[Haskell-cafe] Problem on using class as type.
jesseschalken at gmail.com
Mon Oct 3 16:02:37 CEST 2011
What about "users :: ToJson a => a"?
On Tue, Oct 4, 2011 at 12:42 AM, Magicloud Magiclouds <
magicloud.magiclouds at gmail.com> wrote:
> I have a function:
> post :: (ToJson p, FromJson q) => String -> String -> String ->
> Map.Map String p -> IO q
> Now I'd like to call it like:
> r <- post site token "user.addMedia" (Map.fromList [ ("users", users ::
> , ("medias", medias
> :: ToJson) ])
> So I got the problem. If I used things like "users :: ToJson", then
> class used as a type error occurred. But if I did not use them, since
> users and medias were actually different types, then fromList failed,
> required the type of medias the same with users.
> How to resolve the conflict?
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Haskell-Cafe