Demand Analyser testcase: Unsaturated functions

1 files changed, 29 insertions, 0 deletions

diff --git a/testsuite/tests/stranal/sigs/UnsatFun.hs b/testsuite/tests/stranal/sigs/UnsatFun.hs
new file mode 100644
index 0000000000..23ba6426cd
--- /dev/null
+++ b/testsuite/tests/stranal/sigs/UnsatFun.hs
@@ -0,0 +1,29 @@
+module UnsatFun where
+
+-- Here we test how a partially applied function (f x)
+-- with a bottom result affects the strictness signature
+-- when used strictly (g) and lazily (g')
+--
+-- In both cases, the parameter x should not be absent
+
+f :: Int -> Int -> Int
+f x y = error (show x)
+{-# NOINLINE f #-}
+
+h :: (Int -> Int) -> Int
+h f = f 2
+{-# NOINLINE h #-}
+
+h2 :: Bool -> (Int -> Int) -> Int
+h2 True  _ = 0
+h2 False f = f 2
+{-# NOINLINE h2 #-}
+
+-- Should get a bottom result
+g :: Int -> Int
+g x = let f' = f x
+      in h f'
+
+g2 :: Int -> Int
+g2 x = let f' = f x
+       in h2 True f'