/// <summary>
/// Creates an observable sequence by reading lines to the end of the specified <paramref name="reader"/> each time
/// the <paramref name="textAvailable"/> sequence notifies that additional text is available to be read
/// and advances the position within the reader to the end of the stream.
/// </summary>
/// <typeparam name="TOther">The type of elements in the sequence that notifies when text is available to be read.</typeparam>
/// <param name="reader">The object from which lines are read as they become available.</param>
/// <param name="textAvailable">An observable sequence that notifies when additional text is available to be read.</param>
/// <remarks>
/// <para>
/// The <paramref name="textAvailable"/> sequence does not have to notify when new lines are available. It only must notify when
/// new text is available, which may or may not have new lines. Characters that are read up to the end of the stream are automatically
/// buffered until a new line sequence is encountered in a subsequent read. A consequence of this behavior is that if the stream does
/// not end with a new line sequence and it's not going to receive any more text, then the last line will not be read until
/// <paramref name="textAvailable"/> calls <strong>OnCompleted</strong>.
/// </para>
/// <para>
/// The generated sequence is intended to match the underlying stream; however, this behavior
/// depends on whether the reader is well-behaved and whether the reader is not being shared. Reading always starts from the
/// current position of the reader in the underlying stream. The reader is expected to increment its position in the stream
/// when it's read. Each time that the <paramref name="textAvailable"/> sequence notifies that additional text is available,
/// reading is expected to begin at the previous position in the stream, but if the reader is shared or it's not well-behaved,
/// then the generated sequence may contain unexpected data.
/// </para>
/// </remarks>
/// <returns>An observable sequence of lines read from the specified <paramref name="reader"/>.</returns>
public static IObservable <string> ToObservableLines <TOther>(this TextReader reader, IObservable <TOther> textAvailable)
{
Contract.Requires(reader != null);
Contract.Requires(textAvailable != null);
Contract.Ensures(Contract.Result <IObservable <string> >() != null);
return(reader.ToObservableLines(textAvailable, Scheduler.CurrentThread));
}
