avtk/avtk/picojson.hxx

/*
 * Copyright 2009-2010 Cybozu Labs, Inc.
 * Copyright 2011-2014 Kazuho Oku
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef picojson_h
#define picojson_h

#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <iterator>
#include <limits>
#include <map>
#include <stdexcept>
#include <string>
#include <vector>

// for isnan/isinf
#if __cplusplus>=201103L
# include <cmath>
#else
extern "C" {
# ifdef _MSC_VER
#  include <float.h>
# elif defined(__INTEL_COMPILER)
#  include <mathimf.h>
# else
#  include <math.h>
# endif
}
#endif

// experimental support for int64_t (see README.mkdn for detail)
#ifdef PICOJSON_USE_INT64
# define __STDC_FORMAT_MACROS
# include <errno.h>
# include <inttypes.h>
#endif

// to disable the use of localeconv(3), set PICOJSON_USE_LOCALE to 0
#ifndef PICOJSON_USE_LOCALE
# define PICOJSON_USE_LOCALE 1
#endif
#if PICOJSON_USE_LOCALE
extern "C" {
# include <locale.h>
}
#endif

#ifndef PICOJSON_ASSERT
# define PICOJSON_ASSERT(e) do { if (! (e)) throw std::runtime_error(#e); } while (0)
#endif

#ifdef _MSC_VER
#define SNPRINTF _snprintf_s
#pragma warning(push)
#pragma warning(disable : 4244) // conversion from int to char
#pragma warning(disable : 4127) // conditional expression is constant
#pragma warning(disable : 4702) // unreachable code
#else
#define SNPRINTF snprintf
#endif

namespace picojson
{

enum {
	null_type,
	boolean_type,
	number_type,
	string_type,
	array_type,
	object_type
#ifdef PICOJSON_USE_INT64
	, int64_type
#endif
};

enum {
	INDENT_WIDTH = 2
};

struct null {};

class value
{
public:
	typedef std::vector<value> array;
	typedef std::map<std::string, value> object;
	union _storage {
		bool boolean_;
		double number_;
#ifdef PICOJSON_USE_INT64
		int64_t int64_;
#endif
		std::string* string_;
		array* array_;
		object* object_;
	};
protected:
	int type_;
	_storage u_;
public:
	value();
	value(int type, bool);
	explicit value(bool b);
#ifdef PICOJSON_USE_INT64
	explicit value(int64_t i);
#endif
	explicit value(double n);
	explicit value(const std::string& s);
	explicit value(const array& a);
	explicit value(const object& o);
	explicit value(const char* s);
	value(const char* s, size_t len);
	~value();
	value(const value& x);
	value& operator=(const value& x);
	void swap(value& x);
	template <typename T> bool is() const;
	template <typename T> const T& get() const;
	template <typename T> T& get();
	bool evaluate_as_boolean() const;
	const value& get(size_t idx) const;
	const value& get(const std::string& key) const;
	value& get(size_t idx);
	value& get(const std::string& key);

	bool contains(size_t idx) const;
	bool contains(const std::string& key) const;
	std::string to_str() const;
	template <typename Iter> void serialize(Iter os, bool prettify = false) const;
	std::string serialize(bool prettify = false) const;
private:
	template <typename T> value(const T*); // intentionally defined to block implicit conversion of pointer to bool
	template <typename Iter> static void _indent(Iter os, int indent);
	template <typename Iter> void _serialize(Iter os, int indent) const;
	std::string _serialize(int indent) const;
};

typedef value::array array;
typedef value::object object;

inline value::value() : type_(null_type) {}

inline value::value(int type, bool) : type_(type)
{
	switch (type) {
#define INIT(p, v) case p##type: u_.p = v; break
		INIT(boolean_, false);
		INIT(number_, 0.0);
#ifdef PICOJSON_USE_INT64
		INIT(int64_, 0);
#endif
		INIT(string_, new std::string());
		INIT(array_, new array());
		INIT(object_, new object());
#undef INIT
	default:
		break;
	}
}

