Re: [Haskell-cafe] A functional programming solution for Mr and Mrs Hollingberry

On 26/05/2012, at 4:16 AM, David Turner wrote:

I don't. I think the trouble is that classes don't add value in exercises of this size.

This was the key point, I think. In this example, there wasn't any significant behaviour that could be moved to superclasses. For that matter, whether a supplier is plain, preferred, or problematic is, one hopes, not a *permanent* property of a supplier. Sometimes higher-order functions can substitute for classes.