Re: Remark about SCXML "entry set" definition (section 3.11)

Ate,
   You are right.  In the current public draft there is a conflict 
between the text and the algorithm, and the algorithm is correct and the 
text is incorrect.  I propose expanding the definition of entry set as 
follows, so that it will match the algorithm:

"[Definition: The /entry set/ of a transition in configuration C is the 
set of states that are entered when the transition is taken. If a 
transition does not contain a 'target', its entry set is empty. 
Otherwise, it consists of all members of the transition's complete 
target set that that are not currently active or are in the exit set. 
(Thus the entry set consists of all members of the transition's complete 
target set that will not be active once the states in the exit set have 
been exited.) The entry set of a set of transitions is the union of the 
entry sets of the individual transitions.]"

(By the way, the correct section number is 3.13, not 3.11.)

Please let me know if you are satisfied with this response.  If we do 
not hear from you by March 24th, we will assume that you are.

Best,
Jim Barnett

On 3/7/2014 6:57 AM, Ate Douma wrote:
> (I send this same email on March 4th, but never seem to have gotten 
> through)
>
> Hi there,
>
> After reading the current SCXML spec, I find the definition of "entry 
> set" confusing, possible incorrect.
>
> In section 3.11, for [Definition: The entry set ...] the following is 
> stated:
>
>   [...] Otherwise, it consists of all members of the transition's 
> complete target set that are not currently active. [..]
>
> Maybe I'm missing something obvious here, but it seem to me this can't 
> be correct. Why are only 'not currently active' states considered?
> A currently active state can be both exited and (re)entered as result 
> of a single transition, so should (and IMO is to) be included in the 
> entry set as well.
>
> The "computeEntrySet" procedure in appendix A also doesn't reflect 
> this AFAICT, only determining the entry set based on the transition 
> targets only, not the (at that time already exited) current active states
>
> Thanks,
>
> Ate
>
> (working on Apache Commons SCXML 2.0 towards spec compliance)
>
>

-- 
Jim Barnett
Genesys