inline value::value(bool b) : type_(boolean_type)
{
	u_.boolean_ = b;
}

#ifdef PICOJSON_USE_INT64
inline value::value(int64_t i) : type_(int64_type)
{
	u_.int64_ = i;
}
#endif

inline value::value(double n) : type_(number_type)
{
	if (
#ifdef _MSC_VER
	        ! _finite(n)
#elif __cplusplus>=201103L || !(defined(isnan) && defined(isinf))
	        std::isnan(n) || std::isinf(n)
#else
	        isnan(n) || isinf(n)
#endif
	) {
		throw std::overflow_error("");
	}
	u_.number_ = n;
}

inline value::value(const std::string& s) : type_(string_type)
{
	u_.string_ = new std::string(s);
}

inline value::value(const array& a) : type_(array_type)
{
	u_.array_ = new array(a);
}

inline value::value(const object& o) : type_(object_type)
{
	u_.object_ = new object(o);
}

inline value::value(const char* s) : type_(string_type)
{
	u_.string_ = new std::string(s);
}

inline value::value(const char* s, size_t len) : type_(string_type)
{
	u_.string_ = new std::string(s, len);
}

inline value::~value()
{
	switch (type_) {
#define DEINIT(p) case p##type: delete u_.p; break
		DEINIT(string_);
		DEINIT(array_);
		DEINIT(object_);
#undef DEINIT
	default:
		break;
	}
}

inline value::value(const value& x) : type_(x.type_)
{
	switch (type_) {
#define INIT(p, v) case p##type: u_.p = v; break
		INIT(string_, new std::string(*x.u_.string_));
		INIT(array_, new array(*x.u_.array_));
		INIT(object_, new object(*x.u_.object_));
#undef INIT
	default:
		u_ = x.u_;
		break;
	}
}

inline value& value::operator=(const value& x)
{
	if (this != &x) {
		this->~value();
		new (this) value(x);
	}
	return *this;
}

inline void value::swap(value& x)
{
	std::swap(type_, x.type_);
	std::swap(u_, x.u_);
}

#define IS(ctype, jtype)			     \
  template <> inline bool value::is<ctype>() const { \
    return type_ == jtype##_type;		     \
  }
IS(null, null)
IS(bool, boolean)
#ifdef PICOJSON_USE_INT64
IS(int64_t, int64)
#endif
IS(std::string, string)
IS(array, array)
IS(object, object)
#undef IS
template <> inline bool value::is<double>() const
{
	return type_ == number_type
#ifdef PICOJSON_USE_INT64
	       || type_ == int64_type
#endif
	       ;
}

#define GET(ctype, var)						\
  template <> inline const ctype& value::get<ctype>() const {	\
    PICOJSON_ASSERT("type mismatch! call is<type>() before get<type>()" \
	   && is<ctype>());				        \
    return var;							\
  }								\
  template <> inline ctype& value::get<ctype>() {		\
    PICOJSON_ASSERT("type mismatch! call is<type>() before get<type>()"	\
	   && is<ctype>());					\
    return var;							\
  }
GET(bool, u_.boolean_)
GET(std::string, *u_.string_)
GET(array, *u_.array_)
GET(object, *u_.object_)
#ifdef PICOJSON_USE_INT64
GET(double, (type_ == int64_type && (const_cast<value*>(this)->type_ = number_type, const_cast<value*>(this)->u_.number_ = u_.int64_), u_.number_))
GET(int64_t, u_.int64_)
#else
GET(double, u_.number_)
#endif
#undef GET

inline bool value::evaluate_as_boolean() const
{
	switch (type_) {
	case null_type:
		return false;
	case boolean_type:
		return u_.boolean_;
	case number_type:
		return u_.number_ != 0;
	case string_type:
		return ! u_.string_->empty();
	default:
		return true;
	}
}

