Class-based object-oriented features in class-less script language

• US 7,992,130 B2
• Filed: 05/07/2007
• Issued: 08/02/2011
• Est. Priority Date: 05/07/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Van Gogh, Jeffrey, Beck, Steven Thomas, Meijer, Henricus Johannes Maria, Zhu, Wei, Bozza, Bruno S.
• Primary Examiner(s): Khatri; Anil
• Application Number:
  US11/745,125
• Publication Number:
  US 20080282260A1
• Time in Patent Office: 1,548 Days
• Field of Search: 717105-110, 717114-117, 717120-121, 709203-204
• US Class Current: 717/116
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution

Abstract

Dynamic dispatch for classes and interfaces is encapsulated in a class-less scripting language. A plurality of mechanisms is employed to facilitate dynamic polymorphism. One or more target-language constructs, such as dictionary objects, prototype objects and/or derived types, are utilized to capture class and interface-method implementations. These constructs are subsequently referenced at runtime to invoke appropriate code.

Claims

1. A program transformation system, comprising:

a processor coupled to a memory, the processor configured to execute the following computer-executable components stored in the memory;

a code generation component that generates semantically equivalent code in a class-less scripting language from an object-oriented programming language representation of a hierarchy of one or more classes or interfaces and

a virtual constructor component that produces a dispatch construct that captures class and/or interface method implementation to facilitate dynamic dispatch.

2. The system of claim 1, the dispatch construct is a dictionary object.

3. The system of claim 1, a dictionary object maps method names to one or more method implementations.

4. The system of claim 1, the dispatch construct is a linked list.

5. The system of claim 1, the dispatch construct is a prototype object.

6. The system of claim 1, comprising an object creation component that generates a new object with a reference to an associated dispatch construct.

7. The system of claim 1, comprising a call component that translates a virtual method call to a call to a function that identifies a method invocation from the dispatch construct for an object and returns results of execution thereof.

8. The system of claim 1, comprising an optimization component that eliminates dynamic dispatch when a static type is equivalent to a dynamic type of an object and/or lookup can be performed statically.

9. The system of claim 1, the representation is intermediate language code.

10. A method of dynamic dispatch, comprising:

employing at least one processor configured to execute computer-executable instructions stored in memory to perform the following acts;

identifying a representation of a virtual method call in a class-less scripting language; and

locating an implementation for the virtual method call at runtime in a dispatch construct that maps method names to method implementations for objects utilizing code that captures class and/or interface inheritances relationships in the language.

11. The method of claim 10, locating the implementation in a dictionary object.

12. The method of claim 10, locating the implementation in a linked list.

13. A program compilation system, comprising:

computer-implemented means for acquiring an inheritance hierarchy of classes represented in intermediate language code; and

computer-implemented means for implementing code semantics in a class-less scripting programming language; and

computer-implemented means for generating a dispatch construct in the class-less scripting programming language that identifies method names and related method implementations.

14. The system of claim 13, the computer-implemented means for generating the dispatch construct generates a dictionary object.