--- /dev/null
+/* 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.
+ */
+
+#include "json11.hpp"
+#include <cassert>
+#include <cmath>
+#include <cstdlib>
+#include <cstdio>
+#include <limits>
+
+namespace json11 {
+
+static const int max_depth = 200;
+
+using std::string;
+using std::vector;
+using std::map;
+using std::make_shared;
+using std::initializer_list;
+using std::move;
+
+/* Helper for representing null - just a do-nothing struct, plus comparison
+ * operators so the helpers in JsonValue work. We can't use nullptr_t because
+ * it may not be orderable.
+ */
+struct NullStruct {
+ bool operator==(NullStruct) const { return true; }
+ bool operator<(NullStruct) const { return false; }
+};
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Serialization
+ */
+
+static void dump(NullStruct, string &out) {
+ out += "null";
+}
+
+static void dump(double value, string &out) {
+ if (std::isfinite(value)) {
+ char buf[32];
+ snprintf(buf, sizeof buf, "%.17g", value);
+ out += buf;
+ } else {
+ out += "null";
+ }
+}
+
+static void dump(int value, string &out) {
+ char buf[32];
+ snprintf(buf, sizeof buf, "%d", value);
+ out += buf;
+}
+
+static void dump(bool value, string &out) {
+ out += value ? "true" : "false";
+}
+
+static void dump(const string &value, string &out) {
+ out += '"';
+ for (size_t i = 0; i < value.length(); i++) {
+ const char ch = value[i];
+ if (ch == '\\') {
+ out += "\\\\";
+ } else if (ch == '"') {
+ out += "\\\"";
+ } else if (ch == '\b') {
+ out += "\\b";
+ } else if (ch == '\f') {
+ out += "\\f";
+ } else if (ch == '\n') {
+ out += "\\n";
+ } else if (ch == '\r') {
+ out += "\\r";
+ } else if (ch == '\t') {
+ out += "\\t";
+ } else if (static_cast<uint8_t>(ch) <= 0x1f) {
+ char buf[8];
+ snprintf(buf, sizeof buf, "\\u%04x", ch);
+ out += buf;
+ } else if (static_cast<uint8_t>(ch) == 0xe2 && static_cast<uint8_t>(value[i+1]) == 0x80
+ && static_cast<uint8_t>(value[i+2]) == 0xa8) {
+ out += "\\u2028";
+ i += 2;
+ } else if (static_cast<uint8_t>(ch) == 0xe2 && static_cast<uint8_t>(value[i+1]) == 0x80
+ && static_cast<uint8_t>(value[i+2]) == 0xa9) {
+ out += "\\u2029";
+ i += 2;
+ } else {
+ out += ch;
+ }
+ }
+ out += '"';
+}
+
+static void dump(const Json::array &values, string &out) {
+ bool first = true;
+ out += "[";
+ for (const auto &value : values) {
+ if (!first)
+ out += ", ";
+ value.dump(out);
+ first = false;
+ }
+ out += "]";
+}
+
+static void dump(const Json::object &values, string &out) {
+ bool first = true;
+ out += "{";
+ for (const auto &kv : values) {
+ if (!first)
+ out += ", ";
+ dump(kv.first, out);
+ out += ": ";
+ kv.second.dump(out);
+ first = false;
+ }
+ out += "}";
+}
+
+void Json::dump(string &out) const {
+ m_ptr->dump(out);
+}
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Value wrappers
+ */
+
+template <Json::Type tag, typename T>
+class Value : public JsonValue {
+protected:
+
+ // Constructors
+ explicit Value(const T &value) : m_value(value) {}
+ explicit Value(T &&value) : m_value(move(value)) {}
+
+ // Get type tag
+ Json::Type type() const override {
+ return tag;
+ }
+
+ // Comparisons