inline const value& value::get(size_t idx) const
{
	static value s_null;
	PICOJSON_ASSERT(is<array>());
	return idx < u_.array_->size() ? (*u_.array_)[idx] : s_null;
}

inline value& value::get(size_t idx)
{
	static value s_null;
	PICOJSON_ASSERT(is<array>());
	return idx < u_.array_->size() ? (*u_.array_)[idx] : s_null;
}

inline const value& value::get(const std::string& key) const
{
	static value s_null;
	PICOJSON_ASSERT(is<object>());
	object::const_iterator i = u_.object_->find(key);
	return i != u_.object_->end() ? i->second : s_null;
}

inline value& value::get(const std::string& key)
{
	static value s_null;
	PICOJSON_ASSERT(is<object>());
	object::iterator i = u_.object_->find(key);
	return i != u_.object_->end() ? i->second : s_null;
}

inline bool value::contains(size_t idx) const
{
	PICOJSON_ASSERT(is<array>());
	return idx < u_.array_->size();
}

inline bool value::contains(const std::string& key) const
{
	PICOJSON_ASSERT(is<object>());
	object::const_iterator i = u_.object_->find(key);
	return i != u_.object_->end();
}

inline std::string value::to_str() const
{
	switch (type_) {
	case null_type:
		return "null";
	case boolean_type:
		return u_.boolean_ ? "true" : "false";
#ifdef PICOJSON_USE_INT64
	case int64_type: {
		char buf[sizeof("-9223372036854775808")];
		SNPRINTF(buf, sizeof(buf), "%" PRId64, u_.int64_);
		return buf;
	}
#endif
	case number_type:    {
		char buf[256];
		double tmp;
		SNPRINTF(buf, sizeof(buf), fabs(u_.number_) < (1ULL << 53) && modf(u_.number_, &tmp) == 0 ? "%.f" : "%.17g", u_.number_);
#if PICOJSON_USE_LOCALE
		char *decimal_point = localeconv()->decimal_point;
		if (strcmp(decimal_point, ".") != 0) {
			size_t decimal_point_len = strlen(decimal_point);
			for (char *p = buf; *p != '\0'; ++p) {
				if (strncmp(p, decimal_point, decimal_point_len) == 0) {
					return std::string(buf, p) + "." + (p + decimal_point_len);
				}
			}
		}
#endif
		return buf;
	}
	case string_type:
		return *u_.string_;
	case array_type:
		return "array";
	case object_type:
		return "object";
	default:
		PICOJSON_ASSERT(0);
#ifdef _MSC_VER
		__assume(0);
#endif
	}
	return std::string();
}

template <typename Iter> void copy(const std::string& s, Iter oi)
{
	std::copy(s.begin(), s.end(), oi);
}

template <typename Iter> void serialize_str(const std::string& s, Iter oi)
{
	*oi++ = '"';
	for (std::string::const_iterator i = s.begin(); i != s.end(); ++i) {
		switch (*i) {
#define MAP(val, sym) case val: copy(sym, oi); break
			MAP('"', "\\\"");
			MAP('\\', "\\\\");
			MAP('/', "\\/");
			MAP('\b', "\\b");
			MAP('\f', "\\f");
			MAP('\n', "\\n");
			MAP('\r', "\\r");
			MAP('\t', "\\t");
#undef MAP
		default:
			if (static_cast<unsigned char>(*i) < 0x20 || *i == 0x7f) {
				char buf[7];
				SNPRINTF(buf, sizeof(buf), "\\u%04x", *i & 0xff);
				copy(buf, buf + 6, oi);
			} else {
				*oi++ = *i;
			}
			break;
		}
	}
	*oi++ = '"';
}

template <typename Iter> void value::serialize(Iter oi, bool prettify) const
{
	return _serialize(oi, prettify ? 0 : -1);
}

inline std::string value::serialize(bool prettify) const
{
	return _serialize(prettify ? 0 : -1);
}

