note description: "Dispensers where the earliest added element is accessible." author: "Nadia Polikarpova" model: sequence manual_inv: true false_guards: true deferred class V_QUEUE [G] inherit V_DISPENSER [G] redefine extend, is_model_equal end feature -- Extension extend (v: G) -- Push `v' on the stack. deferred ensure then sequence_effect: sequence ~ old sequence & v end feature -- Specification is_model_equal (other: like Current): BOOLEAN -- Is the abstract state of `Current' equal to that of `other'? note status: ghost, functional, nonvariant do Result := sequence ~ other.sequence end note copyright: "Copyright (c) 1984-2014, 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