ukui-search/libchinese-segmentation/cppjieba/MPSegment.hpp

138 lines
3.6 KiB
C++

#ifndef CPPJIEBA_MPSEGMENT_H
#define CPPJIEBA_MPSEGMENT_H
#include <algorithm>
#include <set>
#include <cassert>
#include "limonp/Logging.hpp"
#include "DictTrie.hpp"
#include "SegmentTagged.hpp"
#include "PosTagger.hpp"
namespace cppjieba {
class MPSegment: public SegmentTagged {
public:
MPSegment(const string& dictPath, const string& userDictPath = "")
: dictTrie_(new DictTrie(dictPath, userDictPath)), isNeedDestroy_(true) {
}
MPSegment(const DictTrie* dictTrie)
: dictTrie_(dictTrie), isNeedDestroy_(false) {
assert(dictTrie_);
}
~MPSegment() {
if (isNeedDestroy_) {
delete dictTrie_;
}
}
void Cut(const string& sentence, vector<string>& words) const {
Cut(sentence, words, MAX_WORD_LENGTH);
}
void Cut(const string& sentence,
vector<string>& words,
size_t max_word_len) const {
vector<Word> tmp;
Cut(sentence, tmp, max_word_len);
GetStringsFromWords(tmp, words);
}
void Cut(const string& sentence,
vector<Word>& words,
size_t max_word_len = MAX_WORD_LENGTH) const {
PreFilter pre_filter(symbols_, sentence);
PreFilter::Range range;
vector<WordRange> wrs;
wrs.reserve(sentence.size()/2);
while (pre_filter.HasNext()) {
range = pre_filter.Next();
Cut(range.begin, range.end, wrs, max_word_len);
}
words.clear();
words.reserve(wrs.size());
GetWordsFromWordRanges(sentence, wrs, words);
}
void Cut(RuneStrArray::const_iterator begin,
RuneStrArray::const_iterator end,
vector<WordRange>& words,
size_t max_word_len = MAX_WORD_LENGTH) const {
vector<Dag> dags;
dictTrie_->Find(begin,
end,
dags,
max_word_len);
CalcDP(dags);
CutByDag(begin, end, dags, words);
}
const DictTrie* GetDictTrie() const {
return dictTrie_;
}
bool Tag(const string& src, vector<pair<string, string> >& res) const {
return tagger_.Tag(src, res, *this);
}
bool IsUserDictSingleChineseWord(const Rune& value) const {
return dictTrie_->IsUserDictSingleChineseWord(value);
}
private:
void CalcDP(vector<Dag>& dags) const {
size_t nextPos;
const DictUnit* p;
double val;
for (vector<Dag>::reverse_iterator rit = dags.rbegin(); rit != dags.rend(); rit++) {
rit->pInfo = NULL;
rit->weight = MIN_DOUBLE;
assert(!rit->nexts.empty());
for (LocalVector<pair<size_t, const DictUnit*> >::const_iterator it = rit->nexts.begin(); it != rit->nexts.end(); it++) {
nextPos = it->first;
p = it->second;
val = 0.0;
if (nextPos + 1 < dags.size()) {
val += dags[nextPos + 1].weight;
}
if (p) {
val += p->weight;
} else {
val += dictTrie_->GetMinWeight();
}
if (val > rit->weight) {
rit->pInfo = p;
rit->weight = val;
}
}
}
}
void CutByDag(RuneStrArray::const_iterator begin,
RuneStrArray::const_iterator end,
const vector<Dag>& dags,
vector<WordRange>& words) const {
size_t i = 0;
while (i < dags.size()) {
const DictUnit* p = dags[i].pInfo;
if (p) {
assert(p->word.size() >= 1);
WordRange wr(begin + i, begin + i + p->word.size() - 1);
words.push_back(wr);
i += p->word.size();
} else { //single chinese word
WordRange wr(begin + i, begin + i);
words.push_back(wr);
i++;
}
}
}
const DictTrie* dictTrie_;
bool isNeedDestroy_;
PosTagger tagger_;
}; // class MPSegment
} // namespace cppjieba
#endif