    indexing
    	description: "Action sequence for EV_CHECKABLE_LIST check events."
    	legal: "See notice at end of class."
    	status: "See notice at end of class."
    	date: "$Date: 2006-01-22 18:25:44 -0800 (Sun, 22 Jan 2006) $"
    	revision: "$Revision: 56675 $"

    class interface
    	EV_TREE_ITEM_CHECK_ACTION_SEQUENCE

    create
    	default_create
    			-- Begin in Normal_state.
    			-- (from ACTION_SEQUENCE)

    create {EV_TREE_ITEM_CHECK_ACTION_SEQUENCE}
    	make_filled (n: INTEGER_32)
    			-- Allocate list with `n' items.
    			-- (`n' may be zero for empty list.)
    			-- This list will be full.
    			-- (from ARRAYED_LIST)
    		require -- from ARRAYED_LIST
    			valid_number_of_items: n >= 0
    		ensure -- from ARRAYED_LIST
    			correct_position: before
    			filled: full

    feature -- Initialization

    	arrayed_list_make (n: INTEGER_32)
    			-- Allocate list with `n' items.
    			-- (`n' may be zero for empty list.)
    			-- (from ARRAYED_LIST)
    		require -- from ARRAYED_LIST
    			valid_number_of_items: n >= 0
    		ensure -- from ARRAYED_LIST
    			correct_position: before
    			is_empty: is_empty

    	make_filled (n: INTEGER_32)
    			-- Allocate list with `n' items.
    			-- (`n' may be zero for empty list.)
    			-- This list will be full.
    			-- (from ARRAYED_LIST)
    		require -- from ARRAYED_LIST
    			valid_number_of_items: n >= 0
    		ensure -- from ARRAYED_LIST
    			correct_position: before
    			filled: full

    	make_from_array (a: ARRAY [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]])
    			-- Create list from array `a'.
    			-- (from ARRAYED_LIST)
    		require -- from ARRAY
    			array_exists: a /= Void
    		ensure then -- from ARRAYED_LIST
    			correct_position: before
    			filled: count = a.count

    feature -- Access

    	cursor: ARRAYED_LIST_CURSOR
    			-- Current cursor position
    			-- (from ARRAYED_LIST)
    		ensure -- from CURSOR_STRUCTURE
    			cursor_not_void: Result /= Void

    	first: like item
    			-- Item at first position
    			-- (from ARRAYED_LIST)
    		require -- from CHAIN
    			not_empty: not is_empty

    	force_extend (action: PROCEDURE [ANY, TUPLE])
    			-- Extend without type checking.

    	generating_type: STRING_8
    			-- Name of current object's generating type
    			-- (type of which it is a direct instance)
    			-- (from ANY)

    	generator: STRING_8
    			-- Name of current object's generating class
    			-- (base class of the type of which it is a direct instance)
    			-- (from ANY)

    	has (v: like item): BOOLEAN
    			-- Does current include `v'?
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from ARRAYED_LIST)
    		require -- from  CONTAINER
    			True
    		ensure -- from CONTAINER
    			not_found_in_empty: Result implies not is_empty

    	i_th alias "[]" (i: INTEGER_32): like item assign put_i_th
    			-- Item at `i'-th position
    			-- Was declared in ARRAYED_LIST as synonym of infix "@".
    			-- (from ARRAYED_LIST)
    		require -- from TABLE
    			valid_key: valid_index (i)

    	index: INTEGER_32
    			-- Index of item, if valid.
    			-- (from ARRAYED_LIST)

    	index_of (v: like item; i: INTEGER_32): INTEGER_32
    			-- Index of `i'-th occurrence of item identical to `v'.
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- 0 if none.
    			-- (from CHAIN)
    		require -- from LINEAR
    			positive_occurrences: i > 0
    		ensure -- from LINEAR
    			non_negative_result: Result >= 0

    	item: PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]
    			-- Current item
    			-- (from ARRAYED_LIST)
    		require -- from TRAVERSABLE
    			not_off: not off
    		require -- from ACTIVE
    			readable: readable
    		require else -- from ARRAYED_LIST
    			index_is_valid: valid_index (index)

