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

/proj/asl/lieber/java/java-envs/jk-smallest

Consider the following behavior file program.beh. 
Find the SMALLEST (in terms of number
of characters) class dictionary program.cd so that 
program.beh and program.cd result in an executable
Java program.


program.beh
============================
A{
  traversal t(V v) {
    to D;}
}

ClassGraph {
  traversal f() {
   to *;}
}

V {
  before B (@ set_i(new Integer(5)); @)
  before C (@ System.out.println(get_i()); @)
  before D (@ Q q = new R(); @)
}

Main {
(@
  static public void main(String args[]) throws Exception {

    ClassGraph a = ClassGraph.parse(System.in);
    a.f();

    A a1 = A.parse(System.in);
    V v = new V();
    a1.t(v);

    System.out.println("done ");
  }
@)
}

Fill in the UNKNOWNS below:

A = UNKNOWN.
B = UNKNOWN.
C = UNKNOWN.
D = .
V = UNKNOWN .
UNKNOWN = .
Main = .

UNKNOWN : UNKNOWN.
R = .


sol:
A = B.
B = C.
C = D.
D = .
V = <i> Integer .
ClassGraph = .
Main = .

Q : R.
R = .

Question 2:

/proj/asl/lieber/java/java-envs/jk-sys-simpler

Consider files program.beh, program.cd and program.input below.
Find the unknowns in the output shown after program.input.

program.beh
------------------------------------------

EquationSystem{
  (@
  void f() {
    V1 v1 = new V1();
    t1(v1);
  }
  @)
  (@
  void g(Variable w) {
    // creates a new visitor object for each call
    V2 v2 = new V2(new Equation(), w);
    t2(v2);
  }
  @)
  traversal t1(V1 v1) {
    bypassing Exp
    to Variable;} 
  traversal t2(V2 v2) {
    bypassing {-> Equation,var,Variable}
    to Variable;}
}

V1{
  before EquationSystem (@ e = host; @)
  before Variable (@ 
    // find out where used
    System.out.println(" V1 " + host.get_variableName().toString());
    e.g(host);
  @)
}

V2{
  before * (@ System.out.println("V2 is in " +host.getClass().toString()); @)
  before Equation (@ equation = host; @)
  before Variable (@
    System.out.println(" V2 variable " + host.get_variableName().toString()); 
    if (host.get_variableName().equals(variable.get_variableName())) {
       System.out.println(" V2 " + host.get_variableName().toString() 
       + " is used in an equation"); 
    }  
  @)
}

Main {
(@
  static public void main(String args[]) throws Exception {
      EquationSystem e = EquationSystem.parse(System.in);
      e.f();

      System.out.println("done: ");
}
@)
}

program.cd
--------------------------------------------------

EquationSystem = <eqs> List(Equation).
Equation =
  <var> Variable "="
  <exp> Exp "." .
Exp : 
  FunctionCall |
  Variable |
  Numbe.
FunctionCall = "call" <fn> Function
  <args> CommaList(Variable) .
Variable = <variableName> Ident.
Function = <functionName> Ident.
Numbe = <n> Integer.
List(S) ~ {S}.
CommaList(S) ~ "(" S {"," S} ")".

Main = .

// visitors

V1 = <e> EquationSystem.
V2 =  Equation  Variable.

program.input
--------------------------------------------

A = B.
B = 2.
C = 3.
Z = call f(A, B, C).


