/**
 * This allows access to the memory
 * the SaM Processor uses
 */
public interface Memory {
	/** 
	 * Memory limit.  
	 */
	final static int MEMORYLIMIT = 10000;
	/**
	 * Stack limit. 
	 */
	final static int STACKLIMIT = 1000;
	/**
	* Stack Type: Memory Address 
	*
	 */
	final static byte MA = 0;
	/**
	 * Stack Type: Integer
	 */
	final static byte INT = 1;
	/**
	 * Stack Type: Floating Point Number
	 */
	final static byte FLOAT = 2;
	/**
	 * Stack Type: Program Address
	 */
	final static byte PA = 3;
	/**	
	 * Stack Type: Character
	 */
	final static byte CH = 4;
	/**
	 * Reset memory to default state (0). 
	 **/
	void reset();
	/**
	 * Returns the requested memory position
	 * @param pos the memory address
	 * @return the value of the memory at the specified position
	 */
	int getMem(int pos) throws SystemException;
	/**
	 * Returns the type of the value at the requested memory position.
	 * @param pos the memory address
	 * @return the type of the memory address specified by pos
	 */
	byte getType(int pos) throws SystemException;
	/**
	 * Sets the value at the given memory address (INT type)
	 * @param pos the memory address to change
	 * @param value the value
	 */
	void setMem(int pos, int value) throws SystemException;
	/**
	 * Sets the value at the given memory address, with the given type
	 * @param pos The address of the memory to set
	 * @param type The type of the new value
	 * @param value The value 
	 */
	void setMem(int pos, byte type, int value) throws SystemException;
	/**
	 * Returns an array containing the current stack.
	 */
	int[] getStack();
	/**
	 * Returns an array containing the current heap.
	 */
	int[] getHeap();
	/**
	 * Returns an array containg the requested memory range.
	 */
	int[] getMemoryRange(int low, int high);
	/**
	 * Returns an array containing the types of the values on the stack.
	 */
	byte[] getStackTypes();
	/**
	 * Returns an array containing the types of the values in the heap.
	 */
	byte[] getHeapTypes();
	/** 
	 * Returns an array containing the types of the values in the requested
	 * memory range.
	 */
	byte[] getTypesRange(int low, int high);
	/**
	 * Pushes a value onto the stack (INT type)
	 * @param value the value to push onto the stack
	 * @throws SystemException if htere is an error accessing the stack
	 */
	void push(int value) throws SystemException;
	/** 
	 * Pushes a value onto the stack with the given type. 
	 * @param type the type of the value to push
	 * @param value the value to push
	 * @throws SystemException if there is an error while adding to the stack
	 */
	void push(byte type, int value) throws SystemException;
	/**
	 * Pops a value off the stack
	 * @throws SystemException if there is an error accessing the stack
	 * @return The value popped off the stack
	 */
	int pop() throws SystemException;
	/**
	 * Allocates the specified amount of memory on the heap + 1,
	 * sets HP to the address of the allocated memory, and pushes
	 * that on the stack.
	 * @param size the amount of memory to allocate
	 * @throws SystemException if there is an error allocating memory
	 */
	void malloc(int size) throws SystemException;
}