examples/validator/json11.hpp - third_party/tinygltf - Git at Google

 /* json11
  *
  * json11 is a tiny JSON library for C++11, providing JSON parsing and serialization.
  *
  * The core object provided by the library is json11::Json. A Json object represents any JSON
  * value: null, bool, number (int or double), string (std::string), array (std::vector), or
  * object (std::map).
  *
  * Json objects act like values: they can be assigned, copied, moved, compared for equality or
  * order, etc. There are also helper methods Json::dump, to serialize a Json to a string, and
  * Json::parse (static) to parse a std::string as a Json object.
  *
  * Internally, the various types of Json object are represented by the JsonValue class
  * hierarchy.
  *
  * A note on numbers - JSON specifies the syntax of number formatting but not its semantics,
  * so some JSON implementations distinguish between integers and floating-point numbers, while
  * some don't. In json11, we choose the latter. Because some JSON implementations (namely
  * Javascript itself) treat all numbers as the same type, distinguishing the two leads
  * to JSON that will be *silently* changed by a round-trip through those implementations.
  * Dangerous! To avoid that risk, json11 stores all numbers as double internally, but also
  * provides integer helpers.
  *
  * Fortunately, double-precision IEEE754 ('double') can precisely store any integer in the
  * range +/-2^53, which includes every 'int' on most systems. (Timestamps often use int64
  * or long long to avoid the Y2038K problem; a double storing microseconds since some epoch
  * will be exact for +/- 275 years.)
  */

 /* Copyright (c) 2013 Dropbox, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #pragma once

 #include <string>
 #include <vector>
 #include <map>
 #include <memory>
 #include <initializer_list>

 #ifdef _MSC_VER
     #if _MSC_VER <= 1800 // VS 2013
         #ifndef noexcept
             #define noexcept throw()
         #endif

         #ifndef snprintf
             #define snprintf _snprintf_s
         #endif
     #endif
 #endif

 namespace json11 {

 enum JsonParse {
     STANDARD, COMMENTS
 };

 class JsonValue;

 class Json final {
 public:
     // Types
     enum Type {
         NUL, NUMBER, BOOL, STRING, ARRAY, OBJECT
     };

     // Array and object typedefs
     typedef std::vector<Json> array;
     typedef std::map<std::string, Json> object;

     // Constructors for the various types of JSON value.
     Json() noexcept;                // NUL
     Json(std::nullptr_t) noexcept;  // NUL
     Json(double value);             // NUMBER
     Json(int value);                // NUMBER
     Json(bool value);               // BOOL
     Json(const std::string &value); // STRING
     Json(std::string &&value);      // STRING
     Json(const char * value);       // STRING
     Json(const array &values);      // ARRAY
     Json(array &&values);           // ARRAY
     Json(const object &values);     // OBJECT
     Json(object &&values);          // OBJECT

     // Implicit constructor: anything with a to_json() function.
     template <class T, class = decltype(&T::to_json)>
     Json(const T & t) : Json(t.to_json()) {}

     // Implicit constructor: map-like objects (std::map, std::unordered_map, etc)
     template <class M, typename std::enable_if<
         std::is_constructible<std::string, decltype(std::declval<M>().begin()->first)>::value
         && std::is_constructible<Json, decltype(std::declval<M>().begin()->second)>::value,
             int>::type = 0>
     Json(const M & m) : Json(object(m.begin(), m.end())) {}

     // Implicit constructor: vector-like objects (std::list, std::vector, std::set, etc)
     template <class V, typename std::enable_if<
         std::is_constructible<Json, decltype(*std::declval<V>().begin())>::value,
             int>::type = 0>
     Json(const V & v) : Json(array(v.begin(), v.end())) {}

     // This prevents Json(some_pointer) from accidentally producing a bool. Use
     // Json(bool(some_pointer)) if that behavior is desired.
     Json(void *) = delete;

     // Accessors
     Type type() const;

     bool is_null()   const { return type() == NUL; }
     bool is_number() const { return type() == NUMBER; }
     bool is_bool()   const { return type() == BOOL; }
     bool is_string() const { return type() == STRING; }
     bool is_array()  const { return type() == ARRAY; }
     bool is_object() const { return type() == OBJECT; }

     // Return the enclosed value if this is a number, 0 otherwise. Note that json11 does not
     // distinguish between integer and non-integer numbers - number_value() and int_value()
     // can both be applied to a NUMBER-typed object.
     double number_value() const;
     int int_value() const;

     // Return the enclosed value if this is a boolean, false otherwise.
     bool bool_value() const;
     // Return the enclosed string if this is a string, "" otherwise.
     const std::string &string_value() const;
     // Return the enclosed std::vector if this is an array, or an empty vector otherwise.
     const array &array_items() const;
     // Return the enclosed std::map if this is an object, or an empty map otherwise.
     const object &object_items() const;

     // Return a reference to arr[i] if this is an array, Json() otherwise.
     const Json & operator[](size_t i) const;
     // Return a reference to obj[key] if this is an object, Json() otherwise.
     const Json & operator[](const std::string &key) const;

