constraints 0.9 → 0.9.1

raw patch · 6 files changed

+147/−11 lines, 6 filesdep ~transformersPVP: major bump suggested

API removals or changes: PVP suggests a major version bump

Dependency ranges changed: transformers

API changes (from Hackage documentation)

Files

• CHANGELOG.markdown +14/−0
• constraints.cabal +1/−1
• src/Data/Constraint.hs +119/−1
• src/Data/Constraint/Deferrable.hs +7/−3
• src/Data/Constraint/Nat.hs +2/−2
• src/Data/Constraint/Symbol.hs +4/−4

@@ -1,3 +1,17 @@+0.9.1+-----+* Correct an improper use of `unsafeCoerce` in the internals of+  `Data.Constraint.Nat` and `Data.Constraint.Symbol`+* Correctly identify the mismatched types when you defer an unsatisfiable+  equality constraint through `Data.Constraint.Deferrable`+* Re-export the `(:~~:)` defined in `base` from `Data.Constraint.Deferred` with+  GHC 8.2 or later+* Add several new `(:=>)` instances for `Bits`, `Identity`, `Const`, `Natural`,+  `IO`, and `Word`.+* Modernize some existing `Class` and `(:=>)` instances to reflect the fact+  that `Applicative` is now a superclass of `Monad` on recent versions of+  `base`.+ 0.9 --- * Changes to `Data.Constraint`:

@@ -1,6 +1,6 @@ name:          constraints category:      Constraints-version:       0.9+version:       0.9.1 license:       BSD2 cabal-version: >= 1.10 license-file:  LICENSE