template <typename Iter> void value::_indent(Iter oi, int indent)
{
	*oi++ = '\n';
	for (int i = 0; i < indent * INDENT_WIDTH; ++i) {
		*oi++ = ' ';
	}
}

template <typename Iter> void value::_serialize(Iter oi, int indent) const
{
	switch (type_) {
	case string_type:
		serialize_str(*u_.string_, oi);
		break;
	case array_type: {
		*oi++ = '[';
		if (indent != -1) {
			++indent;
		}
		for (array::const_iterator i = u_.array_->begin();
		     i != u_.array_->end();
		     ++i) {
			if (i != u_.array_->begin()) {
				*oi++ = ',';
			}
			if (indent != -1) {
				_indent(oi, indent);
			}
			i->_serialize(oi, indent);
		}
		if (indent != -1) {
			--indent;
			if (! u_.array_->empty()) {
				_indent(oi, indent);
			}
		}
		*oi++ = ']';
		break;
	}
	case object_type: {
		*oi++ = '{';
		if (indent != -1) {
			++indent;
		}
		for (object::const_iterator i = u_.object_->begin();
		     i != u_.object_->end();
		     ++i) {
			if (i != u_.object_->begin()) {
				*oi++ = ',';
			}
			if (indent != -1) {
				_indent(oi, indent);
			}
			serialize_str(i->first, oi);
			*oi++ = ':';
			if (indent != -1) {
				*oi++ = ' ';
			}
			i->second._serialize(oi, indent);
		}
		if (indent != -1) {
			--indent;
			if (! u_.object_->empty()) {
				_indent(oi, indent);
			}
		}
		*oi++ = '}';
		break;
	}
	default:
		copy(to_str(), oi);
		break;
	}
	if (indent == 0) {
		*oi++ = '\n';
	}
}

inline std::string value::_serialize(int indent) const
{
	std::string s;
	_serialize(std::back_inserter(s), indent);
	return s;
}

template <typename Iter> class input
{
protected:
	Iter cur_, end_;
	int last_ch_;
	bool ungot_;
	int line_;
public:
	input(const Iter& first, const Iter& last) : cur_(first), end_(last), last_ch_(-1), ungot_(false), line_(1) {}
	int getc()
	{
		if (ungot_) {
			ungot_ = false;
			return last_ch_;
		}
		if (cur_ == end_) {
			last_ch_ = -1;
			return -1;
		}
		if (last_ch_ == '\n') {
			line_++;
		}
		last_ch_ = *cur_ & 0xff;
		++cur_;
		return last_ch_;
	}
	void ungetc()
	{
		if (last_ch_ != -1) {
			PICOJSON_ASSERT(! ungot_);
			ungot_ = true;
		}
	}
	Iter cur() const
	{
		return cur_;
	}
	int line() const
	{
		return line_;
	}
	void skip_ws()
	{
		while (1) {
			int ch = getc();
			if (! (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r')) {
				ungetc();
				break;
			}
		}
	}
	bool expect(int expect)
	{
		skip_ws();
		if (getc() != expect) {
			ungetc();
			return false;
		}
		return true;
	}
	bool match(const std::string& pattern)
	{
		for (std::string::const_iterator pi(pattern.begin());
		     pi != pattern.end();
		     ++pi) {
			if (getc() != *pi) {
				ungetc();
				return false;
			}
		}
		return true;
	}
};

template<typename Iter> inline int _parse_quadhex(input<Iter> &in)
{
	int uni_ch = 0, hex;
	for (int i = 0; i < 4; i++) {
		if ((hex = in.getc()) == -1) {
			return -1;
		}
		if ('0' <= hex && hex <= '9') {
			hex -= '0';
		} else if ('A' <= hex && hex <= 'F') {
			hex -= 'A' - 0xa;
		} else if ('a' <= hex && hex <= 'f') {
			hex -= 'a' - 0xa;
		} else {
			in.ungetc();
			return -1;
		}
		uni_ch = uni_ch * 16 + hex;
	}
	return uni_ch;
}

