import/instance bug

[Conal Elliott]

In Zeep.hs:

    module Zeep where
    instance Eq [(Int, Int)]

In tst.hs:

    import Zeep
    import IOExts

The result:

    bash-2.05a$ hugs
    __   __ __  __  ____   ___
_________________________________________
    ||   || ||  || ||  || ||__      Hugs 98: Based on the Haskell 98
standard
    ||___|| ||__|| ||__||  __||     Copyright (c) 1994-2001
    ||---||         ___||           World Wide Web:
http://haskell.org/hugs
    ||   ||                         Report bugs to:
hugs-bugs@haskell.org
    ||   || Version: December 2001
_________________________________________

    Hugs mode: Restart with command line option +98 for Haskell 98 mode

    Reading file "c:\hugs98/lib\Prelude.hs":
    Type :? for help
    Prelude> :l Tst.hs
    Reading file "Tst.hs":
    Reading file "Zeep.hs":
    Reading file "c:\hugs98/lib/exts\IOExts.hs":
    Reading file "c:\hugs98/lib\IO.hs":
    Reading file "c:\hugs98/lib\Ix.hs":
    Reading file "c:\hugs98/lib\IO.hs":
    Reading file "c:\hugs98/lib\Array.hs":
    Reading file "c:\hugs98/lib\List.hs":
    Reading file "c:\hugs98/lib\Maybe.hs":
    Reading file "c:\hugs98/lib\List.hs":
    Reading file "c:\hugs98/lib\Array.hs":
    ERROR "c:\hugs98/lib\Array.hs":60 - Cannot justify constraints in
instance member binding
    *** Expression    : (=3D=3D)
    *** Type          : Eq (Array a b) =3D> Array a b -> Array a b -> =
Bool
    *** Given context : Eq (Array a b)
    *** Constraints   : Eq [(a,b)]

My hugs settings are: +fe.qouiR -stgGlQwkIH -h5000000 -p"%s> " -r$$ -c40

    - Conal