public static IEnumerable <Sandwich <TSource> > Sandwich <TSource>(this IEnumerable <TSource> source)
{
var withExtras = source.AddFakeSlices();
var sandwiches = withExtras
.Skip(1)
.Zip(withExtras, (curr, prev) => new
{
Current = curr,
Previous = prev
})
.Zip(withExtras.Skip(2), (curr, next) => new
{
curr.Previous,
curr.Current,
Next = next
});
foreach (var item in sandwiches)
{
var sandwich = new Sandwich <TSource>()
{
Previous = item.Previous,
Current = item.Current,
Next = item.Next
};
yield return(sandwich);
}
}
public static IEnumerable <TResult> Sandwich <TSource, TResult>(this IEnumerable <TSource> source, Func <TSource, TSource, TSource, TResult> projection) where TSource : class
{
var withExtras = source.AddFakeSlices();
var prevCurrNext = withExtras
.Skip(1)
.Zip(withExtras, (curr, prev) => new
{
Current = curr,
Previous = prev
})
.Zip(withExtras.Skip(2), (curr, next) => new
{
curr.Previous,
curr.Current,
Next = next
});
foreach (var item in prevCurrNext)
{
yield return(projection(item.Previous, item.Current, item.Next));
}
}