template<typename String, typename Iter> inline bool _parse_codepoint(String& out, input<Iter>& in)
{
	int uni_ch;
	if ((uni_ch = _parse_quadhex(in)) == -1) {
		return false;
	}
	if (0xd800 <= uni_ch && uni_ch <= 0xdfff) {
		if (0xdc00 <= uni_ch) {
			// a second 16-bit of a surrogate pair appeared
			return false;
		}
		// first 16-bit of surrogate pair, get the next one
		if (in.getc() != '\\' || in.getc() != 'u') {
			in.ungetc();
			return false;
		}
		int second = _parse_quadhex(in);
		if (! (0xdc00 <= second && second <= 0xdfff)) {
			return false;
		}
		uni_ch = ((uni_ch - 0xd800) << 10) | ((second - 0xdc00) & 0x3ff);
		uni_ch += 0x10000;
	}
	if (uni_ch < 0x80) {
		out.push_back(uni_ch);
	} else {
		if (uni_ch < 0x800) {
			out.push_back(0xc0 | (uni_ch >> 6));
		} else {
			if (uni_ch < 0x10000) {
				out.push_back(0xe0 | (uni_ch >> 12));
			} else {
				out.push_back(0xf0 | (uni_ch >> 18));
				out.push_back(0x80 | ((uni_ch >> 12) & 0x3f));
			}
			out.push_back(0x80 | ((uni_ch >> 6) & 0x3f));
		}
		out.push_back(0x80 | (uni_ch & 0x3f));
	}
	return true;
}

template<typename String, typename Iter> inline bool _parse_string(String& out, input<Iter>& in)
{
	while (1) {
		int ch = in.getc();
		if (ch < ' ') {
			in.ungetc();
			return false;
		} else if (ch == '"') {
			return true;
		} else if (ch == '\\') {
			if ((ch = in.getc()) == -1) {
				return false;
			}
			switch (ch) {
#define MAP(sym, val) case sym: out.push_back(val); break
				MAP('"', '\"');
				MAP('\\', '\\');
				MAP('/', '/');
				MAP('b', '\b');
				MAP('f', '\f');
				MAP('n', '\n');
				MAP('r', '\r');
				MAP('t', '\t');
#undef MAP
			case 'u':
				if (! _parse_codepoint(out, in)) {
					return false;
				}
				break;
			default:
				return false;
			}
		} else {
			out.push_back(ch);
		}
	}
	return false;
}

template <typename Context, typename Iter> inline bool _parse_array(Context& ctx, input<Iter>& in)
{
	if (! ctx.parse_array_start()) {
		return false;
	}
	size_t idx = 0;
	if (in.expect(']')) {
		return ctx.parse_array_stop(idx);
	}
	do {
		if (! ctx.parse_array_item(in, idx)) {
			return false;
		}
		idx++;
	} while (in.expect(','));
	return in.expect(']') && ctx.parse_array_stop(idx);
}

template <typename Context, typename Iter> inline bool _parse_object(Context& ctx, input<Iter>& in)
{
	if (! ctx.parse_object_start()) {
		return false;
	}
	if (in.expect('}')) {
		return true;
	}
	do {
		std::string key;
		if (! in.expect('"')
		    || ! _parse_string(key, in)
		    || ! in.expect(':')) {
			return false;
		}
		if (! ctx.parse_object_item(in, key)) {
			return false;
		}
	} while (in.expect(','));
	return in.expect('}');
}

template <typename Iter> inline std::string _parse_number(input<Iter>& in)
{
	std::string num_str;
	while (1) {
		int ch = in.getc();
		if (('0' <= ch && ch <= '9') || ch == '+' || ch == '-'
		    || ch == 'e' || ch == 'E') {
			num_str.push_back(ch);
		} else if (ch == '.') {
#if PICOJSON_USE_LOCALE
			num_str += localeconv()->decimal_point;
#else
			num_str.push_back('.');
#endif
		} else {
			in.ungetc();
			break;
		}
	}
	return num_str;
}

