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
25namespace 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 */
35class 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