luaexpat: lom.assemble?

[Dirk Laurie <dirk.laurie@...>]

For the record: luarocks installs a 5.3 version of luaexpat
right out of the box.

An obvious use case for luaexpat is to convert an XML
document to a Lua table, do things to it, and convert
back to XML. For this last step, it seems not very hard
to roll one's own. But surely it must have been already
done somewhere else?