free 4.8 → 4.8.0.1

raw patch · 4 files changed

+29/−14 lines, 4 filesdep ~basePVP ok

version bump matches the API change (PVP)

Dependency ranges changed: base

API changes (from Hackage documentation)

Files

• CHANGELOG.markdown +4/−0
• free.cabal +1/−1
• src/Control/Monad/Free.hs +6/−1
• src/Control/Monad/Free/Church.hs +18/−12

@@ -1,3 +1,7 @@+4.8.0.1+-------+* Allow complation with older versions of `base`. (Foldable didn't add foldl' until base 4.6)+ 4.8 ----- * Added a `MonadFree` instance for `EitherT` (frrom the `either` package).

@@ -1,6 +1,6 @@ name:          free category:      Control, Monads-version:       4.8+version:       4.8.0.1 license:       BSD3 cabal-version: >= 1.10 license-file:  LICENSE

@@ -7,10 +7,13 @@ #if __GLASGOW_HASKELL__ >= 707 {-# LANGUAGE DeriveDataTypeable #-} #endif+#ifndef MIN_VERSION_base+#define MIN_VERSION_base(x,y,z) 1+#endif ----------------------------------------------------------------------------- -- | -- Module      :  Control.Monad.Free--- Copyright   :  (C) 2008-2013 Edward Kmett+-- Copyright   :  (C) 2008-2014 Edward Kmett -- License     :  BSD-style (see the file LICENSE) -- -- Maintainer  :  Edward Kmett <ekmett@gmail.com>@@ -219,12 +222,14 @@         Free fa -> foldr (flip go) r fa   {-# INLINE foldr #-} +#if MIN_VERSION_base(4,6,0)   foldl' f = go where     go r free =       case free of         Pure a -> f r a         Free fa -> foldl' go r fa   {-# INLINE foldl' #-}+#endif  instance Foldable1 f => Foldable1 (Free f) where   foldMap1 f = go where

@@ -1,7 +1,11 @@+{-# LANGUAGE CPP #-} {-# LANGUAGE Rank2Types #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE MultiParamTypeClasses #-}+#ifndef MIN_VERSION_base+#define MIN_VERSION_base(x,y,z) 1+#endif ----------------------------------------------------------------------------- -- | -- Module      :  Control.Monad.Free.Church@@ -18,7 +22,7 @@ -- datatype that allows for arbitrarily deep nesting of the base functor. This is -- akin to a tree, with the leaves containing the values, and the nodes being a -- level of 'Functor' over subtrees.--- +-- -- For each time that the `fmap` or `>>=` operations is used, the old tree is -- traversed up to the leaves, a new set of nodes is allocated, and -- the old ones are garbage collected. Even if the Haskell runtime@@ -30,12 +34,12 @@ -- -- * All uses of `fmap` are collapsed into a single one, so that the values on the --   _leaves_ are transformed in one pass.--- +-- --   prop> fmap f . fmap g == fmap (f . g)--- +-- -- * All uses of `>>=` are right associated, so that every new subtree created --   is final.--- +-- --   prop> (m >>= f) >>= g == m >>= (\x -> f x >>= g) -- -- Asymptotically, the Church encoding supports the monadic operations more@@ -73,9 +77,9 @@ import Prelude hiding (foldr)  -- | The Church-encoded free monad for a functor @f@.--- +-- -- It is /asymptotically/ more efficient to use ('>>=') for 'F' than it is to ('>>=') with 'Free'.--- +-- -- <http://comonad.com/reader/2011/free-monads-for-less-2/> newtype F f a = F { runF :: forall r. (a -> r) -> (f r -> r) -> r } @@ -113,9 +117,11 @@     foldr f r xs = runF xs f (foldr (.) id) r     {-# INLINE foldr #-} -    foldl' f r xs = runF xs (flip f) (foldr (!>>>) id) r-      where (!>>>) f g = \r -> g $! f r+#if MIN_VERSION_base(4,6,0)+    foldl' f z xs = runF xs (flip f) (foldr (!>>>) id) z+      where (!>>>) h g = \r -> g $! h r     {-# INLINE foldl' #-}+#endif  instance MonadPlus f => MonadPlus (F f) where   mzero = F (\_ kf -> kf mzero)@@ -170,13 +176,13 @@   go kp kf (Free fma) = kf (fmap (go kp kf) fma)  -- | Improve the asymptotic performance of code that builds a free monad with only binds and returns by using 'F' behind the scenes.--- +-- -- This is based on the \"Free Monads for Less\" series of articles by Edward Kmett:--- +-- -- * <http://comonad.com/reader/2011/free-monads-for-less/   Free monads for less — Part 1>--- +-- -- * <http://comonad.com/reader/2011/free-monads-for-less-2/ Free monads for less — Part 2>---   +-- -- and <http://www.iai.uni-bonn.de/~jv/mpc08.pdf \"Asymptotic Improvement of Computations over Free Monads\"> by Janis Voightländer. improve :: Functor f => (forall m. MonadFree f m => m a) -> Free f a improve m = fromF m