On Wed, 2011-01-05 at 12:07 -0800, Jeff Davis wrote:
> The current design for range types doesn't ask for add or subtract.
> Although it might be interesting to try to use such an interface for
> range types, it introduces a lot of complexity and makes it easier to
> cause subtle problems (consider that addition of timestamps and
> intervals is not commutative).
A consequence of this design is that some generic range functions, like
"length" or "distance" would need to rely on the polymorphism of "+" and
"-" to work.
I'm also not sure if a constructor like "range(start, offset) returns
anyrange" could be made to work generically at all, because the start
and offset may be two different types (and a function that takes
ANYELEMENT requires that all ANYELEMENT arguments are the same type).
Does anyone see a problem with that?
Regards,Jeff Davis