bfinterp.h

#pragma once

#include<iostream>
#include<vector>
#include<stack>

class Interpreter
{
public:
	static void Run(std::string input)
	{
		std::vector<char> m_data;
		for (int i = 0; i < 30000; i++)
			m_data.push_back(0);

		std::stack<int> m_instructionPtrStack;	//for []

		int m_dataPointer = 0, m_instructionPointer = 0;

		while (m_instructionPointer < input.size())
		{
			char cur = input[m_instructionPointer];

			switch (cur)
			{
			case '>':
				m_dataPointer++;
				break;
			case '<':
				m_dataPointer--;
				break;
			case '+':
				m_data[m_dataPointer]++;
				break;
			case '-':
				m_data[m_dataPointer]--;
				break;
			case '.':
				std::cout << m_data[m_dataPointer];
				break;
			case ',':
				std::cout << "INPUT required: ";
				std::cin >> m_data[m_dataPointer];
				break;
			case '[':
				m_instructionPtrStack.push(m_instructionPointer);
				if (m_data[m_dataPointer] == 0)
				{
					int m_tempInstructionPointer = m_instructionPointer;
					while (++m_tempInstructionPointer < input.size())
					{
						char tempItem = input[m_tempInstructionPointer];
						if (tempItem == '[')
							m_instructionPtrStack.push(m_tempInstructionPointer);
						else if (tempItem == ']')
						{
							int m_endInstructionPtr = m_instructionPtrStack.top();
							m_instructionPtrStack.pop();
							if (m_endInstructionPtr == m_instructionPointer)	//if we popped the original instruction ptr off the stack then we have reached the matching one
							{
								m_instructionPointer = m_endInstructionPtr;
								break;
							}
						}
					}
				}
				break;
			case ']':
				if (m_data[m_dataPointer] == 0)
					m_instructionPtrStack.pop();	//if zero just continue execution
				else
					m_instructionPointer = m_instructionPtrStack.top();	//otherwise we keep going
				break;
			default:
				break;
			}


			m_instructionPointer++;
		}

		std::cout << std::endl << "Finished executing. " << std::endl;
	}
};