1 // Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors
2 // Distributed under MIT license, or public domain if desired and
3 // recognized in your jurisdiction.
4 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
5
6 #ifndef JSON_H_INCLUDED
7 #define JSON_H_INCLUDED
8
9 #if !defined(JSON_IS_AMALGAMATION)
10 #include "forwards.h"
11 #endif // if !defined(JSON_IS_AMALGAMATION)
12
13 // Conditional NORETURN attribute on the throw functions would:
14 // a) suppress false positives from static code analysis
15 // b) possibly improve optimization opportunities.
16 // For compatibility, [[noreturn]] is not used
17 #if !defined(JSONCPP_NORETURN)
18 #if defined(_MSC_VER)
19 #define JSONCPP_NORETURN __declspec(noreturn)
20 #elif defined(__GNUC__) || defined(__clang__)
21 #define JSONCPP_NORETURN __attribute__((noreturn))
22 #else
23 #define JSONCPP_NORETURN
24 #endif
25 #endif // if !defined(JSONCPP_NORETURN)
26
27 // Support for '= delete' with template declarations was a late addition
28 // to the c++11 standard and is rejected by clang 3.8 and Apple clang 8.2
29 // even though these declare themselves to be c++11 compilers.
30 #if !defined(JSONCPP_TEMPLATE_DELETE)
31 #if defined(__clang__) && defined(__apple_build_version__)
32 #if __apple_build_version__ <= 8000042
33 #define JSONCPP_TEMPLATE_DELETE
34 #endif
35 #elif defined(__clang__)
36 #if __clang_major__ == 3 && __clang_minor__ <= 8
37 #define JSONCPP_TEMPLATE_DELETE
38 #endif
39 #endif
40 #if !defined(JSONCPP_TEMPLATE_DELETE)
41 #define JSONCPP_TEMPLATE_DELETE = delete
42 #endif
43 #endif
44
45 #if JSONCPP_CXX_STD_11
46 #else
47 #undef JSONCPP_TEMPLATE_DELETE
48 #define JSONCPP_TEMPLATE_DELETE
49 #include <string.h>
50 #endif
51
52 #include <exception>
53 #include <map>
54 #include <string>
55 #include <vector>
56
57 // Disable warning C4251: <data member>: <type> needs to have dll-interface to
58 // be used by...
59 #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
60 #pragma warning(push)
61 #pragma warning(disable : 4251)
62 #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
63
64 #pragma pack(push, 8)
65
66 /** \brief JSON (JavaScript Object Notation).
67 */
68 namespace Json {
69
70 #if JSON_USE_EXCEPTION
71 /** Base class for all exceptions we throw.
72 *
73 * We use nothing but these internally. Of course, STL can throw others.
74 */
75 class JSON_API Exception : public std::exception {
76 public:
77 Exception(String msg);
78 ~Exception() JSONCPP_NOEXCEPT JSONCPP_OVERRIDE;
79 char const* what() const JSONCPP_NOEXCEPT JSONCPP_OVERRIDE;
80
81 protected:
82 String msg_;
83 };
84
85 /** Exceptions which the user cannot easily avoid.
86 *
87 * E.g. out-of-memory (when we use malloc), stack-overflow, malicious input
88 *
89 * \remark derived from Json::Exception
90 */
91 class JSON_API RuntimeError : public Exception {
92 public:
93 RuntimeError(String const& msg);
94 };
95
96 /** Exceptions thrown by JSON_ASSERT/JSON_FAIL macros.
97 *
98 * These are precondition-violations (user bugs) and internal errors (our bugs).
99 *
100 * \remark derived from Json::Exception
101 */
102 class JSON_API LogicError : public Exception {
103 public:
104 LogicError(String const& msg);
105 };
106 #endif
107
108 /// used internally
109 JSONCPP_NORETURN void throwRuntimeError(String const& msg);
110 /// used internally
111 JSONCPP_NORETURN void throwLogicError(String const& msg);
112
113 /** \brief Type of the value held by a Value object.
114 */
115 enum ValueType {
116 nullValue = 0, ///< 'null' value
117 intValue, ///< signed integer value
118 uintValue, ///< unsigned integer value
119 realValue, ///< double value
120 stringValue, ///< UTF-8 string value
121 booleanValue, ///< bool value
122 arrayValue, ///< array value (ordered list)
123 objectValue ///< object value (collection of name/value pairs).
