xml-dev - tabs to indent for pretty-printing

[Imran Rashid <imranr@wolfram.com>]

(either I'm a moron for thinking of this idea in the first place, or I'm a
moron for not thinking of it earlier, I'm not sure which.)

I indent the XML files I create so that nesting is more visible. eg.
<parent>
 <child>
  <childOfchild/>
 </child>
</parent>

instead of <parent><child><childOfchild/></child></parent>

  What I've been doing is using 1 space per level of indentation.  The
problem is, some of the files I create are really, *really* deeply nested,
and those spaces take up a large amount of the space in the file.
    So I had this idea that I would save space by representing every spaces
w/ a tab.  There is the problem that tabs aren't a standard size, but I
figure I can just put a comment at the top of the XML file, like

<!-- set tab size to 4 spaces for proper indentation-->

while slightly hack-y, it doesn't change the actual content of the XML file
at all (of course I'm always talking about ignorable whitespace), and it
makes a big difference for me, often cutting files to 2/3 their original
size.

it seems so obvious now, but I dont' remember ever seeing any other comments
about taking this approach.  do you think its OK to do this??

thanks,
Imran Rashid