/* linbox/vector/bit-vector.h
 * Copyright (C) 2003 Bradford Hovinen
 *
 * -------------------------------------------------
 *
 * 
 * ========LICENCE========
 * This file is part of the library LinBox.
 * 
 * LinBox is free software: you can redistribute it and/or modify
 * it under the terms of the  GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * ========LICENCE========
 *.
 */

#ifndef __LINBOX_bit_vector_H
#define __LINBOX_bit_vector_H

#include <iterator>
#include <vector>
#include <stdexcept>

#include "linbox/vector/vector-traits.h"

namespace LinBox
{

	/** Binary constant defined both for 32 and 64 bits
	*/
#if (__LINBOX_SIZEOF_LONG == 4)
#define __LINBOX_BITSOF_LONG 32
#define __LINBOX_BITSOF_LONG_MUN 31
#define __LINBOX_LOGOF_SIZE 5
#define __LINBOX_POS_ALL_ONES 0x1F
	const unsigned long __LINBOX_ALL_ONES = static_cast<unsigned long>(-1);
#define __LINBOX_PARITY(s) ParallelParity(s)

	inline bool ParallelParity(unsigned long t) {
		t ^= (t >> 16);
		t ^= (t >> 8);
		t ^= (t >> 4);
		t &= 0xf;
		return bool( (0x6996 >> t) & 0x1);
	}
#elif (__LINBOX_SIZEOF_LONG == 8)
#define __LINBOX_BITSOF_LONG 64
#define __LINBOX_BITSOF_LONG_MUN 63
#define __LINBOX_LOGOF_SIZE 6
#define __LINBOX_POS_ALL_ONES 0x3F
	const unsigned long __LINBOX_ALL_ONES = static_cast<unsigned long>(-1);
#define __LINBOX_PARITY(s) ParallelParity(s)

	inline bool ParallelParity(unsigned long t) {
		t ^= (t >> 32);
		t ^= (t >> 16);
		t ^= (t >> 8);
		t ^= (t >> 4);
		t &= 0xf;
		return bool( (0x6996 >> t) & 0x1);
	}
#else
#pragma message "error SIZEOF_LONG not defined !"
#endif

	/** A vector of boolean 0-1 values, stored compactly to save space.
	 *
	 * BitVector provides an additional iterator, word_iterator, that gives
	 * the bits in compact 32-bit words, so that vector operations may be done in
	 * parallel. It is similar to the STL bit_vector except that it provides the
	 * aforementioned additional iterator.
	 \ingroup vector
	 */

	class BitVector {
	public:
		typedef bool        value_type;
		typedef size_t      size_type;
		typedef long         difference_type;
		typedef std::vector<unsigned long>::iterator               word_iterator;
		typedef std::vector<unsigned long>::const_iterator         const_word_iterator;
		typedef std::vector<unsigned long>::reverse_iterator       reverse_word_iterator;
		typedef std::vector<unsigned long>::const_reverse_iterator const_reverse_word_iterator;

		BitVector () {}
		BitVector (std::vector<bool> &v)
		{ *this = v; }
		BitVector (std::vector<unsigned long> &v) :
		       	_v (v), _size (_v.size () * __LINBOX_BITSOF_LONG) {}
		BitVector (size_t n, bool val = false)
		{ resize (n, val); }

		// Copy constructor
		BitVector (const BitVector &v) :
		       	_v (v._v), _size (v._size) {}

		~BitVector () {}

		// Reference

		class reference;
		class const_reference;

		// Iterators

		class iterator;
		class const_iterator;

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

		typedef iterator    pointer;
		typedef const_iterator    const_pointer;

		inline iterator                    begin      (void);
		inline const_iterator              begin      (void) const;
		inline iterator                    end        (void);
		inline const_iterator              end        (void) const;

		inline reverse_iterator            rbegin     (void);
		inline const_reverse_iterator      rbegin     (void) const;
		inline reverse_iterator            rend       (void);
		inline const_reverse_iterator      rend       (void) const;

		inline word_iterator               wordBegin  (void)       { return _v.begin (); }
		inline const_word_iterator         wordBegin  (void) const { return _v.begin (); }
		inline word_iterator               wordEnd    (void)       { return _v.end (); }
		inline const_word_iterator         wordEnd    (void) const { return _v.end (); }

		inline reverse_word_iterator       wordRbegin (void)       { return _v.rbegin (); }
		inline const_reverse_word_iterator wordRbegin (void) const { return _v.rbegin (); }
		inline reverse_word_iterator       wordRend   (void)       { return _v.rend (); }
		inline const_reverse_word_iterator wordRend   (void) const { return _v.rend (); }

		// Element access

		inline reference       operator[] (size_type n);
		inline const_reference operator[] (size_type n) const;

		reference at       (size_type n);
		const_reference at (size_type n) const;

		inline reference       front (void);
		inline const_reference front (void) const;
		inline reference       back  (void);
		inline const_reference back  (void) const;

		template<class Container>
		BitVector &operator = (const Container& x);

		void resize (size_type new_size, bool val = false);

		inline size_type size      (void) const { return _size;            }
		inline bool      empty     (void) const { return _v.empty ();      }
		inline size_type max_size  (void) const { return _v.size  () * __LINBOX_BITSOF_LONG; }

		bool operator == (const BitVector &v) const;

	protected:

		std::vector<unsigned long> _v;
		size_t              _size;

	}; // template <class Vector> class ReverseVector

	// Vector traits for BitVector wrapper
	template <>
	struct VectorTraits<BitVector>
	{
		typedef BitVector VectorType;
		typedef VectorCategories::DenseZeroOneVectorTag VectorCategory;
	};

} // namespace LinBox

// RawVector for GF2
namespace LinBox
{
	template <>
	struct RawVector<bool> {
	public:
		typedef BitVector Dense;
		typedef std::vector<size_t> Sparse;
		typedef std::vector<size_t> SparseSeq;
		typedef std::vector<size_t> SparseMap;
		typedef std::vector<size_t> SparsePar;
	};

}
#include "linbox/vector/bit-vector.inl"

#endif // __LINBOX_bit_vector_H


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