Dict.hpp

/*
 * Open Chinese Convert
 *
 * Copyright 2010-2020 Carbo Kuo <byvoid@byvoid.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#pragma once
 
#include <list>
#include <string_view>
 
#include "Common.hpp"
#include "DictEntry.hpp"
 
namespace opencc {

enum class DictGroupMatchPolicy {
  ShortCircuit,
  Union,
};

struct OPENCC_EXPORT PrefixMatchView {
  bool matched = false;
  size_t keyLength = 0;
  std::string_view key;
  std::string_view value;
};

class OPENCC_EXPORT Dict {
public:
  virtual Optional<const DictEntry*> Match(const char* word,
                                           size_t len) const = 0;

  Optional<const DictEntry*> Match(const std::string& word) const {
    return Match(word.c_str(), word.length());
  }

  virtual Optional<const DictEntry*> MatchPrefix(const char* word,
                                                 size_t len) const;

  Optional<const DictEntry*> MatchPrefix(const char* word) const {
    return MatchPrefix(word, KeyMaxLength());
  }

  Optional<const DictEntry*> MatchPrefix(const std::string& word) const {
    return MatchPrefix(word.c_str(), word.length());
  }

  virtual std::vector<const DictEntry*> MatchAllPrefixes(const char* word,
                                                         size_t len) const;

  std::vector<const DictEntry*>
  MatchAllPrefixes(const std::string& word) const {
    return MatchAllPrefixes(word.c_str(), word.length());
  }

  virtual size_t KeyMaxLength() const = 0;

  virtual LexiconPtr GetLexicon() const = 0;

  virtual const std::list<DictPtr>* GetDictGroupItems() const {
    return nullptr;
  }

  virtual DictGroupMatchPolicy GetMatchPolicy() const {
    return DictGroupMatchPolicy::ShortCircuit;
  }

  virtual bool SupportsFastPrefixMatch() const { return false; }

  virtual PrefixMatchView MatchPrefixValue(const char* word,
                                           size_t len) const {
    return PrefixMatchView{};
  }
 
  virtual ~Dict() = default;
};
} // namespace opencc