[project @ 1998-06-11 10:32:06 by sof]

Testing the illegal use of pattern syntax in expressions (and vice versa)

ghc/tests/reader/should_fail/read003.stderr

@@ -14,9 +14,9 @@ module Read003 where
  
 read003.hs:8:
     Occurs check: cannot construct the infinite type:
-	    aMm = (aMm, aMp, aMs)
-    Expected: (aMm, [aMA], aMs)
-    Inferred: aMm
+	    aKy = (aKy, aKB, aKE)
+    Expected: (aKy, [aKM], aKE)
+    Inferred: aKy
     In a pattern binding:
 	~(a, b, c)
 	    | nullity b = a

ghc/tests/reader/should_fail/read006.hs

+--!!! Using pattern syntax on RHS
+module ShouldFail where
+
+f :: Int -> Int
+f x = _
+
+g :: Int -> Int
+g x = 2 + 2@_
+

ghc/tests/reader/should_fail/read006.stderr

+read006.hs:5:7: pattern syntax used in expression on input: "_"

ghc/tests/reader/should_fail/read007.hs

+--!!! Expressions as patterns inside do stmt blocks
+module ShouldFail where
+
+f :: Int -> IO Int
+f x = do
+  (2+2) <- 2
+  return x
+

ghc/tests/reader/should_fail/read007.stderr

+read007.hs:7:3: variable application in pattern on input: "return"