ghc puzzling behaviour

[Simon Peyton-Jones]

Thank you.  A palpable bug.  Fixed.

Simon

|  -----Original Message-----
|  From: glasgow-haskell-users-admin@haskell.org
[mailto:glasgow-haskell-users-
|  admin@haskell.org] On Behalf Of Ketil Z. Malde
|  Sent: 07 April 2003 13:33
|  To: glasgow-haskell-users@haskell.org
| =20
| =20
|  Hi,
| =20
|  When compiling with -funbox-strict-fields, the supplied code doesn't
|  seem to compile, requiring 'Ord Foo' to derive 'Ord Zot', even if
'Ord
|  Bar' is explicitly declared.  Without the flag, it works as expected.
| =20
|  Is this intentional?  I'll get by by dropping -funbox, or explicitly
|  declaring the instance, so it's no big deal -- just slightly
|  surprising.
| =20
|  --T1.hs--
| =20
|  > module T1 where
|  >
|  > data Foo =3D Foo Int String
|  > data Bar =3D Bar Int Foo
|  >
|  > instance Ord Bar where
|  >     compare (Bar i _) (Bar j _) =3D compare i j
|  >
|  > instance Eq Bar where
|  >     (Bar i _) =3D=3D (Bar j _) =3D i =3D=3D j
| =20
|  --T2.hs--
| =20
|  > module Main where
|  >
|  > import T1
|  >
|  > data Zot =3D Zot !Bar !String deriving (Ord,Eq)
|  >
|  > main =3D putStrLn "Success"
| =20
|  -kzm
|  --
|  If I haven't seen further, it is by standing in the footprints of
giants
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