/// <summary>
/// Select items with keys in the specified range in key order (in the direction from <paramref name="fromRangeKey"/>
/// to <paramref name="toRangeKey"/>. Lower limit is inclusive, higher - exclusive
/// </summary>
/// <param name="fromRangeKey">
/// Selection range start (inclusive if less than <paramref name="toRangeKey"/> and exclusive otherwise)
/// </param>
/// <param name="toRangeKey">
/// Selection range end (inclusive if less than <paramref name="fromRangeKey"/> and exclusive otherwise)
/// </param>
/// <returns>
/// <see cref="IDirectedEnumerable<V>"/>
/// </returns>
/// <remarks>
/// Note that when going forward the item with range covering <paramref name="fromRangeKey"/> but starting before
/// it will not be returned. Similarly when going backwards the last range starting before the end of the range
/// will not be returned.
/// </remarks>
public IDirectedEnumerable <V> Select(K fromRangeKey, K toRangeKey)
{
C5.IDirectedEnumerable <C5.KeyValuePair <K, V> > seq;
if (fromRangeKey.CompareTo(toRangeKey) < 0)
{
// ascending
seq = _dictionary.RangeFromTo(fromRangeKey, toRangeKey);
}
else
{
// descending
seq = _dictionary.RangeFromTo(toRangeKey, fromRangeKey).Backwards();
}
return(new C5DirectedEnumerable <V>(new DictionaryEnumerableValueAdapter <K, V>(seq)));
}