[commit: testsuite] master: Test Trac #8155 (11eb77f)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/testsuite

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/11eb77f7cb410dc76d982b731ffadb69116291ce/testsuite

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

commit 11eb77f7cb410dc76d982b731ffadb69116291ce
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Wed Aug 28 16:40:44 2013 +0100

    Test Trac #8155


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

11eb77f7cb410dc76d982b731ffadb69116291ce
 tests/indexed-types/should_fail/T8155.hs     |   30 ++++++++++++++++++++++++++
 tests/indexed-types/should_fail/T8155.stderr |    9 ++++++++
 tests/indexed-types/should_fail/all.T        |    1 +
 3 files changed, 40 insertions(+)

diff --git a/tests/indexed-types/should_fail/T8155.hs b/tests/indexed-types/should_fail/T8155.hs
new file mode 100644
index 0000000..97f8961
--- /dev/null
+++ b/tests/indexed-types/should_fail/T8155.hs
@@ -0,0 +1,30 @@
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE FlexibleInstances #-}
+
+module Test where
+
+
+data Vector a = Vector a
+data Matrix a = Matrix a
+
+class Build f where
+    build' :: BoundsOf f -> f -> ContainerOf f
+
+
+
+type family BoundsOf x where
+    BoundsOf (a->a->a) = (Int,Int)
+    BoundsOf (a->a)    = Int
+
+type family ContainerOf x where
+    ContainerOf (a->a)    = Vector a
+    ContainerOf (a->a->a) = Matrix a
+
+
+
+instance (Num a) => Build (a->a) where
+    build' = buildV
+
+
+buildV :: (Integral a, Num b) => a -> (b -> c) -> Vector c
+buildV _ _ = undefined
diff --git a/tests/indexed-types/should_fail/T8155.stderr b/tests/indexed-types/should_fail/T8155.stderr
new file mode 100644
index 0000000..c85b84b
--- /dev/null
+++ b/tests/indexed-types/should_fail/T8155.stderr
@@ -0,0 +1,9 @@
+
+T8155.hs:26:14:
+    Could not deduce (Integral (BoundsOf (a -> a)))
+      arising from a use of ‛buildV’
+    from the context (Num a)
+      bound by the instance declaration at T8155.hs:25:10-32
+    In the expression: buildV
+    In an equation for ‛build'’: build' = buildV
+    In the instance declaration for ‛Build (a -> a)’
diff --git a/tests/indexed-types/should_fail/all.T b/tests/indexed-types/should_fail/all.T
index 14344da..68fb9ea 100644
--- a/tests/indexed-types/should_fail/all.T
+++ b/tests/indexed-types/should_fail/all.T
@@ -106,3 +106,4 @@ test('T7938', normal, compile_fail, [''])
 test('ClosedFam3', extra_clean(['ClosedFam3.o-boot', 'ClosedFam3.hi-boot']),
      multimod_compile_fail, ['ClosedFam3', '-v0'])
 test('ClosedFam4', normal, compile_fail, [''])
+test('T8155', normal, compile_fail, [''])