1 #pragma once 2 3 #include <exception> // exception 4 #include <stdexcept> // runtime_error 5 #include <string> // to_string 6 7 #include <nlohmann/detail/input/position_t.hpp> 8 9 namespace nlohmann 10 { 11 namespace detail 12 { 13 //////////////// 14 // exceptions // 15 //////////////// 16 17 /*! 18 @brief general exception of the @ref basic_json class 19 20 This class is an extension of `std::exception` objects with a member @a id for 21 exception ids. It is used as the base class for all exceptions thrown by the 22 @ref basic_json class. This class can hence be used as "wildcard" to catch 23 exceptions. 24 25 Subclasses: 26 - @ref parse_error for exceptions indicating a parse error 27 - @ref invalid_iterator for exceptions indicating errors with iterators 28 - @ref type_error for exceptions indicating executing a member function with 29 a wrong type 30 - @ref out_of_range for exceptions indicating access out of the defined range 31 - @ref other_error for exceptions indicating other library errors 32 33 @internal 34 @note To have nothrow-copy-constructible exceptions, we internally use 35 `std::runtime_error` which can cope with arbitrary-length error messages. 36 Intermediate strings are built with static functions and then passed to 37 the actual constructor. 38 @endinternal 39 40 @liveexample{The following code shows how arbitrary library exceptions can be 41 caught.,exception} 42 43 @since version 3.0.0 44 */ 45 class exception : public std::exception 46 { 47 public: 48 /// returns the explanatory string what() const49 const char* what() const noexcept override 50 { 51 return m.what(); 52 } 53 54 /// the id of the exception 55 const int id; 56 57 protected: exception(int id_,const char * what_arg)58 exception(int id_, const char* what_arg) : id(id_), m(what_arg) {} 59 name(const std::string & ename,int id_)60 static std::string name(const std::string& ename, int id_) 61 { 62 return "[json.exception." + ename + "." + std::to_string(id_) + "] "; 63 } 64 65 private: 66 /// an exception object as storage for error messages 67 std::runtime_error m; 68 }; 69 70 /*! 71 @brief exception indicating a parse error 72 73 This exception is thrown by the library when a parse error occurs. Parse errors 74 can occur during the deserialization of JSON text, CBOR, MessagePack, as well 75 as when using JSON Patch. 76 77 Member @a byte holds the byte index of the last read character in the input 78 file. 79 80 Exceptions have ids 1xx. 81 82 name / id | example message | description 83 ------------------------------ | --------------- | ------------------------- 84 json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. 85 json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. 86 json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. 87 json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. 88 json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. 89 json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number without a leading `0`. 90 json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. 91 json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. 92 json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. 93 json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. 94 json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xF8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. 95 json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. 96 json.exception.parse_error.114 | parse error: Unsupported BSON record type 0x0F | The parsing of the corresponding BSON record type is not implemented (yet). 97 98 @note For an input with n bytes, 1 is the index of the first character and n+1 99 is the index of the terminating null byte or the end of file. This also 100 holds true when reading a byte vector (CBOR or MessagePack). 101 102 @liveexample{The following code shows how a `parse_error` exception can be 103 caught.,parse_error} 104 105 @sa - @ref exception for the base class of the library exceptions 106 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 107 @sa - @ref type_error for exceptions indicating executing a member function with 108 a wrong type 109 @sa - @ref out_of_range for exceptions indicating access out of the defined range 110 @sa - @ref other_error for exceptions indicating other library errors 111 112 @since version 3.0.0 113 */ 114 class parse_error : public exception 115 { 116 public: 117 /*! 118 @brief create a parse error exception 119 @param[in] id_ the id of the exception 120 @param[in] pos the position where the error occurred (or with 121 chars_read_total=0 if the position cannot be 122 determined) 123 @param[in] what_arg the explanatory string 124 @return parse_error object 125 */ create(int id_,const position_t & pos,const std::string & what_arg)126 static parse_error create(int id_, const position_t& pos, const std::string& what_arg) 127 { 128 std::string w = exception::name("parse_error", id_) + "parse error" + 129 position_string(pos) + ": " + what_arg; 130 return parse_error(id_, pos.chars_read_total, w.c_str()); 131 } 132 create(int id_,std::size_t byte_,const std::string & what_arg)133 static parse_error create(int id_, std::size_t byte_, const std::string& what_arg) 134 { 135 std::string w = exception::name("parse_error", id_) + "parse error" + 136 (byte_ != 0 ? (" at byte " + std::to_string(byte_)) : "") + 137 ": " + what_arg; 138 return parse_error(id_, byte_, w.c_str()); 139 } 140 141 /*! 