[project @ 2000-06-26 16:09:40 by simonpj]

Add test for filterFB

ghc/tests/simplCore/should_run/Makefile

+TOP = ../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/should_run.mk
+
+SRC_HC_OPTS += -dcore-lint
+
+include $(TOP)/mk/target.mk
+
+

ghc/tests/simplCore/should_run/simplrun001.hs

+{-# OPTIONS -O #-}
+
+-- !!! Test filter fusion
+
+-- In GHC 4.06, the filterFB rule was back to front, which
+-- made this program hit the "error foo" case instead of
+-- working fine.
+
+
+module Main where
+
+main :: IO ()
+main = print (length (filter (not . foo)
+                             (filter (const False) [Nothing])))
+  where foo (Just x) = x
+        foo _        = error "foo"

ghc/tests/simplCore/should_run/simplrun001.stderr

+
+Fail: foo

ghc/tests/simplCore/should_run/simplrun001.stdout

+0