]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.cpp
- Do not bother to rename indices if object has no indices at all [Sheplyakov].
[ginac.git] / ginac / expairseq.cpp
index 8e9594b6e312b640775ad59fd8d0cb8e66b8592a..788f7834f4a5fc82a1a713e1f770ecaa194abdb0 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of sequences of expression pairs. */
 
 /*
- *  GiNaC Copyright (C) 1999-2006 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2007 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
@@ -24,6 +24,7 @@
 #include <algorithm>
 #include <string>
 #include <stdexcept>
+#include <iterator>
 
 #include "expairseq.h"
 #include "lst.h"
@@ -145,13 +146,17 @@ expairseq::expairseq(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst
        , hashtabsize(0)
 #endif
 {
-       for (unsigned int i=0; true; i++) {
+       archive_node::archive_node_cit first = n.find_first("rest");
+       archive_node::archive_node_cit last = n.find_last("coeff");
+       ++last;
+       seq.reserve((last-first)/2);
+
+       for (archive_node::archive_node_cit loc = first; loc < last;) {
                ex rest;
                ex coeff;
-               if (n.find_ex("rest", rest, sym_lst, i) && n.find_ex("coeff", coeff, sym_lst, i))
-                       seq.push_back(expair(rest, coeff));
-               else
-                       break;
+               n.find_ex_by_loc(loc++, rest, sym_lst);
+               n.find_ex_by_loc(loc++, coeff, sym_lst);
+               seq.push_back(expair(rest, coeff));
        }
 
        n.find_ex("overall_coeff", overall_coeff, sym_lst);
@@ -263,6 +268,26 @@ void expairseq::do_print_tree(const print_tree & c, unsigned level) const
 
 bool expairseq::info(unsigned inf) const
 {
+       switch(inf) {
+               case info_flags::expanded:
+                       return (flags & status_flags::expanded);
+               case info_flags::has_indices: {
+                       if (flags & status_flags::has_indices)
+                               return true;
+                       else if (flags & status_flags::has_no_indices)
+                               return false;
+                       for (epvector::const_iterator i = seq.begin(); i != seq.end(); ++i) {
+                               if (i->rest.info(info_flags::has_indices)) {
+                                       this->setflag(status_flags::has_indices);
+                                       this->clearflag(status_flags::has_no_indices);
+                                       return true;
+                               }
+                       }
+                       this->clearflag(status_flags::has_indices);
+                       this->setflag(status_flags::has_no_indices);
+                       return false;
+               }
+       }
        return inherited::info(inf);
 }
 
@@ -285,7 +310,7 @@ ex expairseq::op(size_t i) const
 ex expairseq::map(map_function &f) const
 {
        std::auto_ptr<epvector> v(new epvector);
-       v->reserve(seq.size());
+       v->reserve(seq.size()+1);
 
        epvector::const_iterator cit = seq.begin(), last = seq.end();
        while (cit != last) {
@@ -295,8 +320,15 @@ ex expairseq::map(map_function &f) const
 
        if (overall_coeff.is_equal(default_overall_coeff()))
                return thisexpairseq(v, default_overall_coeff(), true);
-       else
-               return thisexpairseq(v, f(overall_coeff), true);
+       else {
+               ex newcoeff = f(overall_coeff);
+               if(is_a<numeric>(newcoeff))
+                       return thisexpairseq(v, newcoeff, true);
+               else {
+                       v->push_back(split_ex_to_pair(newcoeff));
+                       return thisexpairseq(v, default_overall_coeff(), true);
+               }
+       }
 }
 
 /** Perform coefficient-wise automatic term rewriting rules in this class. */
@@ -780,8 +812,8 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
                                construct_from_2_ex_via_exvector(lh,rh);
                        } else {
 #endif // EXPAIRSEQ_USE_HASHTAB
-                               if(is_a<mul>(lh))
-                               {
+                               if (is_a<mul>(lh) && lh.info(info_flags::has_indices) && 
+                                       rh.info(info_flags::has_indices)) {
                                        ex newrh=rename_dummy_indices_uniquely(lh, rh);
                                        construct_from_2_expairseq(ex_to<expairseq>(lh),
                                                                   ex_to<expairseq>(newrh));
@@ -1015,61 +1047,6 @@ void expairseq::construct_from_epvector(const epvector &v, bool do_index_renamin
 #endif // EXPAIRSEQ_USE_HASHTAB
 }
 
