Survey of existing languages and selection of an appropriate language

Task: B.1
Task Leader: INRIA
Participants: INRIA 2 mm
From: T0 To: T0+6
Input from:
Output to: A.1, B.2
Deliverable: INRIA-1 (Report): Survey of languages and description of the selected language
Due at: T0+12
Milestones: Report on survey of languages at T0+4. Draft version of the final report at T0+6
Description:
In order to avoid defining yet another language and to reuse as much as possible results of other projects, this task aims at performing a careful survey of the existing languages which may be good candidates for expressing application high level requirements with respect to the Application Level Framing and Integrated Layer Processing Concepts.

Several languages and formal description techniques (for instance: Esterel, LOTOS and extensions, Estelle and extensions, ASN.1 and extensions, ADA and extensions, etc.) will be assessed with respect to a set of criteria, to be defined by the task. These criteria will be classified into three main categories:

1. criteria assessing the language expressing power: presence of high level mechanisms for expressing concurrency, synchronization, non determinism, action refinement, ...
2. criteria assessing the adequacy of the language with respect to the ALF and ILP concepts,
3. criteria assessing the data typing mechanisms and, in particular, their suitability for taking into account the specification and handling of data in a heterogeneous distributed system.

Following the survey, we will define the formal language used in the project for specifying application profiles. Taking into account earlier experience in the field, it is expected that the selected language presents the following features:

1. it is a formal language, with a formal syntax and semantics,
2. the language is made up of a behavior part and a data part which are to be as independent as possible
3. the data part (for instance ASN.1 typing mechanisms) should be consistent with the behavior part, in order to be able to validate a whole specification, and not only the subset corresponding to the behavior part of the specification
4. the language should include features making it possible to perform stepwise refinement of the application profiles specification [32].