You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

124 lines
5.1 KiB

/*
* Copyright (C) 2018 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_ANNOTATOR_DATETIME_REGEX_PARSER_H_
#define LIBTEXTCLASSIFIER_ANNOTATOR_DATETIME_REGEX_PARSER_H_
#include <memory>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "annotator/datetime/extractor.h"
#include "annotator/datetime/parser.h"
#include "annotator/model_generated.h"
#include "annotator/types.h"
#include "utils/base/integral_types.h"
#include "utils/base/statusor.h"
#include "utils/calendar/calendar.h"
#include "utils/strings/stringpiece.h"
#include "utils/utf8/unicodetext.h"
#include "utils/utf8/unilib.h"
#include "utils/zlib/zlib.h"
namespace libtextclassifier3 {
// Parses datetime expressions in the input and resolves them to actual absolute
// time.
class RegexDatetimeParser : public DatetimeParser {
public:
static std::unique_ptr<DatetimeParser> Instance(
const DatetimeModel* model, const UniLib* unilib,
const CalendarLib* calendarlib, ZlibDecompressor* decompressor);
// Parses the dates in 'input' and fills result. Makes sure that the results
// do not overlap.
// If 'anchor_start_end' is true the extracted results need to start at the
// beginning of 'input' and end at the end of it.
StatusOr<std::vector<DatetimeParseResultSpan>> Parse(
const std::string& input, int64 reference_time_ms_utc,
const std::string& reference_timezone, const LocaleList& locale_list,
ModeFlag mode, AnnotationUsecase annotation_usecase,
bool anchor_start_end) const override;
// Same as above but takes UnicodeText.
StatusOr<std::vector<DatetimeParseResultSpan>> Parse(
const UnicodeText& input, int64 reference_time_ms_utc,
const std::string& reference_timezone, const LocaleList& locale_list,
ModeFlag mode, AnnotationUsecase annotation_usecase,
bool anchor_start_end) const override;
protected:
explicit RegexDatetimeParser(const DatetimeModel* model, const UniLib* unilib,
const CalendarLib* calendarlib,
ZlibDecompressor* decompressor);
// Returns a list of locale ids for given locale spec string (collection of
// locale names).
std::vector<int> ParseAndExpandLocales(
const std::vector<StringPiece>& locales) const;
// Helper function that finds datetime spans, only using the rules associated
// with the given locales.
StatusOr<std::vector<DatetimeParseResultSpan>> FindSpansUsingLocales(
const std::vector<int>& locale_ids, const UnicodeText& input,
const int64 reference_time_ms_utc, const std::string& reference_timezone,
ModeFlag mode, AnnotationUsecase annotation_usecase,
bool anchor_start_end, const std::string& reference_locale,
std::unordered_set<int>* executed_rules) const;
StatusOr<std::vector<DatetimeParseResultSpan>> ParseWithRule(
const CompiledRule& rule, const UnicodeText& input,
int64 reference_time_ms_utc, const std::string& reference_timezone,
const std::string& reference_locale, const int locale_id,
bool anchor_start_end) const;
// Converts the current match in 'matcher' into DatetimeParseResult.
bool ExtractDatetime(const CompiledRule& rule,
const UniLib::RegexMatcher& matcher,
int64 reference_time_ms_utc,
const std::string& reference_timezone,
const std::string& reference_locale, int locale_id,
std::vector<DatetimeParseResult>* results,
CodepointSpan* result_span) const;
// Parse and extract information from current match in 'matcher'.
StatusOr<std::vector<DatetimeParseResultSpan>> HandleParseMatch(
const CompiledRule& rule, const UniLib::RegexMatcher& matcher,
int64 reference_time_ms_utc, const std::string& reference_timezone,
const std::string& reference_locale, int locale_id) const;
private:
bool initialized_;
const UniLib& unilib_;
const CalendarLib& calendarlib_;
std::vector<CompiledRule> rules_;
std::unordered_map<int, std::vector<int>> locale_to_rules_;
std::vector<std::unique_ptr<const UniLib::RegexPattern>> extractor_rules_;
std::unordered_map<DatetimeExtractorType, std::unordered_map<int, int>>
type_and_locale_to_extractor_rule_;
std::unordered_map<std::string, int> locale_string_to_id_;
std::vector<int> default_locale_ids_;
bool use_extractors_for_locating_;
bool generate_alternative_interpretations_when_ambiguous_;
bool prefer_future_for_unspecified_date_;
};
} // namespace libtextclassifier3
#endif // LIBTEXTCLASSIFIER_ANNOTATOR_DATETIME_REGEX_PARSER_H_