diff options
| -rw-r--r-- | testsuite/tests/typecheck/should_compile/T13951.hs | 19 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_compile/all.T | 1 |
2 files changed, 20 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/T13951.hs b/testsuite/tests/typecheck/should_compile/T13951.hs new file mode 100644 index 0000000000..8cbeb8c11a --- /dev/null +++ b/testsuite/tests/typecheck/should_compile/T13951.hs @@ -0,0 +1,19 @@ +{-# LANGUAGE PolyKinds, GADTs, Rank2Types, ScopedTypeVariables, Trustworthy #-} +module Control.Monad.Skeleton.Internal where + +data Cat k a b where + Empty :: Cat k a a + Leaf :: k a b -> Cat k a b + Tree :: Cat k a b -> Cat k b c -> Cat k a c + +viewL :: forall k a b r. Cat k a b + -> ((a ~ b) => r) + -> (forall x. k a x -> Cat k x b -> r) + -> r +viewL Empty e _ = e +viewL (Leaf k) _ r = k `r` Empty +viewL (Tree a b) e r = go a b where + go :: Cat k a x -> Cat k x b -> r + go Empty t = viewL t e r + go (Leaf k) t = r k t + go (Tree c d) t = go c (Tree d t) diff --git a/testsuite/tests/typecheck/should_compile/all.T b/testsuite/tests/typecheck/should_compile/all.T index dae5b6feea..1284d8a011 100644 --- a/testsuite/tests/typecheck/should_compile/all.T +++ b/testsuite/tests/typecheck/should_compile/all.T @@ -669,3 +669,4 @@ test('T16188', normal, compile, ['']) test('T16204a', normal, compile, ['']) test('T16204b', normal, compile, ['']) test('T16225', normal, compile, ['']) +test('T13951', normal, compile, ['']) |