Consider the following class dictionary, program, input
and output. Find the UNKNOWNS.

Notice that the class dictionary for class dictionaries
used below is different than the standard one.
The changes are clearly marked.

// generate.cd -- class dictionary for DemeterJ code generator
// $Id: generate.cd,v 1.11 2000/09/19 21:08:21 dougo Exp $
// modified for syntax commands 2004/04/19  

import edu.neu.ccs.demeter.dj.*;
import java.util.*;
import java.io.*;

Main	= .
Input = ClassGraphh SyntaxEnhancement.

ClassGraphh		= <classes> DList(Definition).

Definition		: ClassDef.

public ClassDef		= 
			  ParamClassName 
			  *s ClassParts "." . 

ParamClassName		= ClassName ["(" <parameters> Commalist(ClassName) ")"].

ClassParts		: ConstOrAltClass | RepetitionClass.

ConstOrAltClass		: ConstructionClass | AlternationClass
			*common* +
// The following:
//				<parts> List(ClassElement)
// changed to:
				<parts> List(ClassElementWithSyntax)
				 -.

// The following:
// ClassElement		: Part | OptionalPart | Syntax.
// changed to:
ClassElement		: Part | OptionalPart .
ClassElementWithSyntax		: ClassElement | SandwichedClassElement .
SandwichedClassElement 	= PSandwich(ClassElement).
PSandwich(S) = "{" Sandwich(S) "}".

Part			= *l [ "<" PartName ">" *s ]
			  ClassSpec. 

OptionalPart		= *l "[" <part> Sandwich(Part) "]".

ConstructionClass	= "=".

AlternationClass	= ":" + [ <subclasses> Barlist(ClassSpec) ] -
			"common".

RepetitionClass		= "~" <sandwiched> Sandwich(RepeatedPart).

RepeatedPart		= [ <nonempty> ClassSpec ]
			"{" <repeated> Sandwich(ClassSpec)
			*s "}".

Sandwich(S)		= <first> List(Syntax) *s <inner> S <second> List(Syntax) .

ClassSpec		= ClassName
			["(" <actual_parameters> Commalist(ClassSpec) ")" ]
			.

Syntax			: SyntaxToken | PrintCommand.

SyntaxToken		= <string> String.

PrintCommand		: PrintIndent | PrintUnindent | PrintSkip | PrintSpace.
PrintIndent		= "+" .
PrintUnindent		= "-" .
PrintSkip		= "*l" .
PrintSpace		= "*s" .

// Terminal buffer classes.
ClassName	        = Ident.
PartName		= <name> Ident.

// Parameterized class definitions.
List(S) ~ {*s S}.
NList(S) ~ S {*s S}.
SList(S) ~ S { *l S } .
DList(S) ~ S { *l *l S } *l .
Commalist(S) ~ S {"," *s S}.
Barlist(S) ~ S { *l "|" *s S}.



//////////////////////
//syntax enhancement//
//////////////////////

SyntaxEnhancement = List(Enhancement) EOF.
Enhancement = *l Where EnhancementBody.
EnhancementBody : ClassBody | PartCoordinate | OptionalPartCoordinate |  
  CollectionCoordinate common ":" SyntaxToken .
// also applies outside of optional parts
PartCoordinate = "part"  SyntaxClassName "." SyntaxPartName.
// only for optional parts
OptionalPartCoordinate = "inside" "optional" "part"  SyntaxClassName "." SyntaxPartName.
ClassBody = "class"  SyntaxClassName.
CollectionCoordinate = "collection" SyntaxClassName  CurlyBracket.
CurlyBracket : Left | Right.
Left = "{".
Right = "}".

SyntaxClassName = Ident.
SyntaxPartName = Ident.

Where : Before | After.
Before = "before".
After = "after".

//populates hashtable with classgraph information
ClassGraphVisitor = extends Visitor.
//provides behavior for different types of syntax commands
CommandVisitor = extends Visitor.

//three types
ClassCommandVisitor = extends Visitor.
CollectionCommandVisitor = extends Visitor.
PartCommandVisitor = extends Visitor.



