At 12:45 AM +0200 5/7/06, mAsterdam wrote:
Okay, thank you both for clarifying this.
Conceptually in my mind, a Range is entirely appropriate to
represent a mathematical interval, but I was mistaken about Range
being more constrained than it actually is.
So, there you go mAsterdam; Range is indeed the interval you are looking for.
I hope it is also the appropriate type for implementing
relations with temporal attributes.
Thank you all for your prompt discussion.
It should work just fine.
Keep in mind that your concern about relations is orthogonal to the
concern about intervals or temporal data.
An attribute of a relation can be any arbitrary data type at all
(including another relation).
So the only real concern here is whether there is a data type that
can represent a single piece of temporal data. But one can easily be
defined using Perl's standard class definition abilities if it isn't
pre-defined.
Note that I am of the opinion that Perl probably should not have
built-in data types that are specific to temporal or spacial data; it
is better for these to be extensions (like "DateTime" etc) defined
over built-ins like numbers or ranges or collections. Temporal or
spacial data in common use today is just too complicated and
non-generic, I think.
(Whereas, the existing built-ins, and relations, are very generic and simple.)
-- Darren Duncan