+ bool equals(const JsonValue * other) const override {
+ return m_value == static_cast<const Value<tag, T> *>(other)->m_value;
+ }
+ bool less(const JsonValue * other) const override {
+ return m_value < static_cast<const Value<tag, T> *>(other)->m_value;
+ }
+
+ const T m_value;
+ void dump(string &out) const override { json11::dump(m_value, out); }
+};
+
+class JsonDouble final : public Value<Json::NUMBER, double> {
+ double number_value() const override { return m_value; }
+ int int_value() const override { return static_cast<int>(m_value); }
+ bool equals(const JsonValue * other) const override { return m_value == other->number_value(); }
+ bool less(const JsonValue * other) const override { return m_value < other->number_value(); }
+public:
+ explicit JsonDouble(double value) : Value(value) {}
+};
+
+class JsonInt final : public Value<Json::NUMBER, int> {
+ double number_value() const override { return m_value; }
+ int int_value() const override { return m_value; }
+ bool equals(const JsonValue * other) const override { return m_value == other->number_value(); }
+ bool less(const JsonValue * other) const override { return m_value < other->number_value(); }
+public:
+ explicit JsonInt(int value) : Value(value) {}
+};
+
+class JsonBoolean final : public Value<Json::BOOL, bool> {
+ bool bool_value() const override { return m_value; }
+public:
+ explicit JsonBoolean(bool value) : Value(value) {}
+};
+
+class JsonString final : public Value<Json::STRING, string> {
+ const string &string_value() const override { return m_value; }
+public:
+ explicit JsonString(const string &value) : Value(value) {}
+ explicit JsonString(string &&value) : Value(move(value)) {}
+};
+
+class JsonArray final : public Value<Json::ARRAY, Json::array> {
+ const Json::array &array_items() const override { return m_value; }
+ const Json & operator[](size_t i) const override;
+public:
+ explicit JsonArray(const Json::array &value) : Value(value) {}
+ explicit JsonArray(Json::array &&value) : Value(move(value)) {}
+};
+
+class JsonObject final : public Value<Json::OBJECT, Json::object> {
+ const Json::object &object_items() const override { return m_value; }
+ const Json & operator[](const string &key) const override;
+public:
+ explicit JsonObject(const Json::object &value) : Value(value) {}
+ explicit JsonObject(Json::object &&value) : Value(move(value)) {}
+};
+
+class JsonNull final : public Value<Json::NUL, NullStruct> {
+public:
+ JsonNull() : Value({}) {}
+};
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Static globals - static-init-safe
+ */
+struct Statics {
+ const std::shared_ptr<JsonValue> null = make_shared<JsonNull>();
+ const std::shared_ptr<JsonValue> t = make_shared<JsonBoolean>(true);
+ const std::shared_ptr<JsonValue> f = make_shared<JsonBoolean>(false);
+ const string empty_string;
+ const vector<Json> empty_vector;
+ const map<string, Json> empty_map;
+ Statics() {}
+};
+
+static const Statics & statics() {
+ static const Statics s {};
+ return s;
+}
+
+static const Json & static_null() {
+ // This has to be separate, not in Statics, because Json() accesses statics().null.
