Ariana wrote:
> Thank you very much for the answer. There is a slight misunderstanding
> on what I want to do with the breaks. For example, my example 2:
> 
>> Example 2:
>> <xml>
>>   <p>Aaaaaa</p>
>>   <break/>
>>   <p>Bbbbbb</p>
>> </xml>
> 
> should be transformed as follows:
> 
> <xml>
>   <section>
>     <p>Aaaaaa</p>
>   </section>
>   <section>
>     <p>Bbbbbb</p>
>   </section>
> </xml>
> 
> In other words, <section> elements should contain everything that
> starts and/or finishes with a <break/> element. 

Ah. OK, that changes the rules significantly.

> And therein lies the
> rub, since the <break/> element only appears in between "sections", so
> it is difficult to programmatically find the start of the first section
> and the end of the last one.

This is where the SGML solution still works: if you modify the content
model for section...

<!DOCTYPE xml [
<!ELEMENT xml - - (chapter+)>
<!ELEMENT chapter O O (title?,section+)>
<!ELEMENT section O O (break?,p+)>
<!ELEMENT (title,p) - - (#PCDATA)>
<!ELEMENT break - O EMPTY>
]>
<xml>
   <p>Aaaaaa</p>
   <break>
   <p>Bbbbbb</p>
</xml>

Now a break element will cause a new section:

<xml>
<chapter>
<section>
<p>Aaaaaa</p>
</section>
<section>
<break>
<p>Bbbbbb</p>
</section>
</chapter>
</xml>

You will of course have to remove the unwanted break elements
afterwards, but that is easy enough to script.

> The caveat about character encoding suggests that this may not be the
> best solution in any case, since several of the files are in Spanish
> and therefore contain a very high proportion of non-ASCII characters.

But they are easy to change into numeric character references or even
character entity references. A simple sed script can do that very fast.

> But aside from that, the SGML solution you proposed is interesting -
> it's good to know it still has its uses even though I haven't used it
> for years (over 10, in fact - boy, I feel old :)

Hehe. Still life in the old dog yet.

///Peter