lvoc.h.svn-base

moses开源的机器翻译系统

#ifndef LVOC_H
#define LVOC_H

#include<map>
#include<vector>
#include<iostream>
#include<fstream>
#include <sstream>

typedef unsigned LabelId;
extern const LabelId InvalidLabelId;
extern const LabelId Epsilon;

typedef std::vector<LabelId> IPhrase;

// A = type of things to numberize, ie, std::string
// B = map type to use, might consider using hash_map for better performance
template<typename A,typename B=std::map<A,LabelId> >
class LVoc {
  typedef A Key;
  typedef B M;
  typedef std::vector<Key> V;
  M m;
  V data;
public:
  LVoc() {}

  bool isKnown(const Key& k) const {return m.find(k)!=m.end();}
  LabelId index(const Key& k) const {
    typename M::const_iterator i=m.find(k);
    return i!=m.end()? i->second : InvalidLabelId;}
  LabelId add(const Key& k) {
    std::pair<typename M::iterator,bool> p
			=m.insert(std::make_pair(k,data.size()));
    if(p.second) data.push_back(k);
		assert(static_cast<size_t>(p.first->second)<data.size());
    return p.first->second;
  }
  Key const& symbol(LabelId i) const {
    assert(static_cast<size_t>(i)<data.size());
    return data[i];}

  typedef typename V::const_iterator const_iterator;
  const_iterator begin() const {return data.begin();}
  const_iterator end() const {return data.end();}
  
  void Write(const std::string& fname) const {
  	std::ofstream out(fname.c_str()); Write(out);}
  void Write(std::ostream& out) const {
  	for(int i=data.size()-1;i>=0;--i)
  		out<<i<<' '<<data[i]<<'\n';
  }
  void Read(const std::string& fname) {
  	std::ifstream in(fname.c_str());Read(in);}
  void Read(std::istream& in) {
  	Key k;size_t i;std::string line;
  	while(getline(in,line)) {
  		std::istringstream is(line);
  		if(is>>i>>k) {
				if(i>=data.size()) data.resize(i+1);
  			data[i]=k;
  			m[k]=i;
  		}
  	}
  }	
};

#endif //LVOC_H