March 20 2008 - P1778 workgroup Meeting Minutes

• Workgroup: P1778 - Esterel v7 language standardization
• Location: Teleconference (see Next Meeting to connect)
• Date: 20 March 2008
• Chair: Gerard Berry
• Vice Chair: Stephen Edwards
• Secretary: Sylvan Dissoubray

Attendance

• See Attendance Record for meetings participation history

Agenda

Goal: this is mostly non-technical meeting, oriented towards process convergence. We have now discussed enough together to be able to put in place a more focused organization, and we need to establish a solid planning.

1. Current state
   • rewriting started with grammar etc, see Stephen's comments
   • need for a more organized planning

1. Planning
   • chapters list (see Excel proposal)
   • current chapter status
   • immediate planning
   • middle-term planning
   • expected draft delivery date

1. Workgroups
   • WG1, data: towards draft chapter
   • WG2, signals, interfaces, ports : towards draft chapter
   • WG3, units, inheritance, genericity : not yet constituted
   • WG4, tasking: progress report?
   • WG5, to be installed today : statements
   • other workgroups proposals?

1. Organization
   • Physical meeting organization for near future
   • miscellaneous

The agenda is approved by participants.

Process

• Start: Chair declares the meeting open at 4:05
• Agenda: The agenda is approved by participants
• Minutes: No objections about last meeting minutes -- they are approved
• Patents: No new item . The page IEEE Patent Policy holds the call for patent, and workgroup status.

Technical topics

Brief summary of discussion, pros and cons, and conclusions

• Lexical and types chapters have been updated and distrinuted in ieee pdf format. WG gives positive feedback about changes. SE and LZ have already sent some feedback. MP will integrate and distribute new releases in April. These chapters are close to final.

• A planning of chapters review was sent by email prior to the meeting and discussed. All agree to proceed this way to accelerate.

• WG5 Statements is constituted with Shyam, Ramesh, Claus. One objective is to remove unused or questionable statements, as possibly abort ... after, finalize, etc. A suggested way to describe reasonably fomally the semantics is to describe in english words what the SOS rules say. Static cycles and constructivity is a difficult subject that may be mentioned in an annex.

• Discussion about the C-like syntax concludes it should not be defined in the first version of the language. However, it is welcome if someone can start studying this as a student project.

• Name spaces and scopes are best described together with the concerned chapters, e.g. signals. For data objects, it is probably good to have this in a chapter together with units and other top-level objects.

• N.B. The workgroup will tell when the language is stable enough so that implementers may start organizing existing programs migration (signals mem, temp, etc).

• Multiclock syntactic aspects will be best treated in the top-level chapter describing units. Semantics will be adressed in a separate specific multiclock chapter.

• Genericity will be discussed together with units (which are compilation units as well.

• Issue with for dopar to decide whether iteration index is authorized in statically evaluable expressions or not. if it is authorised it may forces compile time expansion, which is usually prohibitely expensive. In esterel technologies compiler, it is currently not authorized. SE mentions that static recursion of run statements could be supported and mentions an article about static elaboration for recursion he wrote '''SE can you add reference here'''.

Adjournment and Next meeting date

Physical meeting dates and locations are discussed like DAC, CAV, Synchron. Not many people attending. Proposal of dates will be circulated.

Completion of votes for items to decide: Esterel v7 Tex LRM Data chapter#To_Decide and Esterel v7 Tex LRM Signals and Interfaces chapter#To_Decide will be organized by email.

Next meeting will be decided by email

Meeting is closed at 4.55 PM.