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 #include <nlohmann/detail/macro_scope.hpp> 9 10 namespace nlohmann 11 { 12 namespace detail 13 { 14 //////////////// 15 // exceptions // 16 //////////////// 17 18 /*! 19 @brief general exception of the @ref basic_json class 20 21 This class is an extension of `std::exception` objects with a member @a id for 22 exception ids. It is used as the base class for all exceptions thrown by the 23 @ref basic_json class. This class can hence be used as "wildcard" to catch 24 exceptions. 25 26 Subclasses: 27 - @ref parse_error for exceptions indicating a parse error 28 - @ref invalid_iterator for exceptions indicating errors with iterators 29 - @ref type_error for exceptions indicating executing a member function with 30 a wrong type 31 - @ref out_of_range for exceptions indicating access out of the defined range 32 - @ref other_error for exceptions indicating other library errors 33 34 @internal 35 @note To have nothrow-copy-constructible exceptions, we internally use 36 `std::runtime_error` which can cope with arbitrary-length error messages. 37 Intermediate strings are built with static functions and then passed to 38 the actual constructor. 39 @endinternal 40 41 @liveexample{The following code shows how arbitrary library exceptions can be 42 caught.,exception} 43 44 @since version 3.0.0 45 */ 46 class exception : public std::exception 47 { 48 public: 49 /// returns the explanatory string 50 JSON_HEDLEY_RETURNS_NON_NULL what() const51 const char* what() const noexcept override 52 { 53 return m.what(); 54 } 55 56 /// the id of the exception 57 const int id; 58 59 protected: 60 JSON_HEDLEY_NON_NULL(3) exception(int id_,const char * what_arg)61 exception(int id_, const char* what_arg) : id(id_), m(what_arg) {} 62 name(const std::string & ename,int id_)63 static std::string name(const std::string& ename, int id_) 64 { 65 return "[json.exception." + ename + "." + std::to_string(id_) + "] "; 66 } 67 68 private: 69 /// an exception object as storage for error messages 70 std::runtime_error m; 71 }; 72 73 /*! 74 @brief exception indicating a parse error 75 76 This exception is thrown by the library when a parse error occurs. Parse errors 77 can occur during the deserialization of JSON text, CBOR, MessagePack, as well 78 as when using JSON Patch. 79 80 Member @a byte holds the byte index of the last read character in the input 81 file. 82 83 Exceptions have ids 1xx. 84 85 name / id | example message | description 86 ------------------------------ | --------------- | ------------------------- 87 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. 88 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. 89 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. 90 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. 91 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. 92 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`. 93 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. 94 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. 95 json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. 96 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. 97 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. 98 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. 99 json.exception.parse_error.114 | parse error: Unsupported BSON record type 0x0F | The parsing of the corresponding BSON record type is not implemented (yet). 100 101 @note For an input with n bytes, 1 is the index of the first character and n+1 102 is the index of the terminating null byte or the end of file. This also 103 holds true when reading a byte vector (CBOR or MessagePack). 104 105 @liveexample{The following code shows how a `parse_error` exception can be 106 caught.,parse_error} 107 108 @sa - @ref exception for the base class of the library exceptions 109 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 110 @sa - @ref type_error for exceptions indicating executing a member function with 111 a wrong type 112 @sa - @ref out_of_range for exceptions indicating access out of the defined range 113 @sa - @ref other_error for exceptions indicating other library errors 114 115 @since version 3.0.0 116 */ 117 class parse_error : public exception 118 { 119 public: 120 /*! 121 @brief create a parse error exception 122 @param[in] id_ the id of the exception 123 @param[in] pos the position where the error occurred (or with 124 chars_read_total=0 if the position cannot be 125 determined) 126 @param[in] what_arg the explanatory string 127 @return parse_error object 128 */ create(int id_,const position_t & pos,const std::string & what_arg)129 static parse_error create(int id_, const position_t& pos, const std::string& what_arg) 130 { 131 std::string w = exception::name("parse_error", id_) + "parse error" + 132 position_string(pos) + ": " + what_arg; 133 return parse_error(id_, pos.chars_read_total, w.c_str()); 134 } 135 create(int id_,std::size_t byte_,const std::string & what_arg)136 static parse_error create(int id_, std::size_t byte_, const std::string& what_arg) 137 { 138 std::string w = exception::name("parse_error", id_) + "parse error" + 139 (byte_ != 0 ? (" at byte " + std::to_string(byte_)) : "") + 140 ": " + what_arg; 141 return parse_error(id_, byte_, w.c_str()); 142 } 143 144 /*! 