    	last: like first
    			-- Item at last position
    			-- (from ARRAYED_LIST)
    		require -- from CHAIN
    			not_empty: not is_empty

    	name: STRING_8
    			-- Textual description.
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			equal_to_name_internal: equal (Result, name_internal)

    	sequential_occurrences (v: like item): INTEGER_32
    			-- Number of times `v' appears.
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from LINEAR)
    		require -- from  BAG
    			True
    		ensure -- from BAG
    			non_negative_occurrences: Result >= 0

    	wrapper (a_tree_item: EV_TREE_NODE; action: PROCEDURE [ANY, TUPLE])
    			-- Use this to circumvent tuple type checking. (at your own risk!)
    			-- Calls `action' passing all other arguments.

    	infix "@" (i: INTEGER_32): like item assign put_i_th
    			-- Item at `i'-th position
    			-- Was declared in ARRAYED_LIST as synonym of i_th.
    			-- (from ARRAYED_LIST)
    		require -- from TABLE
    			valid_key: valid_index (i)

    feature -- Measurement

    	count: INTEGER_32
    			-- Number of items.
    			-- (from ARRAYED_LIST)

    	index_set: INTEGER_INTERVAL
    			-- Range of acceptable indexes
    			-- (from CHAIN)
    		require -- from  INDEXABLE
    			True
    		ensure -- from INDEXABLE
    			not_void: Result /= Void
    		ensure then -- from CHAIN
    			count_definition: Result.count = count

    	occurrences (v: like item): INTEGER_32
    			-- Number of times `v' appears.
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from CHAIN)
    		require -- from  BAG
    			True
    		require -- from  LINEAR
    			True
    		ensure -- from BAG
    			non_negative_occurrences: Result >= 0

    feature {ANY} -- Measurement

    	capacity: INTEGER_32
    			-- Number of available indices
    			-- Was declared in ARRAY as synonym of count.
    			-- (from ARRAY)
    		require -- from  BOUNDED
    			True
    		ensure then -- from ARRAY
    			consistent_with_bounds: Result = upper - lower + 1

    feature -- Comparison

    	frozen deep_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void
    			-- or attached to isomorphic object structures?
    			-- (from ANY)
    		ensure -- from ANY
    			shallow_implies_deep: standard_equal (some, other) implies Result
    			both_or_none_void: (some = Void) implies (Result = (other = Void))
    			same_type: (Result and (some /= Void)) implies some.same_type (other)
    			symmetric: Result implies deep_equal (other, some)

    	frozen equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void or attached
    			-- to objects considered equal?
    			-- (from ANY)
    		ensure -- from ANY
    			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.is_equal (other))

    	is_equal (other: like Current): BOOLEAN
    			-- Does `other' contain the same elements?
    			-- (from LIST)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			symmetric: Result implies other.is_equal (Current)
    			consistent: standard_is_equal (other) implies Result
    		ensure then -- from LIST
    			indices_unchanged: index = old index and other.index = old other.index
    			true_implies_same_size: Result implies count = other.count

    	frozen standard_equal (some: ANY; other: like arg #1): BOOLEAN
    			-- Are `some' and `other' either both void or attached to
    			-- field-by-field identical objects of the same type?
    			-- Always uses default object comparison criterion.
    			-- (from ANY)
    		ensure -- from ANY
    			definition: Result = (some = Void and other = Void) or else ((some /= Void and other /= Void) and then some.standard_is_equal (other))

    	frozen standard_is_equal (other: like Current): BOOLEAN
    			-- Is `other' attached to an object of the same type
    			-- as current object, and field-by-field identical to it?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			same_type: Result implies same_type (other)
    			symmetric: Result implies other.standard_is_equal (Current)

    feature -- Status report

    	after: BOOLEAN
    			-- Is there no valid cursor position to the right of cursor?
    			-- (from LIST)
    		require -- from  LINEAR
    			True

