XMLDecode in Roblox Luau!

xmldecode.lua

type table = {any}
type dict = {[string|boolean]: any}

local specialTags, doNotNeedClosingTag = {}, {}

local find
find = function(originalTable, findValue)
	for index, wrappedTable in pairs(originalTable) do
		if wrappedTable == findValue then
			return wrappedTable
		else
			return nil
		end
	end
end

local findIndexInDictionary
findIndexInDictionary = function(originalTable, findIndex)
	for index, wrappedTable in pairs(originalTable) do
		if index == "_parent" or index == "ATTRIBUTES" or index == "innerText" then
			continue
		elseif index == findIndex then
			return wrappedTable
		elseif type(wrappedTable) == "table" then
			local returnVal = findIndexInDictionary(wrappedTable, findIndex)
			if not returnVal then continue else return returnVal end
		else
			return nil
		end
	end
end

return function(xml: string)
	xml = xml:gsub("\n", "")
	xml = xml:gsub("\t", "")
	
	local tree: any = {}
	local tokens = xml:split("")
	local currentIndex: number = 1
	local currentToken: string|nil = tokens[currentIndex]
	local currentText: string, currentTag: string = "", ""
	local currentTag: any = tree
	local indexedTable = {}
	
	local function assignParent(tbl, parent)
		if type(tbl) == "table" and parent then
			rawset(tbl, "_parent", parent)
		end
	end
	
	local function findAvailableNumber(tagName)
		local recursive
		recursive = function(num)
			if findIndexInDictionary(tree, tagName..tostring(num)) then
				return recursive(num + 1)
			else
				return num
			end
		end
		
		return recursive(1)
	end
	
	local function advance()
		currentIndex += 1
		currentToken = tokens[currentIndex]
	end
	
	local function getRawTextUntil(endToken: string|nil)
		local text = ''
		repeat
			advance()
			text ..= type(currentToken) == 'string' and tostring(currentToken) or '' -- shorthand concatenation + ternary operation
		until currentToken == endToken
		text = text:gsub(">", ""):lower()
		return text
	end
	
	local function separateAttributesFromRawTag(rawTag: string)
		local split: table = rawTag:split(" ")
		local tag: string = tostring(table.remove(split, 1))
		local propsOld: table = split
		local propsNew: table = {}
		for i, v in ipairs(propsOld) do
			local splitAgain = v:split("=")
			propsNew[splitAgain[1]] = splitAgain[2] and splitAgain[2]:gsub("\"", "") or ''
		end
		return tag, propsNew
	end
	
	while type(currentToken) == 'string' do
		if currentToken == "<" then
			local tagName = getRawTextUntil('>')
			if tagName:sub(1, 1) ~= "/" then
				local tag, props = separateAttributesFromRawTag(tagName)
				if table.find(specialTags, tag) then
					table.insert(indexedTable, tag)
					currentTag[tag] = { ATTRIBUTES = props, innerText = "" }
					assignParent(currentTag[tag], currentTag)
					currentTag = currentTag[tag]
				else
					local name = tag..findAvailableNumber(tag)
					table.insert(indexedTable, name)
					currentTag[tostring(name)] = { ATTRIBUTES = props, innerText = "" }
					assignParent(currentTag[tostring(name)], currentTag)
					currentTag = currentTag[tostring(name)]
				end
				if table.find(doNotNeedClosingTag, tag) then
					currentTag = currentTag._parent
				end
			else
				currentTag = currentTag._parent
			end
		else
			currentTag.innerText ..= currentToken
		end
		advance()
	end
	
	return {dictionary = tree, indexedTable = indexedTable}
end