X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fexpairseq.h;h=2eb245a929b40d01cb42bd34b3b17571af0ae91c;hp=1b980cfc5eba2424d07b07af6a52eba8637efcd5;hb=9507ddbf35326a15e98428f81b095d300b1a84cc;hpb=f303227c240827857e2fb0631c537f553a9845e2

diff --git a/ginac/expairseq.h b/ginac/expairseq.h
index 1b980cfc..2eb245a9 100644
--- a/ginac/expairseq.h
+++ b/ginac/expairseq.h
@@ -30,6 +30,7 @@
 #include <algorithm>
 
 #include "expair.h"
+#include "indexed.h"
 
 namespace GiNaC {
 
@@ -171,6 +172,60 @@ protected:
 #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, 1))
+					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 (is_a<numeric>(coeff) && coeff.is_equal(GiNaC::numeric(1)))
+				dummies_of_factor = get_all_dummy_indices_safely(x);
+			else if (is_a<numeric>(coeff) && coeff.is_equal(GiNaC::numeric(2)))
+				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;
+};
+
 } // namespace GiNaC
 
 #endif // ndef __GINAC_EXPAIRSEQ_H__