CorbaScript

CorbaScript is an object-oriented scripting language designed to support interaction with Common Object Request Broker Architecture (CORBA) objects. It was developed to provide a flexible scripting environment for both client- and server-side CORBA application development, leveraging dynamic invocation and interface reflection capabilities.

CorbaScript is a dynamic, interpreted language whose syntax resembles that of C++ and Java. However, it integrates several design elements from dynamic languages such as Python and Smalltalk. Like those languages, CorbaScript treats all values as objects and supports dynamic type checking at runtime. Source code is translated into pseudocode executed by a dedicated Virtual Object-Oriented Machine that includes a simple reference-counting garbage collector.^[1]

Features

Basic scripting

CorbaScript includes typical scripting features:

Interpreted execution, suitable for both interactive mode and batch modes.
Runtime type checking.
Basic types including long, double, boolean, char, string, array, and dictionary.
Control structures such as if-else, while, do-while, and for-in.
Exception handling using throw, try-catch-finally.
User-defined procedures and modules (reusable script files).
Object-oriented programming constructs, including classes, multiple inheritance, and polymorphism.

The runtime includes a simple garbage collector based on reference counting.

CORBA integration

CorbaScript is tightly integrated with CORBA middleware and provides full access to both the Dynamic Invocation Interface (DII) and Dynamic Skeleton Interface (DSI):

Invocation of any CORBA object via DII, enabling scripting of CORBA clients.
Implementation of CORBA objects via DSI, allowing servers to be written in CorbaScript.
Full support for OMG Interface Definition Language (IDL)-defined data types, including complex types such as struct, union, sequence and array.
Access to in, out, and inout parameters using the CORBA DynAny API.
Type checking supported via the Interface Repository, with optional caching to improve performance.
Scripting access to the structure of IDL interfaces for dynamic discovery and reflection.

Advanced integration

CorbaScript also includes additional capabilities beyond basic scripting:

Dynamic loading of C libraries for native code integration.
Experimental support for interaction with a Java Virtual Machine.
Extensible runtime that allows embedding new functionality in C++.

Modules

CorbaScript allows any script to function as an importable module. Some standard modules include:

LIBC: dynamic access to standard C library functions.
IO: support for reading/writing binary and text files.
math: standard math operations.
POSIX: POSIX system calls like system() and fork().
socket: TCP/IP networking support.
IOR: simplified storage/retrieval of CORBA object references (IORs).
NSTools and CosNamingImpl: tools and implementation for managing the CORBA Naming service.
shell: base class for creating shell programs.
SMTP: a basic SMTP implementation.
time: date and time utilities.

Demonstrations

A number of example applications and tools are included in the CorbaScript distribution:

hello: a basic CORBA client/server "Hello World" application.
calc: a simple calculator service.
chat: a chat system implementing factory and observer design patterns.
component: client callback components using implicit connections.
computer: a distributed prime number service.
event: event channel implementation using the OMG Event Service.
grid: factory pattern for grid objects.
ir: navigation through the CORBA Interface Repository.
linked: demonstration of recursive object invocation.
naming: integration with the CORBA Naming Service.
test: argument type and passing mode demonstrations.
worker: client-server example using deferred (asynchronous) invocations.
remote_cssh: scripting engine interface using OMG IDL and shell-based remote invocation.
process: CORBA object access and factory pattern using URLs.

Examples

Hello Example

The following illustrates how CorbaScript can be used to interact with a CORBA object defined by the following OMG IDL interface:

interfaceHello{voidhello();voiddisplay(instringmessage);};

Using CorbaScript, you can invoke operations on a CORBA object implementing this interface:

>>> # the `hello` variable refers to a CORBA `Hello` object.>>> hello=Hello("IOR:....")>>> # invoking the 'hello' operation>>> hello.hello()>>> # invoking the 'display' operation>>> hello.display("Hello World!")>>> # obtain the CORBA Naming Service>>> NS=CORBA.ORB.resolve_initial_references("NameService")>>> # resolve a name in the CORBA Naming Service>>> object=NS.resolve(CosNaming.Name(CosNaming.NameComponent("anHelloObject","")))>>> # easier syntax with automatic sequence conversion>>> object=NS.resolve([["anHelloObject",""]])>>> #解決されたオブジェクトに対して操作を実行する>>> object.display ( " Hello World!" )

CorbaScriptを使用すると、CORBAオブジェクトを簡単かつ直感的に呼び出すことができます。

CorbaScriptでCORBAオブジェクトを実装する

以下の例は、CorbaScriptで`Hello`インターフェースを実装する方法を示しています。

# Helloインターフェースを実装するスクリプトクラスを定義しますclass HelloImpl { # コンストラクタproc __HelloImpl__ ( self ) {}# `hello`操作の実装proc hello ( self ) { println ( "OMG IDLの`hello`操作が呼び出されました。" ) }# `display`操作の実装proc display ( self , message ) { println ( message ) } }

>>> # インスタンスを作成>>> hello = HelloImpl ()>>> # ローカル呼び出し>>> hello . hello () OMG IDL の `hello` 操作が呼び出されます。>>> hello.display ( " Hello World!" ) Hello World!>>> # CORBAに接続し、実装インターフェースを指定します>>> CORBA.ORB.connect ( hello , Hello )>>> # CORBAネーミングサービスにオブジェクトを登録>>> NS = CORBA.ORB.resolve_initial_references ( " NameService" ) >>> NS.bind ( [[ " anHelloObject " , "" ] ] , hello._this )

この例は、CorbaScript が CORBA オブジェクトの呼び出しと実装の両方をいかに簡素化するかを示しています。CORBA ネーミングサービスシェルや CORBA CosNaming の実装など、その他の例も CorbaScript の配布パッケージに含まれています。

可用性

CorbaScriptインタープリタはC++で実装されており、 Windowsだけでなく、ほとんどの主要なUnix系システムで利用可能です。

参考文献

↑ CorbaScriptの機能、corbaweb.lifl.fr（2005年4月22日アーカイブ）

外部リンク

CorbaScript言語（アーカイブ）
CORBAスクリプティング共同改訂版提出
正規表現：スクリプトでCORBAを管理する– ITworld
Christophe GransartによるIDLScript/CorbaScriptチュートリアル

[1] CorbaScriptの機能、corbaweb.lifl.fr（2005年4月22日アーカイブ）

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