Review Textual Syntax for SyncCharts - II

• Please refer to the first part of this discussion to learn about the decisions, made so far.

Open Questions

• States
  According to our meta-model, our states have two boolean flags initial, final and a state type, which can be set to pseudo, textual or reference. We have not yet decided about
  • whether or not to make the keyword state obligatory
  • the order of the keywords (state before or between the modifiers?)
    
  So would a state declaration look like if we
  • make the keyword state obligatory and place it before the state modifier(s)

    state init final reference power_off "P_OFF"
    

  • make the keyword state obligatory and place it between the flags and the state kind

    init final state reference power_off "P_OFF"
    

  • make the keyword state optional

    init final reference power_off "P_OFF"
    

Question: If we would make the keyword state optional, then how would we be able to differentiate between the two possible semantics of the following statement (Is B is a reference to a state, declared elsewhere, or is it a new state declaration?) Do we have to differentiate between them anyway?

A --> B 

• ID scopes for states (global?)
  • path-notation with dot (macroStateName.myState)
  • unique names in parallel regions?

• Regions
  • Do regions have names???

Example

reincarnation{
	input c,d
        output v:=1:combine integer with *

	extern init innermacro[A/a, B/b]
	--> innermacro with c/v(7)
	--> with #d/v(11)
}

// ----------------------------------------------------------
innermacro{
        input a,b

	init  {
	      onentry v:=2
	}
	o-> with a/v(3)
	o-> nameMe with #b/v(5) 
}

• referencing and renaming

renamingstates{
        input d
        output w:=0 combine integer with +

	inner1 @ extern innermacro [A1/a,A2/b]
        o-> inner2 with #d/w(1)
||
        inner2 @ extern innermacro[A2/a,A2/b]
        o-> innermacro with #d/w(1)
|| 
        extern innermacro
}

// ----------------------------------------------------------
innermacro{
        input a,b
        output v:=1:combine integer with *

	init  {
	      onentry v:=2
	}
	o-> with a/v(3)
	o-> nameMe with #b/v(5) 
}

• suspension could look like this? how to differentiate the last two finals?

  interruption{
  	output susp
  	
  	extern init aTask
  	o- # susp
  ||
  	
  	init
  	o-> extern interruptHandler with #irq
  	>->  
  		
  }
  
  //---------------------------------
  
  aTask {
  	// has some complex task to do
  }
  
  //---------------------------------
  
  interruptHandler{
          output resume
  
  	init{
  	    onentry susp
  	}
  	o-> final with resume
  ||
  	init ISR
  	>-> final with resume
  }
  

• do we allow not unique state identifiers?