Assignment 7 problem 1

import tester.Tester;

// Represents an arithmetic sequence
interface IArith {

  <R> R accept(IArithVisitor<R> visitor);
}

// Represents a function
interface IFunc2<A, B, R> {

}

// represents a constant
class Const implements IArith {
  double num;

  Const(double num) {
    this.num = num;
        }

        public <R> R accept(IArithVisitor<R> visitor) {
    return visitor.visitIArithConst(this);

        }
}

// represents a arithmetic formula
class formula implements IArith {
  IFunc2<Double, Double, Double> fun;
  String name;
  IArith left;
  IArith right;

  formula(IFunc2 fun, String name, IArith left, IArith right) {
    this.fun = fun;
    this.name = name;
    this.left = left;
    this.right = right;
  }


  // Accepts an apply the visitor to the formula
  public <R> R accept(IArithVisitor<R> visitor) {
    return visitor.visitIArithFormula(this);
  }
}

// Represents an arithmetic visitor for a formula or constant.
interface IArithVisitor<R> extends IFunc2<Const, Const, R> {

  R visitIArith(IArith a);

  R visitIArithConst(IArith a);

  R visitIArithFormula(IArith a);
}