public static IEnumerable <T> EnumReverse <T>(this IList <T> list, int beginIdx, int endIdx)
{
beginIdx = RangeUtils.PutInRange(-1, list.Count - 1, beginIdx);
endIdx = RangeUtils.PutInRange(-1, list.Count - 1, endIdx);
for (int i = beginIdx; i > endIdx; --i)
{
yield return(list[i]);
}
}
public static IEnumerable <T> EnumForward <T>(this IList <T> list, int beginIdx, int endIdx)
{
beginIdx = RangeUtils.PutInRange(0, list.Count, beginIdx);
endIdx = RangeUtils.PutInRange(0, list.Count, endIdx);
for (int i = beginIdx; i < endIdx; ++i)
{
yield return(list[i]);
}
}