[mikmoila]

Looks good! Does the xpath expression support XML namespaces?

[mdaniel]

No, and arguably worse: it completely ignores them

  $ echo '<a xmlns="http://www.w3.org/2005/Atom"><b xmlns="urn:beta">hello</b></a>' | xq --xpath '/a/b/text()'
  hello

Only partial support for functions, too, it would appear

  $ echo '<a xmlns="http://www.w3.org/2005/Atom"><b xmlns="urn:beta">hello</b></a>' | xq --xpath 'count(/a/*)'
  $

Some A++ error handling, too, as it just calls panic when angry

[mikmoila]

Ah ok; Namespace support before XPath 3.0 with Q{nsname}localname would make cli tool like this a bit too verbose. Of course you could store ns-prefix to ns mappings to conf file or environment variables...

[mdaniel]

I actually tried the lxml syntax "/{urn:beta}b" and that's how I learned about the panic-based error handling, but I didn't know about that Q syntax, so thank you for bringing it to my attention

    $ echo '<a xmlns="urn:alpha">hello</a>' | xq --xpath '/Q{urn:alpha}a/text()'
    panic: /Q{urn:alpha}a/text() has an invalid token.

    goroutine 18 [running]:
    github.com/antchfx/xmlquery.Find(...)
        github.com/antchfx/xmlquery@v1.3.8/query.go:76
    ...

It seems to be a problem with that backing xmlquery library, and I did a quick GitHub topics search and found https://github.com/zzossig/rabbit which claimed to be XPath 3, but then https://github.com/zzossig/rabbit#what-is-not-supported says "lol, namespaces, wat?" so :-(

[mikmoila]

There aren't that many libraries available with full XPath 3.x conformance. In order to give some constructive feedback, perhaps an optional .conf file with ns-prefix->ns-name mappings could be read and passed to the XPath engine as ns-context? Even w/o the XPath functions support and only XPath selector expression this would make the tool to cover most of the usecases eg. simply finding elements.