@@ -84,6 +84,14 @@ import Data.Data import qualified GHC.Exts as Exts (Any) import GHC.Exts (Constraint)+import Data.Bits (Bits)+import Data.Functor.Identity (Identity)+#if MIN_VERSION_base(4,8,0)+import Numeric.Natural (Natural)+#endif+#if !MIN_VERSION_base(4,8,0)+import Data.Word (Word)+#endif  -- | Values of type @'Dict' p@ capture a dictionary for a constraint of type @p@. --@@ -172,7 +180,7 @@ -- What are the two ways? -- -- Well, we can go from @'Ord' a ':-' 'Eq' a@ via the--- superclass relationship, and them from @'Eq' a ':-' 'Eq' [a]@ via the+-- superclass relationship, and then from @'Eq' a ':-' 'Eq' [a]@ via the -- instance, or we can go from @'Ord' a ':-' 'Ord' [a]@ via the instance -- then from @'Ord' [a] ':-' 'Eq' [a]@ through the superclass relationship -- and this diagram by definition must \"commute\".@@ -406,6 +414,12 @@ instance (Eq a, Eq b) :=> Eq (Either a b) where ins = Sub Dict instance () :=> Eq (Dict a) where ins = Sub Dict instance () :=> Eq (a :- b) where ins = Sub Dict+instance () :=> Eq Word where ins = Sub Dict+instance Eq a :=> Eq (Identity a) where ins = Sub Dict+#if MIN_VERSION_base(4,8,0)+instance Eq a :=> Eq (Const a b) where ins = Sub Dict+instance () :=> Eq Natural where ins = Sub Dict+#endif  -- Ord instance Class (Eq a) (Ord a) where cls = Sub Dict@@ -423,6 +437,12 @@ instance Integral a :=> Ord (Ratio a) where ins = Sub Dict instance () :=> Ord (Dict a) where ins = Sub Dict instance () :=> Ord (a :- b) where ins = Sub Dict+instance () :=> Ord Word where ins = Sub Dict+instance Ord a :=> Ord (Identity a) where ins = Sub Dict+#if MIN_VERSION_base(4,8,0)+instance Ord a :=> Ord (Const a b) where ins = Sub Dict+instance () :=> Ord Natural where ins = Sub Dict+#endif  -- Show instance Class () (Show a) where cls = Sub Dict@@ -438,6 +458,12 @@ instance (Integral a, Show a) :=> Show (Ratio a) where ins = Sub Dict instance () :=> Show (Dict a) where ins = Sub Dict instance () :=> Show (a :- b) where ins = Sub Dict+instance () :=> Show Word where ins = Sub Dict+instance Show a :=> Show (Identity a) where ins = Sub Dict+#if MIN_VERSION_base(4,8,0)+instance Show a :=> Show (Const a b) where ins = Sub Dict+instance () :=> Show Natural where ins = Sub Dict+#endif  -- Read instance Class () (Read a) where cls = Sub Dict@@ -451,6 +477,12 @@ instance (Read a, Read b) :=> Read (a, b) where ins = Sub Dict instance (Read a, Read b) :=> Read (Either a b) where ins = Sub Dict instance (Integral a, Read a) :=> Read (Ratio a) where ins = Sub Dict+instance () :=> Read Word where ins = Sub Dict+instance Read a :=> Read (Identity a) where ins = Sub Dict+#if MIN_VERSION_base(4,8,0)+instance Read a :=> Read (Const a b) where ins = Sub Dict+instance () :=> Read Natural where ins = Sub Dict+#endif  -- Enum instance Class () (Enum a) where cls = Sub Dict@@ -463,6 +495,14 @@ instance () :=> Enum Float where ins = Sub Dict instance () :=> Enum Double where ins = Sub Dict instance Integral a :=> Enum (Ratio a) where ins = Sub Dict+instance () :=> Enum Word where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Enum a :=> Enum (Identity a) where ins = Sub Dict+instance Enum a :=> Enum (Const a b) where ins = Sub Dict+#endif+#if MIN_VERSION_base(4,8,0)+instance () :=> Enum Natural where ins = Sub Dict+#endif  -- Bounded instance Class () (Bounded a) where cls = Sub Dict@@ -472,6 +512,11 @@ instance () :=> Bounded Int where ins = Sub Dict instance () :=> Bounded Char where ins = Sub Dict instance (Bounded a, Bounded b) :=> Bounded (a,b) where ins = Sub Dict+instance () :=> Bounded Word where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Bounded a :=> Bounded (Identity a) where ins = Sub Dict+instance Bounded a :=> Bounded (Const a b) where ins = Sub Dict+#endif  -- Num instance Class () (Num a) where cls = Sub Dict@@ -481,6 +526,14 @@ instance () :=> Num Double where ins = Sub Dict instance RealFloat a :=> Num (Complex a) where ins = Sub Dict instance Integral a :=> Num (Ratio a) where ins = Sub Dict+instance () :=> Num Word where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Num a :=> Num (Identity a) where ins = Sub Dict+instance Num a :=> Num (Const a b) where ins = Sub Dict+#endif+#if MIN_VERSION_base(4,8,0)+instance () :=> Num Natural where ins = Sub Dict+#endif  -- Real instance Class (Num a, Ord a) (Real a) where cls = Sub Dict@@ -489,35 +542,81 @@ instance () :=> Real Float where ins = Sub Dict instance () :=> Real Double where ins = Sub Dict instance Integral a :=> Real (Ratio a) where ins = Sub Dict+instance () :=> Real Word where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Real a :=> Real (Identity a) where ins = Sub Dict+instance Real a :=> Real (Const a b) where ins = Sub Dict+#endif+#if MIN_VERSION_base(4,8,0)+instance () :=> Real Natural where ins = Sub Dict+#endif  -- Integral instance Class (Real a, Enum a) (Integral a) where cls = Sub Dict instance () :=> Integral Int where ins = Sub Dict instance () :=> Integral Integer where ins = Sub Dict+instance () :=> Integral Word where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Integral a :=> Integral (Identity a) where ins = Sub Dict+instance Integral a :=> Integral (Const a b) where ins = Sub Dict+#endif+#if MIN_VERSION_base(4,8,0)+instance () :=> Integral Natural where ins = Sub Dict+#endif +-- Bits+instance Class (Eq a) (Bits a) where cls = Sub Dict+instance () :=> Bits Bool where ins = Sub Dict+instance () :=> Bits Int where ins = Sub Dict+instance () :=> Bits Integer where ins = Sub Dict+instance () :=> Bits Word where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Bits a :=> Bits (Identity a) where ins = Sub Dict+instance Bits a :=> Bits (Const a b) where ins = Sub Dict+#endif+#if MIN_VERSION_base(4,8,0)+instance () :=> Bits Natural where ins = Sub Dict+#endif+ -- Fractional instance Class (Num a) (Fractional a) where cls = Sub Dict instance () :=> Fractional Float where ins = Sub Dict instance () :=> Fractional Double where ins = Sub Dict instance RealFloat a :=> Fractional (Complex a) where ins = Sub Dict instance Integral a :=> Fractional (Ratio a) where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Fractional a :=> Fractional (Identity a) where ins = Sub Dict+instance Fractional a :=> Fractional (Const a b) where ins = Sub Dict+#endif  -- Floating instance Class (Fractional a) (Floating a) where cls = Sub Dict instance () :=> Floating Float where ins = Sub Dict instance () :=> Floating Double where ins = Sub Dict instance RealFloat a :=> Floating (Complex a) where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Floating a :=> Floating (Identity a) where ins = Sub Dict+instance Floating a :=> Floating (Const a b) where ins = Sub Dict+#endif  -- RealFrac instance Class (Real a, Fractional a) (RealFrac a) where cls = Sub Dict instance () :=> RealFrac Float where ins = Sub Dict instance () :=> RealFrac Double where ins = Sub Dict instance Integral a :=> RealFrac (Ratio a) where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance RealFrac a :=> RealFrac (Identity a) where ins = Sub Dict+instance RealFrac a :=> RealFrac (Const a b) where ins = Sub Dict+#endif  -- RealFloat instance Class (RealFrac a, Floating a) (RealFloat a) where cls = Sub Dict instance () :=> RealFloat Float where ins = Sub Dict instance () :=> RealFloat Double where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance RealFloat a :=> RealFloat (Identity a) where ins = Sub Dict+instance RealFloat a :=> RealFloat (Const a b) where ins = Sub Dict+#endif  -- Monoid instance Class () (Monoid a) where cls = Sub Dict@@ -526,6 +625,13 @@ instance () :=> Monoid [a] where ins = Sub Dict instance Monoid a :=> Monoid (Maybe a) where ins = Sub Dict instance (Monoid a, Monoid b) :=> Monoid (a, b) where ins = Sub Dict+instance Monoid a :=> Monoid (Const a b) where ins = Sub Dict+#if MIN_VERSION_base(4,9,0)+instance Monoid a :=> Monoid (Identity a) where ins = Sub Dict+#endif+#if MIN_VERSION_base(4,9,0)+instance Monoid a :=> Monoid (IO a) where ins = Sub Dict+#endif  -- Functor instance Class () (Functor f) where cls = Sub Dict@@ -536,6 +642,8 @@ instance () :=> Functor ((,) a) where ins = Sub Dict instance () :=> Functor IO where ins = Sub Dict instance Monad m :=> Functor (WrappedMonad m) where ins = Sub Dict+instance () :=> Functor Identity where ins = Sub Dict+instance () :=> Functor (Const a) where ins = Sub Dict  -- Applicative instance Class (Functor f) (Applicative f) where cls = Sub Dict@@ -545,6 +653,7 @@ instance () :=> Applicative ((->)a) where ins = Sub Dict instance () :=> Applicative IO where ins = Sub Dict instance Monoid a :=> Applicative ((,)a) where ins = Sub Dict+instance Monoid a :=> Applicative (Const a) where ins = Sub Dict instance Monad m :=> Applicative (WrappedMonad m) where ins = Sub Dict  -- Alternative@@ -554,14 +663,23 @@ instance MonadPlus m :=> Alternative (WrappedMonad m) where ins = Sub Dict  -- Monad+#if MIN_VERSION_base(4,8,0)+instance Class (Applicative f) (Monad f) where cls = Sub Dict+#else instance Class () (Monad f) where cls = Sub Dict+#endif instance () :=> Monad [] where ins = Sub Dict instance () :=> Monad ((->) a) where ins = Sub Dict instance () :=> Monad (Either a) where ins = Sub Dict instance () :=> Monad IO where ins = Sub Dict+instance () :=> Monad Identity where ins = Sub Dict  -- MonadPlus+#if MIN_VERSION_base(4,8,0)+instance Class (Monad f, Alternative f) (MonadPlus f) where cls = Sub Dict+#else instance Class (Monad f) (MonadPlus f) where cls = Sub Dict+#endif instance () :=> MonadPlus [] where ins = Sub Dict instance () :=> MonadPlus Maybe where ins = Sub Dict 

