Method for creating an object subclass with selective inheritance

• US 5,493,680 A
• Filed: 02/25/1994
• Issued: 02/20/1996
• Est. Priority Date: 07/06/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Danforth, Scott H.
• Primary Examiner(s): Heckler, Thomas M.
• Application Number:
  US08/201,835
• Time in Patent Office: 725 Days
• Field of Search: 395/600, 395/700
• US Class Current: 717/108
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution

Abstract

A method, system and program for defining classes of objects using traditional subclassing inheritance and abstract inheritance using a neutral set of information from which object support for any language, including support between languages, is disclosed. The information is parsed and compiled to generate a bindings file which is input along with method information to the target language compiler to create an object file. The object file is thereafter link edited to create executable programs. Target languages include C, Fortran, C++, COBOL or any other compiled language whether or not the particular language has object programming support. Messages are displayed on a display to aid a user.

Claims

1. A computer implemented method for creating new subclasses in an object oriented computer system having a processor and storage, said storage containing classes each of said classes having a method invocation interface, method procedure code and instance data, the method comprising the steps of:

receiving a command to create a subclass from a parent class;

creating a subclass by allocating a portion of said storage to said subclass and assigning a subclass name;

creating a method table data structure in said allocated storage to store data about said method procedure code and said method invocation interface;

testing said command for inheritance type;

copying said method procedure code and said instance variables from said parent class into said allocated storage only if the inheritance type is full inheritance.

2. The method of claim 1, wherein said step of creating a method data structure includes creating a subclass method invocation interface equivalent to said parent class method invocation interface.

3. A Computer implemented method for constructing an object subclass in an object oriented computer system having a processor and data storage means, the object subclass having data storage, method invocation interfaces and method logic, the object subclass being derived from a parent class having data storage, method invocation interfaces and method logic, the method comprising the steps of:

receiving a subclass construction request;

initializing a subclass data area in a data storage means;

testing said subclass construction request to determine whether full inheritance is requested;

copying said parent class data storage into said subclass data area if said request is for full inheritance;

initializing a method table area in said data storage means for each subclass construction request;

copying said parent class method invocation interfaces for each subclass construction request; and

copying said parent class method logic if said request is for full inheritance.

4. The method of claim 3, wherein the step of initializing a method table comprises the steps of:

determining the number and size of static methods;

determining the size of a method table to contain all static and dynamic methods;

allocating a method data structure in said data storage means based upon said determined size;

initializing said method data structure to contain entries for each of said static or dynamic methods.