142 @brief byte index of the parse error 143 144 The byte index of the last read character in the input file. 145 146 @note For an input with n bytes, 1 is the index of the first character and 147 n+1 is the index of the terminating null byte or the end of file. 148 This also holds true when reading a byte vector (CBOR or MessagePack). 149 */ 150 const std::size_t byte; 151 152 private: parse_error(int id_,std::size_t byte_,const char * what_arg)153 parse_error(int id_, std::size_t byte_, const char* what_arg) 154 : exception(id_, what_arg), byte(byte_) {} 155 position_string(const position_t & pos)156 static std::string position_string(const position_t& pos) 157 { 158 return " at line " + std::to_string(pos.lines_read + 1) + 159 ", column " + std::to_string(pos.chars_read_current_line); 160 } 161 }; 162 163 /*! 164 @brief exception indicating errors with iterators 165 166 This exception is thrown if iterators passed to a library function do not match 167 the expected semantics. 168 169 Exceptions have ids 2xx. 170 171 name / id | example message | description 172 ----------------------------------- | --------------- | ------------------------- 173 json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. 174 json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. 175 json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. 176 json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. 177 json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. 178 json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. 179 json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. 180 json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. 181 json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. 182 json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. 183 json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. 184 json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. 185 json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compared, because JSON objects are unordered. 186 json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). 187 188 @liveexample{The following code shows how an `invalid_iterator` exception can be 189 caught.,invalid_iterator} 190 191 @sa - @ref exception for the base class of the library exceptions 192 @sa - @ref parse_error for exceptions indicating a parse error 193 @sa - @ref type_error for exceptions indicating executing a member function with 194 a wrong type 195 @sa - @ref out_of_range for exceptions indicating access out of the defined range 196 @sa - @ref other_error for exceptions indicating other library errors 197 198 @since version 3.0.0 199 */ 200 class invalid_iterator : public exception 201 { 202 public: create(int id_,const std::string & what_arg)203 static invalid_iterator create(int id_, const std::string& what_arg) 204 { 205 std::string w = exception::name("invalid_iterator", id_) + what_arg; 206 return invalid_iterator(id_, w.c_str()); 207 } 208 209 private: invalid_iterator(int id_,const char * what_arg)210 invalid_iterator(int id_, const char* what_arg) 211 : exception(id_, what_arg) {} 212 }; 213 214 /*! 215 @brief exception indicating executing a member function with a wrong type 216 217 This exception is thrown in case of a type error; that is, a library function is 218 executed on a JSON value whose type does not match the expected semantics. 219 220 Exceptions have ids 3xx. 221 222 name / id | example message | description 223 ----------------------------- | --------------- | ------------------------- 224 json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. 225 json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. 226 json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a @ref basic_json object with @ref get_ref, the type of the reference must match the value type. For instance, for a JSON array, the @a ReferenceType must be @ref array_t &. 227 json.exception.type_error.304 | cannot use at() with string | The @ref at() member functions can only be executed for certain JSON types. 228 json.exception.type_error.305 | cannot use operator[] with string | The @ref operator[] member functions can only be executed for certain JSON types. 229 json.exception.type_error.306 | cannot use value() with string | The @ref value() member functions can only be executed for certain JSON types. 230 json.exception.type_error.307 | cannot use erase() with string | The @ref erase() member functions can only be executed for certain JSON types. 231 json.exception.type_error.308 | cannot use push_back() with string | The @ref push_back() and @ref operator+= member functions can only be executed for certain JSON types. 232 json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. 233 json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. 234 json.exception.type_error.311 | cannot use emplace_back() with string | The @ref emplace_back() member function can only be executed for certain JSON types. 235 json.exception.type_error.312 | cannot use update() with string | The @ref update() member functions can only be executed for certain JSON types. 236 json.exception.type_error.313 | invalid value to unflatten | The @ref unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. 237 json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. 