    	before: BOOLEAN
    			-- Is there no valid cursor position to the left of cursor?
    			-- (from LIST)
    		require -- from  BILINEAR
    			True

    	blocked_state: INTEGER_32 is 3
    			-- (from ACTION_SEQUENCE)

    	call_is_underway: BOOLEAN
    			-- Is call currently being executed?
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			Result = not is_aborted_stack.is_empty

    	changeable_comparison_criterion: BOOLEAN
    			-- May object_comparison be changed?
    			-- (Answer: yes by default.)
    			-- (from CONTAINER)

    	conforms_to (other: ANY): BOOLEAN
    			-- Does type of current object conform to type
    			-- of `other' (as per Eiffel: The Language, chapter 13)?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void

    	exhausted: BOOLEAN
    			-- Has structure been completely explored?
    			-- (from LINEAR)
    		ensure -- from LINEAR
    			exhausted_when_off: off implies Result

    	extendible: BOOLEAN is True
    			-- May new items be added? (Answer: yes.)
    			-- (from DYNAMIC_CHAIN)

    	full: BOOLEAN
    			-- Is structure filled to capacity?
    			-- (from ARRAYED_LIST)
    		require -- from  BOX
    			True

    	is_empty: BOOLEAN
    			-- Is structure empty?
    			-- (from FINITE)

    	is_inserted (v: PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]): BOOLEAN
    			-- Has `v' been inserted at the end by the most recent put or
    			-- extend?
    			-- (from ARRAYED_LIST)

    	isfirst: BOOLEAN
    			-- Is cursor at first position?
    			-- (from CHAIN)
    		ensure -- from CHAIN
    			valid_position: Result implies not is_empty

    	islast: BOOLEAN
    			-- Is cursor at last position?
    			-- (from CHAIN)
    		ensure -- from CHAIN
    			valid_position: Result implies not is_empty

    	normal_state: INTEGER_32 is 1
    			-- (from ACTION_SEQUENCE)

    	object_comparison: BOOLEAN
    			-- Must search operations use equal rather than `='
    			-- for comparing references? (Default: no, use `='.)
    			-- (from CONTAINER)

    	off: BOOLEAN
    			-- Is there no current item?
    			-- (from CHAIN)
    		require -- from  TRAVERSABLE
    			True

    	paused_state: INTEGER_32 is 2
    			-- (from ACTION_SEQUENCE)

    	prunable: BOOLEAN
    			-- May items be removed? (Answer: yes.)
    			-- (from ARRAYED_LIST)
    		require -- from  COLLECTION
    			True

    	readable: BOOLEAN
    			-- Is there a current item that may be read?
    			-- (from SEQUENCE)
    		require -- from  ACTIVE
    			True

    	same_type (other: ANY): BOOLEAN
    			-- Is type of current object identical to type of `other'?
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			definition: Result = (conforms_to (other) and other.conforms_to (Current))

    	state: INTEGER_32
    			-- One of Normal_state Paused_state or Blocked_state
    			-- (from ACTION_SEQUENCE)

    	valid_cursor (p: CURSOR): BOOLEAN
    			-- Can the cursor be moved to position `p'?
    			-- (from ARRAYED_LIST)

    	valid_cursor_index (i: INTEGER_32): BOOLEAN
    			-- Is `i' correctly bounded for cursor movement?
    			-- (from CHAIN)
    		ensure -- from CHAIN
    			valid_cursor_index_definition: Result = ((i >= 0) and (i <= count + 1))

    	valid_index (i: INTEGER_32): BOOLEAN
    			-- Is `i' a valid index?
    			-- (from ARRAYED_LIST)
    		require -- from  TABLE
    			True
    		require -- from  TO_SPECIAL
    			True
    		ensure then -- from INDEXABLE
    			only_if_in_index_set: Result implies ((i >= index_set.lower) and (i <= index_set.upper))
    		ensure then -- from CHAIN
    			valid_index_definition: Result = ((i >= 1) and (i <= count))

    	writable: BOOLEAN
    			-- Is there a current item that may be modified?
    			-- (from SEQUENCE)
    		require -- from  ACTIVE
    			True

