Hi everyone, Yes, the current overlap checker thinks all view patterns are overlapped. The pattern overlap/exhaustiveness checker needs to be rewritten to account for GADTs and view patterns. You can use -fno-warn-overlapping-patterns to suppress these warning (along with any actual overlaps, though, unfortunately). -Dan On Nov05, Cale Gibbard wrote:

2008/11/5 Cetin Sert :

...

<interactive>:1:4: Warning: Pattern match(es) are overlapped In the definition of `emp': emp ((has -> True)) = ... emp ((has -> False)) = ...

Why do I get this error in ghc or when I try to compile a file with view patterns? (using -fglasgow-exts and -XViewPatterns, ghc 6.10.1)

This is a bug which appears to be known about: http://hackage.haskell.org/trac/ghc/ticket/2395

- Cale _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe