ilist.h

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/******************************************************************************
The MIT License(MIT)

Embedded Template Library.

Copyright(c) 2014 jwellbelove

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions :

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
******************************************************************************/

#ifndef __ETL_ILIST__
#define __ETL_ILIST__
#define __ETL_IN_ILIST_H__

#if WIN32
#undef min
#endif

#include <iterator>
#include <algorithm>
#include <functional>
#include <stddef.h>

#include "nullptr.h"
#include "list_base.h"
#include "type_traits.h"
#include "parameter_type.h"

namespace etl
{
  //***************************************************************************
  //***************************************************************************
  template <typename T>
  class ilist : public list_base
  {
  public:

    typedef T        value_type;
    typedef T*       pointer;
    typedef const T* const_pointer;
    typedef T&       reference;
    typedef const T& const_reference;
    typedef size_t   size_type;

  protected:
    
    typedef typename parameter_type<T, is_fundamental<T>::value || is_pointer<T>::value>::type parameter_t;


    //*************************************************************************
    //*************************************************************************
    struct Node
    {
      //***********************************************************************
      //***********************************************************************
      Node()
        : previous(nullptr),
          next(nullptr)
      {
      }

      //***********************************************************************
      //***********************************************************************
      void mark_as_free()
      {
        previous = nullptr;
        next     = nullptr;
      }

      //***********************************************************************
      //***********************************************************************
      bool is_free() const
      {
        return next == nullptr;
      }

      //***********************************************************************
      //***********************************************************************
      void reverse()
      {
        std::swap(previous, next);
      }

      Node* previous;
      Node* next;
    };

    //*************************************************************************
    //*************************************************************************
    struct Data_Node : public Node
    {
      T value;
    };

    Node terminal_node;  

  private:

    Data_Node* node_pool;

    //*************************************************************************
    //*************************************************************************
    static Data_Node* data_cast(Node* p_node)
    {
      return static_cast<Data_Node*>(p_node);
    }

    //*************************************************************************
    //*************************************************************************
    static Data_Node& data_cast(Node& node)
    {
      return static_cast<Data_Node&>(node);
    }

    //*************************************************************************
    //*************************************************************************
    static const Data_Node* data_cast(const Node* p_node)
    {
      return static_cast<const Data_Node*>(p_node);
    }

    //*************************************************************************
    //*************************************************************************
    static const Data_Node& data_cast(const Node& node)
    {
      return static_cast<const Data_Node&>(node);
    }

  public:

    //*************************************************************************
    //*************************************************************************
    class iterator : public std::iterator<std::bidirectional_iterator_tag, T>
    {
    public:

      friend class ilist;

      iterator()
        : p_node(nullptr)
      {
      }

      iterator(Node& node)
        : p_node(&node)
      {
      }

      iterator(const iterator& other)
        : p_node(other.p_node)
      {
      }

      iterator& operator ++()
      {
        p_node = p_node->next;
        return *this;
      }

      iterator operator ++(int)
      {
        iterator temp(*this);
        p_node = p_node->next;
        return temp;
      }

      iterator& operator --()
      {
        p_node = p_node->previous;
        return *this;
      }

      iterator operator --(int)
      {
        iterator temp(*this);
        p_node = p_node->previous;
        return temp;
      }

      iterator operator =(const iterator& other)
      {
        p_node = other.p_node;
        return *this;
      }

      reference operator *()
      {
        return ilist::data_cast(p_node)->value;
      }

      const_reference operator *() const
      {
        return p_node->value;
      }

      pointer operator &()
      {
        return &(ilist::data_cast(p_node)->value);
      }

      const_pointer operator &() const
      {
        return &(ilist::data_cast(p_node)->value);
      }

      pointer operator ->()
      {
        return &(ilist::data_cast(p_node)->value);
      }

      const_pointer operator ->() const
      {
        return &(ilist::data_cast(p_node)->value);
      }

      friend bool operator == (const iterator& lhs, const iterator& rhs)
      {
        return lhs.p_node == rhs.p_node;
      }

      friend bool operator != (const iterator& lhs, const iterator& rhs)
      {
        return !(lhs == rhs);
      }

    private:

