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Object-oriented Systems                         Fall 1995
COM 3360/NTU SE737
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Oct. 30, 1995

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Midterm					YOUR NAME:
					YOUR NAME:
					YOUR NAME:
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Open book and open notes. 

PLEASE GIVE YOUR ANSWERS ON THIS FORM

Question 1: 
==================================================

UNKNOWN1 = StandardDirective | ExtendedDirective .


UNKNOWN2 =
< directive > Directive
[ < implicitVertices > Directive ]
[ < implicitEdges > Directive ] .


UNKNOWN3 = Compound .


UNKNOWN4 = Join | Merge | Intersection | Complement | ToStop .


UNKNOWN5 = Intersection


UNKNOWN6 = DirectiveName


UNKNOWN7 = Simple | Compound .



UNKNOWN8 = NOTHING


UNKNOWN9 = NOTHING


UNKNOWN10 = NOTHING


UNKNOWN11 = NOTHING


UNKNOWN12 = < arg > Directive .



Question 2: 
==================================================



UNKNOWN1 = (. [A,B], [X,Y])

UNKNOWN2 = |

UNKNOWN3 = [A, vertices A,B through, edges -> A,b,B bypassing Z]

UNKNOWN4 = A

UNKNOWN5 = A

UNKNOWN6 = X

UNKNOWN7 = A

UNKNOWN8 = A

UNKNOWN9 = [ A , vertices A , B bypassing , edges -> A , b , B through Z ]

UNKNOWN10 = A

UNKNOWN11 = A

UNKNOWN12 = Y

UNKNOWN13 = B

UNKNOWN14 = Y

UNKNOWN15 = B

UNKNOWN16 = B

UNKNOWN17 = Z

UNKNOWN18 = Z

UNKNOWN19 = 0

UNKNOWN20 = 1

UNKNOWN21 = 1

UNKNOWN22 = 1

UNKNOWN23 = 1

UNKNOWN24 = 1

UNKNOWN25 = 1

UNKNOWN26 = 

*operation* int check()
  *init* (@ 0 @)
  *wrapper* Merge (@ @)
  *wrapper* Intersection (@ @)
  *wrapper* Join (@ return_val = this -> check_join(); @)

*operation* int check_join()
  // check whether target of ith directive
  // matches source of i+1 directive.
  *traverse*
    *from* Join
      // want top-level directives
    *to-stop* Directive_CommaList
*wrapper* Directive_CommaList  
(@ Directive_list_iterator	next_Directive(*this);
  Directive*		each_Directive = next_Directive();
  Vertex* target_previous = each_Directive -> target();
  return_val = each_Directive -> well_formed(); 
  while ( (each_Directive = next_Directive()) && return_val )
  { if (((each_Directive->source()) ->g_equal(target_previous)) &&
	each_Directive -> well_formed())
	   {target_previous = each_Directive -> target();}
         else
	   {return_val = 0;} }
@)

Question 3: 
==================================================

UNKNOWN1 = 

Initialize vdefault differently
============================================================
< (@ static Vertex* vdefault =
<      new Vertex(new DemIdent("default"));
---
> (@ static Vertex_List* vdefault =
>      new Vertex_List(new Vertex(new DemIdent("default")));

UNKNOWN2 =

Change return type of source
============================================================
< *operation* Vertex* source()
---
> *operation* Vertex_List* source()


UNKNOWN3 =

Change return type of target
============================================================
< *operation* Vertex* target()
---
> *operation* Vertex_List* target()





Question 4: 
==================================================

UNKNOWN1 = 
Through | Bypassing *common* GraphElements.
GraphElements : Vertices | Edges.




UNKNOWN2 =
"(" <vertices> CommaList(Vertex) ")" .





UNKNOWN3 =
"(" <vertices> CommaList(Edge) ")".



UNKNOWN4 =
There is no change needed since the changes to
the class dictionary  do not influence the propagation graph
in this case.