/// <summary>
/// Creates a <c>MultiEnumerator</c> that serially chains the two
/// enumerators passed as arguments.
/// </summary>
public MultiEnumerator(IEnumerator ie1, IEnumerator ie2, EnumeratorFilter filter, object context)
{
this.filter = filter;
this.context = context;
ies = new IEnumerator[]{ie1, ie2};
ies[0].Reset();
ies[1].Reset();
}
/// <summary>
/// Construct an enumerable that enumerators over ieable1, then ieable2. Each element
/// is passed to the filter which can decide if the element should be returned by
/// the enumerator or not. The filter can also change the element (map).
/// </summary>
/// <param name="filter">can be null</param>
/// <param name="context">passed to filter</param>
public CompoundEnumerable (
IEnumerable ieable1,
IEnumerable ieable2,
EnumeratorFilter filter,
object context)
{
this.ieable1 = ieable1;
this.ieable2 = ieable2;
this.filter = filter;
this.context = context;
}