#include "stack.h"
// note -- don't need destructor, copy constructor
//      -- subject to typos

//------------------------------ constructor ---------------------------------
Stack::Stack() {
   top = -1;
}

//------------------------------ clear ---------------------------------------
// deallocate memory (or just set top to -1 if there's no dynamic memory)
void Stack::clear() {
   for (int i = 0; i <= top; i++) {
      delete array[i];
      array[i] = NULL;
   }
   top = -1;
}

//------------------------------ isEmpty -------------------------------------
// check to see if stack is empty
bool Stack::isEmpty() const {
   return (top == -1);
}

//------------------------------ isFull --------------------------------------
// check to see if stack is full
bool Stack::isFull() const {
   return (top == MAX-1);
}
//--------------------------------- push -------------------------------------
// push (insert) item onto top of stack
bool Stack::push(NodeData* dataptr) {                    

   if (!isFull()) {
      array[++top] = dataptr;
      return true;
   }
   return false;
}

//---------------------------------- pop -------------------------------------
// pop (remove) item off top of stack
bool Stack::pop(NodeData*& dataptr) {                    
   if (isEmpty())
      return false;
   else {
      dataptr = array[top--];
      return true;
   }
}

//---------------------------------- peek ------------------------------------
// return item at top of stack
bool Stack::peek(NodeData*& dataptr) const {                    
   if (isEmpty())
      return false;
   else {
      dataptr = array[top];
      return true;
   }
}

//----------------------------------  <<  ------------------------------------
// Overloaded output operator for class Stack
ostream& operator<<(ostream& output, const Stack& theStack) {
   
   if (theStack.isEmpty()) 
       output << "There is nothing in the requested stack." << endl;
   else {
      for (int i = theStack.top; i >= 0; i--) 
         output << *theStack.array[i]     // or theStack.array[i]->printNode();
	        << endl;
      output << endl;
   }
   return output;                      
}