indexing
	description: "Objects that may be stored and retrieved along with all their dependents. This class may be used as ancestor by classes needing its facilities."

class interface
	STORABLE

feature -- Access

	Check_instruction: INTEGER is 7
			-- Exception code for violated check
			-- (from EXCEP_CONST)

	Class_invariant: INTEGER is 6
			-- Exception code for violated class invariant
			-- (from EXCEP_CONST)

	Developer_exception: INTEGER is 24
			-- Exception code for developer exception
			-- (from EXCEP_CONST)

	External_exception: INTEGER is 18
			-- Exception code for operating system error
			-- which does not set the errno variable
			-- (Unix-specific)
			-- (from EXCEP_CONST)

	Floating_point_exception: INTEGER is 5
			-- Exception code for floating point exception
			-- (from EXCEP_CONST)

	Incorrect_inspect_value: INTEGER is 9
			-- Exception code for inspect value which is not one
			-- of the inspect constants, if there is no Else_part
			-- (from EXCEP_CONST)

	Io_exception: INTEGER is 21
			-- Exception code for I/O error
			-- (from EXCEP_CONST)

	Loop_invariant: INTEGER is 11
			-- Exception code for violated loop invariant
			-- (from EXCEP_CONST)

	Loop_variant: INTEGER is 10
			-- Exception code for non-decreased loop variant
			-- (from EXCEP_CONST)

	No_more_memory: INTEGER is 2
			-- Exception code for failed memory allocation
			-- (from EXCEP_CONST)

	Operating_system_exception: INTEGER is 22
			-- Exception code for operating system error
			-- which sets the errno variable
			-- (Unix-specific)
			-- (from EXCEP_CONST)

	Postcondition: INTEGER is 4
			-- Exception code for violated postcondition
			-- (from EXCEP_CONST)

	Precondition: INTEGER is 3
			-- Exception code for violated precondition
			-- (from EXCEP_CONST)

	Rescue_exception: INTEGER is 14
			-- Exception code for exception in rescue clause
			-- (from EXCEP_CONST)

	retrieve_by_name (file_name: STRING): ANY
			-- Retrieve object structure, from external
			-- representation previously stored in a file
			-- called file_name.
			-- To access resulting object under correct type,
			-- use assignment attempt.
			-- Will raise an exception (code Retrieve_exception)
			-- if file content is not a stored Eiffel structure.
			-- Will return Void if the file does not exist or
			-- is not readable.
		require
			file_name_exists: file_name /= void;
			file_name_meaningful: not file_name.empty

	Retrieve_exception: INTEGER is 23
			-- Exception code for retrieval error;
			-- may be raised by retrieved in IO_MEDIUM.
			-- (from EXCEP_CONST)

	retrieved (medium: IO_MEDIUM): ANY
			-- Retrieved object structure, from external
			-- representation previously stored in medium.
			-- To access resulting object under correct type,
			-- use assignment attempt.
			-- Will raise an exception (code Retrieve_exception)
			-- if medium content is not a stored Eiffel structure.
		require
			medium_not_void: medium /= void;
			medium_exists: medium.exists;
			medium_is_open_read: medium.is_open_read;
			medium_supports_storable: medium.support_storable
		ensure
			result_exists: Result /= void

	Routine_failure: INTEGER is 8
			-- Exception code for failed routine
			-- (from EXCEP_CONST)

	Signal_exception: INTEGER is 12
			-- Exception code for operating system signal
			-- (from EXCEP_CONST)

	Void_assigned_to_expanded: INTEGER is 19
			-- Exception code for assignment of void value
			-- to expanded entity
			-- (from EXCEP_CONST)