     // Serialize.
     void dump(std::string &out) const;
     std::string dump() const {
         std::string out;
         dump(out);
         return out;
     }

     // Parse. If parse fails, return Json() and assign an error message to err.
     static Json parse(const std::string & in,
                       std::string & err,
                       JsonParse strategy = JsonParse::STANDARD);
     static Json parse(const char * in,
                       std::string & err,
                       JsonParse strategy = JsonParse::STANDARD) {
         if (in) {
             return parse(std::string(in), err, strategy);
         } else {
             err = "null input";
             return nullptr;
         }
     }
     // Parse multiple objects, concatenated or separated by whitespace
     static std::vector<Json> parse_multi(
         const std::string & in,
         std::string::size_type & parser_stop_pos,
         std::string & err,
         JsonParse strategy = JsonParse::STANDARD);

     static inline std::vector<Json> parse_multi(
         const std::string & in,
         std::string & err,
         JsonParse strategy = JsonParse::STANDARD) {
         std::string::size_type parser_stop_pos;
         return parse_multi(in, parser_stop_pos, err, strategy);
     }

     bool operator== (const Json &rhs) const;
     bool operator<  (const Json &rhs) const;
     bool operator!= (const Json &rhs) const { return !(*this == rhs); }
     bool operator<= (const Json &rhs) const { return !(rhs < *this); }
     bool operator>  (const Json &rhs) const { return  (rhs < *this); }
     bool operator>= (const Json &rhs) const { return !(*this < rhs); }

     /* has_shape(types, err)
      *
      * Return true if this is a JSON object and, for each item in types, has a field of
      * the given type. If not, return false and set err to a descriptive message.
      */
     typedef std::initializer_list<std::pair<std::string, Type>> shape;
     bool has_shape(const shape & types, std::string & err) const;

 private:
     std::shared_ptr<JsonValue> m_ptr;
 };

 // Internal class hierarchy - JsonValue objects are not exposed to users of this API.
 class JsonValue {
 protected:
     friend class Json;
     friend class JsonInt;
     friend class JsonDouble;
     virtual Json::Type type() const = 0;
     virtual bool equals(const JsonValue * other) const = 0;
     virtual bool less(const JsonValue * other) const = 0;
     virtual void dump(std::string &out) const = 0;
     virtual double number_value() const;
     virtual int int_value() const;
     virtual bool bool_value() const;
     virtual const std::string &string_value() const;
     virtual const Json::array &array_items() const;
     virtual const Json &operator[](size_t i) const;
     virtual const Json::object &object_items() const;
     virtual const Json &operator[](const std::string &key) const;
     virtual ~JsonValue() {}
 };

 } // namespace json11
	/* json11
	*
	* json11 is a tiny JSON library for C++11, providing JSON parsing and serialization.
	*
	* The core object provided by the library is json11::Json. A Json object represents any JSON
	* value: null, bool, number (int or double), string (std::string), array (std::vector), or
	* object (std::map).
	*
	* Json objects act like values: they can be assigned, copied, moved, compared for equality or
	* order, etc. There are also helper methods Json::dump, to serialize a Json to a string, and
	* Json::parse (static) to parse a std::string as a Json object.
	*
	* Internally, the various types of Json object are represented by the JsonValue class
	* hierarchy.
	*
	* A note on numbers - JSON specifies the syntax of number formatting but not its semantics,
	* so some JSON implementations distinguish between integers and floating-point numbers, while
	* some don't. In json11, we choose the latter. Because some JSON implementations (namely
	* Javascript itself) treat all numbers as the same type, distinguishing the two leads
	* to JSON that will be silently changed by a round-trip through those implementations.
	* Dangerous! To avoid that risk, json11 stores all numbers as double internally, but also
	* provides integer helpers.
	*
	* Fortunately, double-precision IEEE754 ('double') can precisely store any integer in the
	* range +/-2^53, which includes every 'int' on most systems. (Timestamps often use int64
	* or long long to avoid the Y2038K problem; a double storing microseconds since some epoch
	* will be exact for +/- 275 years.)
	*/

	/* Copyright (c) 2013 Dropbox, Inc.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#pragma once

	#include <string>
	#include <vector>
	#include <map>
	#include <memory>
	#include <initializer_list>

	#ifdef _MSC_VER
	#if _MSC_VER <= 1800 // VS 2013
	#ifndef noexcept
	#define noexcept throw()
	#endif

	#ifndef snprintf
	#define snprintf _snprintf_s
	#endif
	#endif
	#endif

	namespace json11 {

	enum JsonParse {
	STANDARD, COMMENTS
	};

	class JsonValue;

	class Json final {
	public:
	// Types
	enum Type {
	NUL, NUMBER, BOOL, STRING, ARRAY, OBJECT
	};

	// Array and object typedefs
	typedef std::vector<Json> array;
	typedef std::map<std::string, Json> object;

	// Constructors for the various types of JSON value.
	Json() noexcept; // NUL
	Json(std::nullptr_t) noexcept; // NUL
	Json(double value); // NUMBER
	Json(int value); // NUMBER
	Json(bool value); // BOOL
	Json(const std::string &value); // STRING
	Json(std::string &&value); // STRING
	Json(const char * value); // STRING
	Json(const array &values); // ARRAY
	Json(array &&values); // ARRAY
	Json(const object &values); // OBJECT
	Json(object &&values); // OBJECT

