3 * Interface to GiNaC's indices. */
6 * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #ifndef __GINAC_IDX_H__
24 #define __GINAC_IDX_H__
31 #ifndef NO_NAMESPACE_GINAC
33 #endif // ndef NO_NAMESPACE_GINAC
36 /** This class holds one index of an indexed object. Indices can be symbolic
37 * (e.g. "mu", "i") or numeric (unsigned integer), and they can be contravariant
38 * (the default) or covariant. */
39 class idx : public basic
41 GINAC_DECLARE_REGISTERED_CLASS(idx, basic)
45 explicit idx(bool cov);
46 explicit idx(const std::string & n, bool cov=false);
47 explicit idx(const char * n, bool cov=false);
48 explicit idx(unsigned v, bool cov=false);
50 // functions overriding virtual functions from bases classes
52 basic * duplicate() const;
53 void printraw(std::ostream & os) const;
54 void printtree(std::ostream & os, unsigned indent) const;
55 void print(std::ostream & os, unsigned upper_precedence=0) const;
56 bool info(unsigned inf) const;
58 int compare_same_type(const basic & other) const;
59 bool is_equal_same_type(const basic & other) const;
60 unsigned calchash(void) const;
61 ex subs(const lst & ls, const lst & lr) const;
63 // new virtual functions which can be overridden by derived classes
65 virtual bool is_co_contra_pair(const basic & other) const;
66 virtual ex toggle_covariant(void) const;
68 // non-virtual functions in this class
70 /** Check whether index is symbolic (not numeric). */
71 bool is_symbolic(void) const {return symbolic;}
73 /** Get numeric value of index. Undefined for symbolic indices. */
74 unsigned get_value(void) const {return value;}
76 /** Check whether index is covariant (not contravariant). */
77 bool is_covariant(void) const {return covariant;}
79 void setname(const std::string & n) {name=n;}
80 std::string getname(void) const {return name;}
83 std::string & autoname_prefix(void);
87 unsigned serial; /**< Unique serial number for comparing symbolic indices */
88 bool symbolic; /**< Is index symbolic? */
89 std::string name; /**< Symbolic name (if symbolic == true) */
90 unsigned value; /**< Numeric value (if symbolic == false) */
91 static unsigned next_serial;
92 bool covariant; /**< x_mu, default is contravariant: x~mu */
96 inline const idx &ex_to_idx(const ex &e)
98 return static_cast<const idx &>(*e.bp);
103 int canonicalize_indices(exvector & iv, bool antisymmetric=false);
104 exvector idx_intersect(const exvector & iv1, const exvector & iv2);
105 ex permute_free_index_to_front(const exvector & iv3, const exvector & iv2, int * sig);
106 unsigned subs_index_in_exvector(exvector & v, const ex & is, const ex & ir);
107 ex subs_indices(const ex & e, const exvector & idxv_contra, const exvector & idxv_co);
108 unsigned count_index(const ex & e, const ex & i);
110 #ifndef NO_NAMESPACE_GINAC
112 #endif // ndef NO_NAMESPACE_GINAC
114 #endif // ndef __GINAC_IDX_H__