public static IEnumerable <List <T> > InSetsOf <T>(this IEnumerable <T> items, int setSize, bool fillPartialSetWithDefaultItems, T defaultItemToFillGroups)
{
var counter = 0;
Func <T, T, bool> keepGoing = (current, previous) =>
{
if (++counter > setSize)
{
counter = 0;
}
return(counter != 0);
};
foreach (var list in items.Group(keepGoing).Select(set => set.ToList()))
{
if (list.Count < setSize && fillPartialSetWithDefaultItems)
{
list.AddRange(Enumerable.Repeat(defaultItemToFillGroups, setSize - list.Count));
}
yield return(list);
}
}