diff options
Diffstat (limited to 'testsuite/tests/indexed-types/should_compile/T3017.hs')
-rw-r--r-- | testsuite/tests/indexed-types/should_compile/T3017.hs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/testsuite/tests/indexed-types/should_compile/T3017.hs b/testsuite/tests/indexed-types/should_compile/T3017.hs new file mode 100644 index 0000000000..8e4e5bd999 --- /dev/null +++ b/testsuite/tests/indexed-types/should_compile/T3017.hs @@ -0,0 +1,20 @@ +{-# LANGUAGE TypeFamilies #-} + +-- Trac #3017 + +module Foo where + class Coll c where + type Elem c + empty :: c + insert :: Elem c -> c -> c + + data ListColl a = L [a] + instance Coll (ListColl a) where + type Elem (ListColl a) = a + empty = L [] + insert x (L xs) = L (x:xs) + + emptyL :: ListColl a + emptyL = empty + + test2 c = insert (0, 0) c |