private static void Skip(ref IListContext <T> context, out Option <T> next)
{
context.bd.DetectBacktrack();
var index = context.index + context.step;
if (0 <= index && index < context.size)
{
next = new Option <T>(context.list[index]);
context.index = index;
}
else
{
next = new Option <T>();
context.bd.Release();
}
}
private static void SkipWithIndex(ref IListContext <T> context, out Option <ValueTuple <T, int> > next)
{
context.bd.DetectBacktrack();
var index = context.index + context.step;
if (0 <= index && index < context.size)
{
next = new Option <ValueTuple <T, int> >(new ValueTuple <T, int>(context.list[index], index));
context.index = index;
}
else
{
next = new Option <ValueTuple <T, int> >();
context.bd.Release();
}
}
private static void Remove(ref IListContext <T> context, out Option <T> next)
{
context.bd.DetectBacktrack();
context.list.RemoveAt(context.index);
if (context.step == 0)
{
next = new Option <T>();
context.bd.Release();
}
else
{
if (context.step > 0)
{
--context.index;
}
--context.size;
Skip(ref context, out next);
}
}
private static void DisposeWithIndex(ref IListContext <T> context, out Option <Tuple <T, int> > next)
{
next = new Option <Tuple <T, int> >();
context.bd.Release();
}
private static void Dispose(ref IListContext <T> context, out Option <T> next)
{
next = new Option <T>();
context.bd.Release();
}