    feature -- Status setting

    	abort
    			-- Abort the current call.
    			-- (The current item.call will be completed.)
    			-- (from ACTION_SEQUENCE)
    		require -- from ACTION_SEQUENCE
    			call_is_underway: call_is_underway
    		ensure -- from ACTION_SEQUENCE
    			is_aborted_set: is_aborted_stack.item

    	block
    			-- Ignore subsequent calls.
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			blocked_state: state = blocked_state

    	compare_objects
    			-- Ensure that future search operations will use equal
    			-- rather than `=' for comparing references.
    			-- (from CONTAINER)
    		require -- from CONTAINER
    			changeable_comparison_criterion: changeable_comparison_criterion
    		ensure -- from CONTAINER
    			object_comparison

    	compare_references
    			-- Ensure that future search operations will use `='
    			-- rather than equal for comparing references.
    			-- (from CONTAINER)
    		require -- from CONTAINER
    			changeable_comparison_criterion: changeable_comparison_criterion
    		ensure -- from CONTAINER
    			reference_comparison: not object_comparison

    	flush
    			-- Discard any buffered calls.
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			call_buffer_empty: call_buffer.is_empty

    	pause
    			-- Buffer subsequent calls for later execution.
    			-- If `is_blocked' calls will simply be ignored.
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			paused_state: state = paused_state

    	resume
    			-- Used after block or pause to resume normal call
    			-- execution.  Executes any buffered calls.
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			normal_state: state = normal_state

    feature -- Cursor movement

    	back
    			-- Move cursor one position backward.
    			-- (from ARRAYED_LIST)
    		require -- from BILINEAR
    			not_before: not before

    	finish
    			-- Move cursor to last position if any.
    			-- (from ARRAYED_LIST)
    		require -- from  LINEAR
    			True
    		ensure then -- from CHAIN
    			at_last: not is_empty implies islast
    		ensure then -- from ARRAYED_LIST
    			before_when_empty: is_empty implies before

    	forth
    			-- Move cursor one position forward.
    			-- (from ARRAYED_LIST)
    		require -- from LINEAR
    			not_after: not after
    		ensure then -- from LIST
    			moved_forth: index = old index + 1

    	go_i_th (i: INTEGER_32)
    			-- Move cursor to `i'-th position.
    			-- (from ARRAYED_LIST)
    		require -- from CHAIN
    			valid_cursor_index: valid_cursor_index (i)
    		ensure -- from CHAIN
    			position_expected: index = i

    	go_to (p: CURSOR)
    			-- Move cursor to position `p'.
    			-- (from ARRAYED_LIST)
    		require -- from CURSOR_STRUCTURE
    			cursor_position_valid: valid_cursor (p)

    	move (i: INTEGER_32)
    			-- Move cursor `i' positions.
    			-- (from ARRAYED_LIST)
    		ensure -- from CHAIN
    			too_far_right: (old index + i > count) implies exhausted
    			too_far_left: (old index + i < 1) implies exhausted
    			expected_index: (not exhausted) implies (index = old index + i)

    	search (v: like item)
    			-- Move to first position (at or after current
    			-- position) where item and `v' are equal.
    			-- If structure does not include `v' ensure that
    			-- exhausted will be true.
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from ARRAYED_LIST)
    		require -- from  LINEAR
    			True
    		ensure -- from LINEAR
    			object_found: (not exhausted and object_comparison) implies equal (v, item)
    			item_found: (not exhausted and not object_comparison) implies v = item

    	start
    			-- Move cursor to first position if any.
    			-- (from ARRAYED_LIST)
    		require -- from  TRAVERSABLE
    			True
    		ensure then -- from CHAIN
    			at_first: not is_empty implies isfirst
    		ensure then -- from ARRAYED_LIST
    			after_when_empty: is_empty implies after

    feature -- Element change

    	append (s: SEQUENCE [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]])
    			-- Append a copy of `s'.
    			-- (from ARRAYED_LIST)
    		require -- from SEQUENCE
    			argument_not_void: s /= Void
    		ensure -- from SEQUENCE
    			new_count: count >= old count

