Do you mean xslt? Xpath always looked like the right-est xml technology to me, but xslt like an interesting idea hampered by a horrible implementation language.
I'm mad that I don't have that for XML. I do a lot of tree and graph processing in Postgres and xpath lends itself well for that. However debugging sucks! Also, since you can't store results along the line (like in jq), querying order dependent pairs needs a union. Not so in xpath 2 but PG dropped work on XML right when Json was ramping up. I'm still mad! There was a discussion whether to integrate Zorba into Postgres (which speaks JQ and XPath, using the same type system and query engine) but that never got any traction. So xpath was bastardized into its "modern" variants but something (subjectively) intuitive like jq never developed for it. This is where I see the need for CDuce.
