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Re: ... replacement for 14.4 and C6.2 (interchange encodings)



On Thu, 26 Jun 2014 05:40:37 -0700 (PDT) Dima wrote:
> Revision -r376 contains
> - Corresponding changes in C6.2.
> - §4.2 Definitions entries for "octet" & "octets-encoding".
> - Hyphen in beg-endian and little-endian (according to Wikipedia).
> **File: octets3.pdf

This looks good.  As John Pryce pointed out, and Dima agreed, all
occurrences of "octets-encoding" (there are several) should be
replaced with "octet-encoding".

Also, in the paragraph "Applications exchanging data...", line 5:
   merely requires the parameters -> merely requires that the parameters

I note that 14.4 now explicitly recognizes interchange representations
for both bare and decorated intervals, which is good.

I still think we need to say something about compressed intervals, if
they are supported (they are optional).  That's because these would
need different encodings of the decoration, and here is where my
suggestion that decoration encodings be interpreted as small integers
instead of as bit strings has a definite advantage.  We could show the
decorations both as a small integer and as an 8-bit octet.  Another
possibility (so as not to rewrite the fourth paragraph of 14.4 a few
more times) is to mention the small-integer equivalence in the following
paragraph, which could be inserted after the Note and before the paragraph
that starts with "Export and import...":

    When (optional) compressed intervals are supported, their interchange
    representation is as described above for bare intervals for non-empty
    intervals, but decorations are represented as a pair of floating-point
    datums, the first of which is a generic NaN (no payload information),
    and the second is a floating-point integer that encodes the decoration
    as follows:
       ill    0.0
       emp    2.0
       trv    4.0
       def    8.0
       dac   12.0
    (Note that these encodings match the octet-encoded decorations
    of decorated intervals, when interpreted as small integers, with
    a new decoration *emp* to represent a compressed Empty interval.
    The *com* decoration cannot occur in a compressed interval.)

Michel.
---Sent: 2014-06-26 18:16:46 UTC