Re: NSKeyedArchiver implementation...

[Richard Frith-Macdonald]

On 9 Sep 2004, at 19:45, Richard Frith-Macdonald wrote:

> On 9 Sep 2004, at 19:13, Fred Kiefer wrote:
>
> > At first I thought of this as a very nice solution, doing our own 
> > stuff, while still being able to exchange with Apple applications 
> > would be great. It would even free us of update problems for either 
> > side, as incompatible changes would just result in small changes on 
> > the XSLTs.
> > Than I tried to imagine an XSLT for this and here my fantasy failed 
> > me.
> > So for example how would you transform any of the actual problematic 
> > bits you listed above?
>
> Yes, my feeling too ... I would expect that producing archives in a 
> new gnustep specific format and trying to use xslt to convert between 
> that and macos-x format would be a *LOT* more work than just using the 
> macos-x format to start with.

It occurs to me that it may not be obvious why this is so ...

If we want macosx compatibility at the end of the day, we have to 
reverse engineer the macosx format in order to understand it.  This 
work is required irrespective of the format we use.

So what we are concerned with is how we translate between situations 
where the classes in macosx are not the same as the classes in gnustep, 
and we have to perform some complex mapping between them.

While xslt is very good for performing translations on simple xml 
element hierarchies, Objective-C is a much more powerful language and 
can more easily cope with complex situations ... not to mention that 
anyone writing this code *must* understand the objc classes in order to 
know what the translation should be, and so will be familiar with using 
objc (probably much more so than with xst|).
Also, the macosx archive format (as xml) is not designed for easy 
translation using xslt (it's an xml representation  of a binary 
serialization of a property list) ... so while we could design a 
gnustep format to be easily handled by xslt, the translation would 
still be horribly complex.