+ static const Json json_null;
+ return json_null;
+}
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Constructors
+ */
+
+Json::Json() noexcept : m_ptr(statics().null) {}
+Json::Json(std::nullptr_t) noexcept : m_ptr(statics().null) {}
+Json::Json(double value) : m_ptr(make_shared<JsonDouble>(value)) {}
+Json::Json(int value) : m_ptr(make_shared<JsonInt>(value)) {}
+Json::Json(bool value) : m_ptr(value ? statics().t : statics().f) {}
+Json::Json(const string &value) : m_ptr(make_shared<JsonString>(value)) {}
+Json::Json(string &&value) : m_ptr(make_shared<JsonString>(move(value))) {}
+Json::Json(const char * value) : m_ptr(make_shared<JsonString>(value)) {}
+Json::Json(const Json::array &values) : m_ptr(make_shared<JsonArray>(values)) {}
+Json::Json(Json::array &&values) : m_ptr(make_shared<JsonArray>(move(values))) {}
+Json::Json(const Json::object &values) : m_ptr(make_shared<JsonObject>(values)) {}
+Json::Json(Json::object &&values) : m_ptr(make_shared<JsonObject>(move(values))) {}
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Accessors
+ */
+
+Json::Type Json::type() const { return m_ptr->type(); }
+double Json::number_value() const { return m_ptr->number_value(); }
+int Json::int_value() const { return m_ptr->int_value(); }
+bool Json::bool_value() const { return m_ptr->bool_value(); }
+const string & Json::string_value() const { return m_ptr->string_value(); }
+const vector<Json> & Json::array_items() const { return m_ptr->array_items(); }
+const map<string, Json> & Json::object_items() const { return m_ptr->object_items(); }
+const Json & Json::operator[] (size_t i) const { return (*m_ptr)[i]; }
+const Json & Json::operator[] (const string &key) const { return (*m_ptr)[key]; }
+
+double JsonValue::number_value() const { return 0; }
+int JsonValue::int_value() const { return 0; }
+bool JsonValue::bool_value() const { return false; }
+const string & JsonValue::string_value() const { return statics().empty_string; }
+const vector<Json> & JsonValue::array_items() const { return statics().empty_vector; }
+const map<string, Json> & JsonValue::object_items() const { return statics().empty_map; }
+const Json & JsonValue::operator[] (size_t) const { return static_null(); }
+const Json & JsonValue::operator[] (const string &) const { return static_null(); }
+
+const Json & JsonObject::operator[] (const string &key) const {
+ auto iter = m_value.find(key);
+ return (iter == m_value.end()) ? static_null() : iter->second;
+}
+const Json & JsonArray::operator[] (size_t i) const {
+ if (i >= m_value.size()) return static_null();
+ else return m_value[i];
+}
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Comparison
+ */
+
+bool Json::operator== (const Json &other) const {
+ if (m_ptr == other.m_ptr)
+ return true;
+ if (m_ptr->type() != other.m_ptr->type())
+ return false;
+
+ return m_ptr->equals(other.m_ptr.get());
+}
+
+bool Json::operator< (const Json &other) const {
+ if (m_ptr == other.m_ptr)
+ return false;
+ if (m_ptr->type() != other.m_ptr->type())
+ return m_ptr->type() < other.m_ptr->type();
+
+ return m_ptr->less(other.m_ptr.get());
+}
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Parsing
+ */
+
+/* esc(c)
+ *
+ * Format char c suitable for printing in an error message.
+ */
+static inline string esc(char c) {
+ char buf[12];
+ if (static_cast<uint8_t>(c) >= 0x20 && static_cast<uint8_t>(c) <= 0x7f) {
+ snprintf(buf, sizeof buf, "'%c' (%d)", c, c);
+ } else {
+ snprintf(buf, sizeof buf, "(%d)", c);
+ }
+ return string(buf);
+}
+
+static inline bool in_range(long x, long lower, long upper) {
+ return (x >= lower && x <= upper);
+}
+
+namespace {
+/* JsonParser
+ *
+ * Object that tracks all state of an in-progress parse.
+ */
+struct JsonParser final {
+
+ /* State
+ */
+ const string &str;
+ size_t i;
+ string &err;
+ bool failed;
+ const JsonParse strategy;
+
+ /* fail(msg, err_ret = Json())
+ *
+ * Mark this parse as failed.
+ */
+ Json fail(string &&msg) {
+ return fail(move(msg), Json());
+ }
+
+ template <typename T>
+ T fail(string &&msg, const T err_ret) {
+ if (!failed)
+ err = std::move(msg);
+ failed = true;
+ return err_ret;
+ }
+
+ /* consume_whitespace()
+ *
+ * Advance until the current character is non-whitespace.
+ */
+ void consume_whitespace() {
+ while (str[i] == ' ' || str[i] == '\r' || str[i] == '\n' || str[i] == '\t')
+ i++;
+ }
+
+ /* consume_comment()
+ *
+ * Advance comments (c-style inline and multiline).
