lift $ runStateT c b-  setM l s-  return a--bothM :: MonadState s m => s :-> b -> State b b1 -> m (b, b1)-bothM parent cmp = do-  p <- getM parent-  c <- enterM parent cmp-  return (p, c)--localM :: MonadState s m => s :-> b -> m b1 -> m b1-localM l comp = do-  k <- getM l-  c <- comp-  setM l k-  return c--withM :: MonadState s m => s :-> b -> State b a -> m b1 -> m b1-withM l c d = localM l (enterM l c >> d)- -- Lift list indexing to a label.  list :: Int -> [a] :-> a list i = mkLabel (!! i) (\v a -> take i a ++ [v] ++ drop (i+1) a)++-- View null lists as Nothing.++maybeNull :: [a] :-> Maybe [a]+maybeNull = (\x -> if null x then Nothing else Just x, maybe [] id) `lmap` id 

@@ -1,19 +1,22 @@-name:            fclabels-version:         0.2.0-author:          Sebastiaan Visser, Erik Hesselink-synopsis:        First class record labels-description:     First class labels for records, with combinators, allowing-                 selection, modification and update inside (nested) records.-                 Also includes MonadState versions of these, and template-                 haskell generation of the labels.-maintainer:      Sebastiaan Visser <sfvisser@cs.uu.nl>-license:         BSD3-license-file:    LICENCE-category:        Data-build-type:      Simple-cabal-version:   >= 1.6-exposed-modules: Data.Record.Label-other-modules:   Data.Record.Label.TH--build-depends:   base >= 3 && < 5, template-haskell >= 2.2 && < 2.4, monads-fd ==0.0.*+Name:            fclabels+Version:         0.3.0+Author:          Sebastiaan Visser, Erik Hesselink+Synopsis:        First class accessor labels.+Description:     First class labels that act as bidirectional records fields.+                 The labels are fully composable and can be used to get, set+                 and modify part of datatypes in a consistent way. The label+                 datatype, conveniently called `:->', is an instance of the+                 `Category' type class, so is has a proper identity and+                 composition. The library has support for automatically+                 deriving labels from record selectors that start with an+                 underscore.+Maintainer:      Sebastiaan Visser <sfvisser@cs.uu.nl>+License:         BSD3+License-File:    LICENCE+Category:        Data+Build-Type:      Simple+Cabal-Version:   >= 1.6+Exposed-Modules: Data.Record.Label+Other-Modules:   Data.Record.Label.TH+Build-Depends:   base >= 3 && < 5, template-haskell >= 2.2 && < 2.4, monads-fd ==0.0.*