| Thread Links | Date Links | ||||
|---|---|---|---|---|---|
| Thread Prev | Thread Next | Thread Index | Date Prev | Date Next | Date Index |
Michel On 2014 Jun 22, at 19:11, Michel Hack wrote: > The first three paragraphs of 14.4 are ok. I start with rewriting the > fourth paragraph, which currently begins the same way: > > Interchange Level 4 encoding of an interval datum is a bit string that > comprises, in the order defined above, the platform's representation > of the 754-2008 interchange encodings of the two floating-datums, and > of the decoration represented as a small integer, as detailed below. > Since the 754-2008 standard supports two different encodings for > decimal formats, and does not address the Endianness issue at all, > this standard defines a *standard type signature*, described below, > which incorporates the parameters of the encoding... Personally I would be happy with the scheme you propose. The further discussion with Dmitry seems on the lines of whether what was previously un-plated should be chromium-plated, silver-plated or gold-plated. Stick with chromium, IMO, and defer possible gold to a future revision. But I have these criticisms/queries: 1. "... implementation shall provide, for each interchange encoding, a standard type signature" This is meaningless. An implementation doesn't provide concepts, it provides means to create and manipulate objects. I suggest something like "The standard defines, for each interchange encoding, a standard type signature, which is ... A 754-conforming implementation shall provide means to create the signature of each such encoding. This signature may be included, in an application-defined way, in a header that accompanies interchange-encoded intervals for export. This achieves fairly universal portability." Remove the later sentence about portability. 2. Some wording is insufficiently standardese e.g. the several "(assuming ...)" comments. I suggest these go into the Note at the end. 3. From what you said earlier, the \0 null byte seems to be aimed at making it easier to decide endianness. But why? don't the initial 8 bytes of ASCII tell that? I'm wondering if this byte could be used to distinguish bare from decorated interval data. Attached is my first try at typesetting your proposal (§14.4 only). John Pryce
Attachment:
20140622interchangeHack.pdf
Description: Adobe PDF document