gistfile1.txt

/**
 * Returns an iterator object. Must be implemented to work with foreach etc.
 */
interface iterable {
  public method __iterator();
}


/**
 * Actual iterator interface
 */
interface iterator {
  // Rewinds the iterator back to the first element
  public method __rewind();

  // Returns a tuple with all items for the current element
  public method __current();

  // Move the internal pointer to the next element
  public method __next();

  // Returns true when there is a next element, false otherwise
  public method __hasNext();
}


/**
 * Iterator that implements backward iteration as well
 */
interface bidirectionalIterator implements iterator {
  // Move iternal pointer to the previous element
  public method __prev();

  // Returns true when there is a previous element, false otherwise
  public method __hasPrev();
}


/**
 * Implements a lenght() method that will return the length of the iterator. Only usefull for iterators where the 
 * number of elements are known in advance.
 */
interface rangeIterator implements iterator {
  public method __length();
}


/**
 *
 */
class arrayIterator implements iterable, rangeIterator {
  protected property items;    // Hash with iterable items
  protected property keys;     // List of keys (so we can fetch the Nth index without knowing the key)
  protected property idx = 0;  // internal iterator pointer

  public method __ctor(hash items) {
    self.items = items;
    self.keys = items.__keys();
    self._idx = 0;
  }

  /**
   * This class does not have an external iterator, but implements an iterator in itself
   */
  public method __getIterator() {
    return self;
  }

  public method __rewind() {
    self._idx = 0;
  }

  public method __current() {
    return tuple[
      self.keys[self.idx], 
      self.items[self.keys[self.idx]]
    ];
  }

  public method __next() {
    self.idx++;
  }

  public method __hasNext() {
    return self.idx < self.keys.__length() - 1;
  }

  public method __length() {
    return self.keys.__length();
  }
}



foo = arrayIterator(hash["foo":1, "bar":"baz", true:false]);
foreach (foo as k,v,meta) {
  if (meta.first) io.printf("First item!\n");
  if (meta.last) io.printf("Last item!\n");
  io.printf("Item %d of %d: %s => %s\n", meta.index, meta.count, k, v);
}