diff options
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/T16394.hs | 12 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/T16394.stderr | 5 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/all.T | 1 |
3 files changed, 18 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_fail/T16394.hs b/testsuite/tests/typecheck/should_fail/T16394.hs new file mode 100644 index 0000000000..76ca7a7cf6 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T16394.hs @@ -0,0 +1,12 @@ +{-# LANGUAGE PolyKinds, TypeFamilies, DataKinds #-} + +class C a where + type T (n :: a) + +instance C a => C b => C (a, b) where + type T '(n, m) = (T n, T m) + +-- but this worked fine: +-- +-- instance (C a, C b) => C (a, b) where +-- type T '(n, m) = (T n, T m) diff --git a/testsuite/tests/typecheck/should_fail/T16394.stderr b/testsuite/tests/typecheck/should_fail/T16394.stderr new file mode 100644 index 0000000000..fff51a6e39 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T16394.stderr @@ -0,0 +1,5 @@ +T16394.hs:6:10: error: + Illegal class instance: ‘C a => C b => C (a, b)’ + Class instances must be of the form + context => C ty_1 ... ty_n + where ‘C’ is a class diff --git a/testsuite/tests/typecheck/should_fail/all.T b/testsuite/tests/typecheck/should_fail/all.T index 1a775d3a7c..b92d99ce8f 100644 --- a/testsuite/tests/typecheck/should_fail/all.T +++ b/testsuite/tests/typecheck/should_fail/all.T @@ -510,3 +510,4 @@ test('T16059e', [extra_files(['T16059b.hs'])], multimod_compile_fail, ['T16059e', '-v0']) test('T16255', normal, compile_fail, ['']) test('T16204c', normal, compile_fail, ['']) +test('T16394', normal, compile, ['']) |