(@
  import java.util.*;
  import java.io.*;
@)

// This class dictionary is a subset of evolve.cd that works with 
//  construction, alternation, and terminal classes as well as construction
//  and alternation edges
// This class dictionary does not have the Decorator class which is not needed
//  for our purposes of calculating the subgraph of a specified traversal


UGraph       =       "#Class" "#Dictionary" "#Graph"
                     <vertices> UVertex_List
                     <edges> UEdge_List.

UVertex_List ~       "#Vertex" "#List" {UVertex}.

UVertex      :       UAltVertex | UConstVertex | UTerm
                     *common*
                     <vid> UID
                     <vertexname> UVertexName
                     <position> Coordinates
                     [<incoming> IEdge_List]
                     [<outgoing> OEdge_List].

IEdge_List   ~       "#Incoming" {UID}. 
OEdge_List   ~       "#Outgoing" {UID}.

UConstVertex =       "#ConstVertex".
UAltVertex   =       "#AltVertex".
UTerm        =       "#TermVertex".


UEdge_List   ~       "#Edge" "#List" {UEdge}.

UEdge        :       UAltEdge | UConstEdge 
                     *common*
                     <eid> UID
                     <fromVertex> UID <toVertex> UID.

UAltEdge     =       "#AltEdge".
UConstEdge   =       "#ConstEdge" <edgename> UEdgeName <card> Cardinality.
Cardinality  =       <lower> Lower [<upper> Upper].
Lower        =       <l>Integer.
Upper        =       "." "." <u> String.

// Classes common to UVertex and/or UEdge objects

UID                  =   <id> Integer.
UVertexName          =   <name> Ident.
UEdgeName            =   <name> Ident.

Coordinates          =   "{" <x> X <y> Y "}".
X                    =   <x> Integer.
Y                    =   <y> Integer.


// Visitors and Traversal Specifications

// IndependentTraversal is the class that holds the traversal specification.
//  It handles multiple targets, to or to-stop, and a list of bypassing 
//  elements.  Because of time constraints, we were not able to implement
//  through.
// Both Binoy and Kedar said that it was ok to change the structure of our
//  IndependentTraversal object.
// NOTE:  The bypass clause is at the end of the IndependentTraversal object
//        because we followed the convention of the original Independent-
//        Traversal object in evolve.cd(which also had it at the end)

IndependentTraversal =  <from> From <target> Target [<bypass> Bypass].
From                 =  "from" <sourceid> UID.
Target               :  To | ToStop *common* <destid> List(UID).
To                   =  "to".
ToStop               =  "to-stop".
Bypass               =  "bypassing" <bypassings> List(UID).


HashVisitor          =  <htable> Hashtable.

TargetVisitor        =  <vect> Vector <htable> Hashtable.
BypassVisitor        =  <vect> Vector <htable> Hashtable.

// We noticed that our class dictionary is flattened, and we will change
//  this, if necessary, so that SubgraphMarker will have travinfo and the
//  hashtable object to be common parts for both ForwardMarker and
//  BackwardMarker objects.

SubgraphMarker       :  ForwardMarker | BackwardMarker.

ForwardMarker        =  "#ForwardMarker" <travinfo> IndependentTraversal
				         <forhtable> Hashtable.

BackwardMarker       =  "#BackwardMarker" <travinfo> IndependentTraversal
			                  <backhtable> Hashtable.

PrintingVisitor = .


//Parameterized class definitions.
List(S) ~ {S}.

Main = .