Re: [Haskell-cafe] Defining types (newbie)

On 14/03/07, Bryan O'Sullivan wrote:

John Fouhy wrote:

...

In Haskell, I envisage writing something like:

data ThingCompare = TC Op Field

This wants to be a bit more concrete:

data ThingCompare = TC (a -> a -> Bool) (Thing -> a)

Hi Bryan, I actually had to write: data ThingCompare a = TC (a -> a -> Bool) (Thing -> a) runTC :: ThingCompare a -> Thing -> Thing -> Bool runTC (TC compare extract) x y = compare (extract x) (extract y) But thanks for your help; it set me back on the right track. I think things are slowly starting to come back to me :-) -- John.