iforward_list.h

Go to the documentation of this file.

/******************************************************************************
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 "forward_list_base.h"
#include "type_traits.h"
#include "parameter_type.h"

namespace etl
{
  //***************************************************************************
  //***************************************************************************
  template <typename T>
  class iforward_list : public forward_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 Data_Node;

    struct Node
    {
      Node()
        : next(nullptr)
      {
      }

      void mark_as_free()
      {
        next = nullptr;
      }

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

      Node* next;
    };

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

  public:

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

      friend class iforward_list;

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

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

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

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

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

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

      const_pointer operator ->() const
      {
        return &(iforward_list::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::forward_iterator_tag, const T>
    {
    public:

      friend class iforward_list;

      const_iterator()
        : p_node(nullptr)
      {
      }

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

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

      const_iterator(const typename iforward_list::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 =(const const_iterator& other)
      {
        p_node = other.p_node;
        return *this;
      }

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

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

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

      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;

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

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

    //*************************************************************************
    //*************************************************************************
    iterator before_begin()
    {
      return iterator(static_cast<Data_Node&>(start_node));
    }

    //*************************************************************************
    //*************************************************************************
    const_iterator before_begin() const
    {
      return const_iterator(static_cast<const Data_Node&>(start_node));
    }

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

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

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

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

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

      return *this;
    }

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

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

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

    //*************************************************************************
    //*************************************************************************
    template <typename TIterator>
    void assign(TIterator first, TIterator last)
    {
      // Reset the links.
      join(start_node, end_node);
      join(end_node, start_node);

      size_t i = 0;
      Node* p_last_node = &start_node;

      // Add all of the elements.
      while (first != last)
      {
        if (i < MAX_SIZE)
        {
          Data_Node& data_node = node_pool[i++];
          data_node.value = *first++;
          join(*p_last_node, data_node);
          join(data_node, end_node);
          p_last_node = &data_node;
        }
        else
#ifdef ETL_THROW_EXCEPTIONS
        {
          throw forward_list_full();
        }
#else
        {
          error_handler::error(forward_list_full());
        }
#endif
      }

      next_free = i;
      count     = i;

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

    //*************************************************************************
    //*************************************************************************
    void assign(size_t n, parameter_t value)
    {
      // Reset the links.
      join(start_node, end_node);
      join(end_node, start_node);

      size_t i = 0;
      Node* p_last_node = &start_node;

      // Add all of the elements.
      while (i < n)
      {
        if (i < MAX_SIZE)
        {
          Data_Node& data_node = node_pool[i++];
          data_node.value = value;
          join(*p_last_node, data_node);
          join(data_node, end_node);
          p_last_node = &data_node;
        }
        else
#ifdef ETL_THROW_EXCEPTIONS
        {
          throw forward_list_full();
        }
#else
        {
          error_handler::error(forward_list_full());
        }
#endif
      }

      next_free = i;
      count     = i;

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

    //*************************************************************************
    //*************************************************************************
    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 forward_list_full();
      }
#else
      {
        error_handler::error(forward_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_after(get_head(), data_node);
      }
      else
#ifdef ETL_THROW_EXCEPTIONS
      {
        throw forward_list_full();
      }
#else
      {
        error_handler::error(forward_list_full());
      }
#endif
    }

    //*************************************************************************
    //*************************************************************************
    void pop_front()
    {
      if (!empty())
      {
        remove_node_after(start_node);
      }
    }

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

    //*************************************************************************
    //*************************************************************************
    void resize(size_t n, T value)
    {
      if (n <= MAX_SIZE)
      {
        size_t i = 0;
        iterator i_node = begin();

        // Find where we're currently at.
        while ((i < n) && (i_node != end()))
        {
          ++i;
          ++i_node;
        }

        if (i_node != end())
        {
          // Reduce.
          erase_after(i_node, end());
        }
        else if (i_node == end())
        {
          while (i < n)
          {
            i_node = insert_after(i_node, value);
            ++i;
          }
        }
      }
      else
#ifdef ETL_THROW_EXCEPTIONS
      {
        throw forward_list_full();
      }
#else
      {
        error_handler::error(forward_list_full());
      }
#endif
    }

    //*************************************************************************
    //*************************************************************************
    void reverse()
    {
      if (is_trivial_list())
      {
        return;
      }
      
      Node* p_last    = &start_node;
      Node* p_current = p_last->next;
      Node* p_next    = p_current->next;

      join(*p_current, end_node);

      while (p_next != &end_node)
      {
        p_last = p_current;
        p_current = p_next;
        p_next = p_current->next;

        p_current->next = static_cast<Data_Node*>(p_last);
      }

      join(start_node, *p_current);
    }

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

        insert_node_after(*position.p_node, data_node);

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

    //*************************************************************************
    //*************************************************************************
    void insert_after(iterator position, size_t n, parameter_t value)
    {
      if (!full())
      {
        for (size_t i = 0; !full() && (i < n); ++i)
        {
          // Set up the next free node.
          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 forward_list_full();
      }
#else
      {
        error_handler::error(forward_list_full());
      }
#endif
    }

