CLF : The Coordination Language Facility

The CLF (Coordination Language Facility) is a distributed object-oriented application development tool. It relies on a rich object model, which views objects as resource managers and defines a set of 8 performatives to manipulate these resources. Coordination between objects of this type is expressed by rule-based scripts, which have a high-level declarative meaning in terms of overall cross-object resource manipulations, and a procedural meaning in terms of complex combinations of invocations of the CLF performatives on the different objects. The main features of the CLF are:

  • Dynamic extension of services: a CLF service invocation returns an asynchronous stream of offers, so the server may notify new offers at any time.
  • Multi-party negotiation: the execution of a CLF coordination script integrates at a deep level a negotiation phase and an enactment phase.
  • Reflexivity of the model: CLF coordination scripts are resources which can be manipulated by other scripts.

The CLF has been used in several prototype applications developed at the XRCE: Workflow , XFolders (see the XFolders  prototype) and and Electronic Commerce (see the Xpect  prototype).

Links to:

For further contact about the project please contact Jean-Marc Andreoli , or Fran├žois Pacull .