interesting. it leads to something that feels much more like an object
as far as haskell is concerned, everything has the same type, even
Steve Downey wrote: based, as opposed to a class based, system. though different instances have very different behavior.
.... the question is, which plays nicer with the rest of haskell? that is, if i'm not committing to a closed dsl, which style is more likely to be reusable against other libraries.
I suspect there's no right answer - it's a case of choosing the best approach for the problem. As an example, my charting library (http://dockerz.net/software/chart.html) uses the record of functions approach for composing drawings: data Renderable = Renderable { minsize :: (Render RectSize) render :: (Rect -> Render ()) } Tim