Instance interfaces and mix-ins for dynamic languages

Patent metadata

Field	Value
Publication number	US-9910681-B2
Application number	US-201615145064-A
Country	US
Kind code	B2
Filing date	May 3, 2016
Priority date	Aug 1, 2007
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

Various technologies and techniques are disclosed for using contracts in dynamic languages. For example, a contract can be directly associated with an object. The contract can then be used to provide type safety for the object. As another example, contracts can be used with mix-ins. A declaration for a contract is provided with a mix-in. The contract is associated with a target object at runtime when applying the mix-in. Conditions can be assigned to mix-ins that must be met before the mix-in can be applied to the target object. At runtime, if the target object meets the one or more conditions, then the mix-in can be applied to the target object.

First claim

What is claimed is:

1. A method, comprising:
receiving a method call to register a mix-in, the method call including as a parameter a set of base mix-ins from which the mix-in inherits;
at runtime of a target object, before applying the mix-in to the target object, determining whether the target object meets at least one constraint contract that constrains objects to which the mix-in can be applied;
if the target object meets the at least one constraint contract, at runtime, applying the mix-in to the target object; and
if the target object does not meet the at least one constraint contract, at runtime, throwing an exception.

2. The method of claim 1 , wherein the method call further includes as a parameter at least one of an interface implementation provided by the mix-in or a set of types the mix-in is able to extend.

3. The method of claim 1 , further comprising:
associating with the mix-in the at least one constraint contract that constrains objects to which the mix-in can be applied and that must be met by the target object before the mix-in can applied to the target object.

4. The method of claim 1 , wherein the target object is an instance of a class.

5. The method of claim 1 , wherein determining whether the target object meets the at least one constraint contract is performed using reflection.

6. The method of claim 1 , wherein the at least one constraint contract defines a condition.

7. A memory having computer-executable instructions for causing a computer to perform steps comprising:
receiving a method call to register a mix-in, the method call including as a parameter a set of base mix-ins from which the mix-in inherits;
at runtime of a target object, before applying the mix-in to the target object, determining whether the target object meets at least one constraint contract that constrains objects to which the mix-in can be applied;
if the target object meets the at least one constraint contract, at runtime, applying the mix-in to the target object; and
if the target object does not meet the at least one constraint contract, at runtime, throwing an exception.

8. The memory of claim 7 having further computer-executable instructions for causing the computer to perform steps comprising:
associating with the mix-in the at least one constraint contract that constrains objects to which the mix-in can be applied and that must be met by the target object before the mix-in can be applied to the target object.

9. The computer storage memory of claim 7 , wherein the target object is an instance of a class.

10. The memory of claim 7 , wherein determining whether target object meets the at least one constraint contract is performed using reflection.

11. The memory of claim 7 , wherein the at least one constraint contract defines a condition.

12. A system for restricting the use of mix-ins based on meeting of conditions comprising:
a computer comprising a processing unit coupled to a memory, the memory storing computer-executable instructions which, when executed, cause the processing unit to perform the steps of:
receiving a method call to register a mix-in, the method call including as a parameter a set of base mix-ins from which the mix-in inherits;
at runtime of a target object, before applying the mix-in to the target object, determining whether the target object meets at least one constraint contract that constrains objects to which the mix-in can be applied;
if the target object meets the at least one constraint contract, at runtime, applying the mix-in to the target object; and
if the target object does not meet the at least one constraint contract, at runtime, throwing an exception.

13. The system of claim 12 , wherein the method call further includes as a parameter at least one of an interface implementation provided by the mix-in or a set of types the mix-in is able to extend.

14. The system of claim 12 , the memory storing further computer-executable instructions, which, when executed, cause the processing unit to perform the step of:
associating with the mix-in the at least one constraint contract that constrains objects to which the mix-in can be applied and that must be met by the target object before the mix-in can be applied to the target object.

15. The system of claim 12 , wherein determining whether the target object meets the at least one constraint contract is performed using reflection.

16. The system of claim 12 , wherein the at least one constraint contract defines a condition.

17. The system of claim 12 , wherein the target object is an instance of a class.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Le Roy Bertrand

Classifications

• G06F11/0718

  in an object-oriented system · CPC title

• G06F8/24

  Object-oriented · CPC title

• G06F9/4433 Primary

  Physics · mapped topic

• G06F8/315

  Object-oriented languages · CPC title

• G06F9/4492 Primary

  Inheritance · CPC title