145 @brief byte index of the parse error 146 147 The byte index of the last read character in the input file. 148 149 @note For an input with n bytes, 1 is the index of the first character and 150 n+1 is the index of the terminating null byte or the end of file. 151 This also holds true when reading a byte vector (CBOR or MessagePack). 152 */ 153 const std::size_t byte; 154 155 private: parse_error(int id_,std::size_t byte_,const char * what_arg)156 parse_error(int id_, std::size_t byte_, const char* what_arg) 157 : exception(id_, what_arg), byte(byte_) {} 158 position_string(const position_t & pos)159 static std::string position_string(const position_t& pos) 160 { 161 return " at line " + std::to_string(pos.lines_read + 1) + 162 ", column " + std::to_string(pos.chars_read_current_line); 163 } 164 }; 165 166 /*! 167 @brief exception indicating errors with iterators 168 169 This exception is thrown if iterators passed to a library function do not match 170 the expected semantics. 171 172 Exceptions have ids 2xx. 173 174 name / id | example message | description 175 ----------------------------------- | --------------- | ------------------------- 176 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. 177 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. 178 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. 179 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. 180 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. 181 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. 182 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. 183 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. 184 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. 185 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. 186 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. 187 json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. 188 json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compared, because JSON objects are unordered. 189 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(). 190 191 @liveexample{The following code shows how an `invalid_iterator` exception can be 192 caught.,invalid_iterator} 193 194 @sa - @ref exception for the base class of the library exceptions 195 @sa - @ref parse_error for exceptions indicating a parse error 196 @sa - @ref type_error for exceptions indicating executing a member function with 197 a wrong type 198 @sa - @ref out_of_range for exceptions indicating access out of the defined range 199 @sa - @ref other_error for exceptions indicating other library errors 200 201 @since version 3.0.0 202 */ 203 class invalid_iterator : public exception 204 { 205 public: create(int id_,const std::string & what_arg)206 static invalid_iterator create(int id_, const std::string& what_arg) 207 { 208 std::string w = exception::name("invalid_iterator", id_) + what_arg; 209 return invalid_iterator(id_, w.c_str()); 210 } 211 212 private: 213 JSON_HEDLEY_NON_NULL(3) invalid_iterator(int id_,const char * what_arg)214 invalid_iterator(int id_, const char* what_arg) 215 : exception(id_, what_arg) {} 216 }; 217 218 /*! 219 @brief exception indicating executing a member function with a wrong type 220 221 This exception is thrown in case of a type error; that is, a library function is 222 executed on a JSON value whose type does not match the expected semantics. 223 224 Exceptions have ids 3xx. 225 226 name / id | example message | description 227 ----------------------------- | --------------- | ------------------------- 228 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. 229 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. 230 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 &. 231 json.exception.type_error.304 | cannot use at() with string | The @ref at() member functions can only be executed for certain JSON types. 232 json.exception.type_error.305 | cannot use operator[] with string | The @ref operator[] member functions can only be executed for certain JSON types. 233 json.exception.type_error.306 | cannot use value() with string | The @ref value() member functions can only be executed for certain JSON types. 234 json.exception.type_error.307 | cannot use erase() with string | The @ref erase() member functions can only be executed for certain JSON types. 235 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. 236 json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. 237 json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. 238 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. 239 json.exception.type_error.312 | cannot use update() with string | The @ref update() member functions can only be executed for certain JSON types. 