# Finds all the macros contained in `text` and store them in `macros`.
	#
	# Also build `self` template parts using original template text.
	private fun parse do
		var text = tpl_text
		var pos = 0
		var out = new FlatBuffer
		var start_pos: Int
		var end_pos: Int
		while pos < text.length do
			# lookup opening tag
			start_pos = text.read_until_char(pos, marker, out)
			if start_pos < 0 then
				text.read_until_pos(pos, text.length, out)
				add out.to_s
				break
			end
			add out.to_s
			pos = start_pos + 1
			# lookup closing tag
			out.clear
			end_pos = text.read_until_char(pos, marker, out)
			if end_pos < 0 then
				text.read_until_pos(pos, text.length, out)
				add "%"
				add out.to_s
				break
			end
			pos = end_pos + 1
			# check macro
			var name = out.to_s
			if name.is_valid_macro_name then
				add make_macro(name, start_pos, end_pos)
			else
				add "%"
				add name
				add "%"
			end
			out.clear
		end
	end