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

Re: P1788: Next?





Dear All,

I have attached the relevant pages with the suggestions by Dmitry at the time in blue.
I was thinking to have them in the whole document for a vote on it. It seems we may have to revisit this issue.
My initial view was interval literals of the same radix (p. 21, line 4, red means crossed out),
no rationals, and no uncertain form.

Any suggestions on how to proceed?

Regards,
Ned

> On Feb 9, 2017, at 07:23, John Pryce <j.d.pryce@xxxxxxxxxx> 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

Attachment: p20_23.pdf
Description: p20_23.pdf