+ */
+ bool consume_comment() {
+ bool comment_found = false;
+ if (str[i] == '/') {
+ i++;
+ if (i == str.size())
+ return fail("unexpected end of input after start of comment", false);
+ if (str[i] == '/') { // inline comment
+ i++;
+ // advance until next line, or end of input
+ while (i < str.size() && str[i] != '\n') {
+ i++;
+ }
+ comment_found = true;
+ }
+ else if (str[i] == '*') { // multiline comment
+ i++;
+ if (i > str.size()-2)
+ return fail("unexpected end of input inside multi-line comment", false);
+ // advance until closing tokens
+ while (!(str[i] == '*' && str[i+1] == '/')) {
+ i++;
+ if (i > str.size()-2)
+ return fail(
+ "unexpected end of input inside multi-line comment", false);
+ }
+ i += 2;
+ comment_found = true;
+ }
+ else
+ return fail("malformed comment", false);
+ }
+ return comment_found;
+ }
+
+ /* consume_garbage()
+ *
+ * Advance until the current character is non-whitespace and non-comment.
+ */
+ void consume_garbage() {
+ consume_whitespace();
+ if(strategy == JsonParse::COMMENTS) {
+ bool comment_found = false;
+ do {
+ comment_found = consume_comment();
+ if (failed) return;
+ consume_whitespace();
+ }
+ while(comment_found);
+ }
+ }
+
+ /* get_next_token()
+ *
+ * Return the next non-whitespace character. If the end of the input is reached,
+ * flag an error and return 0.
+ */
+ char get_next_token() {
+ consume_garbage();
+ if (failed) return static_cast<char>(0);
+ if (i == str.size())
+ return fail("unexpected end of input", static_cast<char>(0));
+
+ return str[i++];
+ }
+
+ /* encode_utf8(pt, out)
+ *
+ * Encode pt as UTF-8 and add it to out.
+ */
+ void encode_utf8(long pt, string & out) {
+ if (pt < 0)
+ return;
+
+ if (pt < 0x80) {
+ out += static_cast<char>(pt);
+ } else if (pt < 0x800) {
+ out += static_cast<char>((pt >> 6) | 0xC0);
+ out += static_cast<char>((pt & 0x3F) | 0x80);
+ } else if (pt < 0x10000) {
+ out += static_cast<char>((pt >> 12) | 0xE0);
+ out += static_cast<char>(((pt >> 6) & 0x3F) | 0x80);
+ out += static_cast<char>((pt & 0x3F) | 0x80);
+ } else {
+ out += static_cast<char>((pt >> 18) | 0xF0);
+ out += static_cast<char>(((pt >> 12) & 0x3F) | 0x80);
+ out += static_cast<char>(((pt >> 6) & 0x3F) | 0x80);
+ out += static_cast<char>((pt & 0x3F) | 0x80);
+ }
+ }
+
+ /* parse_string()
+ *
+ * Parse a string, starting at the current position.
+ */
+ string parse_string() {
+ string out;
+ long last_escaped_codepoint = -1;
+ while (true) {
+ if (i == str.size())
+ return fail("unexpected end of input in string", "");
+
+ char ch = str[i++];
+
+ if (ch == '"') {
+ encode_utf8(last_escaped_codepoint, out);
+ return out;
+ }
+
+ if (in_range(ch, 0, 0x1f))
+ return fail("unescaped " + esc(ch) + " in string", "");
+
+ // The usual case: non-escaped characters
+ if (ch != '\\') {
+ encode_utf8(last_escaped_codepoint, out);
+ last_escaped_codepoint = -1;
+ out += ch;
+ continue;
+ }
+
+ // Handle escapes
+ if (i == str.size())
+ return fail("unexpected end of input in string", "");
+
+ ch = str[i++];
+
+ if (ch == 'u') {
+ // Extract 4-byte escape sequence
+ string esc = str.substr(i, 4);
+ // Explicitly check length of the substring. The following loop
+ // relies on std::string returning the terminating NUL when
+ // accessing str[length]. Checking here reduces brittleness.
