einarwh

public class ContinuationIncrementer : IEnumerable<int>
{
  public IEnumerator<int> GetEnumerator()
  {
    int n = 0;
    while (true)
    {
      yield return ++n;
    }
  }

einarwh

foreach (int i in new Incrementer())
{
  Console.WriteLine(i); 
  if (i == 10) { break; } 
}

einarwh

public class NumberSequence : IEnumerable<int>
{
  private readonly int _startValue;
  private readonly int _increment;

  public NumberSequence(int startValue, int increment)
  {
    _startValue = startValue;
    _increment = increment;
  }

einarwh

public class BrokenRecord<T> : IEnumerable<T>
{
  private readonly IEnumerable<T> _seq;

  public BrokenRecord(IEnumerable<T> seq)
  {
    _seq = seq;
  }

  public IEnumerator<T> GetEnumerator()

einarwh

var words = new [] { "Hello", "dear", "friend" }; 
int wordCount = 0; 
foreach (string s in new BrokenRecord(words)) 
{
  Console.WriteLine(s);
  if (++wordCount == 10) { break; } 
}

einarwh

public class PrimeSequence : IEnumerable<int>
{
  public IEnumerator<int> GetEnumerator()
  {
    return new SimplePrimeEnumerator();
  }

  IEnumerator IEnumerable.GetEnumerator()
  {
    return GetEnumerator();

einarwh

public class PrimeSequence : IEnumerable<int>
{
  public IEnumerator<int> GetEnumerator()
  {
    yield return 2;
    var e = new OddPrimeEnumerator();
    while (e.MoveNext()) 
    {
      yield return e.Current;
    }

einarwh

public class OddPrimeEnumerator : IEnumerator<int>
{
  private readonly IEnumerator<int> _candidates = 
    new NumberEnumerator(3, 2);
  private readonly IPriorityQueue<NumberEnumerator> _pq = 
    new IntervalHeap<NumberEnumerator>();

  public int Current
  {
    get { return _candidates.Current; }

einarwh

public class WheelSequence : IEnumerable<int>
{
  private readonly int _startValue;
  private readonly IEnumerable<int> _;

  public WheelSequence(int startValue, 
    IEnumerable<int> skipSequence)
  {
    _startValue = startValue;
    _ = skipSequence;

einarwh

var skip = new[] { 4, 2, 4, 2, 4, 6, 2, 6 };
var skipSequence = new BrokenRecord<int>(skip);