[Haskell-cafe] Re: [Haskell-beginners] Re: Accounting Engine in Haskell

[Stephen Tetley]

On 17 June 2010 19:58, Stephen Tetley <stephen.tetley at gmail.com> wrote:
...
> Area, I'm not sure about. Maybe you **good** integrate the function
> through a space, but this might not be a good idea.

Ahem, swap 'good' for 'could' in that bit...

Antony Courtney used a dual representation for his vector graphics
program - Haven. Images were both a "colour characteristic function"
and proper/plain characteristic function for regions. I think this was
so that "point in polygon" calculations could be made easily.

type Image = (Point -> Color, Region)

Perhaps, it might not be too much of a stretch to model regions both
with a characteristic function and a more concrete representation that
allows area to be taken more easily. The region combinators would
become more complicated though.