240 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. 241 json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. 242 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. 243 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. | 244 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) | 245 246 @liveexample{The following code shows how a `type_error` exception can be 247 caught.,type_error} 248 249 @sa - @ref exception for the base class of the library exceptions 250 @sa - @ref parse_error for exceptions indicating a parse error 251 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 252 @sa - @ref out_of_range for exceptions indicating access out of the defined range 253 @sa - @ref other_error for exceptions indicating other library errors 254 255 @since version 3.0.0 256 */ 257 class type_error : public exception 258 { 259 public: create(int id_,const std::string & what_arg)260 static type_error create(int id_, const std::string& what_arg) 261 { 262 std::string w = exception::name("type_error", id_) + what_arg; 263 return type_error(id_, w.c_str()); 264 } 265 266 private: 267 JSON_HEDLEY_NON_NULL(3) type_error(int id_,const char * what_arg)268 type_error(int id_, const char* what_arg) : exception(id_, what_arg) {} 269 }; 270 271 /*! 272 @brief exception indicating access out of the defined range 273 274 This exception is thrown in case a library function is called on an input 275 parameter that exceeds the expected range, for instance in case of array 276 indices or nonexisting object keys. 277 278 Exceptions have ids 4xx. 279 280 name / id | example message | description 281 ------------------------------- | --------------- | ------------------------- 282 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. 283 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. 284 json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. 285 json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. 286 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. 287 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. 288 json.exception.out_of_range.407 | number overflow serializing '9223372036854775808' | UBJSON and BSON only support integer numbers up to 9223372036854775807. | 289 json.exception.out_of_range.408 | excessive array size: 8658170730974374167 | The size (following `#`) of an UBJSON array or object exceeds the maximal capacity. | 290 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 | 291 292 @liveexample{The following code shows how an `out_of_range` exception can be 293 caught.,out_of_range} 294 295 @sa - @ref exception for the base class of the library exceptions 296 @sa - @ref parse_error for exceptions indicating a parse error 297 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 298 @sa - @ref type_error for exceptions indicating executing a member function with 299 a wrong type 300 @sa - @ref other_error for exceptions indicating other library errors 301 302 @since version 3.0.0 303 */ 304 class out_of_range : public exception 305 { 306 public: create(int id_,const std::string & what_arg)307 static out_of_range create(int id_, const std::string& what_arg) 308 { 309 std::string w = exception::name("out_of_range", id_) + what_arg; 310 return out_of_range(id_, w.c_str()); 311 } 312 313 private: 314 JSON_HEDLEY_NON_NULL(3) out_of_range(int id_,const char * what_arg)315 out_of_range(int id_, const char* what_arg) : exception(id_, what_arg) {} 316 }; 317 318 /*! 319 @brief exception indicating other library errors 320 321 This exception is thrown in case of errors that cannot be classified with the 322 other exception types. 323 324 Exceptions have ids 5xx. 325 326 name / id | example message | description 327 ------------------------------ | --------------- | ------------------------- 328 json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. 329 330 @sa - @ref exception for the base class of the library exceptions 331 @sa - @ref parse_error for exceptions indicating a parse error 332 @sa - @ref invalid_iterator for exceptions indicating errors with iterators 333 @sa - @ref type_error for exceptions indicating executing a member function with 334 a wrong type 335 @sa - @ref out_of_range for exceptions indicating access out of the defined range 336 337 @liveexample{The following code shows how an `other_error` exception can be 338 caught.,other_error} 339 340 @since version 3.0.0 341 */ 342 class other_error : public exception 343 { 344 public: create(int id_,const std::string & what_arg)345 static other_error create(int id_, const std::string& what_arg) 346 { 347 std::string w = exception::name("other_error", id_) + what_arg; 348 return other_error(id_, w.c_str()); 349 } 350 351 private: 352 JSON_HEDLEY_NON_NULL(3) other_error(int id_,const char * what_arg)353 other_error(int id_, const char* what_arg) : exception(id_, what_arg) {} 354 }; 355 } // namespace detail 356 } // namespace nlohmann 357