[project @ 2002-09-02 16:30:17 by simonpj]

Add rank-N test

testsuite/tests/ghc-regress/typecheck/should_compile/all.T

@@ -158,3 +158,4 @@ test('tc157', normal, compile, [''])
 test('tc158', normal, compile, [''])
 test('tc159', normal, compile, [''])
 test('tc160', normal, compile, [''])
+test('tc161', normal, compile, [''])

testsuite/tests/ghc-regress/typecheck/should_compile/tc161.hs

+{-# OPTIONS -fglasgow-exts #-}
+-- Blew up GHC 5.04, with:
+--    Ambiguous type variable(s) `q' in the constraint `Foo q'
+--    arising from a function with an overloaded argument type at Foo.hs:7
+--	Expected type: Int -> (forall q1. (Foo q1) => q1 -> a) -> a
+--	Inferred type: Int -> (q -> a) -> a
+--    In the application `GHC.Err.noMethodBindingError "Foo.hs:7|Foo.foo"#'
+--
+-- Fix is to give wild-card args to the default methods
+-- See TcClassDcl.mkDefMethRhs
+
+module ShouldCompile where
+
+class Foo a where
+  op :: Eq c => c -> (forall b. Eq b => b->b) -> a -> a
+
+instance Foo Int