    	extend (v: like item)
    			-- Add `v' to end.
    			-- Do not move cursor.
    			-- Was declared in ARRAYED_LIST as synonym of force.
    			-- (from ARRAYED_LIST)
    		require -- from COLLECTION
    			extendible: extendible
    		ensure -- from COLLECTION
    			item_inserted: is_inserted (v)
    		ensure then -- from BAG
    			one_more_occurrence: occurrences (v) = old (occurrences (v)) + 1

    	extend_kamikaze (an_item: like item)
    			-- Extend `an_item' and remove it again after it is called.
    			-- (from EV_ACTION_SEQUENCE)

    	fill (other: CONTAINER [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]])
    			-- Fill with as many items of `other' as possible.
    			-- The representations of `other' and current structure
    			-- need not be the same.
    			-- (from CHAIN)
    		require -- from COLLECTION
    			other_not_void: other /= Void
    			extendible: extendible

    	force (v: like item)
    			-- Add `v' to end.
    			-- Do not move cursor.
    			-- Was declared in ARRAYED_LIST as synonym of extend.
    			-- (from ARRAYED_LIST)
    		require -- from SEQUENCE
    			extendible: extendible
    		ensure then -- from SEQUENCE
    			new_count: count = old count + 1
    			item_inserted: has (v)

    	merge_left (other: ARRAYED_LIST [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]])
    			-- Merge `other' into current structure before cursor.
    			-- (from ARRAYED_LIST)
    		require -- from DYNAMIC_CHAIN
    			extendible: extendible
    			not_before: not before
    			other_exists: other /= Void
    			not_current: other /= Current
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count + old other.count
    			new_index: index = old index + old other.count
    			other_is_empty: other.is_empty

    	merge_right (other: ARRAYED_LIST [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]])
    			-- Merge `other' into current structure after cursor.
    			-- (from ARRAYED_LIST)
    		require -- from DYNAMIC_CHAIN
    			extendible: extendible
    			not_after: not after
    			other_exists: other /= Void
    			not_current: other /= Current
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count + old other.count
    			same_index: index = old index
    			other_is_empty: other.is_empty

    	put_i_th (v: like i_th; i: INTEGER_32)
    			-- Replace `i'-th entry, if in index interval, by `v'.
    			-- (from ARRAY)
    		require -- from TABLE
    			valid_key: valid_index (i)
    		require -- from TO_SPECIAL
    			valid_index: valid_index (i)
    		ensure then -- from INDEXABLE
    			insertion_done: i_th (i) = v
    		ensure -- from TO_SPECIAL
    			inserted: array_item (i) = v

    	put (v: like item)
    			-- Replace current item by `v'.
    			-- (Synonym for replace)
    			-- (from CHAIN)
    		require -- from COLLECTION
    			extendible: extendible
    		ensure -- from COLLECTION
    			item_inserted: is_inserted (v)
    		ensure then -- from CHAIN
    			same_count: count = old count

    	put_front (v: like item)
    			-- Add `v' to the beginning.
    			-- Do not move cursor.
    			-- (from ARRAYED_LIST)
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count + 1
    			item_inserted: first = v

    	put_left (v: like item)
    			-- Add `v' to the left of current position.
    			-- Do not move cursor.
    			-- (from ARRAYED_LIST)
    		require -- from DYNAMIC_CHAIN
    			extendible: extendible
    			not_before: not before
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count + 1
    			new_index: index = old index + 1

    	put_right (v: like item)
    			-- Add `v' to the right of current position.
    			-- Do not move cursor.
    			-- (from ARRAYED_LIST)
    		require -- from DYNAMIC_CHAIN
    			extendible: extendible
    			not_after: not after
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count + 1
    			same_index: index = old index

    	replace (v: like first)
    			-- Replace current item by `v'.
    			-- (from ARRAYED_LIST)
    		require -- from ACTIVE
    			writable: writable
    		ensure -- from ACTIVE
    			item_replaced: item = v

