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Re: Illegal configuration with history in pseudocode

From: chris nuernberger <cnuernber@gmail.com>
Date: Fri, 8 Feb 2013 11:36:37 -0700
Message-ID: <CAG=GWve7N1tYTS-sjV226P-_4qSbgP0AbGLYvXYkc7SMwnM3dw@mail.gmail.com>
To: Stefan Radomski <radomski@tk.informatik.tu-darmstadt.de>
Cc: "www-voice@w3.org (www-voice@w3.org)" <www-voice@w3.org>
I had the *exact* same issue.  I *think* it is in the pseudo-code.

I believe the pseudo-code should be ammended to:

modified--
procedure addStatesToEnter(state,statesToEnter,statesForDefaultEntry):
    if isHistoryState(state):
        if historyValue[state.id]:
            for s in historyValue[state.id]:
                addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
                for anc in getProperAncestors(s,state):
                    statesToEnter.add(anc)
        else:
            for t in state.transition:
                for s in getTargetStates(t.target):
                    addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
--begin modifications--
for anc in getProperAncestors(s,state):
statesToEnter.add(anc)
--end modifications--
    else:
        statesToEnter.add(state)
        if isCompoundState(state):
            statesForDefaultEntry.add(state)
            for s in getTargetStates(state.initial):
                addStatesToEnter(s,statesToEnter,statesForDefaultEntry)
        elif isParallelState(state):
            for s in getChildStates(state):
                addStatesToEnter(s,statesToEnter,statesForDefaultEntry)


Chris


On Fri, Feb 8, 2013 at 11:28 AM, Stefan Radomski <
radomski@tk.informatik.tu-darmstadt.de> wrote:

> Hi there,
>
> I do have a problem with the following scxml document putting my
> interpreter in an illegal configuration:
>
> <scxml
>         xmlns="http://www.w3.org/2005/07/scxml"
>         version="1.0"
>         profile="ecmascript"
>         id="root"
>         initial="a">
>
>         <state id="a">
>                 <transition target="h" />
>         </state>
>
>         <state id="b" initial="b1">
>                 <history id="h">
>                         <transition target="b1.2"/>
>                 </history>
>
>                 <state id="b1" initial="b1.1">
>                         <state id="b1.1"/>
>                         <state id="b1.2">
>                                 <transition event="t2" target="b1.3"/>
>                         </state>
>                         <state id="b1.3">
>                                 <transition event="t3" target="a"/>
>                         </state>
>                 </state>
>         </state>
> </scxml>
>
> The problem is with entering state "h" from "a" for the first time. With
> regard to "procedure enterStates(enabledTransitions)", this means that
> tstates
> contains only "h" with "a" as the source state and "root" as their
> ancestor. The procedure
> "addStatesToEnter(s,statesToEnter,statesForDefaultEntry)" will recognize s
> as being a history state and call itself with "b1.2", adding "b1.2" into
> "statesToEnter".
>
> When returning into the enterStates procedure again, only tStates will be
> iterated to get the set of proper ancestors to enter as well, but tStates
> still only contains "h", not "b1.2", meaning "b" will be entered as a
> proper ancestor of "h" but "b1" will not as "b1.2" is only contained in
> statesToEnter, not in tStates and thus, its proper ancestors are never
> added into statesToEnter resulting in a configuration of {"b", "b1.2"}.
>
> What did I miss here? What part of the pseudo-code is supposed to add "b1"
> into statesToEnter with the document above? As having b1.2 and not b1 in
> the configuration is supposed to be illegal.
>
> Best regards
> Stefan
>



-- 
A foolish consistency is the hobgoblin of little minds - Emerson
Received on Friday, 8 February 2013 18:37:08 GMT

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