124 };
125
126 enum CommentPlacement {
127 commentBefore = 0, ///< a comment placed on the line before a value
128 commentAfterOnSameLine, ///< a comment just after a value on the same line
129 commentAfter, ///< a comment on the line after a value (only make sense for
130 /// root value)
131 numberOfCommentPlacement
132 };
133
134 /** \brief Type of precision for formatting of real values.
135 */
136 enum PrecisionType {
137 significantDigits = 0, ///< we set max number of significant digits in string
138 decimalPlaces ///< we set max number of digits after "." in string
139 };
140
141 /** \brief Lightweight wrapper to tag static string.
142 *
143 * Value constructor and objectValue member assignment takes advantage of the
144 * StaticString and avoid the cost of string duplication when storing the
145 * string or the member name.
146 *
147 * Example of usage:
148 * \code
149 * Json::Value aValue( StaticString("some text") );
150 * Json::Value object;
151 * static const StaticString code("code");
152 * object[code] = 1234;
153 * \endcode
154 */
155 class JSON_API StaticString {
156 public:
StaticString(const char * czstring)157 JSONCPP_OP_EXPLICIT StaticString(const char* czstring) : c_str_(czstring) {}
158
159 operator const char*() const { return c_str_; }
160
c_str()161 const char* c_str() const { return c_str_; }
162
163 private:
164 const char* c_str_;
165 };
166
167 /** \brief Represents a <a HREF="http://www.json.org">JSON</a> value.
168 *
169 * This class is a discriminated union wrapper that can represents a:
170 * - signed integer [range: Value::minInt - Value::maxInt]
171 * - unsigned integer (range: 0 - Value::maxUInt)
172 * - double
173 * - UTF-8 string
174 * - boolean
175 * - 'null'
176 * - an ordered list of Value
177 * - collection of name/value pairs (javascript object)
178 *
179 * The type of the held value is represented by a #ValueType and
180 * can be obtained using type().
181 *
182 * Values of an #objectValue or #arrayValue can be accessed using operator[]()
183 * methods.
184 * Non-const methods will automatically create the a #nullValue element
185 * if it does not exist.
186 * The sequence of an #arrayValue will be automatically resized and initialized
187 * with #nullValue. resize() can be used to enlarge or truncate an #arrayValue.
188 *
189 * The get() methods can be used to obtain default value in the case the
190 * required element does not exist.
191 *
192 * It is possible to iterate over the list of member keys of an object using
193 * the getMemberNames() method.
194 *
195 * \note #Value string-length fit in size_t, but keys must be < 2^30.
196 * (The reason is an implementation detail.) A #CharReader will raise an
197 * exception if a bound is exceeded to avoid security holes in your app,
198 * but the Value API does *not* check bounds. That is the responsibility
199 * of the caller.
200 */
201 class JSON_API Value {
202 friend class ValueIteratorBase;
203
204 public:
205 typedef std::vector<String> Members;
206 typedef ValueIterator iterator;
207 typedef ValueConstIterator const_iterator;
208 typedef Json::UInt UInt;
209 typedef Json::Int Int;
210 #if defined(JSON_HAS_INT64)
211 typedef Json::UInt64 UInt64;
212 typedef Json::Int64 Int64;
213 #endif // defined(JSON_HAS_INT64)
214 typedef Json::LargestInt LargestInt;
215 typedef Json::LargestUInt LargestUInt;
216 typedef Json::ArrayIndex ArrayIndex;
217
218 // Required for boost integration, e. g. BOOST_TEST
219 typedef std::string value_type;
220
221 #if JSON_USE_NULLREF
222 // Binary compatibility kludges, do not use.
223 static const Value& null;
224 static const Value& nullRef;
225 #endif
226
227 // null and nullRef are deprecated, use this instead.
228 static Value const& nullSingleton();
229
230 /// Minimum signed integer value that can be stored in a Json::Value.
231 static JSONCPP_CONST LargestInt minLargestInt =
232 LargestInt(~(LargestUInt(-1) / 2));
233 /// Maximum signed integer value that can be stored in a Json::Value.