    feature -- Removal

    	prune (v: like item)
    			-- Remove first occurrence of `v', if any,
    			-- after cursor position.
    			-- Move cursor to right neighbor.
    			-- (or after if no right neighbor or `v' does not occur)
    			-- (from ARRAYED_LIST)
    		require -- from COLLECTION
    			prunable: prunable

    	prune_all (v: like item)
    			-- Remove all occurrences of `v'.
    			-- (Reference or object equality,
    			-- based on object_comparison.)
    			-- (from ARRAYED_LIST)
    		require -- from COLLECTION
    			prunable: prunable
    		ensure -- from COLLECTION
    			no_more_occurrences: not has (v)
    		ensure then -- from DYNAMIC_CHAIN
    			is_exhausted: exhausted
    		ensure then -- from ARRAYED_LIST
    			is_after: after

    	remove
    			-- Remove current item.
    			-- Move cursor to right neighbor
    			-- (or after if no right neighbor)
    			-- (from ARRAYED_LIST)
    		require -- from ACTIVE
    			prunable: prunable
    			writable: writable
    		ensure then -- from DYNAMIC_LIST
    			after_when_empty: is_empty implies after
    		ensure then -- from ARRAYED_LIST
    			index: index = old index

    	remove_left
    			-- Remove item to the left of cursor position.
    			-- Do not move cursor.
    			-- (from ARRAYED_LIST)
    		require -- from DYNAMIC_CHAIN
    			left_exists: index > 1
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count - 1
    			new_index: index = old index - 1

    	remove_right
    			-- Remove item to the right of cursor position
    			-- Do not move cursor
    			-- (from ARRAYED_LIST)
    		require -- from DYNAMIC_CHAIN
    			right_exists: index < count
    		ensure -- from DYNAMIC_CHAIN
    			new_count: count = old count - 1
    			same_index: index = old index

    	wipe_out
    			-- Remove all items.
    			-- (from ARRAYED_LIST)
    		require -- from COLLECTION
    			prunable: prunable
    		ensure -- from COLLECTION
    			wiped_out: is_empty
    		ensure then -- from DYNAMIC_LIST
    			is_before: before

    feature -- Resizing

    	resize (new_capacity: INTEGER_32)
    			-- Resize list so that it can contain
    			-- at least `n' items. Do not lose any item.
    			-- (from ARRAYED_LIST)
    		require -- from ARRAYED_LIST
    			new_capacity_large_enough: new_capacity >= capacity
    		ensure -- from ARRAYED_LIST
    			capacity_set: capacity >= new_capacity

    feature -- Transformation

    	swap (i: INTEGER_32)
    			-- Exchange item at `i'-th position with item
    			-- at cursor position.
    			-- (from ARRAYED_LIST)
    		require -- from CHAIN
    			not_off: not off
    			valid_index: valid_index (i)
    		ensure -- from CHAIN
    			swapped_to_item: item = old i_th (i)
    			swapped_from_item: i_th (i) = old item

    feature -- Conversion

    	linear_representation: LINEAR [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]]
    			-- Representation as a linear structure
    			-- (from LINEAR)
    		require -- from  CONTAINER
    			True

    feature -- Duplication

    	copy (other: like Current)
    			-- Reinitialize by copying all the items of `other'.
    			-- (This is also used by clone.)
    			-- (from ARRAY)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_equal: is_equal (other)
    		ensure then -- from ARRAY
    			equal_areas: area.is_equal (other.area)

    	frozen deep_copy (other: like Current)
    			-- Effect equivalent to that of:
    			--		copy (`other' . deep_twin)
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    		ensure -- from ANY
    			deep_equal: deep_equal (Current, other)

    	frozen deep_twin: like Current
    			-- New object structure recursively duplicated from Current.
    			-- (from ANY)
    		ensure -- from ANY
    			deep_equal: deep_equal (Current, Result)

    	duplicate (n: INTEGER_32): like Current
    			-- Copy of sub-list beginning at current position
    			-- and having min (`n', count - index + 1) items.
    			-- (from ARRAYED_LIST)
    		require -- from CHAIN
    			not_off_unless_after: off implies after
    			valid_subchain: n >= 0

