diff -r 4a61f00ee916 -r 233463804681 src/lxp/totable.lua
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lxp/totable.lua	Fri Apr 23 21:18:24 2021 +0100
@@ -0,0 +1,117 @@
+-- See Copyright Notice in license.html
+-- Based on Luiz Henrique de Figueiredo's lxml:
+-- http://www.tecgraf.puc-rio.br/~lhf/ftp/lua/#lxml
+
+local lxp = require "lxp"
+
+local table = require"table"
+local tinsert, tremove = table.insert, table.remove
+local assert, pairs, tostring, type = assert, pairs, tostring, type
+
+-- auxiliary functions -------------------------------------------------------
+local function starttag (p, tag, attr)
+	local stack = p:getcallbacks().stack
+	local newelement = {[0] = tag}
+	for i = 1, #attr do
+		local attrname = attr[i]
+		local attrvalue = attr[attrname]
+		newelement[attrname] = attrvalue
+	end
+	tinsert(stack, newelement)
+end
+
+local function endtag (p, tag)
+	local stack = p:getcallbacks().stack
+	local element = tremove(stack)
+	assert(element[0] == tag, "Error while closing element: table[0] should be `"..tostring(tag).."' but is `"..tostring(element[0]).."'")
+	local level = #stack
+	tinsert(stack[level], element)
+end
+
+local function text (p, txt)
+	local stack = p:getcallbacks().stack
+	local element = stack[#stack]
+	local n = #element
+	if type(element[n]) == "string" and n > 0 then
+		element[n] = element[n] .. txt
+	else
+		tinsert(element, txt)
+	end
+end
+
+-- main function -------------------------------------------------------------
+local function parse (o)
+	local c = {
+		StartElement = starttag,
+		EndElement = endtag,
+		CharacterData = text,
+		_nonstrict = true,
+		stack = {{}},
+	}
+	local p = lxp.new(c)
+	if type(o) == "string" then
+		local status, err, line, col, pos = p:parse(o)
+		if not status then return nil, err, line, col, pos end
+	else
+		for l in pairs(o) do
+			local status, err, line, col, pos = p:parse(l)
+			if not status then return nil, err, line, col, pos end
+		end
+	end
+	local status, err, line, col, pos = p:parse() -- close document
+	if not status then return nil, err, line, col, pos end
+	p:close()
+	return c.stack[1][1]
+end
+
+-- utility functions ---------------------------------------------------------
+local function compact (t) -- remove empty entries
+	local n = 0
+	for i = 1, #t do
+		local v = t[i]
+		if v then
+			n = n+1
+			if n ~= i then
+				t[n] = v
+				t[i] = nil
+			end
+		else
+			t[i] = nil
+		end
+	end
+end
+
+local function clean (t) -- remove empty strings
+	for i = 1, #t do
+		local v = t[i]
+		local tv = type(v)
+		if tv == "table" then
+			clean (v)
+		elseif tv == "string" and v:match"^%s*$" then
+			t[i] = false
+		end
+	end
+	compact (t)
+end
+
+local function torecord (t) -- move 1-value subtables to table entries
+	for i = 1, #t do
+		local v = t[i]
+		if type(v) == "table" then
+			if #v == 1 and type(v[1]) == "string" and t[v[0]] == nil then
+				t[v[0]] = v[1]
+				t[i] = false
+			else
+				torecord (v)
+			end
+		end
+	end
+	compact (t)
+end
+
+return {
+	clean = clean,
+	compact = compact,
+	parse = parse,
+	torecord = torecord,
+}