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Re: Revision to set-based interval literals

All,

Without studying the details fully, I am nonetheless wondering
if we are not making changes that are "six of one, half
a dozen of the other".  Let's make sure changes we make
at this point actually need to be made.

(I'm not commenting on any particular suggested change, but
am observing a significant volume of changes  -- perhaps they
all actually are necessary.)

Baker

On 03/05/2015 08:38 AM, John Pryce wrote:

Folk

On 5 Mar 2015, at 10:20, Vincent Lefevre <vincent@xxxxxxxxxx> wrote:

On 2015-03-05 11:17:18 +0100, Vincent Lefevre wrote:

On 2015-03-04 16:15:30 +0000, John Pryce wrote:

Comments please on this fairly drastic shortening of §12.11
"Interval and number literals". It needs to be read alongside the
new §9.4, which Dmitry will be revising, or maybe has already.


I'm wondering whether interval literals should be specified mainly
at Level 1 instead of Level 2. The new §12.11.1 says: "This subclause
extends the specifications of 9.4" but §9.4 in mainly about Level 1,
and when one writes "[1.234e5,Inf]", this first designates a Level 1
interval.


I initially thought that Level 2 was OK because a string is the
same datum at Level 1 and Level 2. However the interpretation as
a literal depends on the level, and one normally first considers
the interpretation at Level 1.


I thought about this a lot when we first did (set based) interval literals, and eventually decided to put them into Level 2. I think the old text in 12.11 does make it clear what notions are Level 1. However, I will look at it more broadly and see if the new, shorter, 12.11 should be part of Level 1. BTW I put the latter in the repository, r436.

John Pryce




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Ralph Baker Kearfott,   rbk@xxxxxxxxxxxxx   (337) 482-5346 (fax)
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