Difficulties with Flat XML under source control

[Dennis E. Hamilton]

It occurs to me that Postscript and PDF have dealt with this for imaging models that work consistently.  Here, the "in" is to a renderer, but the model for representation of decimal expressions of find-sensitivity values seems to have been handled (for years).  Those specifications may be some help too.

 - Dennis

-----Original Message-----
From: Thorsten [mailto:netsroth at googlemail.com] On Behalf Of Thorsten Behrens
Sent: Wednesday, June 20, 2012 06:32
To: Dennis E. Hamilton
Cc: 'libreoffice-dev'
Subject: Re: Difficulties with Flat XML under source control

Dennis E. Hamilton wrote:
> For out-in (which this is, presumably), you want to record a
> decimal expression of the internal value that will convert back to
> the exact internal value on re-input.  (The in-out case is that
> the input conversion provide whatever internal representation that
> will convert to the read value on re-output.  Without additional
> information, it is generally very difficult to have these be the
> same.)
> 
> It is also desirable, of course, that any other ODF consumer use
> the same technique so that its in-out conversion satisfies the
> out-in condition of the original source of the decimal expression
> of the value.  
>
Hi Dennis,

yes - but in a first approximation, one can probably relax this a
bit (for the use case at hand): only _after_ the first save
operation this needs to hold. Also, most people would probably be
contempt with this to work for *one* ODF editing application.

> It is also desirable, of course, that any other ODF consumer use
> the same technique so that its in-out conversion satisfies the
> out-in condition of the original source of the decimal expression
> of the value.  
> 
Note that there's a difference between spreadsheet values (for which
I think de facto the above holds true - likely everyone stores those
in IEEE doubles), and other content: consumers might employ rather
complex transformations to arrive at internal values, given e.g. a
gradient center coordinate - asking for common behaviour is very
close to asking for a common ODF application model.

Cheers,

-- Thorsten