      Node* p_node;
    };

    //*************************************************************************
    //*************************************************************************
    class const_iterator : public std::iterator<std::bidirectional_iterator_tag, const T>
    {
    public:

      friend class ilist;

      const_iterator()
        : p_node(nullptr)
      {
      }

      const_iterator(Node& node)
        : p_node(&node)
      {
      }

      const_iterator(const Node& node)
        : p_node(&node)
      {
      }

      const_iterator(const typename ilist::iterator& other)
        : p_node(other.p_node)
      {
      }

      const_iterator(const const_iterator& other)
        : p_node(other.p_node)
      {
      }

      const_iterator& operator ++()
      {
        p_node = p_node->next;
        return *this;
      }

      const_iterator operator ++(int)
      {
        const_iterator temp(*this);
        p_node = p_node->next;
        return temp;
      }

      const_iterator& operator --()
      {
        p_node = p_node->previous;
        return *this;
      }

      const_iterator operator --(int)
      {
        const_iterator temp(*this);
        p_node = p_node->previous;
        return temp;
      }

      const_iterator operator =(const const_iterator& other)
      {
        p_node = other.p_node;
        return *this;
      }

      const_reference operator *() const
      {
        return ilist::data_cast(p_node)->value;
      }

      const_pointer operator &() const
      {
        return ilist::data_cast(p_node)->value;
      }

      const Data_Node* operator ->() const
      {
        return p_node;
      }

      friend bool operator == (const const_iterator& lhs, const const_iterator& rhs)
      {
        return lhs.p_node == rhs.p_node;
      }

      friend bool operator != (const const_iterator& lhs, const const_iterator& rhs)
      {
        return !(lhs == rhs);
      }

    private:

      const Node* p_node;
    };

        typedef typename std::iterator_traits<iterator>::difference_type difference_type;

    typedef std::reverse_iterator<iterator>       reverse_iterator;
    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

    //*************************************************************************
    //*************************************************************************
    ilist& operator = (const ilist& rhs)
    {
      assign(rhs.cbegin(), rhs.cend());

      return *this;
    }

    //*************************************************************************
    //*************************************************************************
    iterator begin()
    {
      return iterator(get_head());
    }

    //*************************************************************************
    //*************************************************************************
    const_iterator begin() const
    {
      return const_iterator(get_head());
    }

    //*************************************************************************
    //*************************************************************************
    iterator end()
    {
      return iterator(terminal_node);
    }

    //*************************************************************************
    //*************************************************************************
    const_iterator end() const
    {
      return const_iterator(static_cast<const Data_Node&>(terminal_node));
    }

    //*************************************************************************
    //*************************************************************************
    const_iterator cbegin() const
    {
      return const_iterator(get_head());
    }

    //*************************************************************************
    //*************************************************************************
    const_iterator cend() const
    {
      return const_iterator(static_cast<const Data_Node&>(terminal_node));
    }

    //*************************************************************************
    //*************************************************************************
    reverse_iterator rbegin()
    {
      return reverse_iterator(terminal_node);
    }

    //*************************************************************************
    //*************************************************************************
    const_reverse_iterator rbegin() const
    {
      return const_reverse_iterator(static_cast<const Data_Node&>(terminal_node));
    }

    //*************************************************************************
    //*************************************************************************
    reverse_iterator rend()
    {
      return reverse_iterator(get_head());
    }

    //*************************************************************************
    //*************************************************************************
    const_reverse_iterator crbegin() const
    {
      return const_reverse_iterator(static_cast<const Data_Node&>(terminal_node));
    }

