[commit: testsuite] master: Test Trac #6020 (4c7a4b2)

[Simon Peyton Jones]

Repository : ssh://darcs.haskell.org//srv/darcs/testsuite

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/4c7a4b24ddda2ad5f2798a90f97d47c65f00a874

>---------------------------------------------------------------

commit 4c7a4b24ddda2ad5f2798a90f97d47c65f00a874
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Sun Apr 22 17:54:51 2012 +0100

    Test Trac #6020

>---------------------------------------------------------------

 tests/polykinds/T6020.hs |   17 +++++++++++++++++
 tests/polykinds/all.T    |    1 +
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/tests/polykinds/T6020.hs b/tests/polykinds/T6020.hs
new file mode 100644
index 0000000..fa7de49
--- /dev/null
+++ b/tests/polykinds/T6020.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE DataKinds, FunctionalDependencies, FlexibleInstances,
+             UndecidableInstances, PolyKinds, KindSignatures,
+             ConstraintKinds, FlexibleContexts #-}
+module T6020 where
+
+import GHC.Prim (Constraint)
+
+class Id (a :: k) (b :: k) | a -> b
+instance Id a a
+
+class Test (x :: a) (y :: a) | x -> y
+instance (Id x y, Id y z) => Test x z
+
+test :: Test True True => ()
+test = ()
+
+foo = test
diff --git a/tests/polykinds/all.T b/tests/polykinds/all.T
index 3676c8d..fee495d 100644
--- a/tests/polykinds/all.T
+++ b/tests/polykinds/all.T
@@ -33,3 +33,4 @@ test('T5937', normal, compile, [''])
 test('T5935', normal, compile, [''])
 test('T5938', normal, compile, [''])
 test('T5948', normal, compile, [''])
+test('T6020', normal, compile, [''])