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#include "Cleanup.hh"
#include "algorithms/combine.hh"
#include "properties/Matrix.hh"
using namespace cadabra;
combine::combine(const Kernel& k, Ex& e, Ex& t)
: Algorithm(k, e), trace_op(t)
{
}
bool combine::can_apply(iterator it)
{
if(*it->name=="\\prod") return true;
return false;
}
Algorithm::result_t combine::apply(iterator& it)
{
sibling_iterator sib=tr.begin(it);
index_map_t ind_free, ind_dummy;
std::vector<Ex::iterator> dummies;
while(sib!=tr.end(it)) { // iterate over all factors in the product
sibling_iterator ch=tr.begin(sib);
while(ch!=tr.end(sib)) { // iterate over all indices of this factor
// auto parent=tr.parent(sib);
if(ch->fl.parent_rel==str_node::p_sub || ch->fl.parent_rel==str_node::p_super) {
classify_add_index(ch, ind_free, ind_dummy);
}
++ch;
}
++sib;
}
if(ind_dummy.size()==0) return result_t::l_no_action;
while(ind_dummy.begin()!=ind_dummy.end()) {
bool found=false;
index_map_t::iterator start=ind_dummy.begin(), backup;
while(!found && start!=ind_dummy.end()) {
iterator parent=tr.parent(start->second);
sibling_iterator ch=tr.begin(parent), last_part;
while(ch!=tr.end(parent)) {
auto fnd=ind_dummy.find((Ex::iterator)ch);
if(fnd!=ind_dummy.end()) last_part=ch;
++ch;
}
if(last_part==start->second) {
++last_part;
if(last_part==tr.end(parent)) {
// Dummy index with nothing to the right is preferred
found=true;
}
else backup=start;
}
if(!found) ++start;
}
// As a backup, we use a dummy index with only non-dummies to the right
if(!found) start=backup;
bool paired=true;
while(paired && start!=ind_dummy.end()) {
iterator parent=tr.parent(start->second);
sibling_iterator ch=tr.begin(parent), last_part;
while(ch!=tr.end(parent) && ind_dummy.size()>0) {
auto fnd2=ind_dummy.equal_range((Ex::iterator)ch);
auto fnd1=fnd2.first;
if(fnd1->second!=ch) ++fnd1;
if(fnd1->second==ch) {
dummies.insert(dummies.end(), ch);
ind_dummy.erase(fnd1);
last_part=ch;
}
++ch;
}
auto fnd=ind_dummy.find((Ex::iterator)last_part);
if(fnd==ind_dummy.end()) {
last_part->flip_parent_rel();
fnd=ind_dummy.find((Ex::iterator)last_part);
last_part->flip_parent_rel();
}
if(fnd==ind_dummy.end()) {
// Contraction ends because we are on a vector
// It could also be a trace if we removed the paired index more than one iteration ago
paired=false;
}
else {
start=fnd;
index_map_t::iterator check=ind_dummy.end();
iterator parent=tr.parent(start->second);
sibling_iterator ch=tr.begin(parent), first_part;
while(check==ind_dummy.end()) {
first_part=ch;
check=ind_dummy.find((Ex::iterator)ch);
++ch;
}
if(first_part!=start->second) {
throw NotYetImplemented("Evaluation requires transposing a matrix.");
return result_t::l_no_action;
}
}
}
}
std::string trace_start="";
std::vector<Ex::iterator>::iterator dums1=dummies.begin(), dums2;
dums2=dums1;
++dums2;
while(dums1!=dummies.end() && dums2!=dummies.end()) {
// txtout << "analysing " << std::endl;
// txtout << *(dums1->second->name) << std::endl;
bool isbrack1=false, isbrack2=false;
bool ismatorvec1=false, ismatorvec2=false;
// These are both to recognize traces
bool diffparents=tr.parent(*dums1)!=tr.parent(*dums2);
bool consecutive=*(*dums1)->name==*(*dums2)->name;
const Matrix *mat1=kernel.properties.get<Matrix>(tr.parent(*dums1));
if(mat1)
ismatorvec1=true;
else if(*(tr.parent(*dums1)->name)=="\\indexbracket") {
ismatorvec1=true;
isbrack1=true;
}
else if(tr.number_of_children(tr.parent(*dums1))==1)
ismatorvec1=true;
const Matrix *mat2=kernel.properties.get<Matrix>(tr.parent(*dums2));
if(mat2)
ismatorvec2=true;
else if(*(tr.parent(*dums2)->name)=="\\indexbracket") {
