private static IList <T> GetAdapterForEnumerable(IEnumerable <T> source, int start, int count)
{
return(source switch
{
StringSliceAdapter str_adapter => new StringSliceAdapter(str_adapter, start, count) as IList <T>,
ArraySegment <T> segment => new ArraySegment <T>(segment.Array, start + segment.Offset, count),
ListSliceAdapter <T> list_adapter => new ListSliceAdapter <T>(list_adapter, start, count),
Memoizer <T> memo_adapter => new ListSliceAdapter <T>(memo_adapter, start, count),
Slice <T> slice => GetAdapterForEnumerable(slice.adapter, start, count),
string str => new StringSliceAdapter(str, start, count) as IList <T>,
T[] arr when start == 0 && count == arr.Length => arr,
T[] arr => new ArraySegment <T>(arr, start, count),
IList <T> list when start == 0 && count == list.Count => list,
IList <T> list => new ListSliceAdapter <T>(list, start, count),
_ => new ListSliceAdapter <T>(new Memoizer <T>(source), start, count),
});
public StringSliceAdapter(StringSliceAdapter source, int offset, int?count)
: this(source.source_string, offset + source.Offset, count ?? source.end_index - (offset + source.Offset))
{
}
