# Is the last read byte matches the `NameStartChar` production?
	fun is_name_start_char: Bool do
		# TODO: Handle code points above 0x7F.
		return ['A'.code_point .. 'Z'.code_point].has(last_char) or
				['a'.code_point .. 'z'.code_point].has(last_char) or
				last_char == '_'.code_point or
				last_char == ':'.code_point or
				last_char > 127
	end