234 static JSONCPP_CONST LargestInt maxLargestInt =
235 LargestInt(LargestUInt(-1) / 2);
236 /// Maximum unsigned integer value that can be stored in a Json::Value.
237 static JSONCPP_CONST LargestUInt maxLargestUInt = LargestUInt(-1);
238
239 /// Minimum signed int value that can be stored in a Json::Value.
240 static JSONCPP_CONST Int minInt = Int(~(UInt(-1) / 2));
241 /// Maximum signed int value that can be stored in a Json::Value.
242 static JSONCPP_CONST Int maxInt = Int(UInt(-1) / 2);
243 /// Maximum unsigned int value that can be stored in a Json::Value.
244 static JSONCPP_CONST UInt maxUInt = UInt(-1);
245
246 #if defined(JSON_HAS_INT64)
247 /// Minimum signed 64 bits int value that can be stored in a Json::Value.
248 static JSONCPP_CONST Int64 minInt64 = Int64(~(UInt64(-1) / 2));
249 /// Maximum signed 64 bits int value that can be stored in a Json::Value.
250 static JSONCPP_CONST Int64 maxInt64 = Int64(UInt64(-1) / 2);
251 /// Maximum unsigned 64 bits int value that can be stored in a Json::Value.
252 static JSONCPP_CONST UInt64 maxUInt64 = UInt64(-1);
253 #endif // defined(JSON_HAS_INT64)
254 /// Default precision for real value for string representation.
255 static JSONCPP_CONST UInt defaultRealPrecision = 17;
256 // The constant is hard-coded because some compiler have trouble
257 // converting Value::maxUInt64 to a double correctly (AIX/xlC).
258 // Assumes that UInt64 is a 64 bits integer.
259 static JSONCPP_CONST double maxUInt64AsDouble = 18446744073709551615.0;
260 // Workaround for bug in the NVIDIAs CUDA 9.1 nvcc compiler
261 // when using gcc and clang backend compilers. CZString
262 // cannot be defined as private. See issue #486
263 #ifdef __NVCC__
264 public:
265 #else
266 private:
267 #endif
268 #ifndef JSONCPP_DOC_EXCLUDE_IMPLEMENTATION
269 class CZString {
270 public:
271 enum DuplicationPolicy { noDuplication = 0, duplicate, duplicateOnCopy };
272 CZString(ArrayIndex index);
273 CZString(char const* str, unsigned length, DuplicationPolicy allocate);
274 CZString(CZString const& other);
275 #if JSONCPP_CXX_STD_11
276 CZString(CZString&& other);
277 #endif
278 ~CZString();
279 CZString& operator=(const CZString& other);
280 #if JSONCPP_CXX_STD_11
281 CZString& operator=(CZString&& other);
282 #endif
283 bool operator<(CZString const& other) const;
284 bool operator==(CZString const& other) const;
285 ArrayIndex index() const;
286 // const char* c_str() const; ///< \deprecated
287 char const* data() const;
288 unsigned length() const;
289 bool isStaticString() const;
290
291 private:
292 void swap(CZString& other);
293
294 struct StringStorage {
295 unsigned policy_ : 2;
296 unsigned length_ : 30; // 1GB max
297 };
298
299 char const* cstr_; // actually, a prefixed string, unless policy is noDup
300 union {
301 ArrayIndex index_;
302 StringStorage storage_;
303 };
304 };
305
306 public:
307 typedef std::map<CZString, Value> ObjectValues;
308 #endif // ifndef JSONCPP_DOC_EXCLUDE_IMPLEMENTATION
309
310 public:
311 /**
312 * \brief Create a default Value of the given type.
313 *
314 * This is a very useful constructor.
315 * To create an empty array, pass arrayValue.
316 * To create an empty object, pass objectValue.
317 * Another Value can then be set to this one by assignment.
318 * This is useful since clear() and resize() will not alter types.
319 *
320 * Examples:
321 * \code
322 * Json::Value null_value; // null
323 * Json::Value arr_value(Json::arrayValue); // []
324 * Json::Value obj_value(Json::objectValue); // {}
325 * \endcode
326 */
327 Value(ValueType type = nullValue);
328 Value(Int value);
329 Value(UInt value);
330 #if defined(JSON_HAS_INT64)
331 Value(Int64 value);
332 Value(UInt64 value);
333 #endif // if defined(JSON_HAS_INT64)
334 Value(double value);
335 Value(const char* value); ///< Copy til first 0. (NULL causes to seg-fault.)
336 Value(const char* begin, const char* end); ///< Copy all, incl zeroes.
337 /**
338 * \brief Constructs a value from a static string.
