Re: [boost] Interval comparison operators

From: Joel Young (jdy_at_[hidden])
Date: 2002-09-04 14:08:15

From: "David Bergman" <davidb_at_[hidden]>
> I underline Joel's sumbission.

Thanks David,

From: "David Bergman" <davidb_at_[hidden]>
> I totally agree. Why complicate matters with obscure orderings and
> tribools, when we have quite concrete elements to work with.

This is a pie-in-the-sky vision I have.  

Take a pair of types <t1, t2> and take a set of binary boolean relations
on (t1, t2) and create a new type which manages the application of these
relations to those types.  

For example, say I had <interval, interval> and the 13 relations, I could say:

define I as a set of intervals.
define R as a set of relations.

now return the subset G of intervals of I such that 

for all g in G, g in I .and. g R g

and other tasks such as transitive closures, fixpoints, etc.  

One can express constraint systems:

F, G, H, I be sets of intervals
P, Q, R, S be sets of relations

return me 

set of all tuples (f, g, h, i) over (F, G, H, I) such that

f P g .and. g Q h .and. h R i .and. i S f

Does this make any sense?

Joel