note description: "[ Data structures of the most general kind, used to hold zero or more items. ]" library: "Free implementation of ELKS library" legal: "See notice at end of class." status: "See notice at end of class." names: access; access: membership; contents: generic; date: "$Date$" revision: "$Revision$" deferred class CONTAINER [G] inherit ITERABLE [G] feature -- Access has (v: G): BOOLEAN -- Does structure include `v'? -- (Reference or object equality, -- based on `object_comparison'.) deferred ensure not_found_in_empty: Result implies not is_empty end feature -- Status report is_empty: BOOLEAN -- Is there no element? deferred end empty: BOOLEAN -- Is there no element? obsolete "ELKS 2000: Use `is_empty' instead. [2017-05-31]" do Result := is_empty end object_comparison: BOOLEAN -- Must search operations use `equal' rather than `=' -- for comparing references? (Default: no, use `='.) changeable_comparison_criterion: BOOLEAN -- May `object_comparison' be changed? -- (Answer: yes by default.) do Result := True end feature -- Status setting compare_objects -- Ensure that future search operations will use `equal' -- rather than `=' for comparing references. require changeable_comparison_criterion: changeable_comparison_criterion do object_comparison := True ensure object_comparison end compare_references -- Ensure that future search operations will use `=' -- rather than `equal' for comparing references. require changeable_comparison_criterion: changeable_comparison_criterion do object_comparison := False ensure reference_comparison: not object_comparison end feature -- Conversion linear_representation: LINEAR [G] -- Representation as a linear structure deferred end feature {NONE} -- Measurement estimated_count_of (other: ITERABLE [G]): INTEGER -- Estimated number of elements in `other`. do if attached {FINITE [G]} other as f then Result := f.count elseif attached {READABLE_INDEXABLE [G]} other as r then Result := r.upper - r.lower + 1 end ensure instance_free: class non_negative_result: Result >= 0 end note copyright: "Copyright (c) 1984-2018, Eiffel Software and others" license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)" source: "[ Eiffel Software 5949 Hollister Ave., Goleta, CA 93117 USA Telephone 805-685-1006, Fax 805-685-6869 Website http://www.eiffel.com Customer support http://support.eiffel.com ]" end