Automatic generation produced by ISE Eiffel
indexing description: "[ Possibly circular sequences of items, without commitment to a particular representation ]" status: "See notice at end of class" names: chain, sequence access: index, cursor, membership contents: generic date: "$Date: 2001-11-16 20:32:23 +0000 (Fri, 16 Nov 2001) $" revision: "$Revision: 51435 $" deferred class interface CHAIN [G] feature -- Access cursor: CURSOR -- Current cursor position -- (from CURSOR_STRUCTURE) first: like item -- Item at first position require not_empty: not is_empty has (v: like item): BOOLEAN -- Does chain include v? -- (Reference or object equality, -- based on object_comparison.) ensure -- from CONTAINER not_found_in_empty: Result implies not is_empty i_th (i: INTEGER): like item -- Item at i-th position -- Was declared in CHAIN as synonym of @. require -- from TABLE valid_key: valid_index (k) index: INTEGER -- Current cursor index index_of (v: like item; i: INTEGER): INTEGER -- Index of i-th occurrence of item identical to v. -- (Reference or object equality, -- based on object_comparison.) -- 0 if none. require -- from LINEAR positive_occurrences: i > 0 ensure -- from LINEAR non_negative_result: Result >= 0 item: G -- Item at current position -- (from TRAVERSABLE) require -- from TRAVERSABLE not_off: not off require -- from ACTIVE readable: readable last: like item -- Item at last position require not_empty: not is_empty sequential_occurrences (v: G): INTEGER -- Number of times v appears. -- (Reference or object equality, -- based on object_comparison.) -- (from LINEAR) ensure -- from BAG non_negative_occurrences: Result >= 0 infix "@" (i: INTEGER): like item -- Item at i-th position -- Was declared in CHAIN as synonym of i_th. require -- from TABLE valid_key: valid_index (k) feature -- Measurement count: INTEGER -- Number of items -- (from FINITE) index_set: INTEGER_INTERVAL -- Range of acceptable indexes ensure -- from INDEXABLE not_void: Result /= void ensure then count_definition: Result.count = count occurrences (v: like item): INTEGER -- Number of times v appears. -- (Reference or object equality, -- based on object_comparison.) ensure -- from BAG non_negative_occurrences: Result >= 0 feature -- Status report after: BOOLEAN -- Is there no valid position to the right of current one? -- (from LINEAR) changeable_comparison_criterion: BOOLEAN -- May object_comparison be changed? -- (Answer: yes by default.) -- (from CONTAINER) exhausted: BOOLEAN -- Has structure been completely explored? -- (from LINEAR) ensure -- from LINEAR exhausted_when_off: off implies Result extendible: BOOLEAN -- May new items be added? -- (from COLLECTION) full: BOOLEAN -- Is structure filled to capacity? -- (from BOX) is_empty: BOOLEAN -- Is structure empty? -- (from FINITE) is_inserted (v: G): BOOLEAN -- Has v been inserted by the most recent insertion? -- (By default, the value returned is equivalent to calling -- `has (v)'. However, descendants might be able to provide more -- efficient implementations.) -- (from COLLECTION) isfirst: BOOLEAN -- Is cursor at first position? ensure valid_position: Result implies not is_empty islast: BOOLEAN -- Is cursor at last position? ensure valid_position: Result implies not is_empty 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? prunable: BOOLEAN -- May items be removed? -- (from COLLECTION) readable: BOOLEAN -- Is there a current item that may be read? -- (from SEQUENCE) valid_cursor (p: CURSOR): BOOLEAN -- Can the cursor be moved to position p? -- (from CURSOR_STRUCTURE) valid_cursor_index (i: INTEGER): BOOLEAN -- Is i correctly bounded for cursor movement? ensure valid_cursor_index_definition: Result = ((i >= 0) and (i <= count + 1)) valid_index (i: INTEGER): BOOLEAN -- Is i within allowable bounds? ensure then -- from INDEXABLE only_if_in_index_set: Result implies ((i >= index_set.lower) and (i <= index_set.upper)) ensure then valid_index_definition: Result = ((i >= 1) and (i <= count)) writable: BOOLEAN -- Is there a current item that may be modified? -- (from SEQUENCE) feature -- Status setting compare_objects -- Ensure that future search operations will use equal -- rather than = for comparing references. -- (from CONTAINER) require -- from CONTAINER 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 ensure -- from CONTAINER reference_comparison: not object_comparison feature -- Cursor movement back -- Move to previous position. -- (from BILINEAR) require -- from BILINEAR not_before: not before before: BOOLEAN -- Is there no valid position to the left of