note
	description: "[
		Port accessor factory for creating new instances of port readers and writers.
	]"
	legal   : "See notice at end of class."
	status  : "See notice at end of class.";
	author  : "Paul Bates (paul.a.bates@gmail.com)"
	date    : "$Date$"
	revision: "$Revision$"

deferred class
	PRT_STREAM_FACTORY_I

feature -- Factory Functions

	create_port_reader (a_port: PRT_CONNECTION; a_address_offset: NATURAL_8): PRT_STREAM_READER_I
			-- Creates a new port reader for port `a_port' with an address offset of `a_address_offset'.
			--
			-- `a_port': Parallel port accessor to create a reader for.
			-- `a_address_offset': Parallel port base address offset, in bits.
		require
			a_port_attached: attached a_port
			a_port_is_interface_usable: a_port.is_interface_usable
			a_address_offset_small_enough: a_address_offset < 24
		deferred
		ensure
			result_attached: attached Result
		end

	create_port_writer (a_port: PRT_CONNECTION; a_address_offset: NATURAL_8): PRT_STREAM_WRITER_I
			-- Creates a new port writer for port `a_port' with an address offset of `a_address_offset'.
			--
			-- `a_port': Parallel port accessor to create a writer for.
			-- `a_address_offset': Parallel port base address offset, in bits.
		require
			a_port_attached: attached a_port
			a_port_is_interface_usable: a_port.is_interface_usable
			a_address_offset_small_enough: a_address_offset < 24
		deferred
		ensure
			result_attached: attached Result
		end

end