/*
 * The JastAdd Extensible Java Compiler (http://jastadd.org) is covered
 * by the modified BSD License. You should have received a copy of the
 * modified BSD license with this compiler.
 * 
 * Copyright (c) 2005-2008, Torbjorn Ekman
 * All rights reserved.
 */

aspect DataStructures {
  // A persistent Set
  interface SimpleSet {
    int size();
    boolean isEmpty();
    SimpleSet add(Object o);
    Iterator iterator();
    boolean contains(Object o);
    SimpleSet emptySet = new SimpleSet() {
      public int size() { return 0; }
      public boolean isEmpty() { return true; }
      public SimpleSet add(Object o) {
        if(o instanceof SimpleSet)
          return (SimpleSet)o;
        return new SimpleSetImpl().add(o);
      }
      public boolean contains(Object o) { return false; }
      public Iterator iterator() { return Collections.EMPTY_LIST.iterator(); }
    };
    SimpleSet fullSet = new SimpleSet() {
      public int size() { throw new Error("Operation size not supported on the full set"); }
      public boolean isEmpty() { return false; }
      public SimpleSet add(Object o) { return this; }
      public boolean contains(Object o) { return true; }
      public Iterator iterator() { throw new Error("Operation iterator not support on the full set"); }
    };
    class SimpleSetImpl implements SimpleSet {
      private HashSet internalSet;
      public SimpleSetImpl() {
        internalSet = new HashSet(4);
      }
      private SimpleSetImpl(SimpleSetImpl set) {
        this.internalSet = new HashSet(set.internalSet);
      }
      public int size() {
        return internalSet.size();
      }
      public boolean isEmpty() {
        return internalSet.isEmpty();
      }
      public SimpleSet add(Object o) {
        if(internalSet.contains(o)) return this;
        SimpleSetImpl set = new SimpleSetImpl(this);
        set.internalSet.add(o);
        return set;
      }
      public Iterator iterator() {
        return internalSet.iterator();
      }
      public boolean contains(Object o) {
        return internalSet.contains(o);
      }
    }
  }

  // FieldDeclaration is a SimpleSet
  FieldDeclaration implements SimpleSet;
  syn int FieldDeclaration.size() = 1;
  syn boolean FieldDeclaration.isEmpty() = false;
  public SimpleSet FieldDeclaration.add(Object o) {
    return new SimpleSetImpl().add(this).add(o);
  }
  syn boolean FieldDeclaration.contains(Object o) = this == o;
  
  FieldDeclaration implements Iterator;
  private FieldDeclaration FieldDeclaration.iterElem;
  public Iterator FieldDeclaration.iterator() { iterElem = this; return this; }
  public boolean FieldDeclaration.hasNext() { return iterElem != null; }
  public Object FieldDeclaration.next() { Object o = iterElem; iterElem = null; return o; }
  public void FieldDeclaration.remove() { throw new UnsupportedOperationException(); }

  // VariableDeclaration is a SimpleSet
  VariableDeclaration implements SimpleSet;
  syn int VariableDeclaration.size() = 1;
  syn boolean VariableDeclaration.isEmpty() = false;
  public SimpleSet VariableDeclaration.add(Object o) {
    return new SimpleSetImpl().add(this).add(o);
  }
  syn boolean VariableDeclaration.contains(Object o) = this == o;
  
  VariableDeclaration implements Iterator;
  private VariableDeclaration VariableDeclaration.iterElem;
  public Iterator VariableDeclaration.iterator() { iterElem = this; return this; }
  public boolean VariableDeclaration.hasNext() { return iterElem != null; }
  public Object VariableDeclaration.next() { Object o = iterElem; iterElem = null; return o; }
  public void VariableDeclaration.remove() { throw new UnsupportedOperationException(); }
  
  // ParameterDeclaration is a SimpleSet
  ParameterDeclaration implements SimpleSet;
  syn int ParameterDeclaration.size() = 1;
  syn boolean ParameterDeclaration.isEmpty() = false;
  public SimpleSet ParameterDeclaration.add(Object o) {
    return new SimpleSetImpl().add(this).add(o);
  }
  syn boolean ParameterDeclaration.contains(Object o) = this == o;
  
  ParameterDeclaration implements Iterator;
  private ParameterDeclaration ParameterDeclaration.iterElem;
  public Iterator ParameterDeclaration.iterator() { iterElem = this; return this; }
  public boolean ParameterDeclaration.hasNext() { return iterElem != null; }
  public Object ParameterDeclaration.next() { Object o = iterElem; iterElem = null; return o; }
  public void ParameterDeclaration.remove() { throw new UnsupportedOperationException(); }


  // TypeDecl is a SimpleSet
  TypeDecl implements SimpleSet;
  syn int TypeDecl.size() = 1;
  syn boolean TypeDecl.isEmpty() = false;
  public SimpleSet TypeDecl.add(Object o) {
    return new SimpleSetImpl().add(this).add(o);
  }
  syn boolean TypeDecl.contains(Object o) = this == o;

  TypeDecl implements Iterator;
  private TypeDecl TypeDecl.iterElem;
  public Iterator TypeDecl.iterator() { iterElem = this; return this; }
  public boolean TypeDecl.hasNext() { return iterElem != null; }
  public Object TypeDecl.next() { Object o = iterElem; iterElem = null; return o; }
  public void TypeDecl.remove() { throw new UnsupportedOperationException(); }
  
  // MethodDecl is a SimpleSet
  MethodDecl implements SimpleSet;
  syn int MethodDecl.size() = 1;
  syn boolean MethodDecl.isEmpty() = false;
  public SimpleSet MethodDecl.add(Object o) {
    return new SimpleSetImpl().add(this).add(o);
  }
  syn boolean MethodDecl.contains(Object o) = this == o;

  MethodDecl implements Iterator;
  private MethodDecl MethodDecl.iterElem;
  public Iterator MethodDecl.iterator() { iterElem = this; return this; }
  public boolean MethodDecl.hasNext() { return iterElem != null; }
  public Object MethodDecl.next() { Object o = iterElem; iterElem = null; return o; }
  public void MethodDecl.remove() { throw new UnsupportedOperationException(); }

}