339 *
340 * Like other value string constructor but do not duplicate the string for
341 * internal storage. The given string must remain alive after the call to
342 * this constructor.
343 *
344 * \note This works only for null-terminated strings. (We cannot change the
345 * size of this class, so we have nowhere to store the length, which might be
346 * computed later for various operations.)
347 *
348 * Example of usage:
349 * \code
350 * static StaticString foo("some text");
351 * Json::Value aValue(foo);
352 * \endcode
353 */
354 Value(const StaticString& value);
355 Value(const String& value);
356 Value(bool value);
357 Value(const Value& other);
358 #if JSONCPP_CXX_STD_11
359 Value(Value&& other);
360 #endif
361 ~Value();
362
363 /// \note Overwrite existing comments. To preserve comments, use
364 /// #swapPayload().
365 Value& operator=(const Value& other);
366 #if JSONCPP_CXX_STD_11
367 Value& operator=(Value&& other);
368 #endif
369
370 /// Swap everything.
371 void swap(Value& other);
372 /// Swap values but leave comments and source offsets in place.
373 void swapPayload(Value& other);
374
375 /// copy everything.
376 void copy(const Value& other);
377 /// copy values but leave comments and source offsets in place.
378 void copyPayload(const Value& other);
379
380 ValueType type() const;
381
382 /// Compare payload only, not comments etc.
383 bool operator<(const Value& other) const;
384 bool operator<=(const Value& other) const;
385 bool operator>=(const Value& other) const;
386 bool operator>(const Value& other) const;
387 bool operator==(const Value& other) const;
388 bool operator!=(const Value& other) const;
389 int compare(const Value& other) const;
390
391 const char* asCString() const; ///< Embedded zeroes could cause you trouble!
392 #if JSONCPP_USING_SECURE_MEMORY
393 unsigned getCStringLength() const; // Allows you to understand the length of
394 // the CString
395 #endif
396 String asString() const; ///< Embedded zeroes are possible.
397 /** Get raw char* of string-value.
398 * \return false if !string. (Seg-fault if str or end are NULL.)
399 */
400 bool getString(char const** begin, char const** end) const;
401 Int asInt() const;
402 UInt asUInt() const;
403 #if defined(JSON_HAS_INT64)
404 Int64 asInt64() const;
405 UInt64 asUInt64() const;
406 #endif // if defined(JSON_HAS_INT64)
407 LargestInt asLargestInt() const;
408 LargestUInt asLargestUInt() const;
409 float asFloat() const;
410 double asDouble() const;
411 bool asBool() const;
412
413 bool isNull() const;
414 bool isBool() const;
415 bool isInt() const;
416 bool isInt64() const;
417 bool isUInt() const;
418 bool isUInt64() const;
419 bool isIntegral() const;
420 bool isDouble() const;
421 bool isNumeric() const;
422 bool isString() const;
423 bool isArray() const;
424 bool isObject() const;
425
426 /// The `as<T>` and `is<T>` member function templates and specializations.
427 template <typename T> T as() const JSONCPP_TEMPLATE_DELETE;
428 template <typename T> bool is() const JSONCPP_TEMPLATE_DELETE;
429
430 bool isConvertibleTo(ValueType other) const;
431
432 /// Number of values in array or object
433 ArrayIndex size() const;
434
435 /// \brief Return true if empty array, empty object, or null;
436 /// otherwise, false.
437 bool empty() const;
438
439 /// Return !isNull()
440 JSONCPP_OP_EXPLICIT operator bool() const;
441
442 /// Remove all object members and array elements.
443 /// \pre type() is arrayValue, objectValue, or nullValue
444 /// \post type() is unchanged
445 void clear();
446
447 /// Resize the array to newSize elements.
448 /// New elements are initialized to null.
449 /// May only be called on nullValue or arrayValue.
450 /// \pre type() is arrayValue or nullValue
451 /// \post type() is arrayValue
452 void resize(ArrayIndex newSize);
453
454 //@{
455 /// Access an array element (zero based index). If the array contains less
456 /// than index element, then null value are inserted in the array so that
457 /// its size is index+1.
