On 09/11/10 11:53, Neil Brown wrote:
XMLGenerator.lhs:64:16:
Overlapping instances for EmbedAsChild
(IdentityT IO) (XMLGenT m (XML m))
arising from a use of `asChild' at XMLGenerator.lhs:64:16-22
Matching instances:
instance [overlap ok] (XML m
I'm not sure whether to reply to the list(s) or the ticket; maybe if you
think my comments are valid they can be copied to the ticket. From
looking, it seems to me that you do have overlapping instances, and I
wonder if it's actually a 6.12 bug for accepting the code, not a 7 bug
for rejecting
> instance (EmbedAsChild m c, m1 ~ m) => EmbedAsChild m (XMLGenT m1 c)
That looked to me like a long-winded way of saying:
> instance (EmbedAsChild m c) => EmbedAsChild m (XMLGenT m c)
Unless I'm missing something?
These two instances are not equivalent:
- the first matches even if m and