-// Class to handle the renaming of dummy indices. It holds a vector of
-// indices that are being used in the expression so-far. If the same
-// index occurs again as a dummy index in a factor, it is to be renamed.
-// Unless dummy index renaming was swichted of, of course ;-) .
-class make_flat_inserter
-{
-       public:
-               make_flat_inserter(const epvector &epv, bool b): do_renaming(b)
-               {
-                       if (!do_renaming)
-                               return;
-                       for (epvector::const_iterator i=epv.begin(); i!=epv.end(); ++i)
-                               if(are_ex_trivially_equal(i->coeff, _ex1))
-                                       combine_indices(i->rest.get_free_indices());
-               }
-               make_flat_inserter(const exvector &v, bool b): do_renaming(b)
-               {
-                       if (!do_renaming)
-                               return;
-                       for (exvector::const_iterator i=v.begin(); i!=v.end(); ++i)
-                               combine_indices(i->get_free_indices());
-               }
-               ex handle_factor(const ex &x, const ex &coeff)
-               {
-                       if (!do_renaming)
-                               return x;
-                       exvector dummies_of_factor;
-                       if (coeff == _ex1)
-                               dummies_of_factor = get_all_dummy_indices_safely(x);
-                       else if (coeff == _ex2)
-                               dummies_of_factor = x.get_free_indices();
-                       else
-                               return x;
-                       if (dummies_of_factor.size() == 0)
-                               return x;
-                       sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-                       ex new_factor = rename_dummy_indices_uniquely(used_indices,
-                               dummies_of_factor, x);
-                       combine_indices(dummies_of_factor);
-                       return new_factor;
-               }
-       private:
-               void combine_indices(const exvector &dummies_of_factor)
-               {
-                       exvector new_dummy_indices;
-                       set_union(used_indices.begin(), used_indices.end(),
-                               dummies_of_factor.begin(), dummies_of_factor.end(),
-                               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-                       used_indices.swap(new_dummy_indices);
-               }
-               bool do_renaming;
-               exvector used_indices;
-};
-
-
 /** Combine this expairseq with argument exvector.
  *  It cares for associativity as well as for special handling of numerics. */
 void expairseq::make_flat(const exvector &v)
@@ -1080,6 +1057,7 @@ void expairseq::make_flat(const exvector &v)
        // and their cumulative number of operands
        int nexpairseqs = 0;
        int noperands = 0;
+       bool do_idx_rename = false;
        
        cit = v.begin();
        while (cit!=v.end()) {
@@ -1087,6 +1065,9 @@ void expairseq::make_flat(const exvector &v)
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(*cit).seq.size();
                }
+               if (is_a<mul>(*this) && (!do_idx_rename) &&
+                               cit->info(info_flags::has_indices))
+                       do_idx_rename = true;
                ++cit;
        }
        
@@ -1094,7 +1075,7 @@ void expairseq::make_flat(const exvector &v)
        seq.reserve(v.size()+noperands-nexpairseqs);
        
        // copy elements and split off numerical part
-       make_flat_inserter mf(v, this->tinfo()==&mul::tinfo_static);
+       make_flat_inserter mf(v, do_idx_rename);
        cit = v.begin();
        while (cit!=v.end()) {
                if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
@@ -1128,6 +1109,7 @@ void expairseq::make_flat(const epvector &v, bool do_index_renaming)
        // and their cumulative number of operands
        int nexpairseqs = 0;
        int noperands = 0;
+       bool really_need_rename_inds = false;
        
        cit = v.begin();
        while (cit!=v.end()) {
@@ -1135,8 +1117,12 @@ void expairseq::make_flat(const epvector &v, bool do_index_renaming)
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(cit->rest).seq.size();
                }
+               if ((!really_need_rename_inds) && is_a<mul>(*this) &&
+                               cit->rest.info(info_flags::has_indices))
+                       really_need_rename_inds = true;
                ++cit;
        }
+       do_index_renaming = do_index_renaming && really_need_rename_inds;
        
        // reserve seq and coeffseq which will hold all operands
        seq.reserve(v.size()+noperands-nexpairseqs);