th-instance-reification 0.1.5 → 0.1.5.1

raw patch · 3 files changed

+18/−23 lines, 3 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• src/THInstanceReification.hs +12/−22
• test/Main.hs +5/−0
• th-instance-reification.cabal +1/−1

@@ -1,4 +1,3 @@-{-# LANGUAGE CPP #-} -- | -- Fixed versions of 'reifyInstances' and 'isInstance' as per -- the following ghc issue:@@ -41,14 +40,14 @@     -- Expand type synonyms in type signatures,      -- using 'expandSyns' from the "th-expand-syns" library:     expandedTypes <- mapM expandSyns tl-    expendedInstanceTypes <- mapM expandSyns htl+    expandedInstanceTypes <- mapM expandSyns htl     maybe        (fail $ "Unmatching amounts of types: " <> show expandedTypes <> ", " <> -              show expendedInstanceTypes)+              show expandedInstanceTypes)       (analyze context)       -- 'pair' is a safe version of 'zip' from the "list-extras" library,       -- which returns 'Nothing', when lists differ in size.-      (pair expandedTypes expendedInstanceTypes)+      (pair expandedTypes expandedInstanceTypes)   d -> fail $ "Not an instance dec: " <> show d   where     -- |@@ -60,10 +59,8 @@         -- |         -- A partial function,          -- which returns a tested type by a variable name.-        actualTypeByVarName :: Name -> Type-        actualTypeByVarName = \n ->-          Map.lookup n m ?: -          (error $ "Unexpected key: " <> show n <> ", in a map: " <> show m)+        actualTypeByVarName :: Name -> Maybe Type+        actualTypeByVarName = \n -> Map.lookup n m           where             -- A memoization cache.             m = Map.fromList $ concat $ map accRecords $ typeAssocs@@ -75,25 +72,18 @@                 accRecords = \case                   (AppT al ar, AppT hl hr) -> accRecords (al, hl) ++ accRecords (ar, hr)                   (a, VarT n) -> [(n, a)]-                  (a, h) | a /= h -> error $ "Unmatching types: " <> show a <> ", " <> show h                   _ -> []         -- |         -- Test a predicate by substituting all type vars with associated         -- tested types.         analyzePredicate :: Pred -> Q Bool         analyzePredicate = \case-#if MIN_VERSION_template_haskell(2,10,0)           AppT (AppT EqualityT _) _ -> return True-          AppT (ConT n) t -> do-            let t' = replaceTypeVars actualTypeByVarName t-            isProperInstance n [t']+          AppT (ConT n) t ->+            case replaceTypeVars actualTypeByVarName t of+              Just t' -> isProperInstance n [t']+              _ -> return False           _ -> return True-#else-          EqualP _ _ -> return True-          ClassP n tl -> do-            let tl' = map (replaceTypeVars actualTypeByVarName) tl-            isProperInstance n tl'-#endif  unapplyType :: Type -> [Type] unapplyType = \case@@ -101,9 +91,9 @@   t -> [t]  -- | Deeply traverse the type signature and replace all vars in it.-replaceTypeVars :: (Name -> Type) -> Type -> Type+replaceTypeVars :: (Name -> Maybe Type) -> Type -> Maybe Type replaceTypeVars f = \case-  AppT l r -> AppT (replaceTypeVars f l) (replaceTypeVars f r)+  AppT l r -> AppT <$> replaceTypeVars f l <*> replaceTypeVars f r   VarT n -> f n-  t -> t+  t -> Just t 

@@ -14,6 +14,11 @@   main = defaultMain $ testGroup "" $ [+    testCase "Issue #6" $ do+      assertBool "" $ read $( do+          r <- isProperInstance ''Monoid [VarT (mkName "v")]+          stringE $ show $ r+        ),     testCase "existingInstance" $ do       assertBool "" $ read $( do           t <- [t| (Int, Int) |]

@@ -1,5 +1,5 @@ name: th-instance-reification-version: 0.1.5+version: 0.1.5.1 synopsis: Fixed versions of instances reification functions description:   Provides fixed versions of 'reifyInstances' and 'isInstance' as per