ilookup.h

///\file

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

Embedded Template Library.

Copyright(c) 2014 jwellbelove

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of this software and associated documentation files(the "Software"), to deal
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SOFTWARE.
******************************************************************************/

#ifndef __ETL_ILOOKUP__
#define __ETL_ILOOKUP__
#define __ETL_IN_ILOOKUP_H__

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

#include "lookup_base.h"
#include "type_traits.h"
#include "parameter_type.h"
#include "ivector.h"

#ifndef ETL_THROW_EXCEPTIONS
#include "error_handler.h"
#endif

namespace etl
{
  //***************************************************************************
  /// The base class for specifically sized lookups.
  /// Can be used as a reference type for all lookups containing a specific type.
  ///\ingroup lookup
  //***************************************************************************
  template <typename TKey, typename TMapped, typename TKeyCompare>
  class ilookup : public lookup_base
  {
  public:

    typedef std::pair<TKey, TMapped> value_type;

  private:

    typedef etl::ivector<value_type> buffer_t;

  public:

    typedef TKey                                      key_type;
    typedef TMapped                                   mapped_type;
    typedef TKeyCompare                               key_compare;
    typedef value_type&                               reference;
    typedef const value_type&                         const_reference;
    typedef value_type*                               pointer;
    typedef const value_type*                         const_pointer;
    typedef typename buffer_t::iterator               iterator;
    typedef typename buffer_t::const_iterator         const_iterator;
    typedef typename buffer_t::reverse_iterator       reverse_iterator;
    typedef typename buffer_t::const_reverse_iterator const_reverse_iterator;
    typedef size_t                                    size_type;
    typedef typename std::iterator_traits<iterator>::difference_type difference_type;

  protected:

    typedef typename parameter_type<TKey>::type key_value_parameter_t;

    //*************************************************************************
    /// How to compare elements.
    //*************************************************************************
    struct compare_element
    {
      bool operator ()(const value_type& value1, const value_type& value2) const
      {
        return key_compare()(value1.first, value2.first);
      }
    };

  public:

    //*********************************************************************
    /// Assignment operator.
    /// The source lookup can be larger than the destination, but
    /// only the elements that will fit in the destination will be copied.
    ///\param other The other lookup.
    //*********************************************************************
    ilookup& operator = (ilookup& other)
    {
      buffer.operator=(other.buffer);

      return *this;
    }

    //*********************************************************************
    /// Returns an iterator to the beginning of the lookup.
    ///\return An iterator to the beginning of the lookup.
    //*********************************************************************
    iterator begin()
    {
      return buffer.begin();
    }

    //*********************************************************************
    /// Returns a const_iterator to the beginning of the lookup.
    ///\return A const iterator to the beginning of the lookup.
    //*********************************************************************
    const_iterator begin() const
    {
      return buffer.begin();
    }

    //*********************************************************************
    /// Returns an iterator to the end of the lookup.
    ///\return An iterator to the end of the lookup.
    //*********************************************************************
    iterator end()
    {
      return buffer.end();
    }

    //*********************************************************************
    /// Returns a const_iterator to the end of the lookup.
    ///\return A const iterator to the end of the lookup.
    //*********************************************************************
    const_iterator end() const
    {
      return buffer.end();
    }

    //*********************************************************************
    /// Returns a const_iterator to the beginning of the lookup.
    ///\return A const iterator to the beginning of the lookup.
    //*********************************************************************
    const_iterator cbegin() const
    {
      return buffer.cbegin();
    }

    //*********************************************************************
    /// Returns a const_iterator to the end of the lookup.
    ///\return A const iterator to the end of the lookup.
    //*********************************************************************
    const_iterator cend() const
    {
      return buffer.cend();
    }

    //*********************************************************************
    /// Returns an reverse iterator to the reverse beginning of the lookup.
    ///\return Iterator to the reverse beginning of the lookup.
    //*********************************************************************
    reverse_iterator rbegin()
    {
	    return buffer.rbegin();
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the reverse beginning of the lookup.
    ///\return Const iterator to the reverse beginning of the lookup.
    //*********************************************************************
    const_reverse_iterator rbegin() const
    {
      return buffer.rbegin();
    }

