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Re: [GRAPHS] g-box, g-snap, and g-text

From: Nathan <nathan@webr3.org>
Date: Fri, 25 Feb 2011 18:19:40 +0000
Message-ID: <4D67F2BC.2050506@webr3.org>
To: Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>
CC: Sandro Hawke <sandro@w3.org>, Ivan Herman <ivan@w3.org>, public-rdf-wg <public-rdf-wg@w3.org>
Yup I agree, and also like the lexical/value space way of looking at 
things as Antoine noted earlier.

Pierre-Antoine Champin wrote:
> On 02/25/2011 06:37 PM, Nathan wrote:
>> Sandro / Ivan,
>>
>> AIUI, a g-box is a "box" which contains triples, the contents of the box
>> can change over time, and the contents of the box at a particular point
>> in time form a Set of Triples, a g-snap (a snapshot of the contents, the
>> value of the box at time t, the state of the box at time t), g-snaps can
>> be represented lexically in a data format so that they can be
>> transferred over the wire, these serialized g-snaps are called g-texts.
>>
>> some clarifications to sandro's text following my understanding:
>>
>> Sandro Hawke wrote:
>>> On Fri, 2011-02-25 at 17:30 +0100, Ivan Herman wrote:
>>>> Another way of putting it is that a g-text is a special form of a
>>>> g-box, which has the peculiarity of representing a g-snap in a text
>>>> file.
>>>
>>> No, a g-text is not a special form of a g-box.  A g-text is a fixed
>>> sequence of characters or bytes; a g-box is a potentially-mutable
>>> collection.   If two g-texts are the same sequence, they are the same
>>> g-text; that's not at all true of g-boxes.
>>>
>>> In a low-level language, like assembly or C, g-box would be some area of
>>> memory, while a g-text would be some values that might be stored in that
>>> memory.
>>
>> a g-box would be some area of memory, a g-snap would be the set of
>> values stored in that memory at a point in time, and a g-text would be a
>> serialization of that set of values.
> 
> According to Sandro's original definition [1], a g-snap is "an 
> *idealized* snapshot of a g-box: it's a mathematical set (...)".
> What is stored in memory is *not* a mathematical set, but a 
> *representation* of the set, just as a serialization in a text file is a 
> *representation*. Hence my proposal to unify both under the concept of 
> g-text.
> 
> I like Antoine's proposal in [1] to consider g-snaps as elements of a 
> value space, while g-texts would be elements of a lexical space (Antoine 
> didn't use the g-* terminology, but I think I don't betray his thought).
> 
>>> Computer files are boxes, not texts, in this terminology -- they can
>>> change, and they have an identity separate from their contents.
>>
>> Indeed, and g-texts have their own identity separate to both the
>> contents of the box, and the box it self.
> 
> Agreed; but would you agree that a file foaf.rdf does not contain a 
> graph; it contains a serialization. Similarly, an in-memory structure 
> contains a sequence of bytes which are a *representation* of a graph, 
> not the graph itself. The graph is unreachable.
> 
>> Relating to real life, let's say it's an apple box a-box:
>>
>> An a-box contains apples, the contents of the a-box at a particular
>> point in time is an a-snap, a written list or photo of the contents at
>> that point in time is an a-snap.
> 
> For the last occurence of "a-snap", you mean "a-text", of course :-D
> 
> It seems a bit farfetched to compare a "mathematical set" to a bunch of 
> apples ;-D
> 
> Let me put it another way: if you buy a box containing '10 apples', you 
> wouldn't mind if I ate one of the apples and replaced it with another 
> one, as long as you still have the '10 apples' you paid for in your box. 
> The a-set is the Idea of '10 apples'. The a-text are the 10 actual 
> apples that happen to be in the box. The photo or written list does not 
> count, as you can't eat them!
> 
>> Sorry to be a bit pedantic here, but I feel it's critical to keep clear
>> distinctions between the three concepts
> 
> Sorry to be over-pendantic, but I agree with you that we need to have 
> clear concepts :)
> 
>> box: a container
>> snap: contents of the box at a point in time (or, the state of the box,
>> or, the set of things in the box - set in the mathematical sense)
>> text: a representation of a snap
> 
> again, if the snap is a mathematical object, you can not put it in a 
> box. You can merely put an instance/token/representation of it in the box.
> 
>   pa
> 
> [1] http://lists.w3.org/Archives/Public/public-rdf-wg/2011Feb/0092.html
> [2] http://lists.w3.org/Archives/Public/public-rdf-wg/2011Feb/0083.html
> 
>>
>> Best,
>>
>> Nathan
>>
> 
> 
> 
Received on Friday, 25 February 2011 18:20:55 GMT

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