1 // Copyright (C) 2019 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #ifndef ICING_TRANSFORM_NORMALIZER_H_
16 #define ICING_TRANSFORM_NORMALIZER_H_
17 
18 #include <memory>
19 #include <string>
20 #include <string_view>
21 
22 #include "icing/text_classifier/lib3/utils/base/statusor.h"
23 
24 namespace icing {
25 namespace lib {
26 
27 // Normalizes strings for text matching.
28 //
29 // Example use:
30 //   ICING_ASSIGN_OR_RETURN(auto normalizer,
31 //       normalizer_factory::Create(/*max_term_byte_size=*/5);
32 //
33 //   std::string normalized_text = normalizer->NormalizeText("HELLO!");
34 //   ICING_LOG(INFO) << normalized_text; // prints "hello"
35 class Normalizer {
36  public:
37   virtual ~Normalizer() = default;
38 
39   // Normalizes the input term based on rules. See implementation classes for
40   // specific transformation rules.
41   virtual std::string NormalizeTerm(std::string_view term) const = 0;
42 };
43 
44 }  // namespace lib
45 }  // namespace icing
46 
47 #endif  // ICING_TRANSFORM_NORMALIZER_H_
48