ismatorvec2=true;
isbrack2=true;
}
else if(tr.number_of_children(tr.parent(*dums2))==1)
ismatorvec2=true;
if(ismatorvec1 && ismatorvec2 && diffparents && consecutive) {
// txtout << "gluing " << *(dums2->second->name) << std::endl;
// create new indexbracket with product node
iterator outerbrack=tr.insert(tr.parent(*dums1), str_node("\\indexbracket"));
iterator brackprod=tr.append_child(outerbrack, str_node("\\prod"));
iterator parn1=tr.parent(*dums1);
iterator parn2=tr.parent(*dums2);
// count how many sign changes stand between the two objects
int sign=1;
unsigned int hits=0;
Ex_comparator compare(kernel.properties);
sib=tr.begin(it);
while(hits<2) {
if(hits==1 && sib!=parn2) {
// pass arguments manually as can_swap() does not check them
bool isbrack=*(sib->name)=="\\indexbracket";
if(isbrack && isbrack2) {
auto es=compare.equal_subtree(tr.begin(parn2), tr.begin(sib));
sign*=compare.can_swap_components(tr.begin(parn2), tr.begin(sib), es);
}
else if(isbrack && !isbrack2) {
auto es=compare.equal_subtree(parn2, tr.begin(sib));
sign*=compare.can_swap_components(parn2, tr.begin(sib), es);
}
else if(!isbrack && isbrack2) {
auto es=compare.equal_subtree(tr.begin(parn2), sib);
sign*=compare.can_swap_components(tr.begin(parn2), sib, es);
}
else {
auto es=compare.equal_subtree(parn2, sib);
sign*=compare.can_swap_components(parn2, sib, es);
}
}
if(sib==parn1 || sib==parn2) ++hits;
++sib;
}
if(sign==-1) flip_sign(brackprod->multiplier);
// remove the dummy index from these two objects, and move
// other (dummy or not) indices to the outer indexbracket.
sibling_iterator ind1=tr.begin(tr.parent(*dums1));
sibling_iterator stop1=tr.end(tr.parent(*dums1));
if(isbrack1)
++ind1;
while(ind1!=stop1) {
if(ind1!=*dums1) {
sibling_iterator nxt=ind1;
++nxt;
tr.reparent(outerbrack, ind1, nxt);
}
++ind1;
// ind1=tr.erase(ind1);
}
tr.erase(*dums1);
sibling_iterator ind2=tr.begin(tr.parent(*dums2));
sibling_iterator stop2=tr.end(tr.parent(*dums2));
if(isbrack2)
++ind2;
while(ind2!=stop2) {
if(ind2!=*dums2) {
sibling_iterator nxt=ind2;
++nxt;
tr.reparent(outerbrack, ind2, nxt);
}
++ind2;
// ind2=tr.erase(ind2);
}
tr.erase(*dums2);
// put both objects inside the indexbracket.
if(isbrack1) {
sibling_iterator nxt=tr.begin(parn1);
++nxt;
// tr.begin(parn1)->fl.bracket=str_node::b_round;
tr.reparent(brackprod, tr.begin(parn1), nxt);
multiply(brackprod->multiplier, *parn1->multiplier);
tr.erase(parn1);
}
else {
sibling_iterator nxt=parn1;
++nxt;
// parn1->fl.bracket=str_node::b_round;
tr.reparent(brackprod,parn1,nxt);
}
if(isbrack2) {
sibling_iterator nxt=tr.begin(parn2);
++nxt;
// tr.begin(parn2)->fl.bracket=str_node::b_round;
tr.reparent(brackprod, tr.begin(parn2), nxt);
multiply(brackprod->multiplier, *parn2->multiplier);
tr.erase(parn2);
}
else {
sibling_iterator nxt=parn2;
++nxt;
// parn2->fl.bracket=str_node::b_round;
tr.reparent(brackprod,parn2,nxt);
}
}
if(consecutive) {
++dums1;
++dums2;
if(dums2!=dummies.end() && trace_op.size()>0) {
if(*(*dums2)->name==trace_start) {
iterator parn=tr.parent(*dums2);
iterator trace=tr.insert(parn, str_node(trace_op.begin()->name));
sibling_iterator nxt=tr.begin(parn);
++nxt;
++dums1;
++dums2;
tr.reparent(trace, tr.begin(parn), nxt);
multiply(trace->multiplier, *parn->multiplier);
tr.erase(parn);
trace_start="";
}
}
}
else trace_start=*(*dums1)->name;
++dums1;
++dums2;
}
//std::cerr << it << std::endl;
// prodflatten pf(tr, tr.end());
// pf.apply_recursive(it, false);
cleanup_dispatch(kernel, tr, it);
return result_t::l_applied;
}
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