Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: P1788: Next?



Baker,

I think that it is a precedent.

1788 is trying to be generic.
It has common requirements which can be extended in a potential family of flavors.

This architecture of the standard required more effort of the Working Group
than possible simpler architecture without flavors.
Nevertheless, it can be resulted to a family of flavors which are similar
and so they are easier to learn.
If the WG spent much time on flavor architecture
then it is reasonable to use this architecture and
to ensure that sub-standards of 1788 are flavors of 1788.

Of course it is not always possible. It seems that containment-set approach
conflicts with the 1788 common requirements.

Nevertheless, 1788.1 doesn't conflict with 1788 common requirements.
And I think that we should state this.
The 1788.1 can be a precedent of sub-standard.
If it is stated that 1788.1 is a flavor of 1788 then
it will be easier to require that future possible sub-standards of 1788 are also flavors.

  -Dima


----- Original Message -----
From: rbk5287@xxxxxxxxxxxxx
To: j.d.pryce@xxxxxxxxxx, dmitry.nadezhin@xxxxxxxxxx
Cc: STDS-1788@xxxxxxxxxxxxxxxxx
Sent: Thursday, February 9, 2017 6:12:15 PM GMT +03:00 Iraq
Subject: Re: P1788: Next?

All,

Yes, I'd been wondering about whether or not it is important
that 1788.1 be a flavor.

Baker

On 02/09/2017 06:23 AM, John Pryce wrote:
> Dear all
>
>> On 9 Feb 2017, at 04:00, Dmitry Nadezhin <dmitry.nadezhin@xxxxxxxxxx> wrote:
>> Natalie,
>>
>>> it is not clear to me that 1788.1 is a flavor of 1788…
>>
>> Part 1 "General Requirements" of the 1788 standard defines requirements for a flavor.
>> Which of these requirements are not met by 1788.1 ?
>>
>> Best Regards,
>>  -Dima
>
> I seem to remember this became an essentially technical question and that whether 1788.1 is a flavor or not comes down to how literals are handled, e.g. by numstointerval() and texttointerval(). E.g. does it support mixed radix interval literals (MRILs) as in Table 9.4. "All-flavor bare interval literal examples"? E.g.
>  "[-0x1.3p-1, 2/3]" or "[-0x1.3p-1, 0.6667]"
>
> Dima pressed for a specification that would make it a flavor, while Ned was not keen, on grounds of keeping 1788.1 simple. Vincent Lefevre also expressed some views. The point was, I think, that the computational complexity of deciding if a MRIL represents a valid (nonempty) interval can be very high, and is this a burden worth putting on implementers of a "basic" standard?
>
> I don't recall how the discussion was resolved, if it ever was. Ned, Dima, Vincent?
>
> If it wasn't resolved, personally I would be happy if 1788.1 keeps the simpler spec that means it's not (currently) a flavor. When the main 1788 standard is revised in a few years, we can decide whether to limit literals to follow the 1788.1 form -- in which case 1788.1 would become a flavor!
>
> John
>


-- 

---------------------------------------------------------------
Ralph Baker Kearfott,   rbk@xxxxxxxxxxxxx   (337) 482-5346 (fax)
(337) 482-5270 (work)                     (337) 993-1827 (home)
URL: http://interval.louisiana.edu/kearfott.html
Department of Mathematics, University of Louisiana at Lafayette
(Room 217 Maxim D. Doucet Hall, 1403 Johnston Street)
Box 4-1010, Lafayette, LA 70504-1010, USA
---------------------------------------------------------------