TheArchitect.co.uk - Jorgen Thelin's weblog

Jeff Schneider posts some interesting ideas on his desirable features in a Service Oriented programming language:

Service Oriented, Protocol Connected, Message Based

Here are some casual thoughts on what I would like to see in a service oriented language. This is my first attempt at this... I'm sure I'll get some feedback ;-) and will update it.

Services

• The service is a first order concept, both sending and receiving
• Support for the strong interface (think WSDL)
• Mandatory support for Long Running Transactions
• Faults and Compensation are first order
• Protocols for transport and fulfillment of NFR are intentionally left out of scope

Messages

• Message is a first order concept
• Message is defined using a platform independent markup
• Support for message correlation properties; helpers for distributed state mgmt
• Universal addressing scheme (assumes router)

Types / Vars

• Typing & vars are consistent with message system
• Remote variables (think REST)

Functional Containment

• The 'service' is a container (and managed)
• The 'object' continues to live. Objects are contained in services.

Invocation and Service Hosting

• WSDL's can be imported directly into the runtime. Operations and messages become first order citizens.
• Access & manipulation of binding / listener is first class.
• Language assumes that all systems are peer (both client and server)

Schema Manipulation

• DDL: Import / export / create / modify (consistent with type system)

Data Manipulation

• DML: transform (consistent with type system)

Flow Control

• Usual branching & looping
• Parallel execution; parallel joins (first order)
• Forced sequential processing

Event Based

• Events are a first order concept
• Time & activity based events

Metadata Ready

• Declarative metadata becomes a first order item (see jdk1.5)
• Service oriented loading / unloading of metadata / models / gen'd code at runtime
• Reflective knowledge of declarative non-functional polices (think ws-policy access)

Base Service & Extensions

• Concept of an extendable base service
• Service may have multiple interfaces
• Aspects may easily be applied to service
• Language is extended via "more services" not "more syntax"

Service Network Awareness

• Service is aware of the network that it lives in (topology, routers, etc.)
• Service is aware of service-enabled remedies to non functional requirements (Virtualization, etc.)
• Service has the ability to modify the service network at runtime

OK. So a good question is, "which of these are part of the 'language', which are 'service libraries' or other?" I'm in favor of the *least* amount of required syntax possible. But, I like the idea of having *mandatory* service library extensions.

[ Service Oriented Enterprise - Features of a Service Oriented Language ]

There's definitely some food for thought for language / programming tool designers in that list!