Re: [office-collab] Multiple changes

[Svante Schubert <svante.schubert@gmail.com>]

Hi Patrick,

On 19.09.2012 17:04, Patrick Durusau wrote:
> Svante,
>
>
> On 09/19/2012 08:35 AM, Svante Schubert wrote:
>> Hi Patrick,
>
> <snip>
>> That is at what time does the state of the text become "fixed" so that
>> change tracking is engaged again?
>> With "fixed" you might as well think about a compression/condensation of
>> operations. For example, if someone inserts a word and deletes it again,
>> it will not occur in the CT, although there had been two operations.
> That was my question.
>
> You are presuming a model that does not track changes to changes.
Might be philosophical, as every operation creates a new independent
document state. Therefore two (or more) sequential operations changing
the same data, could be interpreted either as two (or more) independent
changes of the document state or as a change of a change.

After realizing both views are equivalent it is much easier to work
solely with the prior model, where each change is independent and
movable along the sequence of operations (presuming to do the required
OT adaption during movement, i.e. whenever passing a create/delete
operation that influence the position of the moving operation
de/increase the position integer).
>
> Which is one presumption but perhaps not the one that the TC desires
> to make.
The TC is likely to favor the easiest and efficient model being offered.
>
> Can think of compression/condensation of operations but that means the
> CT syntax has to record multiple changes, say make bold and italic
> instead of separate operations of bold, then italic (on the same text).
From a abstract high level view, changing the style on text is nothing
more than an change of properties on a sequence of the document. Someone
might change a single property or multiple properties. Latter might be
done via operations by either passing all properties along or defining a
set beforehand. Someone might even have the vision that some style sets
are being defined before the operations occurs (to follow our convention
over configuration approach), either within the document (as a given
style set) or preferable within the ODF specification, by "style blends"
from the application vendors. For instance, the "heading 1" style set
might be defined before hand, instead of passing the styles for every
document being opened.

Various compressions are thinkable, all they have to have in common is
to keep the information set equivalent.
>
> And, it means we have to define when compression/condensation occurs
> and how it is recorded in syntax.
Uncertain yet, if we have to be necessarily such strict. We definitely
have to define what operations are equivalent. We could even come up
with a normalized form of operations (the most efficient form of
operations to be exchanged).
>
> Not objecting to your answer but it leaves out a lot of detail. ;-)
>
Sure, just wanted to keep the mail short ;)
> Hope you are having a great day!
>
> Patrick
>
Hope you are having a great day as well!
Svante