/// <summary>
/// Ctor
/// </summary>
/// <param name="sequence"></param>
public Subsequence(IList <T> sequence, int start, int length)
{
if (sequence == null)
{
throw new ArgumentNullException("sequence");
}
if (start < 0 || start >= sequence.Count)
{
throw new ArgumentOutOfRangeException("start");
}
if (length < 0 || length > start + sequence.Count)
{
throw new ArgumentOutOfRangeException("length");
}
Subsequence <T> subsequence = sequence as Subsequence <T>;
if (subsequence != null)
{
// optimize by using original internal list
this.Items = subsequence.Items;
this.Start = subsequence.Start + start;
this.Size = length;
return;
}
this.Items = sequence;
this.Start = start;
this.Size = length;
}
/// <summary>
/// Ends chunking at the current index and returns the buffered chunk
/// </summary>
/// <returns></returns>
public override IEnumerable <T> EndChunk()
{
if (this.start < 0)
{
throw new InvalidOperationException("Not currently chunking.");
}
// build chunk value
IEnumerable <T> value = new Subsequence <T>(this.Buffer, this.start, (1 + this.index - this.start));
// reset chunk start
this.start = -1;
return(value);
}