+ if (esc.length() < 4) {
+ return fail("bad \\u escape: " + esc, "");
+ }
+ for (size_t j = 0; j < 4; j++) {
+ if (!in_range(esc[j], 'a', 'f') && !in_range(esc[j], 'A', 'F')
+ && !in_range(esc[j], '0', '9'))
+ return fail("bad \\u escape: " + esc, "");
+ }
+
+ long codepoint = strtol(esc.data(), nullptr, 16);
+
+ // JSON specifies that characters outside the BMP shall be encoded as a pair
+ // of 4-hex-digit \u escapes encoding their surrogate pair components. Check
+ // whether we're in the middle of such a beast: the previous codepoint was an
+ // escaped lead (high) surrogate, and this is a trail (low) surrogate.
+ if (in_range(last_escaped_codepoint, 0xD800, 0xDBFF)
+ && in_range(codepoint, 0xDC00, 0xDFFF)) {
+ // Reassemble the two surrogate pairs into one astral-plane character, per
+ // the UTF-16 algorithm.
+ encode_utf8((((last_escaped_codepoint - 0xD800) << 10)
+ | (codepoint - 0xDC00)) + 0x10000, out);
+ last_escaped_codepoint = -1;
+ } else {
+ encode_utf8(last_escaped_codepoint, out);
+ last_escaped_codepoint = codepoint;
+ }
+
+ i += 4;
+ continue;
+ }
+
+ encode_utf8(last_escaped_codepoint, out);
+ last_escaped_codepoint = -1;
+
+ if (ch == 'b') {
+ out += '\b';
+ } else if (ch == 'f') {
+ out += '\f';
+ } else if (ch == 'n') {
+ out += '\n';
+ } else if (ch == 'r') {
+ out += '\r';
+ } else if (ch == 't') {
+ out += '\t';
+ } else if (ch == '"' || ch == '\\' || ch == '/') {
+ out += ch;
+ } else {
+ return fail("invalid escape character " + esc(ch), "");
+ }
+ }
+ }
+
+ /* parse_number()
+ *
+ * Parse a double.
+ */
+ Json parse_number() {
+ size_t start_pos = i;
+
+ if (str[i] == '-')
+ i++;
+
+ // Integer part
+ if (str[i] == '0') {
+ i++;
+ if (in_range(str[i], '0', '9'))
+ return fail("leading 0s not permitted in numbers");
+ } else if (in_range(str[i], '1', '9')) {
+ i++;
+ while (in_range(str[i], '0', '9'))
+ i++;
+ } else {
+ return fail("invalid " + esc(str[i]) + " in number");
+ }
+
+ if (str[i] != '.' && str[i] != 'e' && str[i] != 'E'
+ && (i - start_pos) <= static_cast<size_t>(std::numeric_limits<int>::digits10)) {
+ return std::atoi(str.c_str() + start_pos);
+ }
+
+ // Decimal part
+ if (str[i] == '.') {
+ i++;
+ if (!in_range(str[i], '0', '9'))
+ return fail("at least one digit required in fractional part");
+
+ while (in_range(str[i], '0', '9'))
+ i++;
+ }
+
+ // Exponent part
+ if (str[i] == 'e' || str[i] == 'E') {
+ i++;
+
+ if (str[i] == '+' || str[i] == '-')
+ i++;
+
+ if (!in_range(str[i], '0', '9'))
+ return fail("at least one digit required in exponent");
+
+ while (in_range(str[i], '0', '9'))
+ i++;
+ }
+
+ return std::strtod(str.c_str() + start_pos, nullptr);
+ }
+
+ /* expect(str, res)
+ *
+ * Expect that 'str' starts at the character that was just read. If it does, advance
+ * the input and return res. If not, flag an error.