PROGRAM ==========================================


Main {
  {{
  public static void main(String args[]) throws Exception
  {
    Input input = Input.parse(System.in);
    input.print();
//    input.trace();
//    input.display();
    ClassGraph cg = new ClassGraph(new ClassGraph(true, false), 
      "from Input bypassing -> *, tail, * to *");

    ClassGraphh cgRootObj = input.get_classgraphh(); 
    System.out.println();
    System.out.println();
    System.out.println(" ClassGraphh-object ============ ");
    cgRootObj.trace();
    SyntaxEnhancement seRootObj = input.get_syntaxenhancement();
    System.out.println();
    System.out.println();
    System.out.println(" SyntaxEnhancement-object ============ ");
    seRootObj.trace();

    //populate hashtable with class and part name key/value pairs
    System.out.println();
    System.out.println(" Populate and print hashtable");
    ClassGraphVisitor cgv = new ClassGraphVisitor();
    cgv.setNameTable(new Hashtable());
    cgv.setCG(cg);
    cg.traverse(cgRootObj,"from ClassGraphh to ClassDef", cgv);
    Hashtable nameTable = cgv.getNameTable();
    System.out.println();
    System.out.println(nameTable);

    //setup syntax command traversals
    System.out.println();
    System.out.println("SyntaxEnhancement-object processing");
    TraversalGraph tgSyntax = new TraversalGraph(
      "from Enhancement to EnhancementBody", cg);
    System.out.println();
    System.out.println("Traversal Graph for:" + 
      "from Enhancement to EnhancementBody");
    System.out.println();
    System.out.println(tgSyntax);
    System.out.println();
    System.out.println("SyntaxEnhancement-object processing continued");
    CommandVisitor cv = new CommandVisitor();
    cv.setNameTable(nameTable);
    cv.setCG(cg);
    //iterate through each syntax command
    Enhancement_List sentences = seRootObj.get_enhancement_list();
    while(sentences.hasMoreElements())
      {
      Enhancement sent = (Enhancement)sentences.nextElement();
      cv.setEnhancement(sent);
      tgSyntax.traverse(sent, cv);
      }
    System.out.println();
    cgRootObj.print();
  }
  }}
}

Input 
{
	void print() to * (PrintVisitor);
	void trace() to * (TraceVisitor);
	void display() to * (DisplayVisitor);
}


ClassGraphh {
	void print() to * (PrintVisitor);
	void trace() to * (TraceVisitor);
	void display() to * (DisplayVisitor);
}


SyntaxEnhancement {
	void print() to * (PrintVisitor);
	void trace() to * (TraceVisitor);
	void display() to * (DisplayVisitor);
}

ClassGraphVisitor
{
  {{
        private Hashtable nameTable;
        public void setNameTable(Hashtable nameTable)
        {
                this.nameTable = nameTable;
        }
        public Hashtable getNameTable() { return nameTable; }

        private ClassGraph cg;
        public void setCG(ClassGraph cg)
        {
                this.cg = cg;
        }
        public ClassGraph getCG() { return cg; }

        void before(ClassDef classdef)
        {
                nameTable.put(classdef.get_paramclassname().get_classname().get_ident(), classdef.get_classparts());

                List partnames = cg.gather(classdef, "from ClassDef through Part to edu.neu.ccs.demeter.Ident");
                Iterator iter = partnames.iterator();
                while(iter.hasNext())
                {
                        Ident oid = (Ident)iter.next();
                        nameTable.put( oid, classdef );
                }
        }
  }}
}
CommandVisitor
{
  {{
	private Hashtable nameTable;
	public void setNameTable(Hashtable nameTable)
	{
		this.nameTable = nameTable;
	}
	public Hashtable getNameTable() { return nameTable; }
	
	private ClassGraph cg;
	public void setCG(ClassGraph cg)
	{
		this.cg= cg;
	}
	public ClassGraph getCG() { return cg; }

	private Enhancement eh;
        public void setEnhancement(Enhancement eh)
        {
                this.eh = eh;
        }
        public Enhancement getEnhancement() { return eh; }

	void before (ClassBody classbody)
	{		
	  System.out.println("visiting ClassBody " + classbody);
		ConstOrAltClass coa = (ConstOrAltClass)nameTable.get((Ident)cg.fetch(classbody, "from ClassBody through SyntaxClassName to edu.neu.ccs.demeter.Ident"));
	}
	
	
	void before(CollectionCoordinate collection)
	{
	  System.out.println("visiting CollectionCoordinate " + collection);
	}

	void before(PartCoordinate partc)
	{
	  System.out.println("visiting PartCoordinate " + partc);
		//grab part list from hashtable
		Ident syntaxpartname = (Ident)cg.fetch(partc, "from PartCoordinate through SyntaxPartName to edu.neu.ccs.demeter.Ident");
		ClassDef cdef = (ClassDef)nameTable.get(syntaxpartname);               
	  System.out.println("SyntaxPartName " + syntaxpartname);
          
	}	
  }}
}


INPUT =============================================

// A = { <b> B } "x" {<c> C}.
// A = [<x> X] "y" [<y> Y].

