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[Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?
From: |
michael josenhans |
Subject: |
[Gnu-arch-users] Re: File-tpye plug-in architecture for Arch? |
Date: |
Mon, 22 Dec 2003 19:54:01 +0100 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20031016 |
Andrew Suffield wrote:
> On Mon, Dec 22, 2003 at 03:33:21PM +0100, Thomas Zander wrote:
>
>>On Monday 22 December 2003 15:12, Andrew Suffield wrote:
>>
>>>>If you say that then I must conclude you fail to appreciate what
XML was
>>>>created for. The whole point of XML based files is to abstract this
kind
>>>>of functionality from lots of different domains into a generic one.
>>>
>>>No, that's the one thing that XML explicitly does not do. The whole
>>>point of XML is that it doesn't do *anything* with "functionality"
>>>(semantics): it is pure syntax.
>>
>>Why is it so hard to understand that XML has achieved more then just
being a
>>syntax.
>
>
> Because it hasn't. Why is it so hard to understand the difference
> between syntax and semantics?
>
I consider the main difference between XML based documents and text
based documents is that xml based documents are trees, while text based
documents are flat.
The trees are written in recursive manner. This makes editing xml
documents by hand a pain and validation of xml documents for being well
formed (being according to XML standard) and valid (the tree node
structure being accoring the grammar defined in the document type
definition.) a must.
The difference above resuts in different change behaviour:
* Text documents: Are often modified, however the boundaries around the
change stay intact. Thus the boundaries can be used as reference to merging.
* In XML documents: The same tags are occuring in many places and nodes
are often moved, deleted, split or merged. This makes XML-diff difficult.
-However XML has other benefits, where can be taken advantage of, when
files are merged:
+ The XML files must be well formed (e.g. all XML nodes opened, must be
closed etc.)
+ The XML files can be validated according to the Document type
Definition grammar. This grammar will restict a majot part of stupid
node nesting an automated XML patch tools would do without.
If this will not help enough to get XML diff working, we can use one of
the following:
+ We could supply to the diff tool more info on how to resovle conflicts
+ If the XML tool knows the tree structure, a dedicated tool might be
able to do smarter merge decisons.
+ If we have the XML data structure under control, we could build is
some info we need for merging (amd especially branching).
This will it make easier for the diff-tool to determine, what had
changed. Examples would be tags with random number. These could be
attached to some or all XML-nodes. (See arch discussion on implicit vs.
explicit tagging.)
+ We could ask the tool we use to modify the XML tree to generate the
patch information.
+ We could ask the tool we use to modify the XML tree to generate the
tags information.
+ Track node changed over patches. E.g. patch branch_1_patch7 has moved
or split a node, while patch branch_2_patch1 still relies that the node
in in the previous position. (I have not seen that any currently
available tool has managed to solve this trouble)
deltaXML
--------
There is a commercial tool claiming to be able to handle diff3:
http://lists.xml.org/archives/xml-dev/200207/msg00517.html
http://lists.xml.org/archives/xml-dev/200312/msg00160.html
This company had created a very nice XML-demo for Scaled Vector Graphics
(SVG).
http://www.deltaxml.com/svg/
Note: Press next on the end of the page.
They have also a nice web based diff, which I used to create the
attached diffs.
Michael
delta-results.zip
Description: Zip archive
- Re: [Gnu-arch-users] File-tpye plug-in architecture for Arch?, (continued)
- Re: [Gnu-arch-users] File-tpye plug-in architecture for Arch?, Tom Lord, 2003/12/18
- Re: [Gnu-arch-users] File-tpye plug-in architecture for Arch?, Robert Collins, 2003/12/19
- [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, michael josenhans, 2003/12/21
- [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Thomas Zander, 2003/12/22
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Andrew Suffield, 2003/12/22
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Thomas Zander, 2003/12/22
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Andrew Suffield, 2003/12/22
- [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?,
michael josenhans <=
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Charles Duffy, 2003/12/22
- [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Tom Lord, 2003/12/21
- [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, michael josenhans, 2003/12/21
Re: [Gnu-arch-users] File-tpye plug-in architecture for Arch?, Thomas Zander, 2003/12/19
- Re: [Gnu-arch-users] File-tpye plug-in architecture for Arch?, Anselm Lingnau, 2003/12/19
- Re: [Gnu-arch-users] File-tpye plug-in architecture for Arch?, Tom Lord, 2003/12/19
- [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, michael josenhans, 2003/12/21
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Tom Lord, 2003/12/21
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Thomas Zander, 2003/12/22
- Re: [Gnu-arch-users] Re: File-tpye plug-in architecture for Arch?, Andrew Suffield, 2003/12/22