[project @ 2005-08-22 08:59:15 by simonpj]

Slightly better overlap checking

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

@@ -59,3 +59,4 @@ test('ds052', expect_fail_if_compiler_type('ghc'), compile, [''])
 test('ds053', normal, compile, [''])
 test('ds054', normal, compile, [''])
 test('ds055', only_compiler_types(['ghc']), compile, [''])
+test('ds056', normal, compile, ['-Wall'])

testsuite/tests/ghc-regress/deSugar/should_compile/ds040.stderr-ghc

-
-ds040.hs:9:0:
-    Warning: Pattern match(es) are overlapped
-	     In the definition of `^^^^': ^^^^ _ _ = ...

testsuite/tests/ghc-regress/deSugar/should_compile/ds052.stderr

+
+ds052.hs:6:0:
+    Warning: Pattern match(es) are non-exhaustive
+	     In the definition of `lazyZip': Patterns not matched: (_ : _) []

testsuite/tests/ghc-regress/deSugar/should_compile/ds056.hs

+-- Check overlap in n+k patterns
+
+module Foo where
+
+g :: Int -> Int
+g (x+1) = x
+g y     = y	
+g _     = 0	-- Overlapped
+
+h :: Int -> Int
+h (x+1) = x
+h _     = 0	-- Not overlapped