[Haskell-beginners] A few really short beginners questions

[Brent Yorgey]

On Sun, Oct 03, 2010 at 09:44:28PM +0200, Klaus Gy wrote:
> Yea, Hugs tells me:
> 
> ERROR (filepath):3 - Syntax error in instance head (constructor expected)
> 
> But since I'm trying to understand Haskell and have nothing particular
> in mind with this program, I'm not stressed finding a solution for
> this. I'm happy if the code is principally correct.

Ah, I see, you are using Hugs.  As I mention in my other email, GHC
has an extension (FlexibleInstances) to allow this.  Hugs might
support this extension as well (I am not sure) but it unfortunately
doesn't mention the possibility in the error message, like GHC does.

-Brent