    //*********************************************************************
    /// Returns a reverse iterator to the end + 1 of the lookup.
    ///\return Reverse iterator to the end + 1 of the lookup.
    //*********************************************************************
    reverse_iterator rend()
    {
      return buffer.rend();
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the end + 1 of the lookup.
    ///\return Const reverse iterator to the end + 1 of the lookup.
    //*********************************************************************
    const_reverse_iterator rend() const
    {
      return buffer.rend();
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the reverse beginning of the lookup.
    ///\return Const reverse iterator to the reverse beginning of the lookup.
    //*********************************************************************
    const_reverse_iterator crbegin() const
    {
      return buffer.crbegin();
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the end + 1 of the lookup.
    ///\return Const reverse iterator to the end + 1 of the lookup.
    //*********************************************************************
    const_reverse_iterator crend() const
    {
      return buffer.crend();
    }

    //*********************************************************************
    /// Returns a reference to the value at index 'key'
    ///\param i The index.
    ///\return A reference to the value at index 'key'
    //*********************************************************************
    mapped_type& operator [](key_value_parameter_t key)
    {
      iterator i_element = std::lower_bound(begin(), end(), value_type(key, TMapped()), compare_element());

      if (i_element->first != key)
      {
        // Doesn't exist, so create a new one.
        i_element = insert(std::make_pair(key, mapped_type()));
      }

      return i_element->second;
    }

    //*********************************************************************
    /// Returns a reference to the value at index 'key'
    /// If ETL_THROW_EXCEPTIONS is defined, emits an etl::lookup_out_of_bounds if the key is not in the range.
    ///\param i The index.
    ///\return A reference to the value at index 'key'
    //*********************************************************************
    mapped_type& at(key_value_parameter_t key)
    {
      iterator i_element = std::lower_bound(begin(), end(), value_type(key, TMapped()), compare_element());

      if (i_element == end())
      {
        // Doesn't exist.
#if ETL_THROW_EXCEPTIONS
        throw lookup_out_of_bounds();
#else
        error_handler::error(lookup_out_of_bounds());

#endif
      }

      return i_element->second;
    }

    //*********************************************************************
    /// Returns a const reference to the value at index 'key'
    /// If ETL_THROW_EXCEPTIONS is defined, emits an etl::lookup_out_of_bounds if the key is not in the range.
    ///\param i The index.
    ///\return A const reference to the value at index 'key'
    //*********************************************************************
    const mapped_type& at(key_value_parameter_t key) const
    {
      typename buffer_t::const_iterator i_element = std::lower_bound(begin(), end(), value_type(key, TMapped()), compare_element());

      if (i_element == end())
      {
        // Doesn't exist.
#if ETL_THROW_EXCEPTIONS
        throw lookup_out_of_bounds();
#else
        error_handler::error(lookup_out_of_bounds());

#endif
      }

      return i_element->second;
    }

    //*********************************************************************
    /// Assigns values to the lookup.
    /// If ETL_THROW_EXCEPTIONS is defined, emits lookup_full if the lookup does not have enough free space.
    /// If ETL_THROW_EXCEPTIONS is defined, emits lookup_iterator if the iterators are reversed.
    ///\param first The iterator to the first element.
    ///\param last  The iterator to the last element + 1.
    //*********************************************************************
    template <typename TIterator>
    void assign(TIterator first, TIterator last)
    {
      clear();

      while (first != last)
      {
        insert(*first++);
      }
    }

    //*********************************************************************
    /// Inserts a value to the lookup.
    /// If ETL_THROW_EXCEPTIONS is defined, emits lookup_full if the lookup is already full.
    ///\param position The position to insert at.
    ///\param value    The value to insert.
    //*********************************************************************
    iterator insert(const value_type& value)
    {
      iterator i_element = std::lower_bound(begin(), end(), value, compare_element());

