This looks ok to me. The two instances do not unify, because (c1 a1) does not unify with (c2 a2, c2 b2) GHC is happy with it. Simon | -----Original Message----- | From: Jonathon Bell [mailto:jbell@mathsoft.com] | Sent: 16 April 2001 22:43 | To: 'hugs-bugs@haskell.org' | Subject: Possible bug? | | | Hi chaps, | | Hugs (Feb 2001) fails to compile the following, complaining | that the instances are not consistent with the dependencies: | | class Foo f a r | f a->r where | | foo::f->a->r | | instance Foo (a->r) (c a) (c r) | | instance Foo ((a,b)->r) (c a,c b)(c r) | | | My intention is to overload the uncurried function foo for | based on both its arity and the kind of tuple it is passed. | Could you please explain what i am doing wrong here? | | Thank you so much, | | _______________________________ | Jonathon Bell jbell@mathsoft.com | MathSoft, Inc. www.mathsoft.com | 101 Main St, Cambridge, MA 02142 | (617) 577-1017 x745 | | | _______________________________________________ | Hugs-Bugs mailing list | Hugs-Bugs@haskell.org | http://www.haskell.org/mailman/listinfo/hugs-bugs |