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authorDavid Terei <davidterei@gmail.com>2011-07-20 11:09:03 -0700
committerDavid Terei <davidterei@gmail.com>2011-07-20 11:26:35 -0700
commit16514f272fb42af6e9c7674a9bd6c9dce369231f (patch)
treee4f332b45fe65e2a7a2451be5674f887b42bf199 /testsuite/tests/typecheck/should_compile/tc087.hs
parentebd422aed41048476aa61dd4c520d43becd78682 (diff)
downloadhaskell-16514f272fb42af6e9c7674a9bd6c9dce369231f.tar.gz
Move tests from tests/ghc-regress/* to just tests/*
Diffstat (limited to 'testsuite/tests/typecheck/should_compile/tc087.hs')
-rw-r--r--testsuite/tests/typecheck/should_compile/tc087.hs32
1 files changed, 32 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/tc087.hs b/testsuite/tests/typecheck/should_compile/tc087.hs
new file mode 100644
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+++ b/testsuite/tests/typecheck/should_compile/tc087.hs
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+{-# LANGUAGE Rank2Types #-}
+
+module ShouldSucceed where
+
+data SeqView t a = Null
+ | Cons a (t a)
+
+class PriorityQueue q where
+ empty :: (Ord a) => q a
+ single :: (Ord a) => a -> q a
+ insert :: (Ord a) => a -> q a -> q a
+ meld :: (Ord a) => q a -> q a -> q a
+ splitMin :: (Ord a) => q a -> SeqView q a
+ insert a q = single a `meld` q
+
+toOrderedList q = case splitMin q of
+ Null -> []
+ Cons a q -> a : toOrderedList q
+
+insertMany x q = foldr insert q x
+pqSort q x = toOrderedList (insertMany x q)
+
+check :: forall q. (PriorityQueue q) => (forall a. Ord a => q a) -> IO ()
+check empty = do
+ putStr "*** sorting\n"
+ out (pqSort empty [1 .. 99])
+ out (pqSort empty [1.0, 1.1 ..99.9])
+
+out :: (Num a) => [a] -> IO ()
+out x | sum x == 0 = putStr "ok\n"
+ | otherwise = putStr "ok\n"
+