idx.h

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/*
 *  GiNaC Copyright (C) 1999-2011 Johannes Gutenberg University Mainz, Germany
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef GINAC_IDX_H
#define GINAC_IDX_H

#include "ex.h"
#include "numeric.h"

namespace GiNaC {

class idx : public basic
{
    GINAC_DECLARE_REGISTERED_CLASS(idx, basic)

    // other constructors
public:
    explicit idx(const ex & v, const ex & dim);

    // functions overriding virtual functions from base classes
public:
    bool info(unsigned inf) const;
    size_t nops() const;
    ex op(size_t i) const;
    ex map(map_function & f) const;
    ex evalf(int level = 0) const;
    ex subs(const exmap & m, unsigned options = 0) const;
    void archive(archive_node& n) const;
    void read_archive(const archive_node& n, lst& syms);
protected:
    ex derivative(const symbol & s) const;
    bool match_same_type(const basic & other) const;
    unsigned calchash() const;

    // new virtual functions in this class
public:
    virtual bool is_dummy_pair_same_type(const basic & other) const;

    // non-virtual functions in this class
public:
    ex get_value() const {return value;}

    bool is_numeric() const {return is_exactly_a<numeric>(value);}

    bool is_symbolic() const {return !is_exactly_a<numeric>(value);}

    ex get_dim() const {return dim;}

    bool is_dim_numeric() const {return is_exactly_a<numeric>(dim);}

    bool is_dim_symbolic() const {return !is_exactly_a<numeric>(dim);}

    ex replace_dim(const ex & new_dim) const;

    ex minimal_dim(const idx & other) const;

protected:
    void print_index(const print_context & c, unsigned level) const;
    void do_print(const print_context & c, unsigned level) const;
    void do_print_csrc(const print_csrc & c, unsigned level) const;
    void do_print_latex(const print_latex & c, unsigned level) const;
    void do_print_tree(const print_tree & c, unsigned level) const;

protected:
    ex value; 
    ex dim;   
};
GINAC_DECLARE_UNARCHIVER(idx); 


class varidx : public idx
{
    GINAC_DECLARE_REGISTERED_CLASS(varidx, idx)

    // other constructors
public:
    varidx(const ex & v, const ex & dim, bool covariant = false);

    // functions overriding virtual functions from base classes
public:
    bool is_dummy_pair_same_type(const basic & other) const;
    void archive(archive_node& n) const;
    void read_archive(const archive_node& n, lst& syms);
protected:
    bool match_same_type(const basic & other) const;

    // non-virtual functions in this class
public:
    bool is_covariant() const {return covariant;}

    bool is_contravariant() const {return !covariant;}

    ex toggle_variance() const;

protected:
    void do_print(const print_context & c, unsigned level) const;
    void do_print_tree(const print_tree & c, unsigned level) const;

    // member variables
protected:
    bool covariant; 
};
GINAC_DECLARE_UNARCHIVER(varidx);


class spinidx : public varidx
{
    GINAC_DECLARE_REGISTERED_CLASS(spinidx, varidx)

    // other constructors
public:
    spinidx(const ex & v, const ex & dim = 2, bool covariant = false, bool dotted = false);

    // functions overriding virtual functions from base classes
public:
    bool is_dummy_pair_same_type(const basic & other) const;
    // complex conjugation
    ex conjugate() const { return toggle_dot(); }
    void archive(archive_node& n) const;
    void read_archive(const archive_node& n, lst& syms);
protected:
    bool match_same_type(const basic & other) const;

    // non-virtual functions in this class
public:
    bool is_dotted() const {return dotted;}

    bool is_undotted() const {return !dotted;}

    ex toggle_dot() const;

    ex toggle_variance_dot() const;

protected:
    void do_print(const print_context & c, unsigned level) const;
    void do_print_latex(const print_latex & c, unsigned level) const;
    void do_print_tree(const print_tree & c, unsigned level) const;

    // member variables
protected:
    bool dotted;
};
GINAC_DECLARE_UNARCHIVER(spinidx);


// utility functions

bool is_dummy_pair(const idx & i1, const idx & i2);

bool is_dummy_pair(const ex & e1, const ex & e2);

void find_free_and_dummy(exvector::const_iterator it, exvector::const_iterator itend, exvector & out_free, exvector & out_dummy);

inline void find_free_and_dummy(const exvector & v, exvector & out_free, exvector & out_dummy)
{
    find_free_and_dummy(v.begin(), v.end(), out_free, out_dummy);
}

inline void find_dummy_indices(const exvector & v, exvector & out_dummy)
{
    exvector free_indices;
    find_free_and_dummy(v.begin(), v.end(), free_indices, out_dummy);
}

inline size_t count_dummy_indices(const exvector & v)
{
    exvector free_indices, dummy_indices;
    find_free_and_dummy(v.begin(), v.end(), free_indices, dummy_indices);
    return dummy_indices.size();
}

inline size_t count_free_indices(const exvector & v)
{
    exvector free_indices, dummy_indices;
    find_free_and_dummy(v.begin(), v.end(), free_indices, dummy_indices);
    return free_indices.size();
}

ex minimal_dim(const ex & dim1, const ex & dim2);

} // namespace GiNaC

#endif // ndef GINAC_IDX_H