    //*************************************************************************
    //*************************************************************************
    const_reverse_iterator crend() const
    {
      return const_reverse_iterator(get_head());
    }

    //*************************************************************************
    //*************************************************************************
    reference front()
    {
      return data_cast(get_head()).value;
    }

    //*************************************************************************
    //*************************************************************************
    const_reference front() const
    {
      return data_cast(get_head()).value;
    }

    //*************************************************************************
    //*************************************************************************
    reference back()
    {
      return data_cast(get_tail()).value;
    }

    //*************************************************************************
    //*************************************************************************
    const_reference back() const
    {
      return data_cast(get_tail()).value;
    }

    //*************************************************************************
    //*************************************************************************
    template <typename TIterator>
    void assign(TIterator first, TIterator last)
    {
      // Reset the links.
      join(terminal_node, terminal_node);
      current_size = 0;

      // Add all of the elements.
      while (first != last)
      {
        if (!full())
        {
          Data_Node& data_node = node_pool[current_size];
          data_node.value = *first;
          join(get_tail(), data_node);
          join(data_node, terminal_node);
        }
        else
        {
#ifdef ETL_THROW_EXCEPTIONS
          throw list_full();
#else
          error_handler::error(list_full());
#endif
        }

        ++first;
        ++current_size;
      }

      next_free = current_size;

      // Clear the remaining elements in the node pool.
      for (size_t i = current_size; i < MAX_SIZE; ++i)
      {
        node_pool[i].mark_as_free();
      }
    }

    //*************************************************************************
    //*************************************************************************
    void assign(size_t n, parameter_t value)
    {
      // Reset the links.
      join(terminal_node, terminal_node);
      current_size = 0;

      // Add all of the elements.
      while (current_size < n)
      {
        if (!full())
        {
          Data_Node& data_node = node_pool[current_size];
          data_node.value = value;
          join(*terminal_node.previous, data_node);
          join(data_node, terminal_node);
        }
        else
        {
#ifdef ETL_THROW_EXCEPTIONS        
          throw list_full();
#else
          error_handler::error(list_full());
#endif
        }

        ++current_size;
      }

      next_free = current_size;

      // Clear the remaining elements in the node pool.
      for (size_t i = current_size; i < MAX_SIZE; ++i)
      {
        node_pool[i].mark_as_free();
      }
    }

    //*************************************************************************
    //*************************************************************************
    void push_front()
    {
      if (!full())
      {
        Data_Node& data_node = node_pool[next_free];
        insert_node(get_head(), data_node);
      }
      else
      {
#ifdef ETL_THROW_EXCEPTIONS        
        throw list_full();
#else
        error_handler::error(list_full());
#endif
      }
    }

    //*************************************************************************
    //*************************************************************************
    void push_front(parameter_t value)
    {
      if (!full())
      {
        Data_Node& data_node = node_pool[next_free];
        data_node.value = value;
        insert_node(get_head(), data_node);
      }
      else
      {
#ifdef ETL_THROW_EXCEPTIONS        
        throw list_full();
#else
        error_handler::error(list_full());
#endif
      }
    }

    //*************************************************************************
    //*************************************************************************
    void pop_front()
    {
      if (!empty())
      {
        remove_node(get_head());
      }
    }

    //*************************************************************************
    //*************************************************************************
    void push_back()
    {
      if (!full())
      {
        Data_Node& data_node = node_pool[next_free];
        insert_node(terminal_node, data_node);
      }
      else
      {
#ifdef ETL_THROW_EXCEPTIONS        
        throw list_full();
#else
        error_handler::error(list_full());
#endif
      }
    }

    //*************************************************************************
    //*************************************************************************
    void push_back(parameter_t value)
    {
      if (!full())
      {
        Data_Node& data_node = node_pool[next_free];
        data_node.value = value;
        insert_node(terminal_node, data_node);
      }
      else
      {
#ifdef ETL_THROW_EXCEPTIONS        
        throw list_full();
#else
        error_handler::error(list_full());
#endif
      }
    }

