Less verbose XML (Was: A little wish for short end tags (Was: RE: SDD bogus))

[Andrew Layman]

This is not to debate the value of short end tags.  That's been debated.
But just as a technical matter, I also ran some tests a while ago, and found
that files with short end tags compress 5 to 10 percent better than those
with full end tags. I believe the reason is that with full end tags there
are more unique pairs of end/start, while with short end tags there are only
as many end/start pairs as types of start tag.  So a compression scheme that
first shortened end tags, then applied a standard compression would be more
efficient size-wise.

-----Original Message-----
From: Rick Jelliffe [mailto:ricko at allette.com.au]
Sent: Friday, May 08, 1998 5:39 PM
To: 'XML-DEV'
Subject: Re: Less verbose XML (Was: A little wish for short end tags
(Was: RE: SDD bogus))


If you are worried about file size, then compress your files.

Tags, being short strings commonly used, compress really nicely with
the common compression algorithms out there.

I once did an experiment (to confirm one that Gavin Nicol had done)
using a document with  several thousand lines, each with one start-tag, 
end-tag pair and no content. I tried compressing this file with
* no minimization
* short end-tags
* end-tag ommission
The uncompressed file was something like 50K. The compressed files
differed by only a few 100bytes from each other. The gains from short
end-tags did not carry over into the compressed versions, and the
compressed versions were so much smaller there seemed little
contest.

Having short-tag ommision can only compress a document by less
than 50% at an improbable maximum (in the case of a document with 
not data, not attributes, no white-space, and incredibly long GIs). 
Compression is a far better approach.

Rick Jelliffe


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