[project @ 2001-07-23 09:45:08 by simonpj]

Add tc131

testsuite/tests/ghc-regress/typecheck/should_compile/all.T

@@ -134,3 +134,4 @@ test "tc127" { myvtc("") }
 test "tc128" { myvtc("") }
 test "tc129" { myvtc("") }
 test "tc130" { myvtc("") }
+test "tc131" { myvtc("") }

testsuite/tests/ghc-regress/typecheck/should_compile/tc131.hs

+{-# OPTIONS -fglasgow-exts #-}
+
+-- !!! Typechecking of functional dependencies
+-- Showed up (another) bug in the newtype-squashing machinery
+
+
+module ShouldCompile where
+
+class Split2 a b | a -> b, b -> a where
+    combine2 :: (b,b) -> a
+
+class Split4 a b | a -> b, b -> a where
+    combine4 :: (b,b) -> a
+
+newtype Word16 = Word16 Int
+newtype Word32 = Word32 Int
+newtype Word64 = Word64 Int
+
+instance Split2 Word32 Word16 where
+    combine2 = undefined
+
+instance Split2 Word64 Word32 where
+    combine2 a = undefined
+
+instance Split4 Word64 Word16 where
+    combine4 (a, b) = 
+        combine2 ( (combine2 (a, b)), combine2 (a, b))
+
+
+