458 /// (You may need to say 'value[0u]' to get your compiler to distinguish
459 /// this from the operator[] which takes a string.)
460 Value& operator[](ArrayIndex index);
461 Value& operator[](int index);
462 //@}
463
464 //@{
465 /// Access an array element (zero based index).
466 /// (You may need to say 'value[0u]' to get your compiler to distinguish
467 /// this from the operator[] which takes a string.)
468 const Value& operator[](ArrayIndex index) const;
469 const Value& operator[](int index) const;
470 //@}
471
472 /// If the array contains at least index+1 elements, returns the element
473 /// value, otherwise returns defaultValue.
474 Value get(ArrayIndex index, const Value& defaultValue) const;
475 /// Return true if index < size().
476 bool isValidIndex(ArrayIndex index) const;
477 /// \brief Append value to array at the end.
478 ///
479 /// Equivalent to jsonvalue[jsonvalue.size()] = value;
480 Value& append(const Value& value);
481 #if JSONCPP_CXX_STD_11
482 Value& append(Value&& value);
483 #endif
484
485 /// \brief Insert value in array at specific index
486 bool insert(ArrayIndex index, const Value& newValue);
487 #if JSONCPP_CXX_STD_11
488 bool insert(ArrayIndex index, Value&& newValue);
489 #endif
490
491 /// Access an object value by name, create a null member if it does not exist.
492 /// \note Because of our implementation, keys are limited to 2^30 -1 chars.
493 /// Exceeding that will cause an exception.
494 Value& operator[](const char* key);
495 /// Access an object value by name, returns null if there is no member with
496 /// that name.
497 const Value& operator[](const char* key) const;
498 /// Access an object value by name, create a null member if it does not exist.
499 /// \param key may contain embedded nulls.
500 Value& operator[](const String& key);
501 /// Access an object value by name, returns null if there is no member with
502 /// that name.
503 /// \param key may contain embedded nulls.
504 const Value& operator[](const String& key) const;
505 /** \brief Access an object value by name, create a null member if it does not
506 * exist.
507 *
508 * If the object has no entry for that name, then the member name used to
509 * store the new entry is not duplicated.
510 * Example of use:
511 * \code
512 * Json::Value object;
513 * static const StaticString code("code");
514 * object[code] = 1234;
515 * \endcode
516 */
517 Value& operator[](const StaticString& key);
518 /// Return the member named key if it exist, defaultValue otherwise.
519 /// \note deep copy
520 Value get(const char* key, const Value& defaultValue) const;
521 /// Return the member named key if it exist, defaultValue otherwise.
522 /// \note deep copy
523 /// \note key may contain embedded nulls.
524 Value get(const char* begin, const char* end,
525 const Value& defaultValue) const;
526 /// Return the member named key if it exist, defaultValue otherwise.
527 /// \note deep copy
528 /// \param key may contain embedded nulls.
529 Value get(const String& key, const Value& defaultValue) const;
530 /// Most general and efficient version of isMember()const, get()const,
531 /// and operator[]const
532 /// \note As stated elsewhere, behavior is undefined if (end-begin) >= 2^30
533 Value const* find(char const* begin, char const* end) const;
534 /// Most general and efficient version of object-mutators.
535 /// \note As stated elsewhere, behavior is undefined if (end-begin) >= 2^30
536 /// \return non-zero, but JSON_ASSERT if this is neither object nor nullValue.
537 Value* demand(char const* begin, char const* end);
538 /// \brief Remove and return the named member.
539 ///
540 /// Do nothing if it did not exist.
541 /// \pre type() is objectValue or nullValue
542 /// \post type() is unchanged
543 void removeMember(const char* key);
544 /// Same as removeMember(const char*)
545 /// \param key may contain embedded nulls.
546 void removeMember(const String& key);
547 /// Same as removeMember(const char* begin, const char* end, Value* removed),
548 /// but 'key' is null-terminated.
549 bool removeMember(const char* key, Value* removed);
550 /** \brief Remove the named map member.
551 *
552 * Update 'removed' iff removed.
553 * \param key may contain embedded nulls.
