It's a GHC weakness. I've added your example to the currently-open bug for it: http://sourceforge.net/tracker/index.php?func=detail&aid=1075259&group_i d=8032&atid=108032 Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users- | bounces@haskell.org] On Behalf Of Neil Mitchell | Sent: 01 December 2005 20:56 | To: glasgow-haskell-users@haskell.org | Subject: -fwarn-incomplete-patterns, not always warns | | Hi, | | I have been playing around with -fwarn-incomplete-patterns under GHC | 6.4.1 on Windows. | | -- no warning | ex1 x = ss | where (s:ss) = x | | -- no warning | ex2 x = let (s:ss) = x in ss | | -- Warning: Pattern match(es) are non-exhaustive | -- In a case alternative: Patterns not matched: [] | ex3 x = case x of ~(s:ss) -> ss | | I have translated all 3 functions using the rules supplied in the | Haskell 98 report, so they all have the same meaning, but only one | gives an error. Is it intentional to ignore where/let pattern matches? | | Thanks | | Neil | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users