[project @ 2005-09-05 15:20:05 by simonpj]

Add a couple of tests

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

@@ -133,3 +133,4 @@ test('tcfail145', normal, compile_fail, [''])
 test('tcfail146', normal, compile_fail, [''])
 test('tcfail147', normal, compile_fail, [''])
 test('tcfail148', normal, compile_fail, [''])
+test('tcfail149', normal, compile_fail, [''])

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail149.hs

+module Main where
+
+class C a where
+  op :: (Show a, Show b) => a -> b -> String
+	-- This class op adds a constraint on 'a'
+

testsuite/tests/ghc-regress/typecheck/should_fail/tcfail149.stderr

+
+tcfail149.hs:3:0:
+    All of the type variables in the constraint `Show a' are already in scope
+	(at least one must be universally quantified here)
+    When checking the class method:
+      op :: forall b. (Show a, Show b) => a -> b -> String
+    In the class declaration for `C'

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

@@ -42,6 +42,7 @@ test('tcrun033', only_compiler_types(['ghc']), compile_and_run, [''])
 test('tcrun034', only_compiler_types(['ghc']), compile_and_run, [''])
 test('tcrun035', only_compiler_types(['ghc']), compile_and_run, [''])
 test('tcrun036', only_compiler_types(['ghc']), compile_and_run, [''])
+test('tcrun037', only_compiler_types(['ghc']), compile_and_run, [''])
 
 test('church', normal, compile_and_run, [''])
 test('testeq2', normal, compile_and_run, [''])

testsuite/tests/ghc-regress/typecheck/should_run/tcrun037.hs

+{-# OPTIONS -fglasgow-exts #-}
+
+module Main where
+
+class C a where
+  op :: (Show a, Show b) => a -> b -> String
+	-- This class op has local quantification, but
+	-- also adds a constraint on 'a'
+
+instance C Bool where
+  op x y = show x ++ " " ++ show y
+
+main = do { putStrLn (op True 'x'); putStrLn (op False (3::Int)) } 

testsuite/tests/ghc-regress/typecheck/should_run/tcrun037.stdout

+True 'x'
+False 3