	Void_call_target: INTEGER is 1
			-- Exception code for feature applied to void reference
			-- (from EXCEP_CONST)
	
feature -- Status report

	assertion_violation: BOOLEAN
			-- Is last exception originally due to a violated
			-- assertion or non-decreasing variant?
			-- (from EXCEPTIONS)

	class_name: STRING
			-- Name of the class that includes the recipient
			-- of original form of last exception
			-- (from EXCEPTIONS)

	developer_exception_name: STRING
			-- Name of last developer-raised exception
			-- (from EXCEPTIONS)
		require -- from EXCEPTIONS
			applicable: is_developer_exception

	exception: INTEGER
			-- Code of last exception that occurred
			-- (from EXCEPTIONS)

	exception_trace: STRING
			-- String representation of the exception trace
			-- (from EXCEPTIONS)

	is_developer_exception: BOOLEAN
			-- Is the last exception originally due to
			-- a developer exception?
			-- (from EXCEPTIONS)

	is_developer_exception_of_name (name: STRING): BOOLEAN
			-- Is the last exception originally due to a developer
			-- exception of name name?
			-- (from EXCEPTIONS)

	is_signal: BOOLEAN
			-- Is last exception originally due to an external
			-- event (operating system signal)?
			-- (from EXCEPTIONS)

	is_system_exception: BOOLEAN
			-- Is last exception originally due to an
			-- external event (operating system error)?
			-- (from EXCEPTIONS)

	meaning (except: INTEGER): STRING
			-- A message in English describing what except is
			-- (from EXCEPTIONS)

	original_class_name: STRING
			-- Name of the class that includes the recipient
			-- of original form of last exception
			-- (from EXCEPTIONS)

	original_exception: INTEGER
			-- Original code of last exception that triggered
			-- current exception
			-- (from EXCEPTIONS)

	original_recipient_name: STRING
			-- Name of the routine whose execution was
			-- interrupted by original form of last exception
			-- (from EXCEPTIONS)

	original_tag_name: STRING
			-- Assertion tag for original form of last
			-- assertion violation.
			-- (from EXCEPTIONS)

	recipient_name: STRING
			-- Name of the routine whose execution was
			-- interrupted by last exception
			-- (from EXCEPTIONS)

	tag_name: STRING
			-- Tag of last violated asssertion clause
			-- (from EXCEPTIONS)
	
feature -- Status setting

	catch (code: INTEGER)
			-- Make sure that any exception of code code will be
			-- caught. This is the default.
			-- (from EXCEPTIONS)

	die (code: INTEGER)
			-- Terminate execution with exit status code,
			-- without triggering an exception.
			-- (from EXCEPTIONS)

	ignore (code: INTEGER)
			-- Make sure that any exception of code code will be
			-- ignored. This is not the default.
			-- (from EXCEPTIONS)

	message_on_failure
			-- Print an exception history table
			-- in case of failure.
			-- This is the default.
			-- (from EXCEPTIONS)

	no_message_on_failure
			-- Do not print an exception history table
			-- in case of failure.
			-- (from EXCEPTIONS)

	raise (name: STRING)
			-- Raise a developer exception of name name.
			-- (from EXCEPTIONS)
	
feature -- Element change

	basic_store (medium: IO_MEDIUM)
			-- Produce on medium an external representation of the
			-- entire object structure reachable from current object.
			-- Retrievable within current system only.
		require
			medium_not_void: medium /= void;
			medium_exists: medium.exists;
			medium_is_open_write: medium.is_open_write;
			medium_supports_storable: medium.support_storable

	general_store (medium: IO_MEDIUM)
			-- Produce on medium an external representation of the
			-- entire object structure reachable from current object.
			-- Retrievable from other systems for same platform
			-- (machine architecture).
		require
			medium_not_void: medium /= void;
			medium_exists: medium.exists;
			medium_is_open_write: medium.is_open_write;
			medium_supports_storable: medium.support_storable

	independent_store (medium: IO_MEDIUM)
			-- Produce on medium an external representation of the
			-- entire object structure reachable from current object.
			-- Retrievable from other systems for the same or other
			-- platform (machine architecture).
		require
			medium_not_void: medium /= void;
			medium_exists: medium.exists;
			medium_is_open_write: medium.is_open_write;
			medium_supports_storable: medium.support_storable

	store_by_name (file_name: STRING)
			-- Produce on file called file_name an external
			-- representation of the entire object structure
			-- reachable from current object.
			-- Retrievable from other systems for same platform
			-- (machine architecture).
		require
			file_name_not_void: file_name /= void;
			file_name_meaningful: not file_name.empty
	
invariant

		-- from GENERAL
	reflexive_equality: standard_is_equal (Current);
	reflexive_conformance: conforms_to (Current);

end -- class STORABLE