| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #ifndef LIBTEXTCLASSIFIER_TOKENIZER_H_ |
| #define LIBTEXTCLASSIFIER_TOKENIZER_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "model_generated.h" |
| #include "types.h" |
| #include "util/base/integral_types.h" |
| #include "util/utf8/unicodetext.h" |
| |
| namespace libtextclassifier2 { |
| |
| const int kInvalidScript = -1; |
| const int kUnknownScript = -2; |
| |
| // Tokenizer splits the input string into a sequence of tokens, according to the |
| // configuration. |
| class Tokenizer { |
| public: |
| explicit Tokenizer( |
| const std::vector<const TokenizationCodepointRange*>& codepoint_ranges, |
| bool split_on_script_change); |
| |
| // Tokenizes the input string using the selected tokenization method. |
| std::vector<Token> Tokenize(const std::string& text) const; |
| |
| // Same as above but takes UnicodeText. |
| std::vector<Token> Tokenize(const UnicodeText& text_unicode) const; |
| |
| protected: |
| // Finds the tokenization codepoint range config for given codepoint. |
| // Internally uses binary search so should be O(log(# of codepoint_ranges)). |
| const TokenizationCodepointRangeT* FindTokenizationRange(int codepoint) const; |
| |
| // Finds the role and script for given codepoint. If not found, DEFAULT_ROLE |
| // and kUnknownScript are assigned. |
| void GetScriptAndRole(char32 codepoint, |
| TokenizationCodepointRange_::Role* role, |
| int* script) const; |
| |
| private: |
| // Codepoint ranges that determine how different codepoints are tokenized. |
| // The ranges must not overlap. |
| std::vector<std::unique_ptr<const TokenizationCodepointRangeT>> |
| codepoint_ranges_; |
| |
| // If true, tokens will be additionally split when the codepoint's script_id |
| // changes. |
| bool split_on_script_change_; |
| }; |
| |
| } // namespace libtextclassifier2 |
| |
| #endif // LIBTEXTCLASSIFIER_TOKENIZER_H_ |