238 json.exception.type_error.315 | values in object must be primitive | The @ref unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. 239 json.exception.type_error.316 | invalid UTF-8 byte at index 10: 0x7E | The @ref dump function only works with UTF-8 encoded strings; that is, if you assign a `std::string` to a JSON value, make sure it is UTF-8 encoded. | 240 json.exception.type_error.317 | JSON value cannot be serialized to requested format | The dynamic type of the object cannot be represented in the requested serialization format (e.g. a raw `true` or `null` JSON object cannot be serialized to BSON) | 241 242 @liveexample{The following code shows how a `type_error` exception can be 243 caught.,type_error} 244 245 @sa - @ref exception for the base class of the library exceptions 246 @sa - @ref parse_error for exceptions indicating a parse error 247 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 248 @sa - @ref out_of_range for exceptions indicating access out of the defined range 249 @sa - @ref other_error for exceptions indicating other library errors 250 251 @since version 3.0.0 252 */ 253 class type_error : public exception 254 { 255 public: create(int id_,const std::string & what_arg)256 static type_error create(int id_, const std::string& what_arg) 257 { 258 std::string w = exception::name("type_error", id_) + what_arg; 259 return type_error(id_, w.c_str()); 260 } 261 262 private: type_error(int id_,const char * what_arg)263 type_error(int id_, const char* what_arg) : exception(id_, what_arg) {} 264 }; 265 266 /*! 267 @brief exception indicating access out of the defined range 268 269 This exception is thrown in case a library function is called on an input 270 parameter that exceeds the expected range, for instance in case of array 271 indices or nonexisting object keys. 272 273 Exceptions have ids 4xx. 274 275 name / id | example message | description 276 ------------------------------- | --------------- | ------------------------- 277 json.exception.out_of_range.401 | array index 3 is out of range | The provided array index @a i is larger than @a size-1. 278 json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. 279 json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. 280 json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. 281 json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. 282 json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. 283 json.exception.out_of_range.407 | number overflow serializing '9223372036854775808' | UBJSON and BSON only support integer numbers up to 9223372036854775807. | 284 json.exception.out_of_range.408 | excessive array size: 8658170730974374167 | The size (following `#`) of an UBJSON array or object exceeds the maximal capacity. | 285 json.exception.out_of_range.409 | BSON key cannot contain code point U+0000 (at byte 2) | Key identifiers to be serialized to BSON cannot contain code point U+0000, since the key is stored as zero-terminated c-string | 286 287 @liveexample{The following code shows how an `out_of_range` exception can be 288 caught.,out_of_range} 289 290 @sa - @ref exception for the base class of the library exceptions 291 @sa - @ref parse_error for exceptions indicating a parse error 292 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 293 @sa - @ref type_error for exceptions indicating executing a member function with 294 a wrong type 295 @sa - @ref other_error for exceptions indicating other library errors 296 297 @since version 3.0.0 298 */ 299 class out_of_range : public exception 300 { 301 public: create(int id_,const std::string & what_arg)302 static out_of_range create(int id_, const std::string& what_arg) 303 { 304 std::string w = exception::name("out_of_range", id_) + what_arg; 305 return out_of_range(id_, w.c_str()); 306 } 307 308 private: out_of_range(int id_,const char * what_arg)309 out_of_range(int id_, const char* what_arg) : exception(id_, what_arg) {} 310 }; 311 312 /*! 313 @brief exception indicating other library errors 314 315 This exception is thrown in case of errors that cannot be classified with the 316 other exception types. 317 318 Exceptions have ids 5xx. 319 320 name / id | example message | description 321 ------------------------------ | --------------- | ------------------------- 322 json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. 323 324 @sa - @ref exception for the base class of the library exceptions 325 @sa - @ref parse_error for exceptions indicating a parse error 326 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 327 @sa - @ref type_error for exceptions indicating executing a member function with 328 a wrong type 329 @sa - @ref out_of_range for exceptions indicating access out of the defined range 330 331 @liveexample{The following code shows how an `other_error` exception can be 332 caught.,other_error} 333 334 @since version 3.0.0 335 */ 336 class other_error : public exception 337 { 338 public: create(int id_,const std::string & what_arg)339 static other_error create(int id_, const std::string& what_arg) 340 { 341 std::string w = exception::name("other_error", id_) + what_arg; 342 return other_error(id_, w.c_str()); 343 } 344 345 private: other_error(int id_,const char * what_arg)346 other_error(int id_, const char* what_arg) : exception(id_, what_arg) {} 347 }; 348 } // namespace detail 349 } // namespace nlohmann 350