	// Implicit constructor: anything with a to_json() function.
	template <class T, class = decltype(&T::to_json)>
	Json(const T & t) : Json(t.to_json()) {}

	// Implicit constructor: map-like objects (std::map, std::unordered_map, etc)
	template <class M, typename std::enable_if<
	std::is_constructible<std::string, decltype(std::declval<M>().begin()->first)>::value
	&& std::is_constructible<Json, decltype(std::declval<M>().begin()->second)>::value,
	int>::type = 0>
	Json(const M & m) : Json(object(m.begin(), m.end())) {}

	// Implicit constructor: vector-like objects (std::list, std::vector, std::set, etc)
	template <class V, typename std::enable_if<
	std::is_constructible<Json, decltype(*std::declval<V>().begin())>::value,
	int>::type = 0>
	Json(const V & v) : Json(array(v.begin(), v.end())) {}

	// This prevents Json(some_pointer) from accidentally producing a bool. Use
	// Json(bool(some_pointer)) if that behavior is desired.
	Json(void *) = delete;

	// Accessors
	Type type() const;

	bool is_null() const { return type() == NUL; }
	bool is_number() const { return type() == NUMBER; }
	bool is_bool() const { return type() == BOOL; }
	bool is_string() const { return type() == STRING; }
	bool is_array() const { return type() == ARRAY; }
	bool is_object() const { return type() == OBJECT; }

	// Return the enclosed value if this is a number, 0 otherwise. Note that json11 does not
	// distinguish between integer and non-integer numbers - number_value() and int_value()
	// can both be applied to a NUMBER-typed object.
	double number_value() const;
	int int_value() const;

	// Return the enclosed value if this is a boolean, false otherwise.
	bool bool_value() const;
	// Return the enclosed string if this is a string, "" otherwise.
	const std::string &string_value() const;
	// Return the enclosed std::vector if this is an array, or an empty vector otherwise.
	const array &array_items() const;
	// Return the enclosed std::map if this is an object, or an empty map otherwise.
	const object &object_items() const;

	// Return a reference to arr[i] if this is an array, Json() otherwise.
	const Json & operator[](size_t i) const;
	// Return a reference to obj[key] if this is an object, Json() otherwise.
	const Json & operator[](const std::string &key) const;

	// Serialize.
	void dump(std::string &out) const;
	std::string dump() const {
	std::string out;
	dump(out);
	return out;
	}

	// Parse. If parse fails, return Json() and assign an error message to err.
	static Json parse(const std::string & in,
	std::string & err,
	JsonParse strategy = JsonParse::STANDARD);
	static Json parse(const char * in,
	std::string & err,
	JsonParse strategy = JsonParse::STANDARD) {
	if (in) {
	return parse(std::string(in), err, strategy);
	} else {
	err = "null input";
	return nullptr;
	}
	}
	// Parse multiple objects, concatenated or separated by whitespace
	static std::vector<Json> parse_multi(
	const std::string & in,
	std::string::size_type & parser_stop_pos,
	std::string & err,
	JsonParse strategy = JsonParse::STANDARD);

	static inline std::vector<Json> parse_multi(
	const std::string & in,
	std::string & err,
	JsonParse strategy = JsonParse::STANDARD) {
	std::string::size_type parser_stop_pos;
	return parse_multi(in, parser_stop_pos, err, strategy);
	}

	bool operator== (const Json &rhs) const;
	bool operator< (const Json &rhs) const;
	bool operator!= (const Json &rhs) const { return !(*this == rhs); }
	bool operator<= (const Json &rhs) const { return !(rhs < *this); }
	bool operator> (const Json &rhs) const { return (rhs < *this); }
	bool operator>= (const Json &rhs) const { return !(*this < rhs); }

	/* has_shape(types, err)
	*
	* Return true if this is a JSON object and, for each item in types, has a field of
	* the given type. If not, return false and set err to a descriptive message.
	*/
	typedef std::initializer_list<std::pair<std::string, Type>> shape;
	bool has_shape(const shape & types, std::string & err) const;

	private:
	std::shared_ptr<JsonValue> m_ptr;
	};

	// Internal class hierarchy - JsonValue objects are not exposed to users of this API.
	class JsonValue {
	protected:
	friend class Json;
	friend class JsonInt;
	friend class JsonDouble;
	virtual Json::Type type() const = 0;
	virtual bool equals(const JsonValue * other) const = 0;
	virtual bool less(const JsonValue * other) const = 0;
	virtual void dump(std::string &out) const = 0;
	virtual double number_value() const;
	virtual int int_value() const;
	virtual bool bool_value() const;
	virtual const std::string &string_value() const;
	virtual const Json::array &array_items() const;
	virtual const Json &operator[](size_t i) const;
	virtual const Json::object &object_items() const;
	virtual const Json &operator[](const std::string &key) const;
	virtual ~JsonValue() {}
	};

	} // namespace json11