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#include "cfg.h"
#include "hg.h"
#include "cfg_format.h"
#include "cfg_binarize.h"
#include "hash.h"
#include "batched_append.h"
#include <limits>
#include "fast_lexical_cast.hpp"
using namespace std;
namespace {
CFG::BinRhs nullrhs(std::numeric_limits<int>::min(),std::numeric_limits<int>::min());
}
WordID CFG::BinName(BinRhs const& b)
{
return TD::Convert(lexical_cast<string>(b.first)+"+"+lexical_cast<string>(b.second));
}
void CFG::Binarize(CFGBinarize const& b) {
if (!b.Binarizing()) return;
if (!b.bin_l2r) {
assert(b.bin_l2r);
return;
}
// l2r only so far:
cerr << "Binarizing "<<b<<endl;
HASH_MAP<BinRhs,NTHandle> bin2lhs; // we're going to hash cons rather than build an explicit trie from right to left.
HASH_MAP_EMPTY(bin2lhs,nullrhs);
int rhsmin=b.bin_unary?0:1;
// iterate using indices and not iterators because we'll be adding to both nodes and edge list. we could instead pessimistically reserve space for both, but this is simpler. also: store original end of nts since we won't need to reprocess newly added ones.
NTs new_nts; // these will be appended at the end, so we don't have to worry about iterator invalidation
Rules new_rules;
//TODO: this could be factored easily into in-place (append to new_* like below) and functional (nondestructive copy) versions (copy orig to target and append to target)
int newnt=nts.size();
int newruleid=rules.size();
BinRhs bin;
for (NTs::const_iterator n=nts.begin(),nn=nts.end();n!=nn;++n) {
NT const& nt=*n;
for (Ruleids::const_iterator ir=nt.ruleids.begin(),er=nt.ruleids.end();ir!=er;++ir) {
RHS &rhs=rules[*ir].rhs; // we're going to binarize this while adding newly created rules to new_...
if (rhs.empty()) continue;
bin.second=rhs.back();
for (int r=rhs.size()-2;r>=rhsmin;--r) { // pairs from right to left (normally we leave the last pair alone)
rhs.pop_back();
bin.first=rhs[r];
if (newnt==(bin.second=(get_default(bin2lhs,bin,newnt)))) {
new_nts.push_back(NT());
new_nts.back().ruleids.push_back(newruleid);
new_rules.push_back(Rule(newnt,bin));
if (b.bin_name_nts)
new_nts.back().from.nt=BinName(bin);
++newnt;++newruleid;
}
}
}
}
batched_append_swap(nts,new_nts);
batched_append_swap(rules,new_rules);
}
namespace {
inline int nt_index(int nvar,Hypergraph::TailNodeVector const& t,bool target_side,int w) {
assert(w<0 || (target_side&&w==0));
return t[target_side?-w:nvar];
}
}
void CFG::Init(Hypergraph const& hg,bool target_side,bool copy_features,bool push_weights) {
uninit=false;
hg_=&hg;
Hypergraph::NodeProbs np;
goal_inside=hg.ComputeNodeViterbi(&np);
pushed_inside=push_weights ? goal_inside : prob_t(1);
int nn=hg.nodes_.size(),ne=hg.edges_.size();
nts.resize(nn);
goal_nt=nn-1;
rules.resize(ne);
for (int i=0;i<nn;++i) {
nts[i].ruleids=hg.nodes_[i].in_edges_;
hg.SetNodeOrigin(i,nts[i].from);
}
for (int i=0;i<ne;++i) {
Rule &cfgr=rules[i];
Hypergraph::Edge const& e=hg.edges_[i];
prob_t &crp=cfgr.p;
crp=e.edge_prob_;
cfgr.lhs=e.head_node_;
#if CFG_DEBUG
cfgr.rule=e.rule_;
#endif
if (copy_features) cfgr.f=e.feature_values_;
if (push_weights) crp /=np[e.head_node_];
TRule const& er=*e.rule_;
vector<WordID> const& rule_rhs=target_side?er.e():er.f();
int nr=rule_rhs.size();
RHS &rhs_out=cfgr.rhs;
rhs_out.resize(nr);
Hypergraph::TailNodeVector const& tails=e.tail_nodes_;
int nvar=0;
//split out into separate target_side, source_side loops?
for (int j=0;j<nr;++j) {
WordID w=rule_rhs[j];
if (w>0)
rhs_out[j]=w;
else {
int n=nt_index(nvar,tails,target_side,w);
++nvar;
if (push_weights) crp*=np[n];
rhs_out[j]=-n;
}
}
assert(nvar==er.Arity());
assert(nvar==tails.size());
}
}
void CFG::Clear() {
rules.clear();
nts.clear();
goal_nt=-1;
hg_=0;
}
void CFG::PrintRule(std::ostream &o,RuleHandle rulei,CFGFormat const& f) const {
Rule const& r=rules[rulei];
f.print_lhs(o,*this,r.lhs);
f.print_rhs(o,*this,r.rhs.begin(),r.rhs.end());
f.print_features(o,r.p,r.f);
#if CFG_DEBUG
o<<f.partsep<<*r.rule;
#endif
}
void CFG::Print(std::ostream &o,CFGFormat const& f) const {
assert(!uninit);
if (!f.goal_nt_name.empty()) {
o << '['<<f.goal_nt_name <<']';
WordID rhs=-goal_nt;
f.print_rhs(o,*this,&rhs,&rhs+1);
if (pushed_inside!=1)
f.print_features(o,pushed_inside);
o<<'\n';
}
for (int i=0;i<nts.size();++i) {
Ruleids const& ntr=nts[i].ruleids;
for (Ruleids::const_iterator j=ntr.begin(),jj=ntr.end();j!=jj;++j) {
PrintRule(o,*j,f);
o<<'\n';
}
}
}
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