Extending the functionality of a host programming language

• US 20090241090A1
• Filed: 03/20/2008
• Published: 09/24/2009
• Est. Priority Date: 03/20/2008
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Sikka, Vishal, Anlauff, Matthias Gerhard
• Granted Patent: US 8,533,672 B2
• Time in Patent Office: Days
• US Class Current: 717/114
• CPC Class Codes: G06F 8/42 Syntactic analysis

Abstract

To enable language-level integration of multiple programming languages into a single programming framework, one or more domain specific languages (DSLs) are specified as incremental extensions to a host programming language. An application created in this framework may include program code written in the host language as well as DSL inset code that is written in any of the DSLs. The extensions to the host language are described in DSL specifications, which define how the DSL inset code is processed. At runtime, DSL inset code in the source code is detected and passed to a DSL inset processor for execution according to an appropriate DSL specification, whereas source code in the host language is executed by a host language processor.

Claims

1. A computer-implemented method for extending the functionality of a host language, the method comprising:

providing a language extension file that defines at least a portion of a domain specific language;

applying a lexer to the language extension file to generate a first portion of a domain specific language specification;

applying a parser to the language extension file to generate a second portion of a domain specific language specification, wherein the domain specific language specification describes a procedure in the host language for executing a set of functions from the domain specific language; and

incorporating the domain specific language specification into a system for executing program code in the host language.

2. The method of claim 1, wherein the language extension file defines a syntax, a set of semantic conditions, and a set of dynamic execution rules for the programming language.

3. The method of claim 1, wherein the domain specific language specification defines a parse method, the parse method operating on a text string that represents program code in the domain specific language and returning a result corresponding to an execution of the text string in the domain specific language.

4. The method of claim 3, wherein the parse method is further configured to receive a binding context that describes a memory state of a computing system, wherein the result returned by the parse method corresponds to an execution of the text string in the domain specific language in the presence of the binding context.

5. The method of claim 1, wherein the host language is Ruby.

6. The method of claim 5, wherein the lexer is Rex and the parser is Racc.

7. The method of claim 1, further comprising:

providing a second language extension file that defines at least a portion of a second domain specific language;

applying a lexer to the second language extension file to generate a first portion of a second domain specific language specification;

applying a parser to the second language extension file to generate a second portion of a second domain specific language specification, wherein the second domain specific language specification describes a procedure for executing a set of functions from the second domain specific language; and

incorporating the second domain specific language specification into a system for executing program code in the host language.

8. A computer program product for extending the functionality of a host language, the computer program product comprising a computer-readable storage medium containing computer program code for:

providing a language extension file that defines at least a portion of a domain specific language;

applying a lexer to the language extension file to generate a first portion of a domain specific language specification;

applying a parser to the language extension file to generate a second portion of a domain specific language specification, wherein the domain specific language specification describes a procedure in the host language for executing a set of functions from the domain specific language; and

incorporating the domain specific language specification into a system for executing program code in the host language.

9. The computer program product of claim 8, wherein the language extension file defines a syntax, a set of semantic conditions, and a set of dynamic execution rules for the programming language.

10. The computer program product of claim 8, wherein the domain specific language specification defines a parse method, the parse method operating on a text string that represents program code in the domain specific language and returning a result corresponding to an execution of the text string in the domain specific language.

11. The computer program product of claim 10, wherein the parse method is further configured to receive a binding context that describes a memory state of a computing system, wherein the result returned by the parse method corresponds to an execution of the text string in the domain specific language in the presence of the binding context.

12. The computer program product of claim 8, wherein the host language is Ruby.

13. The computer program product of claim 12, wherein the lexer is Rex and the parser is Racc.

14. The computer program product of claim 8, further containing computer program code for:

providing a second language extension file that defines at least a portion of a second domain specific language;

applying a lexer to the second language extension file to generate a first portion of a second domain specific language specification;

applying a parser to the second language extension file to generate a second portion of a second domain specific language specification, wherein the second domain specific language specification describes a procedure for executing a set of functions from the second domain specific language; and

incorporating the second domain specific language specification into a system for executing program code in the host language.

15. A computer-implemented method for extending the functionality of a host language, the method comprising:

providing a first language extension file that defines at least a portion of a first domain specific language;

generating a first domain specific language specification based on the first language extension file applying a lexer and parser thereto, wherein the first domain specific language specification describes a procedure in the host language for executing a set of functions from the first domain specific language;

providing a second language extension file that defines at least a portion of a second domain specific language;

generating a second domain specific language specification based on the second language extension file applying a lexer and parser thereto, wherein the second domain specific language specification describes a procedure for executing a set of functions from the first domain specific language, and wherein the second domain specific language specification uses one or more functions defined in the first domain specific language specification;

incorporating the first and second domain specific language specifications into a system for executing program code in the host language.