[Haskell-beginners] print []

[AntC]

> Lukas Lehner <lehner.lukas <at> gmail.com> writes:
> 
> ... My question is that I have to enforce the type that specific way 
(don't want to use ExtendedDefaultRules) or is there some more generic way?
> 

    print flatten (List ([] :: Show a => [a]) 

Even for an empty list, we have to provide evidence that the list is 
showable. That's what the type signature is doing: I am a list of 
something/anything showable.

(If you want all of your NestedLists's to be showable, it's better to put 
a Show constraint on the data decl. But that would take us into 
existential types or GADT's.)

AntC