Hi Bill:

Thank you for filling me in.

>From bdelav@hotmail.com Tue Dec  1 17:42:38 1998
>From: "Bill de la Vega" <bdelav@hotmail.com>
>To: ichenp@ccs.neu.edu
>Cc: lieber@ccs.neu.edu
>Subject: Re: Help (AP Lib tg)!
>
>Sorry it took a while to reply. My ISP was out. 
>
>>        ....
>>    interface class graph icg
>>    application class graph ccg
>>    strategy sicg: strategy for icg
>>    refined strategy rsicg1: for mapping 1 of icg to ccg
>>    refined strategy rsicg2: for mapping 2 of icg to ccg
>>
>>    For example:
>>    sicg: from A to B // counts all Bs
>>    rsicg1: from A bypassing X to B // counts some Bs
>>    rsicg2: from A bypassing Y to B // counts some other Bs
>>
>>Q :
>>(1) In the cd of APPC spec, we can get icg, ccg (I suppose 
>>icg=ccg in our case) and sicg. But I don't know where to 
>>find rsicg1 and rsicg from the cd.
>
>The cd file I recieved from the professor doesn't describe a 
>language that specifies the CCG, the mapping, or refined 
>strategies (that accompany the mapping). That language still 
>needs to be created. 

Why not use theone from the midterm?

/proj/adaptive/www/course/exams/m-3360-f98/midterm
answers

>
>In the discussions I heard it wasn't clear but I believe there 
>will be 3 languages:
>1. APPC (very nearly described in the cd file from Prof.)
>2. CCG (essentially the same language as that used for cd files)
>3. Mapping (which will include associated refined strategies)
>
>
>>    > A strategy transducer is specified by a tuple (s1, s2),
>>    > where s1 and s2 are strategy graphs. It will be
>>    > instantiated by a class graph g. s1 is a strategy for
>>    > traversing g and s2 is a refinement of s1 also for
>>    > traversing g. The nodes of s1 and s2 are contained in the
>>    > nodes of g. The transducer takes as input a traversal
>>    > history Hist(o, s1, g), obtained by traversing object o
>>    > of g according to s1 and creating all node and edge
>>    > events including edge events for s1 (Bill: does your
>>    > traversal bean produce those?), and produces as output a
>>    > traversal history Hist(o,(s1,s2),g) that consists only of
>>    > node and edge events of the positive strategy graph of
>>    > s2. More precisely, an s2 edge event is produced each
>>    > time the target of the edge is reached on a path from the
>>    > source of the edge and satisfying the constraint map. 
>>
>>Q (2) So I'm working on this strategy transducer now (I think it was
>>called event translator before). I'm not sure where it fits in. Prof.
>>gave me a seperate cd,
>>
>>   EventTranslation = <commands> List(Condense).
>>   Condense = "condense" Strategy.
>>               .....
>>
>>So how can I coordinate this program with the rest (APPCs, 
>>traversal bean..)? 
>
>The traversal bean reverse engineering isn't done yet. But, a 
>test program would look something like this:
>
>StrategyTransducer st = new StrategyTransducer();
>Traversal t = new Traversal();
>t.addTraversalListener(st);
>t.traverse(...);
>
>Where you write StrategyTransducer.java & I write Traversal.java.
>Once you call addTraversalListener(), the object st is registered with 
>t. Then when traverse() is called t will call these methods in the 
>StrategyTransducer:
>
>void receiveTraversalEvent(EdgeEvent edgeEv);
>void receiveTraversalEvent(NodeEvent nodeEv);
>

Bill is right. But lets make it simpler for I-Chen:
Let's make it a self-contaioned problem where input is text
and output is text. The text describes the event objects.

I-Chen: Write a program that does the following translation:

Example:
Class graph:
A = B C.
B = D.
C = E F.
D = G.
G = Z.
E = Z.
F = Z.

Object traversed: A-object (there is only one)

Strategy:
S1: A -> *
S2: A -> D D -> Z
S1			S2
before A		before A
before ->A,B		before ->A,D
before B
before ->B,D	
before D    		before D
before ->D,G		before ->D,Z
before G
before ->G,Z	
before Z    		before Z
after Z    		after Z
after ->G,Z
after G
after ->D,G		after ->D,Z	
after D			after D
after B
before C
...			...	
after ->A,B		after ->A,D
after A			after A

The input and output language has a cd like:

Event = Kind NodeOrEdge.
Kind  : Before | After.
Before = "before".
After = "after".
NodeOrEdge : Node | Edge.
Edge = "->" <source> Node <target> Node.
Node = Ident.

You write a program:

Input: 	cd, s1 
	e1 = List(Event) 
Output: e2 = List(Event)
e2 contains only the events at the s1 level.

Notice the simplification: only one strategy!

Let me know when you are done with this
self-contained problem. Then we can bringin the
beans if there is time left.

Let me know if this problem formulation is not clear.

>
>>Q 
>>(3) The mapping process is still very confusing to me, when is it done?
>>I mean, like when the APPC beans are created or ...?
>
>During our discussion on Friday afternoon 11/20/98, I was told that the 
>traversal bean should traverse the objects of the CCG. So the events 
>that you recieve will be over the CCG. 
>

That is correct. 

>
>(Note: I had previously thought that the Traversal Bean would generate 
>events over the ICG, and the Adapter Bean would handle the actual CCG 
>objects.)

This would not work so well because the same traversal might drive
lots of APPCs each one listening to some other part of the traversal.

>
>This means the traversal bean must know about the icg, ccg & the 
>mapping. The strategy transducer needs to know about the ccg & the 
>refined strategy.
>
>>   I think we should just make the Summing example work as our goal.
>>so there will be two APPC beans, (Summing and Container?, not sure ),
>>one traversal bean, the strategy transducer and a Test program
>>(Main.java) which creates all the objects above. 

What are the remaining questions regarding the Summing example?
I was hoping it would be done by now. :-)

>
>I assume you mean reverse engineer those beans (not generate them from 
>the APPC language). It may be as far as we get. The Traversal Bean is 
>not finished yet. It is unfortunate, as I was looking forward to doing 
>something more with Demeter Java. 
>

yes, that was the idea. Mira and David have pitched in quite a 
bit of code to start so that you can do some of the translation
with Demeter/Java. 

Maybe the best thing now is that Bill does the summing example
(with more help from Mira and David, if needed)
and I-Chen the transducer described earlier.
>
>
>Professor Lieberherr, 
>I cced you so you could get a little update as well as respond if I'm 
>mistaken.
>
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-- Karl