Re: Proposal for a new structure of the standard
> Date: Sun, 18 Jul 2010 22:28:35 -2000
> To: stds-1788 <stds-1788@xxxxxxxxxxxxxxxxx>
> From: Michel Hack <hack@xxxxxxxxxxxxxx>
> Subject: Re: Proposal for a new structure of the standard
>
> Dan Zuras wrote:
> > I think it makes more sense to have the set that lives
> > at level 2 be a single instantiation of a GMP object as
> > an interval type indexed by base, precision & range as
> > well as style (explicit/implicit).
>
> But what if the format doesn't have the CONCEPT of bounding
> the range? (I'll admit that not bounding precision does not
> work for floating-point types, unlike some of the types I had
> mentioned in earlier posts.)
>
> Are you simply ruling these out? Perhaps you are.
I am.
>
> Let me suggest an alternative: IF the underlying format does
> not have fixed or at least specifiable bounds on range and
> resolution, THEN functions like TightestHull() MUST have an
> additional parameter that does specify such bounds for that
> invocation.
>
> Michel.
> ---Sent: 2010-07-19 02:28:39 UTC
No bounds implies no limits on the amount of memory
that an interval takes up. While this may be no
problem for you, the compiler guys like to know how
much space to allocate for things.
Yes, it is true that one can allocate pointers into
a heap space. But it slows things down & makes for
garbage collection problems.
Making a datatype of fixed size avoids all these
problems.
You still have the freedom of unlimited precision &
range so long as you consider the movement of a value
from one size to another as a conversion operation.
And fixing the range & precision also helps us come
up with concrete ways of defining the behavior of
intervals.
Sounds to me like we get a lot & give up almost
nothing.
Reasonable?
Dan