indexing
	description: "[
		Objects that are able to iterate over traversable structures,
		on which they can perform repeated actions and tests according
		to a number of predefined control structures such as ``if'',
		``until'' and others.
	]"
	status: "See notice at end of class"
	names: iterators, iteration
	date: "$Date$"
	revision: "$Revision$"

deferred class interface
	ITERATOR [G]

feature -- Initialization

	set (s: like target)
			-- Make s the new target of iterations.
		require
			target_exists: s /= void
		ensure
			target = s
			target /= void

feature -- Access

	target: TRAVERSABLE [G]
			-- The structure to which iteration features will apply

feature -- Status report

	invariant_value: BOOLEAN
			-- Is the invariant satisfied?
			-- (Redefinitions of this feature will usually involve
			-- target; if so, make sure that the result is defined
			-- when `target = Void'.)

feature -- Iteration

	do_all (action: PROCEDURE [ANY, TUPLE [G]])
			-- Apply action to every item of target.
		require
			action_exists: action /= void

	do_if (action: PROCEDURE [ANY, TUPLE [G]]; test: FUNCTION [ANY, TUPLE [G], BOOLEAN])
			-- Apply action to every item of target satisfying test.
		require
			action_exists: action /= void
			test_exists: test /= void

	do_until (action: PROCEDURE [ANY, TUPLE [G]]; test: FUNCTION [ANY, TUPLE [G], BOOLEAN])
			-- Apply action to every item of target up to
			-- and including first one satisfying test.
			-- (Apply to full list if no item satisfies test).
		require
			action_exists: action /= void
			test_exists: test /= void

	do_while (action: PROCEDURE [ANY, TUPLE [G]]; test: FUNCTION [ANY, TUPLE [G], BOOLEAN])
			-- Apply action to every item of target up to
			-- and including first one not satisfying test.
			-- (Apply to full list if all items satisfy test).
		require
			action_exists: action /= void
			test_exists: test /= void

	for_all (test: FUNCTION [ANY, TUPLE [G], BOOLEAN]): BOOLEAN
			-- Is test true for all items of target?
		require
			test_exists: test /= void

	there_exists (test: FUNCTION [ANY, TUPLE [G], BOOLEAN]): BOOLEAN
			-- Is test true for at least one item of target?
		require
			test_exists: test /= void

	until_do (action: PROCEDURE [ANY, TUPLE [G]]; test: FUNCTION [ANY, TUPLE [G], BOOLEAN])
			-- Apply action to every item of target up to
			-- but excluding first one satisfying test.
			-- (Apply to full list if no items satisfy test.)
		require
			action_exists: action /= void
			test_exists: test /= void

	while_do (action: PROCEDURE [ANY, TUPLE [G]]; test: FUNCTION [ANY, TUPLE [G], BOOLEAN])
			-- Apply action to every item of target up to
			-- but excluding first one satisfying not test.
			-- (Apply to full list if all items satisfy test.)
		require
			action_exists: action /= void
			test_exists: test /= void

invariant

	traversable_exists: target /= void
		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

indexing
	library: "[
			EiffelBase: Library of reusable components for Eiffel.
	]"
	status: "[
			Copyright 1986-2001 Interactive Software Engineering (ISE).
			For ISE customers the original versions are an ISE product
			covered by the ISE Eiffel license and support agreements.
	]"
	license: "[
			EiffelBase may now be used by anyone as FREE SOFTWARE to
			develop any product, public-domain or commercial, without
			payment to ISE, under the terms of the ISE Free Eiffel Library
			License (IFELL) at http://eiffel.com/products/base/license.html.
	]"
	source: "[
			Interactive Software Engineering Inc.
			ISE Building
			360 Storke Road, Goleta, CA 93117 USA
			Telephone 805-685-1006, Fax 805-685-6869
			Electronic mail <info@eiffel.com>
			Customer support http://support.eiffel.com
	]"
	info: "[
			For latest info see award-winning pages: http://eiffel.com
	]"

end -- class ITERATOR