554 * \return true iff removed (no exceptions)
555 */
556 bool removeMember(String const& key, Value* removed);
557 /// Same as removeMember(String const& key, Value* removed)
558 bool removeMember(const char* begin, const char* end, Value* removed);
559 /** \brief Remove the indexed array element.
560 *
561 * O(n) expensive operations.
562 * Update 'removed' iff removed.
563 * \return true if removed (no exceptions)
564 */
565 bool removeIndex(ArrayIndex index, Value* removed);
566
567 /// Return true if the object has a member named key.
568 /// \note 'key' must be null-terminated.
569 bool isMember(const char* key) const;
570 /// Return true if the object has a member named key.
571 /// \param key may contain embedded nulls.
572 bool isMember(const String& key) const;
573 /// Same as isMember(String const& key)const
574 bool isMember(const char* begin, const char* end) const;
575
576 /// \brief Return a list of the member names.
577 ///
578 /// If null, return an empty list.
579 /// \pre type() is objectValue or nullValue
580 /// \post if type() was nullValue, it remains nullValue
581 Members getMemberNames() const;
582
583 /// \deprecated Always pass len.
584 JSONCPP_DEPRECATED("Use setComment(String const&) instead.")
585 void setComment(const char* comment, CommentPlacement placement);
586 /// Comments must be //... or /* ... */
587 void setComment(const char* comment, size_t len, CommentPlacement placement);
588 /// Comments must be //... or /* ... */
589 void setComment(const String& comment, CommentPlacement placement);
590 bool hasComment(CommentPlacement placement) const;
591 /// Include delimiters and embedded newlines.
592 String getComment(CommentPlacement placement) const;
593
594 String toStyledString() const;
595
596 const_iterator begin() const;
597 const_iterator end() const;
598
599 iterator begin();
600 iterator end();
601
602 // Accessors for the [start, limit) range of bytes within the JSON text from
603 // which this value was parsed, if any.
604 void setOffsetStart(ptrdiff_t start);
605 void setOffsetLimit(ptrdiff_t limit);
606 ptrdiff_t getOffsetStart() const;
607 ptrdiff_t getOffsetLimit() const;
608
609 private:
setType(ValueType v)610 void setType(ValueType v) {
611 bits_.value_type_ = static_cast<unsigned char>(v);
612 }
isAllocated()613 bool isAllocated() const { return bits_.allocated_; }
setIsAllocated(bool v)614 void setIsAllocated(bool v) { bits_.allocated_ = v; }
615
616 void initBasic(ValueType type, bool allocated = false);
617 void dupPayload(const Value& other);
618 void releasePayload();
619 void dupMeta(const Value& other);
620
621 Value& resolveReference(const char* key);
622 Value& resolveReference(const char* key, const char* end);
623
624 // struct MemberNamesTransform
625 //{
626 // typedef const char *result_type;
627 // const char *operator()( const CZString &name ) const
628 // {
629 // return name.c_str();
630 // }
631 //};
632
633 union ValueHolder {
634 LargestInt int_;
635 LargestUInt uint_;
636 double real_;
637 bool bool_;
638 char* string_; // if allocated_, ptr to { unsigned, char[] }.
639 ObjectValues* map_;
640 } value_;
641
642 struct {
643 // Really a ValueType, but types should agree for bitfield packing.
644 unsigned int value_type_ : 8;
645 // Unless allocated_, string_ must be null-terminated.
646 unsigned int allocated_ : 1;
647 } bits_;
648
649 class Comments {
650 public:
Comments()651 Comments() {}
652 Comments(const Comments& that);
653 Comments& operator=(const Comments& that);
654 bool has(CommentPlacement slot) const;
655 String get(CommentPlacement slot) const;
656 void set(CommentPlacement slot, String s);
657
658 private:
659 String ptr_[numberOfCommentPlacement];
660 };
661 Comments comments_;
662
663 // [start, limit) byte offsets in the source JSON text from which this Value
664 // was extracted.