    	frozen standard_copy (other: like Current)
    			-- Copy every field of `other' onto corresponding field
    			-- of current object.
    			-- (from ANY)
    		require -- from ANY
    			other_not_void: other /= Void
    			type_identity: same_type (other)
    		ensure -- from ANY
    			is_standard_equal: standard_is_equal (other)

    	frozen standard_twin: like Current
    			-- New object field-by-field identical to `other'.
    			-- Always uses default copying semantics.
    			-- (from ANY)
    		ensure -- from ANY
    			standard_twin_not_void: Result /= Void
    			equal: standard_equal (Result, Current)

    	frozen twin: like Current
    			-- New object equal to `Current'
    			-- twin calls copy; to change copying/twining semantics, redefine copy.
    			-- (from ANY)
    		ensure -- from ANY
    			twin_not_void: Result /= Void
    			is_equal: Result.is_equal (Current)

    feature -- Basic operations

    	call (event_data: TUPLE [EV_TREE_NODE])
    			-- Call each procedure in order unless `is_blocked'.
    			-- If `is_paused' delay execution until resume.
    			-- Stop at current point in list on abort.
    			-- (from ACTION_SEQUENCE)
    		ensure -- from ACTION_SEQUENCE
    			is_aborted_stack_unchanged: old is_aborted_stack.is_equal (is_aborted_stack)

    	frozen default: like Current
    			-- Default value of object's type
    			-- (from ANY)

    	frozen default_pointer: POINTER
    			-- Default value of type `POINTER'
    			-- (Avoid the need to write `p'.default for
    			-- some `p' of type `POINTER'.)
    			-- (from ANY)

    	default_rescue
    			-- Process exception for routines with no Rescue clause.
    			-- (Default: do nothing.)
    			-- (from ANY)

    	frozen do_nothing
    			-- Execute a null action.
    			-- (from ANY)

    feature -- Element Change

    	prune_when_called (an_action: like item)
    			-- Remove `an_action' after the next time it is called.
    			-- (from ACTION_SEQUENCE)
    		require -- from ACTION_SEQUENCE
    			has (an_action)

    feature -- Event handling

    	empty_actions: ARRAYED_LIST [PROCEDURE [ANY, TUPLE]]
    			-- Actions to be performed on transition from not is_empty to is_empty.
    			-- (from ACTION_SEQUENCE)

    	not_empty_actions: ARRAYED_LIST [PROCEDURE [ANY, TUPLE]]
    			-- Actions to be performed on transition from is_empty to not is_empty.
    			-- (from ACTION_SEQUENCE)

    feature -- Iteration

    	do_all (action: PROCEDURE [ANY, TUPLE [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]]])
    			-- Apply `action' to every item.
    			-- Semantics not guaranteed if `action' changes the structure;
    			-- in such a case, apply iterator to clone of structure instead.
    			-- (from LINEAR)
    		require -- from TRAVERSABLE
    			action_exists: action /= Void
    		require -- from ARRAY
    			action_not_void: action /= Void

    	do_if (action: PROCEDURE [ANY, TUPLE [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]]]; test: FUNCTION [ANY, TUPLE [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]], BOOLEAN])
    			-- Apply `action' to every item that satisfies `test'.
    			-- Semantics not guaranteed if `action' or `test' changes the structure;
    			-- in such a case, apply iterator to clone of structure instead.
    			-- (from LINEAR)
    		require -- from TRAVERSABLE
    			action_exists: action /= Void
    			test_exits: test /= Void
    		require -- from ARRAY
    			action_not_void: action /= Void
    			test_not_void: test /= Void

    	for_all (test: FUNCTION [ANY, TUPLE [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]], BOOLEAN]): BOOLEAN
    			-- Is `test' true for all items?
    			-- Semantics not guaranteed if `test' changes the structure;
    			-- in such a case, apply iterator to clone of structure instead.
    			-- (from LINEAR)
    		require -- from TRAVERSABLE
    			test_exits: test /= Void
    		require -- from ARRAY
    			test_not_void: test /= Void
    		ensure then -- from LINEAR
    			empty: is_empty implies Result

