DATA DESCRIPTION LANGUAGE FOR RECORD BASED SYSTEMS

• US 20090182760A1
• Filed: 01/14/2008
• Published: 07/16/2009
• Est. Priority Date: 01/14/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Schlimmer, Jeffrey C., Relyea, Robert A., Box, Donald F., Hillberg, Michael J., West, Joel, Chapman, Brian F., Gudgin, Martin J., Jethanandani, Natasha H., Kizer, Geoffrey M., Jazdzewski, Charles P.
• Granted Patent: US 7,882,120 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/8373 Query execution

Abstract

Determining compatibility of data structures. A method may be practiced in a computing environment. The method includes accessing a first type defined in a mark-up object. The first type includes a first structure including a first plurality of fields. A second type defined in a mark-up object is accessed. The second type includes a second structure including a second plurality of fields. The first structure and the second structure are compared. Based on the comparison, a determination is made that the first type is compatible with the second type.

Claims

1. In a computing environment, a method of determining compatibility of data structures, the method comprising:

accessing a first type defined in a mark-up object, the first type comprising a first structure including a first plurality of fields;

accessing a second type defined in a mark-up object, the second type comprising a second structure including a second plurality of fields;

comparing the first structure of the first plurality of fields to the second structure of the second plurality of fields; and

determining based on the comparison that the first type is compatible with the second type.

2. The method of claim 1, wherein at least one of the first type or the second type is a description comprising an instantiation of a type.

3. The method of claim 1, wherein at least one of the first or second plurality of fields comprises at least one of an element or an attribute.

4. The method of claim 1, wherein at least one of the first or second plurality of fields comprises both an element and an attribute.

5. The method of claim 1, wherein at least one of the first or second plurality of fields comprises a property identifying the first or second type as a value type such that identity is not preserved for multi-referenced instances.

6. The method of claim 1, wherein at least one of the first or second plurality of fields comprises a property identifying the first or second type as a reference type such that identity is preserved for multi-referenced instances.

7. The method of claim 1, wherein at least one of the first or second plurality of fields comprises a property identifying the first or second type as nullable by specifying a value may be represented by a null construct.

8. The method of claim 1, wherein comparing the first structure of the first plurality of fields to the second structure of the second plurality of fields comprises comparing fields append to the first structure from a type external to first structure, to the second structure.

9. The method of claim 1, further comprising, nominally determining compatibility of the first and second types by comparing a first name of the first type to a second name of the second type.

10. The method of claim 1, wherein determining based on the comparison that the first type is compatible with the second type comprises determining that an in-memory structure conforms to a particular description.

11. The method of claim 1, wherein determining based on the comparison that the first type is compatible with the second type comprises determining that serialized form conforms to a particular description.

12. The method of claim 1, wherein comparing the first structure of the first plurality of fields to the second structure of the second plurality of fields comprises comparing members of the first and second types and determining that the first and second types comprise at least one member with the same name and a compatible type and that the first and second types have the same values defining their nullability, identity and referenceability.

13. The method of claim 1, wherein determining based on the comparison comprises determining that a value is structurally compatible with a type that specifies that a type is a closed type preventing additional fields from being added to the type when for each member declared by the type, the value has a member with a matching name and a compatible type and the value has no additional members beyond those defined by the type

14. The method of claim 1, wherein determining based on the comparison comprises determining that the first type and the second type, which differ only in that first type specifies a value of true for a nullability property while the second type specifies a value of false for a nullability property, are structurally compatible when the second type is nullable.

15. In a computing environment, a method of defining a type, the method comprising:

defining a name for a first type,

defining a first structure including a first plurality of fields in the first type; and

wherein defining a first structure comprises appending one or more fields from an external second type, to the first type as part of the structure of the first type.

16. The method of claim 15, wherein the first type is a closed type and wherein appending one or more fields from an external second type allows additional fields to be added to the first type.

17. The method of claim 15, further comprising comparing the first type to a third type by comparing a structure of the third type to the first structure including the one or more fields from an external second type and as a result of comparing the first type to the third type, determining that the first type is compatible with the third type.

18. The method of claim 17, wherein the third type does not include appended fields from an external type as part of the structure of the third type.

19. In a computing environment, a computer readable medium comprising computer executable instructions that when executed by a processor cause the following acts to be performed:

accessing a first type defined in a mark-up object, the first type comprising a first structure including a first plurality of fields;

accessing a second type defined in a mark-up object, the second type comprising a second structure including a second plurality of fields;

comparing the first structure of the first plurality of fields to the second structure of the second plurality of fields; and

determining based on the comparison that the first type is compatible with the second type.

20. The computer readable medium of claim 19, wherein the computer readable medium is a physical computer readable medium.