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Re: LDPRs, LDPCs and the mysterious X

From: Henry Story <henry.story@bblfish.net>
Date: Fri, 25 Jan 2013 12:33:00 +0100
Cc: "public-ldp-wg@w3.org" <public-ldp-wg@w3.org>
Message-Id: <9D0B86F5-BADC-4173-846A-6196176751C9@bblfish.net>
To: Nandana Mihindukulasooriya <nmihindu@fi.upm.es>

On 25 Jan 2013, at 11:24, Nandana Mihindukulasooriya <nmihindu@fi.upm.es> wrote:

> Hi,
> 
> On Fri, Jan 25, 2013 at 9:44 AM, Henry Story <henry.story@bblfish.net> wrote:
> What can we call _:X ? My thought was that it is that
> which is contained but which does not contain. In the
> file system, we tend to call these "files". 
> 
> I think file system is a nice analogy. If you read the following text about UNIX file system taken from [1], replaying "UNIX" with LDP, "directory" with LDPC and "file" with LDPR, IMO it still make sense.
> 
> [[
> "On a UNIX system, everything is a file;"
> This statement is true because there are special files that are more than just files (named pipes and sockets, for instance), but to keep things simple, saying that everything is a file is an acceptable generalization. A Linux system, just like UNIX, makes no difference between a file and a directory, since a directory is just a file containing names of other files.
> 
> 3.1.1.2. Sorts of files
> Most files are just files, called regular files; they contain normal data, for example text files, executable files or programs, input for or output from a program and so on. While it is reasonably safe to suppose that everything you encounter on a Linux system is a file, there are some exceptions.
> 
> Directories: files that are lists of other files.
> ]]
> 
> So in that venn diagram there are can be other special sets that we can identify like aggregations, or some other things. But anything that we don't have to specially identify, I think people normally call them by the name of the general set. 

The above would tend to argue for a unix file to be identified with an ldp:Resource, since according
to your text, everything including directories are files.  Clearly I think we would be in agreement
that a unix directory is a subset of those files, and so is similar in that regard to an ldp:Container
as shown in the diagram from the previous mail ( whose pdf I published at [2]) . 

Furthermore deleting a directory requires deleting all its members, and deleting a member of an
directory deletes it from the directory listing, exactly the way ldp:Containers are meant to work.

It seems that on unix one may want a name for those things that are files but not directories,
just the same way we seem to be looking for such a name in the venn diagram I posted [2].

- Usually I think that is what human beings that are not engineers call files... Well it looks like
the word "files" may be problematic to unix engineers then.

- "Content" seems to be problematic as I expect a ldp:Container can contain an ldp:Container,
  and we don't want to say that ldp:Containers are part of this LDPX thing, for we would otherwise
  just end up again with the set of LDPRs.



>  
> Best Regards,
> Nandana
> 
> [1] - http://tldp.org/LDP/intro-linux/html/sect_03_01.html
> P.S. - In the link LDP stands for Linux Documentation Project not Linked Data Platform :)

Yes, is that not weird that that URL contains the three letters "LDP" !? :-)
> 


[2] http://www.w3.org/2012/ldp/wiki/images/b/b5/LDP-RCX.pdf

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Received on Friday, 25 January 2013 11:33:41 UTC

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