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__
34 /** This class holds one index of an indexed object. Indices can be symbolic
35 * (e.g. "mu", "i") or numeric (unsigned integer), and they can be contravariant
36 * (the default) or covariant. */
37 class idx : public basic
39 GINAC_DECLARE_REGISTERED_CLASS(idx, basic)
43 explicit idx(bool cov);
44 explicit idx(const std::string & n, bool cov=false);
45 explicit idx(const char * n, bool cov=false);
46 explicit idx(unsigned v, bool cov=false);
48 // functions overriding virtual functions from bases classes
50 void printraw(std::ostream & os) const;
51 void printtree(std::ostream & os, unsigned indent) const;
52 void print(std::ostream & os, unsigned upper_precedence=0) const;
53 bool info(unsigned inf) const;
55 bool is_equal_same_type(const basic & other) const;
56 unsigned calchash(void) const;
57 ex subs(const lst & ls, const lst & lr) const;
59 // new virtual functions which can be overridden by derived classes
61 virtual bool is_co_contra_pair(const basic & other) const;
62 virtual ex toggle_covariant(void) const;
64 // non-virtual functions in this class
66 /** Check whether index is symbolic (not numeric). */
67 bool is_symbolic(void) const {return symbolic;}
69 /** Get numeric value of index. Undefined for symbolic indices. */
70 unsigned get_value(void) const {return value;}
72 /** Check whether index is covariant (not contravariant). */
73 bool is_covariant(void) const {return covariant;}
75 void setname(const std::string & n) {name=n;}
76 std::string getname(void) const {return name;}
79 std::string & autoname_prefix(void);
83 unsigned serial; /**< Unique serial number for comparing symbolic indices */
84 bool symbolic; /**< Is index symbolic? */
85 std::string name; /**< Symbolic name (if symbolic == true) */
86 unsigned value; /**< Numeric value (if symbolic == false) */
87 static unsigned next_serial;
88 bool covariant; /**< x_mu, default is contravariant: x~mu */
92 inline const idx &ex_to_idx(const ex &e)
94 return static_cast<const idx &>(*e.bp);
99 int canonicalize_indices(exvector & iv, bool antisymmetric=false);
100 exvector idx_intersect(const exvector & iv1, const exvector & iv2);
101 ex permute_free_index_to_front(const exvector & iv3, const exvector & iv2, int * sig);
102 unsigned subs_index_in_exvector(exvector & v, const ex & is, const ex & ir);
103 ex subs_indices(const ex & e, const exvector & idxv_contra, const exvector & idxv_co);
104 unsigned count_index(const ex & e, const ex & i);
108 #endif // ndef __GINAC_IDX_H__