private Option <Tuple <int, int> > GetPreviousBounds(bool stopAtMark, bool ignoreNoMark)
{
Option <int> maybeIndex = new None();
if (stopAtMark)
{
maybeIndex = GetPreviousMarkIndex().Apply(index => _marks[index].BufferIndex);
}
if (!stopAtMark || (maybeIndex.IsNone && ignoreNoMark))
{
maybeIndex = 0;
}
return(maybeIndex.Apply(index => GetPosFromIndex(index)));
}
private Option <Tuple <int, int> > GetNextBounds(bool stopAtMark, bool ignoreNoMark)
{
Option <int> maybeIndex = new None();
if (stopAtMark)
{
maybeIndex = GetNextMarkIndex().Apply(index => _marks[index].BufferIndex);
}
if (!stopAtMark || (maybeIndex.IsNone && ignoreNoMark))
{
maybeIndex = Width.Value * Height.Value - 1;
}
return(maybeIndex.Apply(index => GetPosFromIndex(index)));
}