LastName = Ident.
A = <b> B <c> C {"bd" <d> D "ed"} {"be" ["x" <e> E] "ee"} [<f> F].
B : C | D common <x> X.
C ~ "x" Y { "," Y } ")".

before part LastName.ident : "last: "
before inside optional part A.e : "last: "
before class LastName : "last: "
before collection C { : "last: "

OUTPUT ==================================================
Running the test...
LastName =	
	Ident.

A =	
	<b> B 
	<c> C {"bd" 
	<d> D "ed"} {"be" 
	["x" 
	<e> E]"ee"} 
	[ 
	<f> F].

B :	C
	| D	
		<x> X common.

C ~"x" Y{"," Y }")".

before part LastName.ident:"last: " 
before inside optional part A.e:"last: " 
before class LastName:"last: " 
before collection C{:"last: "

 ClassGraphh-object ============ 
before ClassGraphh
 before -> ClassGraphh, classes, Definition_DList 
  before Definition_DList
   before -> Definition_DList, first, Nonempty_Definition_DList 
    before Nonempty_Definition_DList
     before -> Nonempty_Definition_DList, it, Definition 
      before Definition
       before ClassDef
        before -> ClassDef, paramclassname, ParamClassName 
         before ParamClassName
          before -> ParamClassName, classname, ClassName 
           before ClassName
            before -> ClassName, ident, Ident 

// output part deleted

  after Definition_DList
 after -> ClassGraphh, classes, Definition_DList 
after ClassGraphh


 SyntaxEnhancement-object ============ 
before SyntaxEnhancement
 before -> SyntaxEnhancement, enhancement_list, Enhancement_List 
  before Enhancement_List
   before -> Enhancement_List, first, Nonempty_Enhancement_List 
    before Nonempty_Enhancement_List
     before -> Nonempty_Enhancement_List, it, Enhancement 
      before Enhancement
       before -> Enhancement, where, Where 
        before Where
         before Before


// output part deleted


 Populate and print hashtable

{D=ClassDef@cfec48, C=RepetitionClass@a17083, B=AlternationClass@e1d5ea, X=ClassDef@a31e1b, A=ConstructionClass@10da5eb, Ident=ClassDef@1081d2e, f=ClassDef@cfec48, e=ClassDef@cfec48, d=ClassDef@cfec48, LastName=ConstructionClass@1b3f829, c=ClassDef@cfec48, b=ClassDef@cfec48, x=ClassDef@a31e1b, F=ClassDef@cfec48, E=ClassDef@cfec48}

SyntaxEnhancement-object processing

Traversal Graph for:from Enhancement to EnhancementBody

Start set: [Enhancement: {0}]
Copy 0:
 Nodes:
 Enhancement
 EnhancementBody
 PartCoordinate
 OptionalPartCoordinate
 ClassBody
 CollectionCoordinate
 Edges:
 -> Enhancement,enhancementbody,EnhancementBody
 => EnhancementBody,PartCoordinate
 :> PartCoordinate,EnhancementBody
 => EnhancementBody,OptionalPartCoordinate
 :> OptionalPartCoordinate,EnhancementBody
 => EnhancementBody,ClassBody
 :> ClassBody,EnhancementBody
 => EnhancementBody,CollectionCoordinate
 :> CollectionCoordinate,EnhancementBody
 Edges to other copies:
Finish set: [EnhancementBody: {0}]

SyntaxEnhancement-object processing continued
visiting PartCoordinate PartCoordinate@7c4c51
SyntaxPartName ident
visiting ClassBody ClassBody@148bd3
visiting CollectionCoordinate CollectionCoordinate@e80842

LastName =	
	Ident.

A =	
	<b> B 
	<c> C {"bd" 
	<d> D "ed"} {"be" 
	["x" 
	<e> E]"ee"} 
	[ 
	<f> F].

B :	C
	| D	
		<x> X common.

C ~"x" Y{"," Y }")".