Comment by nithril
7 hours ago
XSLT/XPath have evolved since XSLT 1.0.
Features are now available like key (index) to greatly speedup the processing. Good XSLT implementation like Saxon definitively helps as well on the perf aspect.
When it comes to transform XML to something else, XSLT is quite handy by structuring the logic.
Keys were a thing in XSLT 1.x already.
XSLT 2+ was more about side effects.
I never really grokked later XSLT and XPath standards though.
XSLT 1.0 had a steep learning curve, but it was elegant in a way poetry is elegant because of extra restrictions imposed on it compared to prose. You really had to stretch your mind to do useful stuff with it. Anyone remembers Muenchian grouping? It was gorgeous.
Newer standards lost elegance and kept the ugly syntax.
No wonder they lost mindshare.
"Newer standards lost elegance and kept the ugly syntax."
My biggest problem with XSLT is that I've never encountered a problem that I wouldn't rather solve with an XPath library and literally any other general purpose programming language.
When XSLT was the only thing with XPath you could rely on, maybe it had an edge, but once everyone has an XPath library what's left is a very quirky and restrictive language that I really don't like. And I speak Haskell, so the critic reaching for the reply button can take a pass on the "Oh you must not like functional programming" routine... no, Haskell is included in that set of "literally any other general purpose programming language" above.
Serious question: would it be worth the effort to treat XSLT as a compilation target for a friendlier language, either extant or new?
There's clearly value in XSLT's near-universal support as a web-native system. It provides templating out of the box without invoking JavaScript, and there's demand for that[1]. But it still lacks decent in-browser debugging which JS has in spades.
[1] https://justinfagnani.com/2025/06/26/the-time-is-right-for-a...
1 reply →
XSLT just needs a different, non-XML serialization.
XML (the data structure) needs a non-XML serialization.
Similar to how Semantic Web's Owl has four different serializations, only one of them being the XML serialization. (eg. Owl can be represented in Functional, Turtle, Manchester, Json, and N-triples syntaxes.)
> XML (the data structure) needs a non-XML serialization.
KDL is a very interesting attempt, but my impression is that people are already trying to shove way too much unnecessary complexity into it.
IMO, the KDL's document transformation is not a really good example of a better XSLT, tough. I mean, it's better, but it probably can still be improved a lot.
You're looking for S-expressions.
> XML (the data structure) needs a non-XML serialization.
That's YAML, and it is arguibly worse. Here's a sample YAML 1.2 document straight from their spec:
Nightmare fuel. Just by looking at it, can you tell what it does?
--
Some notes:
- SemWeb also has JSON-LD serialization. It's a good compromise that fits modern tooling nicely.
- XML is still a damn good compromise between human readable and machine readable. Not perfect, but what is perfect anyway?
- HTML5 is now more complex than XHTML ever was (all sorts of historical caveats in this claim, I know, don't worry).
- Markup beauty is relative, we should accept that.
Can you name a non-Saxon XSLT processor? I'd really like one. Preferably, open-source.
- Browsers are XSLT (1.0) processors.
- Xee: https://github.com/Paligo/xee
- xrust: https://docs.rs/xrust/latest/xrust/xslt/
- XJSLT (compiles XSLT to JS): https://github.com/egh/xjslt
Xee is WIP AFAIK and I don't know the maturity of xrust and XJSLT.
I only know libxslt, but it's XSLT 1.0 and some of EXSLT. I don't recommend.