[Haskell-cafe] Selda: confused about type signtures

Marc Busqué marc at lamarciana.com
Fri Apr 20 19:20:48 UTC 2018

On Fri, 20 Apr 2018, Brandon Allbery wrote:

> The more precise answer to your question is that an explicit type signature is taken as exact. If the type needed is some (Ctx a => a), as here,
> but your type signature just says a, you will get a type error exactly as you did.
> "a" there does not mean "figure out a type for me". It means *any type at all*. Including Void, (), Int, etc., which one would not expect to work
> there.

Thanks! That was an illuminating answer :)

Marc Busqué

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