@@ -51,6 +51,10 @@ import GHC.Types (type (~~)) #endif +#if __GLASGOW_HASKELL__ >= 801+import Data.Type.Equality ((:~~:)(HRefl))+#endif+ data UnsatisfiedConstraint = UnsatisfiedConstraint String   deriving (Typeable, Show) @@ -82,7 +86,7 @@ deferEither_ r = deferEither @p Proxy r #endif -#if __GLASGOW_HASKELL__ >= 800+#if __GLASGOW_HASKELL__ >= 800 && __GLASGOW_HASKELL__ < 801 -- | Kind heterogeneous propositional equality. Like '(:~:)', @a :~~: b@ is -- inhabited by a terminating value if and only if @a@ is the same type as @b@. --@@ -112,7 +116,7 @@   deferEither _ r = case cast (Refl :: a :~: a) :: Maybe (a :~: b) of     Just Refl -> Right r     Nothing   -> Left $-      "deferred type equality: type mismatch between `" ++ showTypeRep (Proxy :: Proxy a) ++ "’ and `"  ++ showTypeRep (Proxy :: Proxy a) ++ "'"+      "deferred type equality: type mismatch between `" ++ showTypeRep (Proxy :: Proxy a) ++ "’ and `"  ++ showTypeRep (Proxy :: Proxy b) ++ "'"  #if __GLASGOW_HASKELL__ >= 800 -- | Deferrable heterogenous equality constraints.@@ -122,7 +126,7 @@   deferEither _ r = case cast (HRefl :: a :~~: a) :: Maybe (a :~~: b) of     Just HRefl -> Right r     Nothing   -> Left $-      "deferred type equality: type mismatch between `" ++ showTypeRep (Proxy :: Proxy a) ++ "’ and `"  ++ showTypeRep (Proxy :: Proxy a) ++ "'"+      "deferred type equality: type mismatch between `" ++ showTypeRep (Proxy :: Proxy a) ++ "’ and `"  ++ showTypeRep (Proxy :: Proxy b) ++ "'" #endif  instance (Deferrable a, Deferrable b) => Deferrable (a, b) where