665 ptrdiff_t start_;
666 ptrdiff_t limit_;
667 };
668
669 template <> inline bool Value::as<bool>() const { return asBool(); }
670 template <> inline bool Value::is<bool>() const { return isBool(); }
671
672 template <> inline Int Value::as<Int>() const { return asInt(); }
673 template <> inline bool Value::is<Int>() const { return isInt(); }
674
675 template <> inline UInt Value::as<UInt>() const { return asUInt(); }
676 template <> inline bool Value::is<UInt>() const { return isUInt(); }
677
678 #if defined(JSON_HAS_INT64)
679 template <> inline Int64 Value::as<Int64>() const { return asInt64(); }
680 template <> inline bool Value::is<Int64>() const { return isInt64(); }
681
682 template <> inline UInt64 Value::as<UInt64>() const { return asUInt64(); }
683 template <> inline bool Value::is<UInt64>() const { return isUInt64(); }
684 #endif
685
686 template <> inline double Value::as<double>() const { return asDouble(); }
687 template <> inline bool Value::is<double>() const { return isDouble(); }
688
689 template <> inline String Value::as<String>() const { return asString(); }
690 template <> inline bool Value::is<String>() const { return isString(); }
691
692 /// These `as` specializations are type conversions, and do not have a
693 /// corresponding `is`.
694 template <> inline float Value::as<float>() const { return asFloat(); }
695 template <> inline const char* Value::as<const char*>() const {
696 return asCString();
697 }
698
699 /** \brief Experimental and untested: represents an element of the "path" to
700 * access a node.
701 */
702 class JSON_API PathArgument {
703 public:
704 friend class Path;
705
706 PathArgument();
707 PathArgument(ArrayIndex index);
708 PathArgument(const char* key);
709 PathArgument(String key);
710
711 private:
712 enum Kind { kindNone = 0, kindIndex, kindKey };
713 String key_;
714 ArrayIndex index_;
715 Kind kind_;
716 };
717
718 /** \brief Experimental and untested: represents a "path" to access a node.
719 *
720 * Syntax:
721 * - "." => root node
722 * - ".[n]" => elements at index 'n' of root node (an array value)
723 * - ".name" => member named 'name' of root node (an object value)
724 * - ".name1.name2.name3"
725 * - ".[0][1][2].name1[3]"
726 * - ".%" => member name is provided as parameter
727 * - ".[%]" => index is provided as parameter
728 */
729 class JSON_API Path {
730 public:
731 Path(const String& path, const PathArgument& a1 = PathArgument(),
732 const PathArgument& a2 = PathArgument(),
733 const PathArgument& a3 = PathArgument(),
734 const PathArgument& a4 = PathArgument(),
735 const PathArgument& a5 = PathArgument());
736
737 const Value& resolve(const Value& root) const;
738 Value resolve(const Value& root, const Value& defaultValue) const;
739 /// Creates the "path" to access the specified node and returns a reference on
740 /// the node.
741 Value& make(Value& root) const;
742
743 private:
744 typedef std::vector<const PathArgument*> InArgs;
745 typedef std::vector<PathArgument> Args;
746
747 void makePath(const String& path, const InArgs& in);
748 void addPathInArg(const String& path, const InArgs& in,
749 InArgs::const_iterator& itInArg, PathArgument::Kind kind);
750 static void invalidPath(const String& path, int location);
751
752 Args args_;
753 };
754
755 /** \brief base class for Value iterators.
756 *
757 */
758 class JSON_API ValueIteratorBase {
759 public:
760 typedef std::bidirectional_iterator_tag iterator_category;
761 typedef unsigned int size_t;
762 typedef int difference_type;
763 typedef ValueIteratorBase SelfType;
764
765 bool operator==(const SelfType& other) const { return isEqual(other); }
766
767 bool operator!=(const SelfType& other) const { return !isEqual(other); }
768
769 difference_type operator-(const SelfType& other) const {
770 return other.computeDistance(*this);
771 }
772
773 /// Return either the index or the member name of the referenced value as a
774 /// Value.
775 Value key() const;
776
777 /// Return the index of the referenced Value, or -1 if it is not an
778 /// arrayValue.
779 UInt index() const;
780
781 /// Return the member name of the referenced Value, or "" if it is not an
782 /// objectValue.
783 /// \note Avoid `c_str()` on result, as embedded zeroes are possible.
784 String name() const;
785
786 /// Return the member name of the referenced Value. "" if it is not an
787 /// objectValue.
788 /// \deprecated This cannot be used for UTF-8 strings, since there can be
789 /// embedded nulls.
