Re: Unsigned language in the pvAccess protocol spec

[White, G. <gr...@sl...>]

Hi Ben, did you see Marty's proposal for unsigned? He sent it on Thursday I think. Believe it falls between your definitions. 

Greg

Sent from my iPhone, +1 650 799 5967


On Jan 23, 2012, at 8:11 AM, "Benjamin Franksen" <ben...@he...> wrote:

> On Tuesday, January 17, 2012, White, Greg wrote:
>> [...] clarify the distinction between type indication and
>> data transport.
>> [...] pvAccess does not support unsigned is essential.
>> 
>> I want to indicate the while there's no unsigned integer type in pvAccess
>> [1] (and parenthetically there is therefore no pvData serialization for
>> that) that pvData's API will support indication of type. And I want the
>> phrasing to flow from what's missing to assurance that there will be a
>> work around and how it'll operate.
> 
> Are you guys realy sure you want to do that? I mean, pvAccess is still in
> alpha stage and already you design work-arounds for its limitations...
> 
> Anyway, assuming this is what you want to do, I find none of the proposed
> formulations especially illuminating.
> 
> Let me give you the impression of an outsider here: My basic question,
> reading the protocol spec, would be: well, *can* I send unsigned integers
> over the wire, so that the other side understands which datum is I sent as
> signed and which as unsigned? If the answer to this is "yes", then unsigned
> integers *are* supported.
> 
> It may be that (for reasons obscure to me, but that's not relevant here)
> they are supported only in a kludgy work-around-like way i.e. not as part of
> the regular type information. Whatever. The point is: a special provision in
> the protocol itself to make the signed/unsigned distinction means that there
> is support for unsigned integers.
> 
> If, on the other hand, there is no special provision in the protocol for
> this distinction, so that the user has to *emulate* unsigned integers by
> e.g. using a struct with an integer and a separate flag, then I would say,
> "no" unsigned is not supported, period.
> 
> Cheers
> Ben
> 
> ________________________________
> 
> Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
> 
> Mitglied der Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren e.V.
> 
> Aufsichtsrat: Vorsitzender Prof. Dr. Dr. h.c. mult. Joachim Treusch, stv. Vorsitzende Dr. Beatrix Vierkorn-Rudolph
> Geschäftsführerin: Prof. Dr. Anke Rita Kaysser-Pyzalla
> 
> Sitz Berlin, AG Charlottenburg, 89 HRB 5583
> 
> Postadresse:
> Hahn-Meitner-Platz 1
> D-14109 Berlin
> 
> http://www.helmholtz-berlin.de
> 
> ------------------------------------------------------------------------------
> Try before you buy = See our experts in action!
> The most comprehensive online learning library for Microsoft developers
> is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3,
> Metro Style Apps, more. Free future releases when you subscribe now!
> http://p.sf.net/sfu/learndevnow-dev2