@@ -54,10 +54,10 @@  type Divides n m = n ~ Gcd n m -newtype Magic n r = Magic (KnownNat n => r)+newtype Magic n = Magic (KnownNat n => Dict (KnownNat n))  magic :: forall n m o. (Integer -> Integer -> Integer) -> (KnownNat n, KnownNat m) :- KnownNat o-magic f = Sub $ unsafeCoerce (Magic id) (natVal (Proxy :: Proxy n) `f` natVal (Proxy :: Proxy m))+magic f = Sub $ unsafeCoerce (Magic Dict) (natVal (Proxy :: Proxy n) `f` natVal (Proxy :: Proxy m))  axiom :: forall a b. Dict (a ~ b) axiom = unsafeCoerce (Dict :: Dict (a ~ a))

@@ -48,16 +48,16 @@  -- implementation details -newtype Magic n r = Magic (KnownSymbol n => r)+newtype Magic n = Magic (KnownSymbol n => Dict (KnownSymbol n))  magicNSS :: forall n m o. (Int -> String -> String) -> (KnownNat n, KnownSymbol m) :- KnownSymbol o-magicNSS f = Sub $ unsafeCoerce (Magic id) (fromIntegral (natVal (Proxy :: Proxy n)) `f` symbolVal (Proxy :: Proxy m))+magicNSS f = Sub $ unsafeCoerce (Magic Dict) (fromIntegral (natVal (Proxy :: Proxy n)) `f` symbolVal (Proxy :: Proxy m))  magicSSS :: forall n m o. (String -> String -> String) -> (KnownSymbol n, KnownSymbol m) :- KnownSymbol o-magicSSS f = Sub $ unsafeCoerce (Magic id) (symbolVal (Proxy :: Proxy n) `f` symbolVal (Proxy :: Proxy m))+magicSSS f = Sub $ unsafeCoerce (Magic Dict) (symbolVal (Proxy :: Proxy n) `f` symbolVal (Proxy :: Proxy m))  magicSN :: forall a n. (String -> Int) -> KnownSymbol a :- KnownNat n-magicSN f = Sub $ unsafeCoerce (Magic id) (toInteger (f (symbolVal (Proxy :: Proxy a))))+magicSN f = Sub $ unsafeCoerce (Magic Dict) (toInteger (f (symbolVal (Proxy :: Proxy a))))  axiom :: forall a b. Dict (a ~ b) axiom = unsafeCoerce (Dict :: Dict (a ~ a))