- if (flags & status_flags::expanded)
- return *this;
-
- exvector sub_expanded_seq;
- intvector positions_of_adds;
- intvector number_of_add_operands;
-
- epvector * expanded_seqp = expandchildren(options);
-
- const epvector & expanded_seq = expanded_seqp==0 ? seq : *expanded_seqp;
-
- positions_of_adds.resize(expanded_seq.size());
- number_of_add_operands.resize(expanded_seq.size());
-
- int number_of_adds = 0;
- int number_of_expanded_terms = 1;
-
- unsigned current_position = 0;
- epvector::const_iterator last = expanded_seq.end();
- for (epvector::const_iterator cit = expanded_seq.begin(); cit!=last; ++cit) {
- if (is_ex_exactly_of_type((*cit).rest,add) &&
- ((*cit).coeff.is_equal(_ex1()))) {
- positions_of_adds[number_of_adds] = current_position;
- const add & expanded_addref = ex_to_add((*cit).rest);
- unsigned addref_nops = expanded_addref.nops();
- number_of_add_operands[number_of_adds] = addref_nops;
- number_of_expanded_terms *= addref_nops;
- ++number_of_adds;
- }
- ++current_position;
- }
-
- if (number_of_adds==0) {
- if (expanded_seqp==0)
- return this->setflag(status_flags::expanded);
- else
- return ((new mul(expanded_seqp,overall_coeff))->
- setflag(status_flags::dynallocated |
- status_flags::expanded));
- }
-
- exvector distrseq;
- distrseq.reserve(number_of_expanded_terms);
-
- intvector k;
- k.resize(number_of_adds, 0);
-
- while (1) {
- epvector term;
- term = expanded_seq;
- for (int l=0; l<number_of_adds; ++l) {
- const add & addref = ex_to_add(expanded_seq[positions_of_adds[l]].rest);
- GINAC_ASSERT(term[positions_of_adds[l]].coeff.compare(_ex1())==0);
- term[positions_of_adds[l]]=split_ex_to_pair(addref.op(k[l]));
- }
- distrseq.push_back((new mul(term,overall_coeff))->
- setflag(status_flags::dynallocated |
- status_flags::expanded));
-
- // increment k[]
- int l = number_of_adds-1;
- while ((l>=0) && ((++k[l])>=number_of_add_operands[l])) {
- k[l] = 0;
- --l;
- }
- if (l<0) break;
- }
-
- if (expanded_seqp!=0)
- delete expanded_seqp;
-
- return (new add(distrseq))->setflag(status_flags::dynallocated |
- status_flags::expanded);
-}
-
+ if (flags & status_flags::expanded)
+ return *this;
+
+ exvector sub_expanded_seq;
+
+ epvector * expanded_seqp = expandchildren(options);
+
+ const epvector & expanded_seq = expanded_seqp==0 ? seq : *expanded_seqp;
+
+ int number_of_adds = 0;
+ epvector non_adds;
+ non_adds.reserve(expanded_seq.size());
+ epvector::const_iterator cit = expanded_seq.begin();
+ epvector::const_iterator last = expanded_seq.end();
+ ex last_expanded = _ex1();
+ while (cit!=last) {
+ if (is_ex_exactly_of_type((*cit).rest,add) &&
+ ((*cit).coeff.is_equal(_ex1()))) {
+ ++number_of_adds;
+ if (is_ex_exactly_of_type(last_expanded,add)) {
+ // expand adds
+ const add & add1 = ex_to_add(last_expanded);
+ const add & add2 = ex_to_add((*cit).rest);
+ int n1 = add1.nops();
+ int n2 = add2.nops();
+ exvector distrseq;
+ distrseq.reserve(n1*n2);
+ for (int i1=0; i1<n1; ++i1) {
+ for (int i2=0; i2<n2; ++i2) {
+ distrseq.push_back(add1.op(i1)*add2.op(i2));
+ }
+ }
+ last_expanded = (new add(distrseq))->setflag(status_flags::dynallocated | status_flags::expanded);
+ } else {
+ non_adds.push_back(split_ex_to_pair(last_expanded));
+ last_expanded = (*cit).rest;
+ }
+ } else {
+ non_adds.push_back(*cit);
+ }
+ ++cit;
+ }
+ if (expanded_seqp)
+ delete expanded_seqp;
+
+ if (is_ex_exactly_of_type(last_expanded,add)) {
+ add const & finaladd = ex_to_add(last_expanded);
+ exvector distrseq;
+ int n = finaladd.nops();
+ distrseq.reserve(n);
+ for (int i=0; i<n; ++i) {
+ epvector factors = non_adds;
+ factors.push_back(split_ex_to_pair(finaladd.op(i)));
+ distrseq.push_back((new mul(factors,overall_coeff))->setflag(status_flags::dynallocated | status_flags::expanded));
+ }
+ return ((new add(distrseq))->
+ setflag(status_flags::dynallocated | status_flags::expanded));
+ }
+ non_adds.push_back(split_ex_to_pair(last_expanded));
+ return (new mul(non_adds,overall_coeff))->
+ setflag(status_flags::dynallocated | status_flags::expanded);
+}
+
+