dlib C++ Library - stack_kernel_1.h

// Copyright (C) 2003 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_STACK_KERNEl_1_
#define DLIB_STACK_KERNEl_1_
#include "stack_kernel_abstract.h"
#include "../algs.h"
#include "../interfaces/enumerable.h"
#include "../interfaces/remover.h"
#include "../serialize.h"
namespace dlib
{
 template <
 typename T,
 typename mem_manager = default_memory_manager
 >
 class stack_kernel_1 : public enumerable<T>,
 public remover<T>
 {
 /*!
 INITIAL VALUE
 stack_size == 0 
 top == 0
 current_element == 0
 _at_start == true
 CONVENTION
 at_start() == _at_start
 current_element_valid() == (current_element != 0)
 if (current_element != 0) then
 element() == current_element->item
 stack_size == the number of elements in the stack. 
 Each node points to the next node to be poped off the stack.
 The last node in the list has its next pointer is set to 0.
 
 if (size == 0)
 {
 top == 0
 }
 else
 {
 top == pointer to the last element added to the stack
 }
 !*/
 
 struct node
 {
 node* next;
 T item;
 };
 
 public:
 typedef T type;
 typedef mem_manager mem_manager_type;
 stack_kernel_1(
 ):
 top(0),
 stack_size(0),
 current_element(0),
 _at_start(true)
 {}
 
 virtual ~stack_kernel_1(
 );
 inline void clear(
 );
 inline void push(
 T& item
 );
 void pop(
 T& item
 );
 T& current(
 );
 const T& current(
 ) const;
 inline void swap (
 stack_kernel_1& item
 );
 
 // functions from the remover interface
 inline void remove_any (
 T& item
 ); 
 // functions from the enumerable interface
 inline size_t size (
 ) const;
 inline bool at_start (
 ) const;
 inline void reset (
 ) const;
 bool current_element_valid (
 ) const;
 inline const T& element (
 ) const;
 inline T& element (
 );
 bool move_next (
 ) const;
 private:
 void delete_elements_in_stack(
 node*& top
 );
 /*!
 requires
 - top points to the top of the stack
 ensures
 - all memory has been freed 
 - #top = 0
 !*/
 // data members
 typename mem_manager::template rebind<node>::other pool;
 node* top;
 unsigned long stack_size;
 mutable node* current_element;
 mutable bool _at_start;
 // restricted functions
 stack_kernel_1(stack_kernel_1&); // copy constructor
 stack_kernel_1& operator=(stack_kernel_1&); // assignment operator
 };
 template <
 typename T,
 typename mem_manager
 >
 inline void swap (
 stack_kernel_1<T,mem_manager>& a, 
 stack_kernel_1<T,mem_manager>& b 
 ) { a.swap(b); } 
 template <
 typename T,
 typename mem_manager
 >
 void deserialize (
 stack_kernel_1<T,mem_manager>& item, 
 std::istream& in
 )
 {
 try
 {
 item.clear();
 unsigned long size;
 deserialize(size,in);
 T temp = T();
 stack_kernel_1<T> temp_stack;
 for (unsigned long i = 0; i < size; ++i)
 {
 deserialize(temp,in);
 temp_stack.push(temp);
 }
 while (temp_stack.size() > 0)
 {
 temp_stack.pop(temp);
 item.push(temp);
 }
 }
 catch (serialization_error& e)
 { 
 item.clear();
 throw serialization_error(e.info + "\n while deserializing object of type stack_kernel_1"); 
 }
 }
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 // member function definitions
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 
 template <
 typename T,
 typename mem_manager
 >
 stack_kernel_1<T,mem_manager>::
 ~stack_kernel_1(
 ) 
 {
 delete_elements_in_stack(top);
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 clear(
 )
 {
 if (stack_size != 0)
 {
 delete_elements_in_stack(top);
 stack_size = 0;
 }
 reset();
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 T& stack_kernel_1<T,mem_manager>::
 current(
 )
 {
 return top->item;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 const T& stack_kernel_1<T,mem_manager>::
 current(
 ) const
 {
 return top->item;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 swap(
 stack_kernel_1<T,mem_manager>& item
 )
 {
 pool.swap(item.pool);
 // declare temp variables
 node* top_temp;
 unsigned long stack_size_temp;
 // swap stack_size variables
 stack_size_temp = item.stack_size;
 item.stack_size = stack_size;
 stack_size = stack_size_temp;
 // swap top pointers
 top_temp = item.top;
 item.top = top;
 top = top_temp;
 exchange(current_element,item.current_element);
 exchange(_at_start,item._at_start);
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 push(
 T& item
 )
 {
 // allocate memory for new node
 node* new_node = pool.allocate();
 // swap item into new_node
 exchange(new_node->item,item);
 
 // put new_node into stack
 new_node->next = top;
 top = new_node;
 ++stack_size;
 reset();
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 pop(
 T& item
 )
 {
 node* old_node = top;
 top = top->next;
 // swap the item from the stack into item
 exchange(old_node->item,item);
 
 // free the memory
 pool.deallocate(old_node);
 --stack_size;
 reset();
 }
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 // private member function definitions
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 delete_elements_in_stack(
 node*& top
 )
 {
 node* temp;
 while (top != 0)
 {
 temp = top->next;
 pool.deallocate(top);
 top = temp;
 }
 }
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 // enumerable function definitions
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 
 template <
 typename T,
 typename mem_manager
 >
 size_t stack_kernel_1<T,mem_manager>::
 size (
 ) const
 {
 return stack_size;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 bool stack_kernel_1<T,mem_manager>::
 at_start (
 ) const
 {
 return _at_start;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 reset (
 ) const
 {
 _at_start = true;
 current_element = 0;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 bool stack_kernel_1<T,mem_manager>::
 current_element_valid (
 ) const
 {
 return current_element != 0;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 const T& stack_kernel_1<T,mem_manager>::
 element (
 ) const
 {
 return current_element->item;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 T& stack_kernel_1<T,mem_manager>::
 element (
 )
 {
 return current_element->item;
 }
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 bool stack_kernel_1<T,mem_manager>::
 move_next (
 ) const
 {
 if (!_at_start)
 {
 if (current_element)
 {
 current_element = current_element->next;
 if (current_element)
 return true;
 else
 return false;
 }
 else
 {
 return false;
 }
 }
 else
 {
 _at_start = false;
 if (stack_size)
 {
 current_element = top;
 return true;
 }
 else
 {
 return false;
 }
 }
 }
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 // remover function definitions
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
 template <
 typename T,
 typename mem_manager
 >
 void stack_kernel_1<T,mem_manager>::
 remove_any (
 T& item
 ) 
 {
 pop(item);
 }
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_STACK_KERNEl_1_