match() (find()): use exmap (exset) to store matched subexpressions.

[ginac.git] / ginac / power.cpp

diff --git a/ginac/power.cpp b/ginac/power.cpp
index 10de528d06ad9cf09381b4376f61ff433ca414f6..e4a044cb329ddd2422df5c920fdd187abfd1c796 100644 (file)
--- a/ginac/power.cpp
+++ b/ginac/power.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symbolic exponentiation (basis^exponent). */
 
 /*
- *  GiNaC Copyright (C) 1999-2007 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2008 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
@@ -506,8 +506,8 @@ ex power::eval(int level) const
                // (2*x + 6*y)^(-4) -> 1/16*(x + 3*y)^(-4)
                if (num_exponent->is_integer() && is_exactly_a<add>(ebasis)) {
                        numeric icont = ebasis.integer_content();
-                       const numeric& lead_coeff = 
-                               ex_to<numeric>(ex_to<add>(ebasis).seq.begin()->coeff).div_dyn(icont);
+                       const numeric lead_coeff = 
+                               ex_to<numeric>(ex_to<add>(ebasis).seq.begin()->coeff).div(icont);
 
                        const bool canonicalizable = lead_coeff.is_integer();
                        const bool unit_normal = lead_coeff.is_pos_integer();
@@ -635,7 +635,7 @@ bool power::has(const ex & other, unsigned options) const
 }
 
 // from mul.cpp
-extern bool tryfactsubs(const ex &, const ex &, int &, lst &);
+extern bool tryfactsubs(const ex &, const ex &, int &, exmap&);
 
 ex power::subs(const exmap & m, unsigned options) const
 {      
@@ -651,9 +651,13 @@ ex power::subs(const exmap & m, unsigned options) const
 
        for (exmap::const_iterator it = m.begin(); it != m.end(); ++it) {
                int nummatches = std::numeric_limits<int>::max();
-               lst repls;
-               if (tryfactsubs(*this, it->first, nummatches, repls))
-                       return (ex_to<basic>((*this) * power(it->second.subs(ex(repls), subs_options::no_pattern) / it->first.subs(ex(repls), subs_options::no_pattern), nummatches))).subs_one_level(m, options);
+               exmap repls;
+               if (tryfactsubs(*this, it->first, nummatches, repls)) {
+                       ex anum = it->second.subs(repls, subs_options::no_pattern);
+                       ex aden = it->first.subs(repls, subs_options::no_pattern);
+                       ex result = (*this)*power(anum/aden, nummatches);
+                       return (ex_to<basic>(result)).subs_one_level(m, options);
+               }
        }
 
        return subs_one_level(m, options);
@@ -772,9 +776,12 @@ tinfo_t power::return_type_tinfo() const
 
 ex power::expand(unsigned options) const
 {
-       if (options == 0 && (flags & status_flags::expanded))
+       if (is_a<symbol>(basis) && exponent.info(info_flags::integer)) {
+               // A special case worth optimizing.
+               setflag(status_flags::expanded);
                return *this;
-       
+       }
+
        const ex expanded_basis = basis.expand(options);
        const ex expanded_exponent = exponent.expand(options);
        
@@ -1007,8 +1014,13 @@ ex power::expand_mul(const mul & m, const numeric & n, unsigned options, bool fr
                return _ex1;
        }
 
+       // do not bother to rename indices if there are no any.
+       if ((!(options & expand_options::expand_rename_idx)) 
+                       && m.info(info_flags::has_indices))
+               options |= expand_options::expand_rename_idx;
        // Leave it to multiplication since dummy indices have to be renamed
-       if (get_all_dummy_indices(m).size() > 0 && n.is_positive()) {
+       if ((options & expand_options::expand_rename_idx) &&
+               (get_all_dummy_indices(m).size() > 0) && n.is_positive()) {
                ex result = m;
                exvector va = get_all_dummy_indices(m);
                sort(va.begin(), va.end(), ex_is_less());