    //*************************************************************************
    //*************************************************************************
    void pop_back()
    {
      if (!empty())
      {
        remove_node(get_tail());
      }
    }

    //*************************************************************************
    //*************************************************************************
    iterator insert(iterator position, const value_type& value)
    {
      if (!full())
      {
        Data_Node& data_node = node_pool[next_free];
        data_node.value = value;

        insert_node(*position.p_node, data_node);

        return iterator(data_node);
      }
      else
      {
#ifdef ETL_THROW_EXCEPTIONS        
        throw list_full();
#else
        error_handler::error(list_full());
        return end();
#endif
      }
    }

    //*************************************************************************
    //*************************************************************************
    void insert(iterator position, size_t n, const value_type& value)
    {
      for (size_t i = 0; i < n; ++i)
      {
        if (!full())
        {
          // Set up the next free node and insert.
          Data_Node& data_node = node_pool[next_free];
          data_node.value = value;
          insert_node(*position.p_node, data_node);
        }
        else
        {
#ifdef ETL_THROW_EXCEPTIONS        
          throw list_full();
#else
          error_handler::error(list_full());
#endif
        }
      }
    }

    //*************************************************************************
    //*************************************************************************
    template <typename TIterator>
    void insert(iterator position, TIterator first, TIterator last)
    {
      while (first != last)
      {
        if (!full())
        {
          // Set up the next free node and insert.
          Data_Node& data_node = node_pool[next_free];
          data_node.value = *first++;
          insert_node(*position.p_node, data_node);
        }
        else
        {
#ifdef ETL_THROW_EXCEPTIONS        
          throw list_full();
#else
          error_handler::error(list_full());
#endif
        }
      }
    }

    //*************************************************************************
    //*************************************************************************
    iterator erase(iterator position)
    {
      iterator next(position);
      ++next;

      remove_node(*position.p_node);

      return next;
    }

    //*************************************************************************
    //*************************************************************************
    iterator erase(iterator first, iterator last)
    {
      Node* p_first = first.p_node;
      Node* p_last  = last.p_node;
      Node* p_next;

      // Join the ends.
      join(*(p_first->previous), *p_last);

      // Erase the ones in between.
      while (p_first != p_last)
      {
        // Update the position of the earliest free node in the pool.
        size_t new_free = std::distance(&node_pool[0], data_cast(p_first));
        next_free       = std::min(next_free, new_free);

        // One less.
        --current_size;

        p_next = p_first->next;  // Remember the next node.
        p_first->mark_as_free(); // Free the current node.
        p_first = p_next;        // Move to the next node.
      }

      return last;
    }

    //*************************************************************************
    //*************************************************************************
    void resize(size_t n)
    {
      resize(n, T());
    }

    //*************************************************************************
    //*************************************************************************
    void resize(size_t n, parameter_t value)
    {
      if (n > MAX_SIZE)
      {
#ifdef ETL_THROW_EXCEPTIONS        
        throw list_full();
#else
        error_handler::error(list_full());
        n = MAX_SIZE;
#endif
      }

      // Smaller?
      if (n < size())
      {
        iterator i_start = end();
        std::advance(i_start, -difference_type(size() - n));
        erase(i_start, end());
      }
      // Larger?
      else if (n > size())
      {
        insert(end(), n - size(), value);
      }
    }

    //*************************************************************************
    //*************************************************************************
    void clear()
    {
      initialise();
    }

    //*************************************************************************
    // Removes the values specified.
    //*************************************************************************
    void remove(const value_type& value)
    {
      iterator iValue = begin();

      while (iValue != end())
      {
        if (value == *iValue)
        {
          iValue = erase(iValue);
        }
        else
        {
          ++iValue;
        }
      }
    }