    //*************************************************************************
    //*************************************************************************
    template <typename TIterator>
    void insert_after(iterator position, TIterator first, TIterator last)
    {
      while (first != last)
      {
        if (!full())
        {
          // Set up the next free node.
          Data_Node& data_node = node_pool[next_free];
          data_node.value = *first;

          insert_node_after(*position.p_node, data_node);
          ++first;
          ++position;
        }
        else
#ifdef ETL_THROW_EXCEPTIONS
        {
          throw forward_list_full();
        }
#else
        {
          error_handler::error(forward_list_full());
        }
#endif
      }
    }

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

      remove_node_after(*position.p_node);

      return next;
    }

    //*************************************************************************
    //*************************************************************************
    iterator erase_after(iterator first, iterator last)
    {
      Node* p_first = first.p_node;
      Node* p_last  = last.p_node;
      Node* p_next  = p_first->next;

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

      p_first = p_next;

      // 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], static_cast<Data_Node*>(p_first));
        next_free       = std::min(next_free, new_free);

        // One less.
        --count;

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

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

      Node* last    = &get_head();
      Node* current = last->next;

      while (current != &end_node)
      {
        // Is this value the same as the last?
        if (isEqual(data_cast(current)->value, data_cast(last)->value))
        {
          remove_node_after(*last);
        }
        else
        {
          // Move on one.
          last = current;
        }

        current = last->next;
      }
    }

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

    //*************************************************************************
    //*************************************************************************
    template <typename TCompare>
    void sort(TCompare compare)
    {
      iterator p_left;
      iterator p_right;
      iterator p_node;
      iterator p_head;
      iterator p_tail;
      int      list_size = 1;
      int      number_of_merges;
      int      left_size;
      int      right_size;

      if (is_trivial_list())
      {
          return;
      }

      while (true)
      {
        p_left = begin();
        p_head = before_begin();
        p_tail = before_begin();

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

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

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

            ++p_right;

            if (p_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 && p_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.
                  p_node = p_right;
              ++p_right;
              --right_size;
                }
            else if (right_size == 0 || p_right == end())
            {
                  // Right is empty. The node must come from left.
                  p_node = p_left;
              ++p_left;
              --left_size;
                }
            else if (compare(*p_left, *p_right))
            {
                  // First node of left is lower or same. The node must come from left.
                  p_node = p_left;
              ++p_left;
              --left_size;
                }
            else
            {
                  // First node of right is lower. The node must come from right.
                  p_node  = p_right;
              ++p_right;
              --right_size;
                }

            // Add the next node to the merged head.
            if (p_head == before_begin())
            {
                join(*p_head.p_node, *p_node.p_node);
                p_head = p_node;
                p_tail = p_node;
            }
            else
            {
                join(*p_tail.p_node, *p_node.p_node);
                p_tail = p_node;
            }

            join(*p_tail.p_node, end_node);
          }

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

    //*************************************************************************
    // Removes the values specified.
    //*************************************************************************
    void remove(parameter_t value)
    {
      iterator i_item = begin();
      iterator i_last_item = before_begin();

      while (i_item != end())
      {
        if (*i_item == value)
        {
          i_item = erase_after(i_last_item);
        }
        else
        {
          ++i_item;
          ++i_last_item;
        }
      }
    }

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

      while (i_item != end())
      {
        if (predicate(*i_item))
        {
          i_item = erase_after(i_last_item);
        }
        else
        {
          ++i_item;
          ++i_last_item;
        }
      }
    }

  protected:

    //*************************************************************************
    //*************************************************************************
    iforward_list(Data_Node* node_pool, size_t max_size_)
      : forward_list_base(max_size_),
        node_pool(node_pool)
    {
      initialise();
    }

    Node start_node; 
    Node end_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);
    }

    //*************************************************************************
    //*************************************************************************
    void join(Node& left, Node& right)
    {
      left.next = &static_cast<Data_Node&>(right);
    }

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

    //*************************************************************************
    //*************************************************************************
    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_after(Node& position, Node& node)
    {
      // Connect to the forward_list.
      join(node, *position.next);
      join(position, node);

      // One more.
      ++count;

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

    //*************************************************************************
    //*************************************************************************
    void remove_node_after(Node& node)
    {
      // The node to erase.
      Node* p_node = node.next;

      // One less.
      --count;

      // Disconnect the node from the forward_list.
      join(node, *p_node->next);
      p_node->mark_as_free();

      // Update the position of the next free node in the pool.
      size_t new_free = std::distance(&node_pool[0], static_cast<Data_Node*>(p_node));
      next_free = std::min(next_free, new_free);
    }

    //*************************************************************************
    //*************************************************************************
    Node& get_head()
    {
      return static_cast<Data_Node&>(*start_node.next);
    }

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

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

      next_free = 0;
      count     = 0;
      join(start_node, end_node);
      join(end_node,   start_node);
    }
  };
}

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

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

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

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

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

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

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

#endif