1 | /* |
2 | * Copyright 2011-present Facebook, Inc. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | */ |
16 | |
17 | #pragma once |
18 | |
19 | #include <string> |
20 | #include <vector> |
21 | |
22 | #include <folly/Expected.h> |
23 | #include <folly/Range.h> |
24 | |
25 | namespace folly { |
26 | |
27 | /* |
28 | * json_pointer |
29 | * |
30 | * As described in RFC 6901 "JSON Pointer". |
31 | * |
32 | * Implements parsing. Traversal using the pointer over data structures must be |
33 | * implemented separately. |
34 | */ |
35 | class json_pointer { |
36 | public: |
37 | enum class parse_error { |
38 | invalid_first_character, |
39 | invalid_escape_sequence, |
40 | }; |
41 | |
42 | class parse_exception : public std::runtime_error { |
43 | using std::runtime_error::runtime_error; |
44 | }; |
45 | |
46 | json_pointer() = default; |
47 | ~json_pointer() = default; |
48 | |
49 | /* |
50 | * Parse string into vector of unescaped tokens. |
51 | * Non-throwing and throwing versions. |
52 | */ |
53 | static Expected<json_pointer, parse_error> try_parse(StringPiece const str); |
54 | |
55 | static json_pointer parse(StringPiece const str); |
56 | |
57 | /* |
58 | * Return true if this pointer is proper to prefix to another pointer |
59 | */ |
60 | bool is_prefix_of(json_pointer const& other) const noexcept; |
61 | |
62 | /* |
63 | * Get access to the parsed tokens for applications that want to traverse |
64 | * the pointer. |
65 | */ |
66 | std::vector<std::string> const& tokens() const; |
67 | |
68 | friend bool operator==(json_pointer const& lhs, json_pointer const& rhs) { |
69 | return lhs.tokens_ == rhs.tokens_; |
70 | } |
71 | |
72 | friend bool operator!=(json_pointer const& lhs, json_pointer const& rhs) { |
73 | return lhs.tokens_ != rhs.tokens_; |
74 | } |
75 | |
76 | private: |
77 | explicit json_pointer(std::vector<std::string>) noexcept; |
78 | |
79 | /* |
80 | * Unescape the specified escape sequences, returns false if incorrect |
81 | */ |
82 | static bool unescape(std::string&); |
83 | |
84 | std::vector<std::string> tokens_; |
85 | }; |
86 | |
87 | } // namespace folly |
88 | |