    //*************************************************************************
    //*************************************************************************
    template <typename TPredicate>
    void remove_if(TPredicate predicate)
    {
      iterator iValue = begin();

      while (iValue != end())
      {
        if (predicate(*iValue))
        {
          iValue = erase(iValue);
        }
        else
        {
          ++iValue;
        }
      }
    }

    //*************************************************************************
    //*************************************************************************
    void unique()
    {
        unique(std::equal_to<T>());
    }

    //*************************************************************************
    //*************************************************************************
    template <typename TIsEqual>
    void unique(TIsEqual isEqual)
    {
      if (empty())
      {
        return;
      }

      iterator i_item = begin();
      ++i_item;
      iterator i_previous = begin();

      while (i_item != end())
      {
        if (isEqual(*i_previous, *i_item))
        {
          i_item = erase(i_item);
        }
        else
        {
          i_previous = i_item;
          ++i_item;
        }
      }
    }

    //*************************************************************************
    //*************************************************************************
    void sort()
    {
      sort(std::less<T>());
    }

    //*************************************************************************
    //*************************************************************************
    template <typename TCompare>
    void sort(TCompare compare)
    {
      iterator i_left;
      iterator i_right;
      iterator i_node;
      iterator i_head;
      iterator i_tail;
      int   list_size = 1;
      int   number_of_merges;
      int   left_size;
      int   right_size;

      if (is_trivial_list())
      {
        return;
      }

      while (true)
      {
        i_left = begin();
        i_head = end();
        i_tail = end();

        number_of_merges = 0;  // Count the number of merges we do in this pass.

        while (i_left != end())
        {
          ++number_of_merges;  // There exists a merge to be done.
          i_right = i_left;
          left_size = 0;

          // Step 'list_size' places along from left
          for (int i = 0; i < list_size; ++i)
          {
            ++left_size;
            ++i_right;

            if (i_right == end())
            {
              break;
            }
          }

          // If right hasn't fallen off end, we have two lists to merge.
          right_size = list_size;

          // Now we have two lists. Merge them.
          while (left_size > 0 || (right_size > 0 && i_right != end()))
          {
            // Decide whether the next node of merge comes from left or right.
            if (left_size == 0)
            {
              // Left is empty. The node must come from right.
              i_node = i_right++;
              --right_size;
            }
            else if (right_size == 0 || i_right == end())
            {
              // Right is empty. The node must come from left.
              i_node = i_left++;
              --left_size;
            }
            else if (compare(*i_left, *i_right))
            {
              // First node of left is lower or same. The node must come from left.
              i_node = i_left++;
              --left_size;
            }
            else
            {
              // First node of right is lower. The node must come from right.
              i_node = i_right;
              ++i_right;
              --right_size;
            }

            // Add the next node to the merged head.
            if (i_head == end())
            {
              join(*i_head.p_node, *i_node.p_node);
              i_head = i_node;
              i_tail = i_node;
            }
            else
            {
              join(*i_tail.p_node, *i_node.p_node);
              i_tail = i_node;
            }

            join(*i_tail.p_node, terminal_node);
          }

          // Now left has stepped `list_size' places along, and right has too.
          i_left = i_right;
        }

        // If we have done only one merge, we're finished.
        if (number_of_merges <= 1)   // Allow for number_of_merges == 0, the empty head case
        {
          return;
        }

        // Otherwise repeat, merging lists twice the size
        list_size *= 2;
      }
    }

    //*************************************************************************
    //*************************************************************************
    void reverse()
    {
      if (is_trivial_list())
      {
        return;
      }

      iterator i_item = begin();

      while (i_item != end())
      {
        i_item.p_node->reverse();
        --i_item; // Now we've reversed it, we must decrement it.
      }

      // Terminal node.
      i_item.p_node->reverse();
    }

  protected:

    //*************************************************************************
    //*************************************************************************
    ilist(Data_Node* node_pool, size_t max_size_)
      : list_base(max_size_),
        node_pool(node_pool)
    {
      initialise();
    }

  private:

