#pragma once

#include "Iterator.Base.tlh"


//-----------------------------------------------------------------------------
//		SequenceIterator
//		只支持顺序访问, 但是又想要 Skip 功能的迭代器
//-----------------------------------------------------------------------------
namespace Iterator
{
	template <typename IterType>
	class __SequenceIterator : public __BaseIterator <IterType>
	{
	public:
		///	之前的 Array::Iterator 有防护功能, 因此这里也限制过分的增减
		inline void Skip (int delta)
		{
			if (delta == 0)  return;

			if (delta > 0)
			{
				if (this->m_Index + delta >= this->m_Count)
				{
					this->m_Index = this->m_Count;
					this->m_stdIter = this->m_stdEnd;
				}
				else
				{
					for (int Index = 0; Index < delta; Index ++)
						this->m_stdIter ++;
					this->m_Index += delta;
				}
			}
			else
//			if (delta < 0)
			{
				if (this->m_Index + delta < 0)
				{
					this->m_Index = -1;
					this->m_stdIter = this->m_stdEnd;
				}
				else
				{
					for (int Index = 0; Index < -delta; Index ++)
						this->m_stdIter --;
					this->m_Index += delta;
				}
			}
		}

		inline void operator += (int N)
		{
			Skip (N);
		}

		inline void operator -= (int N)
		{
			Skip (-N);
		}

	};
}