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/**
* Copyright (C) 2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/base/disallow_copying.h"
#include "mongo/base/string_data.h"
#include "mongo/db/fts/fts_tokenizer.h"
#include "mongo/db/fts/stemmer.h"
#include "mongo/db/fts/tokenizer.h"
namespace mongo {
namespace fts {
class FTSLanguage;
class StopWords;
/**
* BasicFTSTokenizer
* A iterator of "documents" where a document contains ASCII space (U+0020) delimited words.
* Uses
* - Tokenizer for tokenizing words via ASCII space (ie, U+0020 space).
* - tolower from the C standard libary to lower letters, ie, it only supports lower casing
* - ASCII letters (U+0000 - U+007F)
* - Stemmer (ie, Snowball Stemmer) to stem words.
* - Embeded stop word lists for each language in StopWord class
*
* For each word returns a stem version of a word optimized for full text indexing.
* Optionally supports returning case sensitive search terms.
*
* BasicFTSTokenizer does not implement the kGenerateDiacriticSensitiveTokens option. All tokens
* generated by the BasicFTSTokenizer are ineherently diacritic sensitive.
*/
class BasicFTSTokenizer final : public FTSTokenizer {
MONGO_DISALLOW_COPYING(BasicFTSTokenizer);
public:
BasicFTSTokenizer(const FTSLanguage* language);
void reset(StringData document, Options options) override;
bool moveNext() override;
StringData get() const override;
private:
const FTSLanguage* const _language;
const Stemmer _stemmer;
const StopWords* const _stopWords;
std::string _document;
std::unique_ptr<Tokenizer> _tokenizer;
Options _options;
std::string _stem;
};
} // namespace fts
} // namespace mongo
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