[Exist-open] Pretty-print xquery

[Chris W. <kit...@gm...>]

I'd like to pretty-print an xquery expression with a function along the
lines of the marklogic xdmp:pretty-print.

Background
I'm working on a framework for executable Entity-Relationship models in
which computations are expressed in XQuery.  It's a eval-fest and may
horrify purists .  See

https://kitwallace.tumblr.com/post/717562715197112320/a-model-for-biodiversity-net-gain-40