/// <summary>
/// Factory method for generic streams
/// </summary>
/// <param name="sequence"></param>
/// <param name="buffered"></param>
/// <returns></returns>
public static IStream <T> Create(IEnumerable <T> sequence, bool buffered)
{
IList <T> list = sequence as IList <T>;
if (list != null)
{
return(new ListStream <T>(list));
}
else if (buffered)
{
list = new SequenceBuffer <T>(sequence);
return(new ListStream <T>(list));
}
return(new EnumerableStream <T>(sequence));
}
/// <summary>
/// Deferred execution of iterator
/// </summary>
private void EnsureReady()
{
// only execute when requested
if (this.isReady || this.isCompleted)
{
return;
}
this.isReady = true;
// store the current item or null if complete
int next = this.index + 1;
SequenceBuffer <T> sBuffer = this.Buffer as SequenceBuffer <T>;
if (sBuffer != null)
{
// avoid using SequenceBuffer<T>.Count as will need to enumerate entire sequence
if (sBuffer.TryAdvance(next))
{
this.current = this.Buffer[next];
}
else
{
this.isCompleted = true;
this.current = default(T);
}
}
else
{
if (next < this.Buffer.Count)
{
this.current = this.Buffer[next];
}
else
{
this.isCompleted = true;
this.current = default(T);
}
}
}
public void WrapResult_LongStringTwice_ReturnsSameSequence()
{
const string input = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
var sequence = new SequenceBuffer <char>(this.GetSequence(new StringStream(input)));
var buffer = new StringBuilder();
foreach (char ch in sequence)
{
buffer.Append(ch);
}
Assert.Equal(input, buffer.ToString());
buffer.Clear();
foreach (char ch in sequence)
{
buffer.Append(ch);
}
// wrapped version iterates multiple times
Assert.Equal(input, buffer.ToString());
}
public void WrapInput_NullString_ReturnsEmptySequence()
{
var buffer = new SequenceBuffer <char>(null);
Assert.Equal(new char[0], buffer.ToArray());
}
/// <summary>
/// Ctor
/// </summary>
/// <param name="sequence"></param>
public Enumerator(SequenceBuffer <T> sequence)
{
this.Sequence = sequence;
this.Index = -1;
}