      if (i_element == end())
      {
        // At the end.
        if (buffer.full())
        {
#ifdef ETL_THROW_EXCEPTIONS
          throw lookup_full();
#else
          error_handler::error(lookup_full());
#endif
        }
        else
        {
          buffer.push_back(value);
        }
      }
      else
      {
        // Not at the end.
        // Existing element?
        if (value.first == i_element->first)
        {
          // Yes.
          i_element->second = value.second;
        }
        else
        {
          // A new one.
          if (buffer.full())
          {
#ifdef ETL_THROW_EXCEPTIONS
            throw lookup_full();
#else
            error_handler::error(lookup_full());
#endif
          }
          else
          {
            buffer.insert(i_element, value);
          }
        }
      }

      return i_element;
    }

    //*********************************************************************
    /// Inserts a range of values to the lookup.
    /// If ETL_THROW_EXCEPTIONS is defined, emits lookup_full if the lookup does not have enough free space.
    ///\param position The position to insert at.
    ///\param first    The first element to add.
    ///\param last     The last + 1 element to add.
    //*********************************************************************
    template <class TIterator>
    void insert(TIterator first, TIterator last)
    {
      while (first != last)
      {
        insert(*first++);
      }
    }

    //*********************************************************************
    /// Erases an element.
    ///\param i_element Iterator to the element.
    ///\return An iterator pointing to the element that followed the erased element.
    //*********************************************************************
    iterator erase(iterator i_element)
    {
      return buffer.erase(i_element);
    }

    //*********************************************************************
    /// Erases a range of elements.
    /// The range includes all the elements between first and last, including the
    /// element pointed by first, but not the one pointed by last.
    ///\param first Iterator to the first element.
    ///\param last  Iterator to the last element.
    ///\return An iterator pointing to the element that followed the erased element.
    //*********************************************************************
    iterator erase(iterator first, iterator last)
    {
      return buffer.erase(first, last);
    }

    //*********************************************************************
    /// Finds an element.
    ///\param key The key to search for.
    ///\return An iterator pointing to the element or end() if not found.
    //*********************************************************************
    iterator find(key_value_parameter_t key)
    {
      return std::lower_bound(begin(), end(), value_type(key, TMapped()), compare_element());
    }

    //*********************************************************************
    /// Finds an element.
    ///\param key The key to search for.
    ///\return An iterator pointing to the element or end() if not found.
    //*********************************************************************
    const_iterator find(key_value_parameter_t key) const
    {
      return std::lower_bound(begin(), end(), value_type(key, TMapped()), compare_element());
    }

  protected:

    //*********************************************************************
    /// Constructor.
    //*********************************************************************
    ilookup(buffer_t& buffer)
      : lookup_base(buffer),
        buffer(buffer)
    {
    }

  private:

    buffer_t& buffer;
  };

  //***************************************************************************
  /// Equal operator.
  ///\param lhs Reference to the first lookup.
  ///\param rhs Reference to the second lookup.
  ///\return <b>true</b> if the arrays are equal, otherwise <b>false</b>
  ///\ingroup lookup
  //***************************************************************************
  template <typename TKey, typename TMapped, typename TKeyCompare>
  bool operator ==(const etl::ilookup<TKey, TMapped, TKeyCompare>& lhs, const etl::ilookup<TKey, TMapped, TKeyCompare>& rhs)
  {
    return (lhs.size() == rhs.size()) && std::equal(lhs.begin(), lhs.end(), rhs.begin());
  }

  //***************************************************************************
  /// Not equal operator.
  ///\param lhs Reference to the first lookup.
  ///\param rhs Reference to the second lookup.
  ///\return <b>true</b> if the arrays are not equal, otherwise <b>false</b>
  ///\ingroup lookup
  //***************************************************************************
  template <typename TKey, typename TMapped, typename TKeyCompare>
  bool operator !=(const etl::ilookup<TKey, TMapped, TKeyCompare>& lhs, const etl::ilookup<TKey, TMapped, TKeyCompare>& rhs)
  {
    return !(lhs == rhs);
  }
}

#undef __ETL_IN_ILOOKUP_H__
#endif