template <typename Context, typename Iter> inline bool _parse(Context& ctx, input<Iter>& in)
{
	in.skip_ws();
	int ch = in.getc();
	switch (ch) {
#define IS(ch, text, op) case ch: \
      if (in.match(text) && op) { \
	return true; \
      } else { \
	return false; \
      }
		IS('n', "ull", ctx.set_null());
		IS('f', "alse", ctx.set_bool(false));
		IS('t', "rue", ctx.set_bool(true));
#undef IS
	case '"':
		return ctx.parse_string(in);
	case '[':
		return _parse_array(ctx, in);
	case '{':
		return _parse_object(ctx, in);
	default:
		if (('0' <= ch && ch <= '9') || ch == '-') {
			double f;
			char *endp;
			in.ungetc();
			std::string num_str = _parse_number(in);
			if (num_str.empty()) {
				return false;
			}
#ifdef PICOJSON_USE_INT64
			{
				errno = 0;
				intmax_t ival = strtoimax(num_str.c_str(), &endp, 10);
				if (errno == 0
				    && std::numeric_limits<int64_t>::min() <= ival
				    && ival <= std::numeric_limits<int64_t>::max()
				    && endp == num_str.c_str() + num_str.size()) {
					ctx.set_int64(ival);
					return true;
				}
			}
#endif
			f = strtod(num_str.c_str(), &endp);
			if (endp == num_str.c_str() + num_str.size()) {
				ctx.set_number(f);
				return true;
			}
			return false;
		}
		break;
	}
	in.ungetc();
	return false;
}

class deny_parse_context
{
public:
	bool set_null()
	{
		return false;
	}
	bool set_bool(bool)
	{
		return false;
	}
#ifdef PICOJSON_USE_INT64
	bool set_int64(int64_t)
	{
		return false;
	}
#endif
	bool set_number(double)
	{
		return false;
	}
	template <typename Iter> bool parse_string(input<Iter>&)
	{
		return false;
	}
	bool parse_array_start()
	{
		return false;
	}
	template <typename Iter> bool parse_array_item(input<Iter>&, size_t)
	{
		return false;
	}
	bool parse_array_stop(size_t)
	{
		return false;
	}
	bool parse_object_start()
	{
		return false;
	}
	template <typename Iter> bool parse_object_item(input<Iter>&, const std::string&)
	{
		return false;
	}
};

class default_parse_context
{
protected:
	value* out_;
public:
	default_parse_context(value* out) : out_(out) {}
	bool set_null()
	{
		*out_ = value();
		return true;
	}
	bool set_bool(bool b)
	{
		*out_ = value(b);
		return true;
	}
#ifdef PICOJSON_USE_INT64
	bool set_int64(int64_t i)
	{
		*out_ = value(i);
		return true;
	}
#endif
	bool set_number(double f)
	{
		*out_ = value(f);
		return true;
	}
	template<typename Iter> bool parse_string(input<Iter>& in)
	{
		*out_ = value(string_type, false);
		return _parse_string(out_->get<std::string>(), in);
	}
	bool parse_array_start()
	{
		*out_ = value(array_type, false);
		return true;
	}
	template <typename Iter> bool parse_array_item(input<Iter>& in, size_t)
	{
		array& a = out_->get<array>();
		a.push_back(value());
		default_parse_context ctx(&a.back());
		return _parse(ctx, in);
	}
	bool parse_array_stop(size_t)
	{
		return true;
	}
	bool parse_object_start()
	{
		*out_ = value(object_type, false);
		return true;
	}
	template <typename Iter> bool parse_object_item(input<Iter>& in, const std::string& key)
	{
		object& o = out_->get<object>();
		default_parse_context ctx(&o[key]);
		return _parse(ctx, in);
	}
private:
	default_parse_context(const default_parse_context&);
	default_parse_context& operator=(const default_parse_context&);
};

