[Bug 5229] Definition of xs:double

http://www.w3.org/Bugs/Public/show_bug.cgi?id=5229





------- Comment #1 from davep@iit.edu  2007-10-30 04:10 -------
(In reply to comment #0)
> Concerning xs:double in Part 2 section 3.3.6
> 
> The definition refers to "with the minor exception noted below". There are many
> notes below, and I can't actually tell which one this is referring to.

As best I can tell, this phrase and the note to which it referred were both
deleted, then the phrase was restored but the note was not.  I believe the only
minor exception still existing is that we don't
distinguish between signalling and quiet nans, nor between all the various
system-defined variant
NaNs.  In one sense, this doesn't *violate* 754, because IIRC it doesn't
require those distinctions to be retained in lexical representations.

> A more substantive criticism (which relates perhaps to bug #3243), is that we
> seem to have both an intensional definition [=IEEE 754] and an extensional
> definition [non-zero numbers  m × 2^e] of the value space and it's not clear
> which one wins.

i'm not sure I see the relationship to bug 3243, but with the exception of the
multiple NaNs, the value spaces from 754 and our spec are isomorphic--i.e.,
abstractly the same.  So it's a tie, except for NaN.  

BTW, this bug and my reply apply equally well to float as well as double.

Received on Tuesday, 30 October 2007 04:10:41 UTC