    	there_exists (test: FUNCTION [ANY, TUPLE [PROCEDURE [ANY, TUPLE [EV_TREE_NODE]]], BOOLEAN]): BOOLEAN
    			-- Is `test' true for at least one item?
    			-- Semantics not guaranteed if `test' changes the structure;
    			-- in such a case, apply iterator to clone of structure instead.
    			-- (from LINEAR)
    		require -- from TRAVERSABLE
    			test_exits: test /= Void
    		require -- from ARRAY
    			test_not_void: test /= Void

    feature -- Output

    	io: STD_FILES
    			-- Handle to standard file setup
    			-- (from ANY)

    	out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of tagged_out.
    			-- (from ANY)

    	print (some: ANY)
    			-- Write terse external representation of `some'
    			-- on standard output.
    			-- (from ANY)

    	frozen tagged_out: STRING_8
    			-- New string containing terse printable representation
    			-- of current object
    			-- Was declared in ANY as synonym of out.
    			-- (from ANY)

    feature -- Platform

    	operating_environment: OPERATING_ENVIRONMENT
    			-- Objects available from the operating system
    			-- (from ANY)

    invariant
    		-- from ACTION_SEQUENCE
    	is_aborted_stack_not_void: is_aborted_stack /= Void
    	call_buffer_not_void: call_buffer /= Void
    	valid_state: state = normal_state or state = paused_state or state = blocked_state
    	call_buffer_consistent: state = normal_state implies call_buffer.is_empty
    	not_empty_actions_not_void: not_empty_actions /= Void
    	empty_actions_not_void: empty_actions /= Void

    		-- from ARRAYED_LIST
    	prunable: prunable
    	starts_from_one: lower = 1
    	empty_means_storage_empty: is_empty implies all_default

    		-- from ARRAY
    	area_exists: area /= Void
    	consistent_size: capacity = upper - lower + 1
    	non_negative_count: count >= 0
    	index_set_has_same_count: valid_index_set

    		-- from RESIZABLE
    	increase_by_at_least_one: minimal_increase >= 1

    		-- from BOUNDED
    	valid_count: count <= capacity
    	full_definition: full = (count = capacity)

    		-- from FINITE
    	empty_definition: is_empty = (count = 0)
    	non_negative_count: count >= 0

    		-- from ANY
    	reflexive_equality: standard_is_equal (Current)
    	reflexive_conformance: conforms_to (Current)

    		-- from INDEXABLE
    	index_set_not_void: index_set /= Void

    		-- from LIST
    	before_definition: before = (index = 0)
    	after_definition: after = (index = count + 1)

    		-- from CHAIN
    	non_negative_index: index >= 0
    	index_small_enough: index <= count + 1
    	off_definition: off = ((index = 0) or (index = count + 1))
    	isfirst_definition: isfirst = ((not is_empty) and (index = 1))
    	islast_definition: islast = ((not is_empty) and (index = count))
    	item_corresponds_to_index: (not off) implies (item = i_th (index))
    	index_set_has_same_count: index_set.count = count

    		-- from ACTIVE
    	writable_constraint: writable implies readable
    	empty_constraint: is_empty implies (not readable) and (not writable)

    		-- from BILINEAR
    	not_both: not (after and before)
    	before_constraint: before implies off

    		-- from LINEAR
    	after_constraint: after implies off

    		-- from TRAVERSABLE
    	empty_constraint: is_empty implies off

    		-- from DYNAMIC_CHAIN
    	extendible: extendible

    indexing
    	copyright: "Copyright (c) 1984-2006, Eiffel Software and others"
    	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
    	source: "[
    		Eiffel Software
    		356 Storke Road, Goleta, CA 93117 USA
    		Telephone 805-685-1006, Fax 805-685-6869
    		Website http://www.eiffel.com
    		Customer support http://support.eiffel.com
    	]"

    end -- class EV_TREE_ITEM_CHECK_ACTION_SEQUENCE