[phh]

> I wonder if that kind of front end was done in the age of SAX parsers?

I though that XPath over SAX was a thing, and xslt was doing sax-like parsing, but turns out I'm wrong. Which is logical considering XPath can refer to previous nodes. That being said, it looks like there is streamable xslt in xslt 3.0, but that looks more niche

[riedel]

I did some automata for parsing, transformation and compression in my PhD. I think that XPath is the major failure in XML standardization, with XSLT building on this. If we had a stricter language we could easily compile much of the XML stuff and do binary XML much more extensively.

[jbverschoor]

Often a combination of sax and dom is usefull. You get many GBs of SAX stream, but it usually contains the same kind of documents. Creating a DOM at the end a specific token means fast processing, but still the easy of use of DOM.