free 3.4.2 → 4.0

raw patch · 5 files changed

+34/−16 lines, 5 filesdep −comonad-transformersdep −comonads-fddep ~bifunctorsdep ~comonaddep ~profunctors

Dependencies removed: comonad-transformers, comonads-fd

Dependency ranges changed: bifunctors, comonad, profunctors, semigroupoids, semigroups

Files

• CHANGELOG.markdown +6/−0
• free.cabal +8/−10
• src/Control/Comonad/Cofree/Class.hs +8/−0
• src/Control/Monad/Free.hs +6/−2
• src/Control/Monad/Free/Class.hs +6/−4

@@ -1,3 +1,9 @@+4.0+---+* Updated to work with `semigroupoids` and `comonad` 4.0+* `instance ComonadCofree Maybe NonEmpty`+* `instance ComonadCofree (Const b) ((,) b)`+ 3.4.2 ----- * Generalized `liftF`.

@@ -1,6 +1,6 @@ name:          free category:      Control, Monads-version:       3.4.2+version:       4.0 license:       BSD3 cabal-version: >= 1.10 license-file:  LICENSE@@ -52,17 +52,15 @@     GADTs    build-depends:-    base                 >= 4       && < 5,-    bifunctors           >= 3,+    base                 == 4.*,+    bifunctors           == 3.*,+    comonad              == 4.*,     distributive         >= 0.2.1,-    transformers         >= 0.2.0   && < 0.4,     mtl                  >= 2.0.1.0 && < 2.2,-    semigroupoids        >= 3,-    comonad              >= 3,-    comonad-transformers >= 3,-    comonads-fd          >= 3,-    semigroups           >= 0.8.3.1,-    profunctors          >= 3.2     && < 4+    profunctors          == 4.*,+    semigroupoids        == 4.*,+    semigroups           >= 0.8.3.1 && < 1,+    transformers         >= 0.2.0   && < 0.4    if impl(ghc)     cpp-options: -DGHC_TYPEABLE

@@ -22,12 +22,20 @@ import Control.Comonad.Trans.Store import Control.Comonad.Trans.Traced import Control.Comonad.Trans.Identity+import Data.List.NonEmpty import Data.Semigroup  -- | Allows you to peel a layer off a cofree comonad. class (Functor f, Comonad w) => ComonadCofree f w | w -> f where   -- | Remove a layer.   unwrap :: w a -> f (w a)++instance ComonadCofree Maybe NonEmpty where+  unwrap (_ :| [])       = Nothing+  unwrap (_ :| (a : as)) = Just (a :| as)++instance ComonadCofree (Const b) ((,) b) where+  unwrap = Const . fst  instance ComonadCofree f w => ComonadCofree f (IdentityT w) where   unwrap = fmap IdentityT . unwrap . runIdentityT

@@ -32,6 +32,7 @@  import Control.Applicative import Control.Monad (liftM, MonadPlus(..))+import Control.Monad.Fix import Control.Monad.Trans.Class import Control.Monad.Free.Class import Control.Monad.Reader.Class@@ -86,8 +87,8 @@ -- -- This can be very useful for modeling domain specific languages, trees, or other constructs. ----- This instance of 'MonadFree' is fairly naive about the encoding. For more efficient free monad implementations that require additional--- extensions and thus aren't included here, you may want to look at the @kan-extensions@ package.+-- This instance of 'MonadFree' is fairly naive about the encoding. For more efficient free monad implementation see "Control.Monad.Free.Church", in particular note the 'Control.Monad.Free.Church.improve' combinator.+-- You may also want to take a look at the @kan-extensions@ package (<http://hackage.haskell.org/package/kan-extensions>). -- -- A number of common monads arise as free monads, --@@ -153,6 +154,9 @@   {-# INLINE return #-}   Pure a >>= f = f a   Free m >>= f = Free ((>>= f) <$> m)++instance Functor f => MonadFix (Free f) where+  mfix f = a where a = f (impure a); impure (Pure x) = x; impure (Free _) = error "mfix (Free f): Free"  -- | This violates the Alternative laws, handle with care. instance Alternative v => Alternative (Free v) where

@@ -37,7 +37,7 @@ -- | -- Monads provide substitution ('fmap') and renormalization ('Control.Monad.join'): ----- @m '>>=' f = 'Control.Monad.join' . 'fmap' f m@+-- @m '>>=' f = 'Control.Monad.join' ('fmap' f m)@ -- -- A free 'Monad' is one that does no work during the normalization step beyond simply grafting the two monadic values together. --@@ -72,9 +72,11 @@ -- Or we could choose to program with @'Control.Monad.Free.Free' Pair@ instead of 'Tree' -- and thereby avoid having to define our own 'Monad' instance. ----- Moreover, the @kan-extensions@ package provides 'MonadFree' instances that can--- improve the /asymptotic/ complexity of code that constructors free monads by--- effectively reassociating the use of ('>>=').+-- Moreover, "Control.Monad.Free.Church" provides a 'MonadFree'+-- instance that can improve the /asymptotic/ complexity of code that+-- constructs free monads by effectively reassociating the use of+-- ('>>='). You may also want to take a look at the @kan-extensions@+-- package (<http://hackage.haskell.org/package/kan-extensions>). -- -- See 'Control.Monad.Free.Free' for a more formal definition of the free 'Monad' -- for a 'Functor'.