GHC 7.10 regression when using foldr

[Malcolm Wallace]

On 20 Jan 2015, at 11:20, Björn Peemöller wrote:

> The reason is the usage of foldr, which changed its type from
>   foldr :: (a -> b -> b) -> b -> [a] -> b -- GHC 7.8.4
> to
>  foldr :: Foldable t => (a -> b -> b) -> b -> t a -> b -- GHC 7.10.1
> Thus, the use of foldr is now ambiguous. I can fix this by providing a
> type signature
>   convert :: ([a], String) -> (List a, String)
> 
> However, is this breaking change intended?

I believe this kind of breakage was predicted by those opposed to the change of signature.  That is not quite the same thing as being intended or desired.

Regards,
    Malcolm