current one? -- (from BILINEAR) finish -- Move cursor to last position. -- (No effect if empty) ensure then at_last: not is_empty implies islast forth -- Move to next position; if no next position, -- ensure that exhausted will be true. -- (from LINEAR) require -- from LINEAR not_after: not after go_i_th (i: INTEGER) -- Move cursor to i-th position. require valid_cursor_index: valid_cursor_index (i) ensure position_expected: index = i go_to (p: CURSOR) -- Move cursor to position p. -- (from CURSOR_STRUCTURE) require -- from CURSOR_STRUCTURE cursor_position_valid: valid_cursor (p) move (i: INTEGER) -- Move cursor i positions. The cursor -- may end up off if the absolute value of i -- is too big. ensure 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 BILINEAR) 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. -- (No effect if empty) ensure then at_first: not is_empty implies isfirst feature -- Element change append (s: SEQUENCE [G]) -- Append a copy of s. -- (from SEQUENCE) require -- from SEQUENCE argument_not_void: s /= void ensure -- from SEQUENCE new_count: count >= old count extend (v: G) -- Add a new occurrence of v. -- (from BAG) 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 fill (other: CONTAINER [G]) -- Fill with as many items of other as possible. -- The representations of other and current structure -- need not be the same. -- (from COLLECTION) require -- from COLLECTION other_not_void: other /= void extendible force (v: like item) -- Add v to end. -- (from SEQUENCE) require -- from SEQUENCE extendible: extendible ensure then -- from SEQUENCE new_count: count = old count + 1 item_inserted: has (v) put (v: like item) -- Replace current item by v. -- (Synonym for replace) require -- from COLLECTION extendible: extendible ensure -- from COLLECTION item_inserted: is_inserted (v) ensure then same_count: count = old count put_i_th (v: like item; i: INTEGER) -- Put v at i-th position. require -- from TABLE valid_key: valid_index (k) ensure then -- from INDEXABLE insertion_done: i_th (k) = v replace (v: G) -- Replace current item by v. -- (from ACTIVE) require -- from ACTIVE writable: writable ensure -- from ACTIVE item_replaced: item = v feature -- Removal prune (v: like item) -- Remove the first occurrence of v if any. -- If no such occurrence go off. -- (from SEQUENCE) require -- from COLLECTION prunable: prunable prune_all (v: like item) -- Remove all occurrences of v; go off. -- (from SEQUENCE) require -- from COLLECTION prunable ensure -- from COLLECTION no_more_occurrences: not has (v) wipe_out -- Remove all items. -- (from COLLECTION) require -- from COLLECTION prunable ensure -- from COLLECTION wiped_out: is_empty feature -- Transformation swap (i: INTEGER) -- Exchange item at i-th position with item -- at cursor position. require not_off: not off valid_index: valid_index (i) ensure swapped_to_item: item = old i_th (i) swapped_from_item: i_th (i) = old item feature -- Conversion linear_representation: LINEAR [G] -- Representation as a linear structure -- (from LINEAR) feature -- Duplication duplicate (n: INTEGER): like Current -- Copy of sub-chain beginning at current position -- and having min (n, from_here) items, -- where from_here is the number of items -- at or to the right of current position. require not_off_unless_after: off implies after valid_subchain: n >= 0 feature -- Iteration do_all (action: PROCEDURE [ANY, TUPLE [G]]) -- 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 do_if (action: PROCEDURE [ANY, TUPLE [G]]; test: FUNCTION [ANY, TUPLE [G], 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 for_all (test: FUNCTION [ANY, TUPLE [G], BOOLEAN]): BOOLEAN -- Is test true for all items? -- (from LINEAR) require -- from TRAVERSABLE test_exits: test /= void there_exists (test: FUNCTION [ANY, TUPLE [G], BOOLEAN]): BOOLEAN -- Is test true for at least one item? -- (from LINEAR) require -- from TRAVERSABLE test_exits: test /= void invariant 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 ANY reflexive_equality: standard_is_equal (Current) reflexive_conformance: conforms_to (Current) -- from ACTIVE writable_constraint: writable implies readable empty_constraint: is_empty implies (not readable) and (not writable) -- from INDEXABLE index_set_not_void: index_set /= void -- 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 FINITE empty_definition: is_empty = (count = 0) non_negative_count: count >= 0 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 CHAIN -- Generated by ISE Eiffel --
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