From b82410ab8908f1ec2a6aa14cce62948c92bcbce9 Mon Sep 17 00:00:00 2001 From: Simon Peyton Jones Date: Fri, 21 Nov 2014 11:16:19 +0000 Subject: Trac #9222 is actually an ambiguous type, now detected --- testsuite/tests/polykinds/T9222.hs | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'testsuite/tests/polykinds/T9222.hs') diff --git a/testsuite/tests/polykinds/T9222.hs b/testsuite/tests/polykinds/T9222.hs index df112519ac..8e46ccb3c5 100644 --- a/testsuite/tests/polykinds/T9222.hs +++ b/testsuite/tests/polykinds/T9222.hs @@ -3,5 +3,11 @@ module T9222 where import Data.Proxy +-- Nov 2014: actually the type of Want is ambiguous if we +-- do the full co/contra thing for subtyping, +-- which we now do +-- So this program is erroneous. (But the original ticket was +-- a crash, and that's still fixed!) + data Want :: (i,j) -> * where Want :: (a ~ '(b,c) => Proxy b) -> Want a -- cgit v1.2.1