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Re: P1788: Next?


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


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:

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,

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!



Ralph Baker Kearfott,   rbk@xxxxxxxxxxxxx   (337) 482-5346 (fax)
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Department of Mathematics, University of Louisiana at Lafayette
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