Hi I-Chen:

You are on the right track!

The translation is best done with Demeter/Java.

-- Karl

>From ichenp@ccs.neu.edu Thu Dec  3 02:17:55 1998
>Subject: Re: Help (AP Lib tg)!
>
>   Do I write this program in Demeter/Java or just Java? I am doing the 
>EventTranslation in Demeter/Java. I guess I'm on the wrong track.
>
> -IC 
>
>On Tue, 1 Dec 1998, Karl Lieberherr wrote:
>
>> 
>> 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.
>> >
>> >______________________________________________________
>> >Get Your Private, Free Email at http://www.hotmail.com
>> >
>> -- Karl
>> 
>
>