class null_parse_context
{
public:
	struct dummy_str {
		void push_back(int) {}
	};
public:
	null_parse_context() {}
	bool set_null()
	{
		return true;
	}
	bool set_bool(bool)
	{
		return true;
	}
#ifdef PICOJSON_USE_INT64
	bool set_int64(int64_t)
	{
		return true;
	}
#endif
	bool set_number(double)
	{
		return true;
	}
	template <typename Iter> bool parse_string(input<Iter>& in)
	{
		dummy_str s;
		return _parse_string(s, in);
	}
	bool parse_array_start()
	{
		return true;
	}
	template <typename Iter> bool parse_array_item(input<Iter>& in, size_t)
	{
		return _parse(*this, in);
	}
	bool parse_array_stop(size_t)
	{
		return true;
	}
	bool parse_object_start()
	{
		return true;
	}
	template <typename Iter> bool parse_object_item(input<Iter>& in, const std::string&)
	{
		return _parse(*this, in);
	}
private:
	null_parse_context(const null_parse_context&);
	null_parse_context& operator=(const null_parse_context&);
};

// obsolete, use the version below
template <typename Iter> inline std::string parse(value& out, Iter& pos, const Iter& last)
{
	std::string err;
	pos = parse(out, pos, last, &err);
	return err;
}

template <typename Context, typename Iter> inline Iter _parse(Context& ctx, const Iter& first, const Iter& last, std::string* err)
{
	input<Iter> in(first, last);
	if (! _parse(ctx, in) && err != NULL) {
		char buf[64];
		SNPRINTF(buf, sizeof(buf), "syntax error at line %d near: ", in.line());
		*err = buf;
		while (1) {
			int ch = in.getc();
			if (ch == -1 || ch == '\n') {
				break;
			} else if (ch >= ' ') {
				err->push_back(ch);
			}
		}
	}
	return in.cur();
}

template <typename Iter> inline Iter parse(value& out, const Iter& first, const Iter& last, std::string* err)
{
	default_parse_context ctx(&out);
	return _parse(ctx, first, last, err);
}

inline std::string parse(value& out, const std::string& s)
{
	std::string err;
	parse(out, s.begin(), s.end(), &err);
	return err;
}

inline std::string parse(value& out, std::istream& is)
{
	std::string err;
	parse(out, std::istreambuf_iterator<char>(is.rdbuf()),
	      std::istreambuf_iterator<char>(), &err);
	return err;
}

template <typename T> struct last_error_t {
	static std::string s;
};
template <typename T> std::string last_error_t<T>::s;

inline void set_last_error(const std::string& s)
{
	last_error_t<bool>::s = s;
}

inline const std::string& get_last_error()
{
	return last_error_t<bool>::s;
}

inline bool operator==(const value& x, const value& y)
{
	if (x.is<null>())
		return y.is<null>();
#define PICOJSON_CMP(type)					\
    if (x.is<type>())						\
      return y.is<type>() && x.get<type>() == y.get<type>()
	PICOJSON_CMP(bool);
	PICOJSON_CMP(double);
	PICOJSON_CMP(std::string);
	PICOJSON_CMP(array);
	PICOJSON_CMP(object);
#undef PICOJSON_CMP
	PICOJSON_ASSERT(0);
#ifdef _MSC_VER
	__assume(0);
#endif
	return false;
}

inline bool operator!=(const value& x, const value& y)
{
	return ! (x == y);
}
}

namespace std
{
template<> inline void swap(picojson::value& x, picojson::value& y)
{
	x.swap(y);
}
}

inline std::istream& operator>>(std::istream& is, picojson::value& x)
{
	picojson::set_last_error(std::string());
	std::string err = picojson::parse(x, is);
	if (! err.empty()) {
		picojson::set_last_error(err);
		is.setstate(std::ios::failbit);
	}
	return is;
}

inline std::ostream& operator<<(std::ostream& os, const picojson::value& x)
{
	x.serialize(std::ostream_iterator<char>(os));
	return os;
}
#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif