diff options
Diffstat (limited to 'testsuite/tests/deriving/should_run/drvrun021.hs')
| -rw-r--r-- | testsuite/tests/deriving/should_run/drvrun021.hs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/testsuite/tests/deriving/should_run/drvrun021.hs b/testsuite/tests/deriving/should_run/drvrun021.hs new file mode 100644 index 0000000000..05c7c8dbf0 --- /dev/null +++ b/testsuite/tests/deriving/should_run/drvrun021.hs @@ -0,0 +1,20 @@ +module Main where + +class Show a => Foo a where + op :: a -> a + +newtype Moose = MkMoose () deriving (Show, Eq, Ord) + +newtype Noose = MkNoose () deriving (Ord) + +instance Eq Noose where + a == b = False -- Non-standard! + +f :: Ord a => a -> Bool +f x = x==x + +main = do print (MkNoose () == MkNoose ()) -- Eq Noose + print (f (MkNoose ())) -- via Ord Noose + print (MkMoose () == MkMoose ()) -- Eq Moose + print (f (MkMoose ())) -- via Ord Moose + putStrLn (show (MkMoose ())) -- Should not use the show () method |