US 5,313,630 A · System of object oriented inheritance using the temporal status of superclasses

Abstract

An object-oriented data base management system connected to a plurality of data bases includes a class definition unit, a static inheritance processing unit included within the class definition unit, a message processing unit, a dynamic inheritance processing unit included within the message processing unit, and an object management unit. The object-oriented data base management system is of the type that defines the inheritance relationship between a plurality of classes and an arbitrary class and the inheritance priority order, the class being a basic unit of programming, and executes the data processing by solving the inheritance relationship between classes in accordance with the priority order. There is prepared, for each class, updatable inheritance solution status information which the static inheritance processing unit causes to be stored in a table. The inheritance solution status information includes status information and time information. The status information is representative of whether or not inheritance between the class and the superclasses can be completely solved, and the time information is representative of a time when the status is established. When a message processing is requested for an object of a class, the dynamic inheritance processing unit searches the method designated by the message while referring to the inheritance solution status information regarding the class and the superclass stored in the table.

Claims7

Dependent claims

A class inheritance solution process for an object-oriented data processing and programming system which defines inheritance relationships between a plurality of superclasses and each class which is a subclass of the superclasses, and the inheritance priority order of the superclasses, and executes the data processing by solving the inheritance relationship of the class in accordance with the priority order, said process comprising the steps of:

at a static inheritance processing unit, storing status information and time information of each class in storage means, said status information being representative of the results of a judgment whether or not inheritance between the class and the superclasses can be completely solved, and said time information being representative of a time when said status is established;
if a judgment of a status of the class is required again, referring to said storage means, and if the status established time of said class is earlier than that of said superclass to be inherited, executing again a status judgment of said superclass and thereafter inheriting the definition contents of said superclass to said class;
if an execution of a method is requested by a message to an object of the class, searching for said method from the class, if said method is not present within said class, sequentially selecting as a search target superclass a superclass of the class having a higher priority order to search the method, if said method is not present within the target superclass, referring to the status of said target superclass stored in said storage means, and in accordance with the status, determining whether or not a search for the method is to be continued using as a search target superclass a superclass having a lower priority order.

Dependencies are inferred from the claim text.

System of object oriented inheritance using the temporal status of superclasses

Life of this patent

System of object oriented inheritance using the temporal status of superclasses

Life of this patent

Abstract

Claims7