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Diffstat (limited to 'testsuite/tests/typecheck/should_compile/tc117.hs')
-rw-r--r-- | testsuite/tests/typecheck/should_compile/tc117.hs | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/tc117.hs b/testsuite/tests/typecheck/should_compile/tc117.hs new file mode 100644 index 0000000000..d27c2b0076 --- /dev/null +++ b/testsuite/tests/typecheck/should_compile/tc117.hs @@ -0,0 +1,19 @@ +{-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, + FlexibleInstances, UndecidableInstances #-} +-- UndecidableInstances now needed because the Coverage Condition fails + +-- !!! Functional dependencies +-- This one gave another fail in tcReadMutVar + +module M1 where + +class HasFoo a foo | a -> foo where + foo :: a -> foo +instance HasFoo Int Int where + foo = id + +instance HasFoo a b => HasFoo [a] b where + foo = foo . head + +test:: [[Int]] -> Int +test = foo |