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/*
 * Copyright 2011,2012 Metamarkets Group Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.metamx.common.guava;

import java.util.Iterator;

/**
 */
public class DroppingIterator implements Iterator
{
  private final Iterator delegate;
  private final int numToDrop;
  private boolean dropped = false;

  public DroppingIterator(
      Iterator delegate,
      int numToDrop
  )
  {
    this.delegate = delegate;
    this.numToDrop = numToDrop;
  }

  public boolean hasNext()
  {
    if (! dropped) {
      for (int i = 0; i < numToDrop; ++i) {
        delegate.next();
      }
      dropped = true;
    }

    return delegate.hasNext();
  }

  public T next()
  {
    if (! dropped) {
      for (int i = 0; i < numToDrop; ++i) {
        delegate.next();
      }
      dropped = true;
    }
    return delegate.next();
  }

  public void remove()
  {
    throw new UnsupportedOperationException();
  }
}