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#include "Cleanup.hh"
#include "algorithms/young_project_product.hh"
#include "algorithms/young_project_tensor.hh"
#include "algorithms/distribute.hh"
#include "algorithms/collect_terms.hh"
#include "algorithms/canonicalise.hh"
using namespace cadabra;
young_project_product::young_project_product(const Kernel& k, Ex& tr)
: Algorithm(k, tr)
{
}
bool young_project_product::can_apply(iterator it)
{
if(*it->name=="\\prod") return true;
return false;
}
Algorithm::result_t young_project_product::apply(iterator& it)
{
result_t res=result_t::l_no_action;
Ex rep;
iterator topsum = rep.set_head(str_node("\\sum"));
sibling_iterator sib=tr.begin(it);
bool first=true;
while(sib!=tr.end(it)) {
young_project_tensor ypt(kernel, tr, true);
sibling_iterator nxt=sib;
++nxt;
if(ypt.can_apply(sib)) {
ypt.modulo_monoterm=true;
iterator ii(sib);
ypt.apply(ii);
if(*ii->name!="\\sum")
ii=tr.wrap(ii, str_node("\\sum"));
res=result_t::l_applied;
if(first) {
// Add a new \prod node to rep for each term in the projected factor.
first=false;
sibling_iterator trm=tr.begin(ii);
while(trm!=tr.end(ii)) {
iterator prod=rep.append_child(topsum, str_node("\\prod"));
prod->fl.bracket=str_node::b_round;
prod->multiplier=it->multiplier;
rep.append_child(prod, iterator(trm));
++trm;
}
}
else {
// Distribute this projected factor over all existing terms in rep,
sibling_iterator trm=rep.begin(topsum);
while(trm!=rep.end(topsum)) {
// iterator tmp=trm;
sibling_iterator nxttrm=trm;
++nxttrm;
// Copy this term out of the sum and append projected factor.
Ex work(trm);
iterator workit=work.begin();
iterator put=rep.append_child(work.begin(), str_node());
if(tr.number_of_children(ii)==1)
rep.replace(put, tr.begin(ii));
else {
rep.replace(put, ii);
// Distribute the product.
distribute dis(kernel, work);
if(dis.can_apply(workit))
dis.apply(workit);
}
// txtout << "GOOD?" << std::endl;
// work.print_recursive_treeform(txtout, work.begin());
// Canonicalise all new products.
canonicalise can(kernel, work);
// txtout << *workit->name << " " << *put->name << std::endl;
can.apply_generic(workit, true, false, 0);
if(*work.begin()->multiplier!=0) {
// The upcoming move wants to see a sum, even if there is only one term
if(*work.begin()->name!="\\sum")
work.wrap(work.begin(), str_node("\\sum"));
// Move back to the original tree.
sibling_iterator cpyit=work.begin(work.begin());
while(cpyit!=work.end(work.begin())) {
sibling_iterator cpyitnxt=cpyit;
++cpyitnxt;
rep.move_before(trm, cpyit);
cpyit=cpyitnxt;
}
}
rep.erase(trm);
trm=nxttrm;
}
collect_terms coll(kernel, rep);
if(coll.can_apply(topsum))
coll.apply(topsum);
// If collect terms removed the sum because there was only
// one term (or zero) left, put it back in.
if(*topsum->name!="\\sum")
topsum=tr.wrap(topsum, str_node("\\sum"));
}
}
else {
if(first) {
first=false;
iterator prod=rep.append_child(topsum, str_node("\\prod"));
prod->fl.bracket=str_node::b_round;
prod->multiplier=it->multiplier;
rep.append_child(prod, iterator(sib));
}
else {
// just multiply all terms with this factor
sibling_iterator trm=rep.begin(topsum);
while(trm!=rep.end(topsum)) {
iterator put=rep.append_child(trm,str_node());
tr.replace(put, iterator(sib));
++trm;
}
}
}
// rep.print_recursive_treeform(debugout, rep.begin());
sib=nxt;
}
if(res==result_t::l_applied) {
it=tr.replace(it, rep.begin());
// FIXME: this canonicalise should really not be necessary
// txtout << "WHOOAAH " << *it->name << std::endl;
// tr.print_recursive_treeform(txtout, it);
// canonicalise can(tr, tr.end());
// can.apply_recursive(it, false);
cleanup_dispatch(kernel, tr, it);
}
return res;
}
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