Re: Exception handling
Guillaume, P-1788:
Please see my interpolated comments.
Best regards,
Baker
On 08/20/2013 02:26 AM, Guillaume Melquiond wrote:
Le 11/08/2013 03:54, Guillaume Melquiond a écrit :
Hi,
.
.
.
Question 3. This question at least got some answers. If I interpret them
correctly, Ian and Michel expect operations returning an IEEE-754 result
to also properly signal IEEE-754 exceptions. Vincent considers that
whether IEEE-754 exceptions are signaled is out of the scope of the
standard, while my opinion is that the standard should recommend that
they are not.
As appropriate, I'd like to encourage someone to submit a motion
to unambiguously clarify P-1788's sentiment concerning this issue.
There are also two new questions that have surfaced in the course of
this discussion (partly in private correspondences, so do not be alarmed
if that does not ring a bell).
Question 4. Should there be a NaI for bare intervals? There are two
points to remember though. First, signaling NaNs almost got phased out
from the IEEE-754 revision (and I believe they will not survive the next
revision), and their bit-pattern is not even specified anyway; so any
solution based on signaling NaNs might be short-sighted. Second,
whichever representation is chosen, it will have a non-negligible cost
for some interval operations implemented using IEEE-754 arithmetic.
Thank you for the information.
Question 5. For the sake of bounded space/time, some operations like
text2interval can be specified so that they always return a correct
result (containment-wise) in the normal case, but fail to signal an
exceptional case (e.g. inverted bounds). Assuming that we allow such a
specification, the question is: should these potential failures be
reported to the user? And if so, how?
Should there be additional formal discussion, or is the issue now clear
enough to formulate a motion?
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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
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