| // Copyright 2020 Google LLC |
| // |
| // 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 |
| // |
| // https://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_ANNOTATOR_GRAMMAR_DATES_EXTRACTOR_H_ |
| #define LIBTEXTCLASSIFIER_ANNOTATOR_GRAMMAR_DATES_EXTRACTOR_H_ |
| |
| #include <vector> |
| |
| #include "annotator/grammar/dates/annotations/annotation-options.h" |
| #include "annotator/grammar/dates/dates_generated.h" |
| #include "utils/base/integral_types.h" |
| #include "utils/grammar/callback-delegate.h" |
| #include "utils/grammar/match.h" |
| #include "utils/grammar/matcher.h" |
| #include "utils/grammar/types.h" |
| #include "utils/strings/stringpiece.h" |
| #include "utils/utf8/unicodetext.h" |
| |
| namespace libtextclassifier3::dates { |
| |
| // A helper class for the datetime parser that extracts structured data from |
| // the datetime grammar matches. |
| // It handles simple sanity checking of the rule matches and interacts with the |
| // grammar matcher to extract all datetime occurrences in a text. |
| class DateExtractor : public grammar::CallbackDelegate { |
| public: |
| // Represents a date match for an extraction rule. |
| struct Output { |
| const ExtractionRuleParameter* rule = nullptr; |
| const grammar::Match* match = nullptr; |
| }; |
| |
| // Represents a date match from a range extraction rule. |
| struct RangeOutput { |
| const grammar::Match* match = nullptr; |
| const grammar::Match* from = nullptr; |
| const grammar::Match* to = nullptr; |
| }; |
| |
| DateExtractor(const std::vector<UnicodeText::const_iterator>& text, |
| const DateAnnotationOptions& options, |
| const DatetimeRules* datetime_rules) |
| : text_(text), options_(options), datetime_rules_(datetime_rules) {} |
| |
| // Handle a rule match in the date time grammar. |
| // This checks the type of the match and does type dependent checks. |
| void MatchFound(const grammar::Match* match, grammar::CallbackId type, |
| int64 value, grammar::Matcher* matcher) override; |
| |
| const std::vector<Output>& output() const { return output_; } |
| const std::vector<RangeOutput>& range_output() const { return range_output_; } |
| |
| private: |
| // Extracts a date from a root rule match. |
| void HandleExtractionRuleMatch(const ExtractionRuleParameter* rule, |
| const grammar::Match* match, |
| grammar::Matcher* matcher); |
| |
| // Extracts a date range from a root rule match. |
| void HandleRangeExtractionRuleMatch(const grammar::Match* match, |
| grammar::Matcher* matcher); |
| |
| const std::vector<UnicodeText::const_iterator>& text_; |
| const DateAnnotationOptions& options_; |
| const DatetimeRules* datetime_rules_; |
| |
| // Extraction results. |
| std::vector<Output> output_; |
| std::vector<RangeOutput> range_output_; |
| }; |
| |
| } // namespace libtextclassifier3::dates |
| |
| #endif // LIBTEXTCLASSIFIER_ANNOTATOR_GRAMMAR_DATES_EXTRACTOR_H_ |