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

EquationSystem  = <equations> List(Equation).
List(S) ~ "(" {S} ")".
Equation = <lhs> Variable "=" <rhs> Expression.
Expression : Simple | Compound.
Simple : Variable | Numerical.
Variable = Ident.
Numerical = <v> int.
Compound = <op> Op List(Expression).
Op : Add.
Add = "+".
Main = .

=====================================================================

// program.prj -- Demeter/Java project file (version 0.8.3)

// NOTE: This file may contain path names or other platform-dependent
// information.  You may need to edit them when moving from one
// platform to another.

// The class dictionary file.
CDFILE = program.cd

// The behavior files.
BEHFILES = program.beh mitch.beh print.beh

// The cool files.
COOLFILES = 

// The ridl files.
RIDLFILES = 

// The name of the class which has the "main" method.
MAIN = Main

// The package your generated code belongs to.  It should match
// the package specified at the beginning of your .cd file.
PACKAGE =

// Code generator arguments.
GENERATE_ARGS = -tracevis -displayvis -printvis -copyvis -equalvis

// The directory into which .java files are generated.
GENDIR = gen

// The parser generator executable.
PARSEGEN = javacc

// Parser generator arguments.
PARSEGEN_ARGS = 

// The Java compiler executable.
COMPILER = javac

// Java compiler arguments.
COMPILE_ARGS = -g -deprecation

// Java classpath to be passed to the COMPILER. Whatever you 
// put here comes after CLASSDIR:GENDIR, but before $CLASSPATH.
CLASSPATH = 

// The directory into which .class files are generated.
CLASSDIR = gen/classes

// The Java virtual machine executable.
JVM = java

// The virtual machine option for setting the class path.
CLASSPATH_OPTION = -classpath

// Arguments for testing the program.
TEST_ARGS =

// Input file for testing the program.
TEST_INPUT = program.input

// Files and directories to be removed when cleaning up.
CLEAN_ARGS = gen

=====================================================================
Main {
{{
  public static void main(String args[]) throws Exception {
    EquationSystem s = EquationSystem.parse(System.in);
    System.out.println("done parsing");
    // ClassGraph cg = new ClassGraph(true, false);
    HashSet used = s.getUsedVars();
    Iterator it = used.iterator();
    System.out.println(" Used Variables");
    while (it.hasNext()){
			    Variable curvar = (Variable) it.next();
			    System.out.println();
			    curvar.print();
    }
    System.out.println();
    HashSet defined = s.getDefinedVars();
    System.out.println("done");
  }
}}
}
EquationSystem {
{{
  static ClassGraph cg = new ClassGraph(true, false);
  static String usedVarsSpec =
    "from EquationSystem via -> *,rhs,* to Variable";
  static String definedVarsSpec =
    "from EquationSystem via -> *,lhs,* to Variable";
  HashSet collectVars(String travspec){
    Visitor v = new Visitor(){
      HashSet return_val = new HashSet();
      void before(Variable v1) {return_val.add(v1);}
      public Object getReturnValue(){return return_val;}
    };
    return (HashSet) cg.traverse(this, travspec, v);
  }
  HashSet getUsedVars() {
    return this.collectVars(usedVarsSpec);
  }
  HashSet getDefinedVars() {
    return this.collectVars(definedVarsSpec);
  }
}}
}
Variable {
  void print() to * (PrintVisitor);
}
=====================================================================
(
a = + (3 4 5)
b = + (c d)
d = 6
)
=====================================================================
Reading project file program.prj...
Running the test...
done parsing
 Used Variables

c
d
done