Partial specialization of generic classes

• US 9,524,152 B2
• Filed: 04/21/2015
• Issued: 12/20/2016
• Est. Priority Date: 04/22/2014
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Goetz, Brian, Rose, John R., Buckley, Alexander R.
• Primary Examiner(s): Chen, Qing
• Assistant Examiner(s): THATCHER, CLINT A
• Application Number:
  US14/692,592
• Publication Number:
  US 20150301807A1
• Time in Patent Office: 609 Days
• Field of Search: 717/140
• US Class Current: 1/1
• CPC Class Codes: G06F 8/24 Object-oriented
• CPC Class Codes: G06F 8/315 Object-oriented languages
• CPC Class Codes: G06F 8/41 Compilation
• CPC Class Codes: G06F 8/437 Type checking
• CPC Class Codes: G06F 8/443 Optimisation
• CPC Class Codes: G06F 8/447 Target code generation
• CPC Class Codes: G06F 8/70 Software maintenance or management
• CPC Class Codes: G06F 8/71 Version control security arrangements therefor G06F21/57; Configuration management
• CPC Class Codes: G06F 8/76 Adapting program code to run in a different environment; Porting
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: G06F 9/4488 Object-oriented
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution
• CPC Class Codes: G06F 9/4492 Inheritance
• CPC Class Codes: G06F 9/4498 Finite state machines
• CPC Class Codes: G06F 9/45516 Runtime code conversion or optimisation

Abstract

Generic classes may have more than one specializable type parameter and it may be desirable to specialize one or more of the type variables while not specializing others. The result of partial specialization may be one or more additional generic classes that are further specializable on the remaining type parameters. A runtime specializer may partially specialize a generic class to produce a partially specialized class and may subsequently further specialize the partially specialized class to generate a fully specialized class. Thus, rather than performing the specialization of a generic class all at once, such as by specializing Map<K, V> into Map<int, int> or Map<long, int>, one type parameter may be partially specialized, such as resulting in Map<K, int>, and then at some later time the remaining type parameter(s) may be specialized, such as to generate Map<int, int> or Map<long, int>.

Claims

1. A non-transitory, computer-readable storage medium storing program instructions that when executed on a computing device cause the computing device to perform:

partially specializing a generic class within a platform independent, object oriented runtime environment, wherein the generic class comprises a plurality of specializable type variables, wherein each of the plurality of specializable type variables are specializable over a plurality of type parameterizations; and

wherein to partially specialize the generic class, the program instructions further cause the computing device to perform;

specializing the generic class for a particular type variable of the plurality of specializable type variables over a particular type parameterization of the plurality of type parameterizations, without specializing the generic class for at least one other of the plurality of specializable type variables, such that the partially specialized generic class is further specializable for the at least one other specializable type variable over each of the plurality of type parameterizations.

2. The non-transitory, computer-readable storage medium of claim 1, wherein the program instructions further cause the computing device to perform:

further specializing, subsequent to said partially specializing, the partially specialized generic class for the at least one other of the plurality of specializable type variables over another of the plurality of type parameterizations such that the partially specialized generic class becomes fully specialized as a result of said further specializing.

3. The non-transitory, computer-readable storage medium of claim 1, wherein to partially specialize the generic class, the program instructions further cause the computing device to perform:

specializing the generic class for a particular type variable of the plurality of specializable type variables over multiple ones of the plurality of type parameterizations, without specializing the generic class for at least one other of the plurality of specializable type variables over any of the plurality of type parameterizations.

4. The non-transitory, computer-readable storage medium of claim 1, wherein the program instructions further cause the computing device to perform:

loading a class file comprising specialization metadata describing the plurality of specializable type variables;

partially specializing the metadata such that the partially specialized metadata includes information describing that the partially specialized generic class was specialized for the particular type variable over the particular type parameterization; and

storing the partially specialized metadata in a classfile corresponding to the partially specialized generic class.

5. The non-transitory, computer-readable storage medium of claim 1, wherein the program instructions further cause the computing device to perform:

determining a dependency relationship between the generic class and another generic class; and

specializing, in response to partially specializing the generic class, the other generic class.

6. The non-transitory, computer-readable storage medium of claim 1, wherein the program instructions further cause the computing device to perform:

determining a refinement method of the generic class that overrides another method of the generic class, wherein the refinement method corresponds to the particular type parameterization;

including the refinement method in the partially specialized generic class; and

not including the other method of the generic class in the partially specialized generic class.