790 JSONCPP_DEPRECATED("Use `key = name();` instead.")
791 char const* memberName() const;
792 /// Return the member name of the referenced Value, or NULL if it is not an
793 /// objectValue.
794 /// \note Better version than memberName(). Allows embedded nulls.
795 char const* memberName(char const** end) const;
796
797 protected:
798 /*! Internal utility functions to assist with implementing
799 * other iterator functions. The const and non-const versions
800 * of the "deref" protected methods expose the protected
801 * current_ member variable in a way that can often be
802 * optimized away by the compiler.
803 */
804 const Value& deref() const;
805 Value& deref();
806
807 void increment();
808
809 void decrement();
810
811 difference_type computeDistance(const SelfType& other) const;
812
813 bool isEqual(const SelfType& other) const;
814
815 void copy(const SelfType& other);
816
817 private:
818 Value::ObjectValues::iterator current_;
819 // Indicates that iterator is for a null value.
820 bool isNull_;
821
822 public:
823 // For some reason, BORLAND needs these at the end, rather
824 // than earlier. No idea why.
825 ValueIteratorBase();
826 JSONCPP_OP_EXPLICIT
827 ValueIteratorBase(const Value::ObjectValues::iterator& current);
828 };
829
830 /** \brief const iterator for object and array value.
831 *
832 */
833 class JSON_API ValueConstIterator : public ValueIteratorBase {
834 friend class Value;
835
836 public:
837 typedef const Value value_type;
838 // typedef unsigned int size_t;
839 // typedef int difference_type;
840 typedef const Value& reference;
841 typedef const Value* pointer;
842 typedef ValueConstIterator SelfType;
843
844 ValueConstIterator();
845 ValueConstIterator(ValueIterator const& other);
846
847 private:
848 /*! \internal Use by Value to create an iterator.
849 */
850 JSONCPP_OP_EXPLICIT
851 ValueConstIterator(const Value::ObjectValues::iterator& current);
852
853 public:
854 SelfType& operator=(const ValueIteratorBase& other);
855
856 SelfType operator++(int) {
857 SelfType temp(*this);
858 ++*this;
859 return temp;
860 }
861
862 SelfType operator--(int) {
863 SelfType temp(*this);
864 --*this;
865 return temp;
866 }
867
868 SelfType& operator--() {
869 decrement();
870 return *this;
871 }
872
873 SelfType& operator++() {
874 increment();
875 return *this;
876 }
877
878 reference operator*() const { return deref(); }
879
880 pointer operator->() const { return &deref(); }
881 };
882
883 /** \brief Iterator for object and array value.
884 */
885 class JSON_API ValueIterator : public ValueIteratorBase {
886 friend class Value;
887
888 public:
889 typedef Value value_type;
890 typedef unsigned int size_t;
891 typedef int difference_type;
892 typedef Value& reference;
893 typedef Value* pointer;
894 typedef ValueIterator SelfType;
895
896 ValueIterator();
897 JSONCPP_OP_EXPLICIT ValueIterator(const ValueConstIterator& other);
898 ValueIterator(const ValueIterator& other);
899
900 private:
901 /*! \internal Use by Value to create an iterator.
902 */
903 JSONCPP_OP_EXPLICIT
904 ValueIterator(const Value::ObjectValues::iterator& current);
905
906 public:
907 SelfType& operator=(const SelfType& other);
908
909 SelfType operator++(int) {
910 SelfType temp(*this);
911 ++*this;
912 return temp;
913 }
914
915 SelfType operator--(int) {
916 SelfType temp(*this);
917 --*this;
918 return temp;
919 }
920
921 SelfType& operator--() {
922 decrement();
923 return *this;
924 }
925
926 SelfType& operator++() {
927 increment();
928 return *this;
929 }
930
931 /*! The return value of non-const iterators can be
932 * changed, so the these functions are not const
933 * because the returned references/pointers can be used
934 * to change state of the base class.
935 */
936 reference operator*() { return deref(); }
937 pointer operator->() { return &deref(); }
938 };
939
swap(Value & a,Value & b)940 inline void swap(Value& a, Value& b) { a.swap(b); }
941
942 } // namespace Json
943
944 #pragma pack(pop)
945
946 #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
947 #pragma warning(pop)
948 #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
949
950 #endif // JSON_H_INCLUDED
951