    //*************************************************************************
    //*************************************************************************
    void join(Node& left, Node& right)
    {
      left.next      = &right;
      right.previous = &left;
    }

    //*************************************************************************
    //*************************************************************************
    void join(Data_Node& left, Data_Node& right)
    {
      left.next      = &right;
      right.previous = &left;
    }

    //*************************************************************************
    //*************************************************************************
    bool is_trivial_list() const
    {
      return (size() < 2);
    }

    //*************************************************************************
    //*************************************************************************
    void find_next_free()
    {
      while (next_free != MAX_SIZE)
      {
        if (node_pool[next_free].is_free())
        {
          return;
        }
        else
        {
          ++next_free;
        }
      }
    }

    //*************************************************************************
    //*************************************************************************
    void insert_node(Node& position, Node& node)
    {
      // Connect to the list.
      join(*position.previous, node);
      join(node,               position);

      // One more.
      ++current_size;

      // Update the position of the next free node in the pool.
      find_next_free();
    }

    //*************************************************************************
    //*************************************************************************
    void remove_node(Node& node)
    {
      // Update the position of the next free node in the pool.
      size_t new_free = std::distance(&node_pool[0], data_cast(&node));
      next_free       = std::min(next_free, new_free);

      // One less.
      --current_size;

      // Disconnect the node from the list.
      join(*node.previous, *node.next);
      node.mark_as_free();
    }

    //*************************************************************************
    //*************************************************************************
    Node& get_head()
    {
      return *terminal_node.next;
    }

    //*************************************************************************
    //*************************************************************************
    const Node& get_head() const
    {
      return *terminal_node.next;
    }

    //*************************************************************************
    //*************************************************************************
    Node& get_tail()
    {
      return *terminal_node.previous;
    }

    //*************************************************************************
    //*************************************************************************
    const Node& get_tail() const
    {
      return *terminal_node.previous;
    }

    //*************************************************************************
    //*************************************************************************
    void initialise()
    {
      // Reset the node pool.
      for (size_t i = 0; i < max_size(); ++i)
      {
        node_pool[i].mark_as_free();
      }

      next_free    = 0;
      current_size = 0;
      join(terminal_node, terminal_node);
    }
  };
}

//*************************************************************************
//*************************************************************************
template <typename T>
bool operator ==(const etl::ilist<T>& lhs, const etl::ilist<T>& rhs)
{
  return (lhs.size() == rhs.size()) && std::equal(lhs.begin(), lhs.end(), rhs.begin());
}

//*************************************************************************
//*************************************************************************
template <typename T>
bool operator !=(const etl::ilist<T>& lhs, const etl::ilist<T>& rhs)
{
  return !(lhs == rhs);
}

//*************************************************************************
//*************************************************************************
template <typename T>
bool operator <(const etl::ilist<T>& lhs, const etl::ilist<T>& rhs)
{
  return std::lexicographical_compare(lhs.begin(),
                                      lhs.end(),
                                      rhs.begin(),
                                      rhs.end());
}

//*************************************************************************
//*************************************************************************
template <typename T>
bool operator >(const etl::ilist<T>& lhs, const etl::ilist<T>& rhs)
{
  return std::lexicographical_compare(lhs.begin(),
                                      lhs.end(),
                                      rhs.begin(),
                                      rhs.end(),
                                      std::greater<T>());
}

//*************************************************************************
//*************************************************************************
template <typename T>
bool operator <=(const etl::ilist<T>& lhs, const etl::ilist<T>& rhs)
{
  return !operator >(lhs, rhs);
}

//*************************************************************************
//*************************************************************************
template <typename T>
bool operator >=(const etl::ilist<T>& lhs, const etl::ilist<T>& rhs)
{
  return !operator <(lhs, rhs);
}

#if WIN32
#define min(a,b) (((a) < (b)) ? (a) : (b))
#endif

#endif