7. The non-transitory, computer-readable storage medium of claim 1, wherein the program instructions further cause the computing device to perform:

determining an additional method of the generic class that corresponds to the particular type parameterization; and

including the additional method in the partially specialized generic class.

8. A method, comprising:

partially specializing, by a platform-independent, object-oriented, runtime environment implemented on one or more computing devices, a generic class within a platform independent, object oriented runtime environment, wherein the generic class comprises a plurality of specializable type variables, wherein each of the plurality of specializable type variables are specializable over a plurality of type parameterizations; and

wherein said partially specializing comprises;

specializing, by the platform-independent, object-oriented, runtime environment, the generic class for a particular type variable of the plurality of specializable type variables over a particular type parameterization of the plurality of type parameterizations, without specializing the generic class for at least one other of the plurality of specializable type variables, such that the partially specialized generic class is further specializable for the at least one other specializable type variable over each of the plurality of type parameterizations.

9. The method of claim 8, further comprising:

further specializing, subsequent to said partially specializing, the partially specialized generic class for the at least one other of the plurality of specializable type variables over another of the plurality of type parameterizations such that the partially specialized generic class becomes fully specialized as a result of said further specializing.

10. The method of claim 8, wherein said partially specializing the generic class comprises:

specializing the generic class for a particular type variable of the plurality of specializable type variables over multiple ones of the plurality of type parameterizations, without specializing the generic class for at least one other of the plurality of specializable type variables over any of the plurality of type parameterizations.

11. The method of claim 8, further comprising:

loading a class file comprising specialization metadata describing the plurality of specializable type variables;

partially specializing the metadata such that the partially specialized metadata includes information describing that the partially specialized generic class was specialized for the particular type variable over the particular type parameterization; and

storing the partially specialized metadata in a classfile corresponding to the partially specialized generic class.

12. The method claim 8, further comprising:

determining a dependency relationship between the generic class and another generic class; and

specializing, in response to partially specializing the generic class, the other generic class.

13. The method claim 8, further comprising:

determining a refinement method of the generic class that overrides another method of the generic class, wherein the refinement method corresponds to the particular type parameterization; and

including the refinement method in the partially specialized generic class; and

not including the other method of the generic class in the partially specialized generic class.

14. The method claim 8, further comprising:

determining an additional method of the generic class that corresponds to the particular type parameterization; and

including the additional method in the partially specialized generic class.

15. A computing device, comprising:

a processor; and

a memory comprising program instructions, that when executed on the processor cause the processor to;

partially specialize a generic class within a platform independent, object oriented runtime environment, wherein the generic class comprises a plurality of specializable type variables, wherein each of the plurality of specializable type variables are specializable over a plurality of type parameterizations; and

wherein to partially specialize the generic class, the program instructions further cause the processor to;

specialize the generic class for a particular type variable of the plurality of specializable type variables over a particular type parameterization of the plurality of type parameterizations, without specializing the generic class for at least one other of the plurality of specializable type variables, such that the partially specialized generic class is further specializable for the at least one other specializable type variable over each of the plurality of type parameterizations.

16. The computing device of claim 15, wherein the program instructions further cause the processor to:

further specialize, subsequent to said partially specializing, the partially specialized generic class for the at least one other of the plurality of specializable type variables over another of the plurality of type parameterizations such that the partially specialized generic class becomes fully specialized as a result of said further specializing.

17. The computing device of claim 15, wherein to partially specialize the generic class, the program instructions further cause the processor to:

specialize the generic class for a particular type variable of the plurality of specializable type variables over multiple ones of the plurality of type parameterizations, without specializing the generic class for at least one other of the plurality of specializable type variables over any of the plurality of type parameterizations.

18. The computing device of claim 15, wherein the program instructions further cause the processor to:

load a class file comprising specialization metadata describing the plurality of specializable type variables;

partially specialize the metadata such that the partially specialized metadata includes information describing that the partially specialized generic class was specialized for the particular type variable over the particular type parameterization; and

store the partially specialized metadata in a classfile corresponding to the partially specialized generic class.

19. The computing device of claim 15, wherein the program instructions further cause the processor to:

determine a dependency relationship between the generic class and another generic class; and

specialize, in response to partially specializing the generic class, the other generic class.

20. The computing device of claim 15, wherein the program instructions further cause the processor to:

determine a refinement method of the generic class that overrides another method of the generic class, wherein the refinement method corresponds to the particular type parameterization;

include the refinement method in the partially specialized generic class; and

not include the other method of the generic class in the partially specialized generic class.