1 files changed, 44 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_run/tcrun010.hs b/testsuite/tests/typecheck/should_run/tcrun010.hs
new file mode 100644
index 0000000000..7621f4d4e0
--- /dev/null
+++ b/testsuite/tests/typecheck/should_run/tcrun010.hs
@@ -0,0 +1,44 @@
+{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies #-}
+
+-- !!! Functional dependencies
+-- This one gave "zonkIdOcc:  FunDep_a11w" in earlier days
+
+module Main (main) where
+
+data ERR a b = EOK a | ERR b deriving (Show)
+data Error   = No | Notatall deriving (Show, Eq)
+
+
+class MonadErr m e | m -> e where
+   aerturn ::           e   -> m a
+   areturn ::           a   -> m a
+   acatch  ::           a   -> (a -> m b) -> (e -> m b) -> m b
+   (>>>=)  ::           m a -> (a -> m b) -> m b
+   (>>>)   ::           m a -> m b        -> m b
+
+data BP a = BP (Int -> (ERR a Error, Int))
+
+instance MonadErr BP Error where
+   aerturn k             = BP $ \s  -> (ERR k, s)
+   areturn k             = BP $ \s  -> (EOK k, s)
+   acatch  k try handler = BP $ \s  -> let BP try'     = try  k
+                                           (r,s1)      = try' s
+                                           (BP c2, s2) = case r of
+                                                           EOK r -> (areturn r, s1)
+                                                           ERR r -> (handler r, s)
+                                       in  c2 s2
+   a >>> b =  a >>>= \_ -> b
+
+   (BP c1) >>>= fc2      = BP $ \s0 -> let (r,s1) = c1 s0
+                                           BP c2 = case r of
+                                                     EOK r -> fc2 r
+                                                     ERR r -> BP (\s -> (ERR r, s))
+                                       in c2 s1
+
+run_BP :: Int -> BP a -> (ERR a Error, Int)
+run_BP st (BP bp) = bp st
+
+foo :: (ERR Int Error, Int)
+foo = run_BP 111 (aerturn No)
+
+main = print (show foo)