The output is below

java Main < program.input
 V1 A
V2 is in class EquationSystem
V2 is in class Equation_List
V2 is in class Nonempty_Equation_List
 V2 variable B
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class FunctionCall
V2 is in class Variable_CommaList
V2 is in class Nonempty_Variable_CommaList
 V2 variable A
 V2 A is used in an equation
V2 is in class Nonempty_Variable_CommaList
 V2 variable B
V2 is in class Nonempty_Variable_CommaList
 V2 variable C
 V1 B
V2 is in class EquationSystem
V2 is in class Equation_List
V2 is in class Nonempty_Equation_List
 V2 variable B
 V2 B is used in an equation
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class FunctionCall
V2 is in class Variable_CommaList
V2 is in class Nonempty_Variable_CommaList
 V2 variable A
V2 is in class Nonempty_Variable_CommaList
 V2 variable B
 V2 B is used in an equation
V2 is in class Nonempty_Variable_CommaList
 V2 variable C
 V1 C
V2 is in class EquationSystem
V2 is in class Equation_List
V2 is in class Nonempty_Equation_List
 V2 variable B
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class FunctionCall
V2 is in class Variable_CommaList
V2 is in class Nonempty_Variable_CommaList
 V2 variable A
V2 is in class Nonempty_Variable_CommaList
 V2 variable B
V2 is in class Nonempty_Variable_CommaList
 V2 variable C
 V2 C is used in an equation
 V1 Z
V2 is in class EquationSystem
V2 is in class Equation_List
V2 is in class Nonempty_Equation_List
 V2 variable B
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class Numbe
V2 is in class Nonempty_Equation_List
V2 is in class FunctionCall
V2 is in class Variable_CommaList
V2 is in class Nonempty_Variable_CommaList
 V2 variable A
V2 is in class Nonempty_Variable_CommaList
 V2 variable B
V2 is in class Nonempty_Variable_CommaList
 V2 variable C
done: 
Question:

Write a class dictionary for your favorite video store.
You will use the class dictionary to keep track of rentals
and returns and of fines.


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

Consider the following sentence describing an object (program.input):

A = call f1(A,B).
B = call f2(C,A).
C = 3.
D = call f(A, B, C).


The class dictionary is (program.cd, same as in question 3):

EquationSystem = <eqs> List(Equation).
Equation =
  <var> Variable "="
  <exp> Exp "." .
Exp : 
  FunctionCall |
  Variable |
  Numbe.
FunctionCall = "call" <fn> Function
  <args> CommaList(Variable) .
Variable = <variableName> Ident.
Function = <functionName> Ident.
Numbe = <n> Integer.
List(S) ~ {S}.
CommaList(S) ~ "(" S {"," S} ")".

Main = .

// visitors

V1 = <e> EquationSystem.
V2 =  Equation  Variable.


Find the unknowns in the following object:


: EquationSystem ( 
   < eqs > : Equation_List { 
      : Equation ( 
         < var > : Variable ( 
            < variableName > : Ident "A" ) 
         < exp > : FunctionCall ( 
            < fn > : Function ( 
               < functionName > : Ident "f1" ) 
            < args > : Variable_CommaList { 
               : Variable ( 
                  < variableName > : Ident "A" ) , 
               : Variable ( 
                  < variableName > : Ident "B" ) } ) ) , 
      : Equation ( 
         < var > : Variable ( 
            < variableName > : Ident "B" ) 
         < exp > : FunctionCall ( 
            < fn > : Function ( 
               < functionName > : Ident "f2" ) 
            < args > : Variable_CommaList { 
               : Variable ( 
                  < variableName > : Ident "C" ) , 
               : Variable ( 
                  < variableName > : Ident "A" ) } ) ) , 
      : Equation ( 
         < var > : Variable ( 
            < variableName > : Ident "C" ) 
         < exp > : Numbe ( 
            < n > : Integer "3" ) ) , 
      : Equation ( 
         < var > : Variable ( 
            < variableName > : Ident "D" ) 
         < exp > : FunctionCall ( 
            < fn > : Function ( 
               < functionName > : Ident "f" ) 
            < args > : Variable_CommaList { 
               : Variable ( 
                  < variableName > : Ident "A" ) , 
               : Variable ( 
                  < variableName > : Ident "B" ) , 
               : Variable ( 
                  < variableName > : Ident "C" ) } ) ) } )