+ */
+ Json expect(const string &expected, Json res) {
+ assert(i != 0);
+ i--;
+ if (str.compare(i, expected.length(), expected) == 0) {
+ i += expected.length();
+ return res;
+ } else {
+ return fail("parse error: expected " + expected + ", got " + str.substr(i, expected.length()));
+ }
+ }
+
+ /* parse_json()
+ *
+ * Parse a JSON object.
+ */
+ Json parse_json(int depth) {
+ if (depth > max_depth) {
+ return fail("exceeded maximum nesting depth");
+ }
+
+ char ch = get_next_token();
+ if (failed)
+ return Json();
+
+ if (ch == '-' || (ch >= '0' && ch <= '9')) {
+ i--;
+ return parse_number();
+ }
+
+ if (ch == 't')
+ return expect("true", true);
+
+ if (ch == 'f')
+ return expect("false", false);
+
+ if (ch == 'n')
+ return expect("null", Json());
+
+ if (ch == '"')
+ return parse_string();
+
+ if (ch == '{') {
+ map<string, Json> data;
+ ch = get_next_token();
+ if (ch == '}')
+ return data;
+
+ while (1) {
+ if (ch != '"')
+ return fail("expected '\"' in object, got " + esc(ch));
+
+ string key = parse_string();
+ if (failed)
+ return Json();
+
+ ch = get_next_token();
+ if (ch != ':')
+ return fail("expected ':' in object, got " + esc(ch));
+
+ data[std::move(key)] = parse_json(depth + 1);
+ if (failed)
+ return Json();
+
+ ch = get_next_token();
+ if (ch == '}')
+ break;
+ if (ch != ',')
+ return fail("expected ',' in object, got " + esc(ch));
+
+ ch = get_next_token();
+ }
+ return data;
+ }
+
+ if (ch == '[') {
+ vector<Json> data;
+ ch = get_next_token();
+ if (ch == ']')
+ return data;
+
+ while (1) {
+ i--;
+ data.push_back(parse_json(depth + 1));
+ if (failed)
+ return Json();
+
+ ch = get_next_token();
+ if (ch == ']')
+ break;
+ if (ch != ',')
+ return fail("expected ',' in list, got " + esc(ch));
+
+ ch = get_next_token();
+ (void)ch;
+ }
+ return data;
+ }
+
+ return fail("expected value, got " + esc(ch));
+ }
+};
+}//namespace {
+
+Json Json::parse(const string &in, string &err, JsonParse strategy) {
+ JsonParser parser { in, 0, err, false, strategy };
+ Json result = parser.parse_json(0);
+
+ // Check for any trailing garbage
+ parser.consume_garbage();
+ if (parser.failed)
+ return Json();
+ if (parser.i != in.size())
+ return parser.fail("unexpected trailing " + esc(in[parser.i]));
+
+ return result;
+}
+
+// Documented in json11.hpp
+vector<Json> Json::parse_multi(const string &in,
+ std::string::size_type &parser_stop_pos,
+ string &err,
+ JsonParse strategy) {
+ JsonParser parser { in, 0, err, false, strategy };
+ parser_stop_pos = 0;
+ vector<Json> json_vec;
+ while (parser.i != in.size() && !parser.failed) {
+ json_vec.push_back(parser.parse_json(0));
+ if (parser.failed)
+ break;
+
+ // Check for another object
+ parser.consume_garbage();
+ if (parser.failed)
+ break;
+ parser_stop_pos = parser.i;
+ }
+ return json_vec;
+}
+
+/* * * * * * * * * * * * * * * * * * * *
+ * Shape-checking
+ */
+
+bool Json::has_shape(const shape & types, string & err) const {
+ if (!is_object()) {
+ err = "expected JSON object, got " + dump();
+ return false;
+ }
+
+ for (auto & item : types) {
+ if ((*this)[item.first].type() != item.second) {
+ err = "bad type for " + item.first + " in " + dump();
+ return false;
+ }
+ }
+
+ return true;
+}
+
+} // namespace json11
--- /dev/null
+/* 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