[Haskell-cafe] Set of reals...?

Stijn De Saeger stijndesaeger at gmail.com
Wed Oct 27 05:41:32 EDT 2004


Thanks for the swift reply,
see inline


On Wed, 27 Oct 2004 09:51:29 +0100, Graham Klyne <gk at ninebynine.org> wrote:
> I think the first question you have to address is whether you really want
> to represent a *set* of reals or an *interval* of reals.  

A set of intervals, I would assume... 
The reason for that is that i will probably end up with 
set theoretic operations like complement, and in that case the
complement of an interval of
reals will have a hole in it somewhere. That's why i represented them
as lists of pairs (lower and upper bound of the sub-interval, so to
speak) , but that will probably get ugly before long.

> Then, some other questions follow:
> - possibly infinite sets within any given interval?

I was not explicitly thinking of  infinite sets, i just wanted to keep
the precision open for now. I would say, up to 4 decimal figures
maximum.

> - open or closed intervals?

closed intervals, but with holes. (see above)

> and probably more.
> 
> #g
> --

cheers,
stijn


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