Hello,
There is nothing wrong with this program. I have run into this
problem and I consider it to be a bug/weakness of the type checking
algorithm used by the implementation.
(I also agree with you that the term "rigid variable" is rather
confusing because it is an artifact of the type checking algorithm
used by GHC.)
-Iavor
On 3/3/07, David House
class Foo a b | a -> b instance Foo Int String bar :: Foo Int b => b bar = "rargh"
Is there any reason why that shouldn't work? GHC gives one of its silly "b is a rigid variable" errors (aside: that's a really confusing error; I'd prefer something like Hugs's "Infered type is not general enough").
-- -David House, dmhouse@gmail.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe