# Use the class as the main enrty point of the program
	# - parse arguments and options of the command
	# - test the parser (see `work`)
	fun main: Node
	do
		if args.is_empty then
			print "usage {name}_test <filepath> | - | -e <text>"
			exit 0
		end

		var filepath = args.shift
		var text
		if filepath == "-" then
			text = sys.stdin.read_all
		else if filepath == "-e" then
			if args.is_empty then
				print "Error: -e need a text"
				exit 1
			end
			text = args.shift
		else
			var f = new FileReader.open(filepath)
			text = f.read_all
			f.close
		end

		if not args.is_empty then
			print "Error: superfluous arguments."
			exit 1
		end

		return work(text)
	end