note description: "[ Base interface for all classes exposing a means to query for a service. Note: Provides access to services registered in by using a {SERVICE_CONTAINER_I}. Services are added and queried for using a service type, which is a TYPE [G]. Queries are always made on a locally available service provider. Any services registered on the local service provider are given priority. If no local service is available a parent service provider is checked for the service all the way up to the root service provider, implemented on {SERVICE_HEAP}. This is also accessible using querying for the service {SERVICE_PROVIDER_S}. Clients are free to query directly for the global service provider using {SERVICE_PROVIDER_S} or {SERVICE_CONTAINER_S}. ]" legal: "See notice at end of class." status: "See notice at end of class."; date: "$Date$"; revision: "$Revision$" deferred class SERVICE_PROVIDER_I feature -- Query service (a_type: TYPE [detachable SERVICE_I]): detachable SERVICE_I -- Attempts to retrieve a service. -- -- `a_type': The service type to query a compatible service for. -- `Result': A service conforming to the specified type of Void if no matching service was found. require a_type_attached: a_type /= Void deferred ensure result_sited: Result /= Void implies Result.site = Current result_compatiable: Result /= Void implies attached (a_type / Result) end note copyright: "Copyright (c) 1984-2017, Eiffel Software" license: "GPL version 2 (see http://www.eiffel.com/licensing/gpl.txt)" licensing_options: "http://www.eiffel.com/licensing" copying: "[ This file is part of Eiffel Software's Eiffel Development Environment. Eiffel Software's Eiffel Development Environment is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2 of the License (available at the URL listed under "license" above). Eiffel Software's Eiffel Development Environment is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Eiffel Software's Eiffel Development Environment; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA ]" 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