# Expect a `AttValue` production.
	#
	# Append the parsed value to `buffer`.
	private fun expect_att_value(buffer: Buffer): Bool do
		var delimiter = lexer.expect_delimiter

		if delimiter < 0 then return false
		loop
			if lexer.accept_int(delimiter) then
				return true
			else if lexer.accept('&') then
				# TODO: [WFC: No < in Attribute Values]
				if not expect_reference(buffer) then return false
			else if not lexer.expect_att_value_char(buffer) then
				return false
			end
		end
	end