PROGRAMMING ENVIRONMENT WITH SUPPORT FOR HANDLE AND NON-HANDLE USER-CREATED CLASSES

• US 20090077536A1
• Filed: 07/10/2008
• Published: 03/19/2009
• Est. Priority Date: 07/12/2007
• Status: Active Grant

• Current Assignee: The MathWorks, Inc.
• Original Assignee: The MathWorks, Inc.
• Inventors: Foti, David A.
• Granted Patent: US 9,311,111 B2
• Time in Patent Office: Days
• US Class Current: 717/116
• CPC Class Codes: G06F 8/315 Object-oriented languages
• CPC Class Codes: G06F 9/4492 Inheritance

Abstract

A language processing environment provides facilities for defining and using handle classes. A handle class is a class that always and only exists as a handle to stored data, yet that data is accessed in the same manner as with non-handle classes. The language processing environment provides syntax such that all values in the language are members of some class and all classes are defined using the same syntax. Methods and properties are supported on both handle and non-handle classes.

Claims

1. A computer-readable medium storing computer-executable instructions for providing a language processing environment, said instructions comprising instructions for:

providing at least one handle base class available for subclassing by users of the language processing environment;

receiving a definition of at least one handle subclass created by subclassing the at least one handle base class;

providing a single syntax for defining all classes including handle classes and non-handle classes; and

storing in memory an object corresponding to an instance of the at least one handle subclass.

2. The medium of claim 1, wherein instructions further comprise instructions for:

providing a single syntax for accessing properties and methods of all classes including handle and non-handle classes.

3. The medium of claim 1, wherein instructions further comprise instructions for:

providing semantics such that instantiation of a handle class allocates storage for all state associated with an instance of the handle class and subsequent copying of this handle does not copy any of the state associated with the handle.

4. The medium of claim 1, wherein instructions further comprise instructions for:

receiving a definition of at least one non-handle class; and

instantiating an object corresponding to an instance of the at least one non-handle class.

5. The medium of claim 1, wherein instructions further comprise instructions for assigning a variable representing the object corresponding to an instance of the at least one handle subclass to another variable such that the assignment not result in creation of a second object corresponding to an instance of the at least one handle subclass.

6. The medium of claim 1, wherein instructions further comprise instructions for:

enforcing uniqueness of the object corresponding to an instance of the at least one handle subclass.

7. The medium of claim 6, wherein instructions for enforcing uniqueness further comprise instructions for:

as a result of an assignment operator between a first variable representing the object corresponding to an instance of the at least one handle subclass and a second variable, assigning to the second variable a reference to the object corresponding to an instance of the at least one handle subclass.

8. The medium of claim 1, wherein the object corresponding to an instance of the at least one handle subclass is used to represent at least one or a combination of:

a file handle, a system resource handle, a function handle, a window handle, or another graphical user interface element handle.

9. The medium of claim 1, wherein the language processing environment is a graphical modeling environment, and wherein the object corresponding to at least one handle subclass represents an element of a graphical model.

10. The medium of claim 1, wherein the language processing environment is an array-based programming environment.

11. The medium of claim 10, wherein the array-based programming environment is capable of processing at least a subset of MATLAB code commands.

12. The medium of claim 1, wherein instructions further comprise instructions for:

deleting, in response to a deletion operation on a variable representing the object corresponding to at least one instance of the at least one handle subclass, the underlying object.

13. The medium of claim 1, wherein instructions further comprise instructions for:

returning a value corresponding to “

true”

in response to a command querying whether the object corresponding to at least one instance of the at least one handle subclass is a handle object.

14. The medium of claim 1, wherein instructions further comprise instructions for:

receiving a definition of a second handle subclass created by subclassing the at least one handle subclass.

15. The medium of claim 1, wherein the single syntax or defining all classes comprises a word “

classdef,”

a name of a class being defined, a less-then sign, and a name of a base class from which the class being defined is a subclass.

16. A computer-implemented method for providing a computer programming environment, said method comprising:

providing the computer programming environment having at least one handle base class available for subclassing;

providing a first interface allowing for definition of at least one handle subclass created by subclassing the at least one handle base class;

providing a second interface allowing for definition of at least one non-handle class, the second interface being identical to the first interface;

receiving computer program code defining at least one handle subclass and at least one non-handle class using the first interface;

processing the computer program code; and

storing the results of the processing in memory.

17. The computer-implemented method of claim 16, wherein processing the computer program code further comprises interpreting and/or compiling the computer program code.

18. The computer-implemented method of claim 16, wherein processing the computer program code further comprises generating executable code that, when executed, is capable of creating one or more instances of the at least one handle subclass and one or more instances of the at least one non-handle class.

19. The computer-implemented method of claim 18, further comprising:

executing the executable code.

20. The computer-implemented method of claim 19, wherein executing the executable code further comprises:

allocating storage for state associated with at least one instance of the at least one handle subclass; and

in response to a command to copy the at least one instance, not copying the state associated with the at least one instance.

21. The computer-implemented method of claim 16, wherein the computer program code comprises at least one assignment operation assigning an object corresponding to an instance of the at least one handle subclass to a variable, said method comprising:

processing the computer program code to generate instructions corresponding to the at least one assignment operation, the instructions not copying to the variables any of state variables associated with the object.

22. The computer-implemented method of claim 16, further comprising:

ensuring uniqueness of instances corresponding to the at least one handle subclass in the computer program code.

23. The computer-implemented method of claim 16, wherein the at least one handle subclass is used to represent at least one or a combination of:

a file handle, a system resource handle, a function handle, a window handle, or another graphical user interface handle.

24. The computer-implemented method of claim 16, wherein the computer program code comprises code in an array-based language.

25. The computer-implemented method of claim 16, wherein the computer program code comprises code at least a subset of which is capable of being executed in MATLAB programming environment.

26. A computer-implemented system for providing a programming environment, said system comprising:

means for providing at least one handle base class available for subclassing by users of the programming environment;

means for receiving a definition of at least one handle subclass created by subclassing the at least one handle base class;

means for providing a single syntax for defining all subclasses including handle subclasses and non-handle subclasses; and

means for storing in memory an object corresponding to an instance of the at least one handle subclass.