# Expect a `SDDecl` token, without the initial `S` token.
	private fun expect_sd_decl: Bool do
		var buf = new FlatBuffer
		var value: String

		if not lexer.expect_string("standalone", "") or not lexer.expect_eq or
				not expect_literal(buf) then
			return false
		end
		value = buf.to_s
		if not value == "yes" and not value == "no" then
			return model.fire_fatal_error("`{value}` is not a valid value for " +
					"the `standalone` declaration. Expecting `yes` or `no`.",
					null)
		end
		# TODO: Do something with the value.
		return true
	end