public InstantiatedTermPositions(InstantiatedIndexReader reader) 
{
    super(reader);
}

 public byte[] getPayload(byte[] data,
    int offset) throws IOException 
{
    byte[] payloads = currentDocumentInformation.getPayloads()[currentTermPositionIndex];
    // read payloads lazily
    if (data == null || data.length - offset <  getPayloadLength()) {
      // the array is too small to store the payload data,
      return payloads;
    } else {
      System.arraycopy(payloads, 0, data, offset, payloads.length);
      return data;
    }
}

 public int getPayloadLength() 
{
    return currentDocumentInformation.getPayloads()[currentTermPositionIndex].length;
}

 public boolean isPayloadAvailable() 
{
    return currentDocumentInformation.getPayloads()[currentTermPositionIndex] != null;
}

 public boolean next() 
{
    currentTermPositionIndex = -1;
    return super.next();
}

Moves to the next pair in the enumeration.

Returns true if there is such a next pair in the enumeration.

 public int nextPosition() 
{
    currentTermPositionIndex++;
    // if you get an array out of index exception here,
    // it might be due to currentDocumentInformation.getIndexFromTerm not being set!!
    return currentDocumentInformation.getTermPositions()[currentTermPositionIndex];
}

Returns next position in the current document. It is an error to call this more than #freq() times without calling #next()

This is invalid until #next() is called for the first time.

 public boolean skipTo(int target) 
{
    currentTermPositionIndex = -1;
    return super.skipTo(target);
}

Skips entries to the first beyond the current whose document number is greater than or equal to target.

Returns true iff there is such an entry.

Behaves as if written:

  boolean skipTo(int target) {
    do {
      if (!next())
	     return false;
    } while (target > doc());
    return true;
  }

Some implementations are considerably more efficient than that.