format_document - optional <xml> tag?

[ArtemGr]

Would you consider making the <xml> tag generation in format_document optional?

When working with XML fragments the tag is not needed.

Right now one has to stream into a temporary buffer first (or something like that) to cut it out.

[shepmaster]

Do you mean the <?xml?> part? That's referred to as the preamble. My biggest concern would be a proliferation of output options and ensuring that the XML continues to be valid.

Could you share a bit more about your use case?

[ArtemGr]

I see how the xml tag validity might be a concern in the presence of namespaces etc.

In my case the tag is generated elsewhere and then undergoes a bit of in-Rust enhancement, I know it's pretty basic and no validity concerns should arise.

But if working with XML fragments is inherently unsafe then I'll understand rejecting the idea.

[wimh]

Another use case for this would be a xslt library which supports <xsl:output method="xml" omit-xml-declaration="yes" />, see https://www.w3.org/TR/xslt#section-XML-Output-Method