| // 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_UTILS_GRAMMAR_PARSING_DERIVATION_H_ |
| #define LIBTEXTCLASSIFIER_UTILS_GRAMMAR_PARSING_DERIVATION_H_ |
| |
| #include <vector> |
| |
| #include "utils/grammar/parsing/parse-tree.h" |
| |
| namespace libtextclassifier3::grammar { |
| |
| // A parse tree for a root rule. |
| struct Derivation { |
| const ParseTree* parse_tree; |
| int64 rule_id; |
| |
| // Checks that all assertions are fulfilled. |
| bool IsValid() const; |
| }; |
| |
| // Deduplicates rule derivations by containing overlap. |
| // The grammar system can output multiple candidates for optional parts. |
| // For example if a rule has an optional suffix, we |
| // will get two rule derivations when the suffix is present: one with and one |
| // without the suffix. We therefore deduplicate by containing overlap, viz. from |
| // two candidates we keep the longer one if it completely contains the shorter. |
| std::vector<Derivation> DeduplicateDerivations( |
| const std::vector<Derivation>& derivations); |
| |
| // Deduplicates and validates rule derivations. |
| std::vector<Derivation> ValidDeduplicatedDerivations( |
| const std::vector<Derivation>& derivations); |
| |
| } // namespace libtextclassifier3::grammar |
| |
| #endif // LIBTEXTCLASSIFIER_UTILS_GRAMMAR_PARSING_DERIVATION_H_ |