[Haskell-cafe] Fwd: constraint inference

[Li-yao Xia]

On 07/07/2017 02:50 AM, Dmitry Olshansky wrote:
> I am not sure why but when I didn't set RankNTypes I got an appropriate
> error. So I specified it.
>
> But if I write
>    let { f :: (forall n. KnownSymbol n => Proxy n) -> String; f p =
> symbolVal p }
> then nothing is changed.
>
>


What would the String (f Proxy) be? (Note that (Proxy :: forall n. 
KnownSymbol n => Proxy n) would be a valid argument here.)