diff options
Diffstat (limited to 'ext/json11')
| -rw-r--r-- | ext/json11/json11.cpp | 784 | ||||
| -rw-r--r-- | ext/json11/json11.hpp | 232 |
2 files changed, 1016 insertions, 0 deletions
diff --git a/ext/json11/json11.cpp b/ext/json11/json11.cpp new file mode 100644 index 0000000..f48833b --- /dev/null +++ b/ext/json11/json11.cpp @@ -0,0 +1,784 @@ +/* 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> +#include <string> + +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->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->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 inside comment", false); + if (str[i] == '/') { // inline comment + i++; + if (i == str.size()) + return fail("unexpected end of input inside inline comment", false); + // advance until next line + while (str[i] != '\n') { + i++; + if (i == str.size()) + return fail("unexpected end of input inside inline comment", false); + } + 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; + if (i == str.size()) + return fail( + "unexpected end of input inside multi-line comment", false); + 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(); + 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 (i == str.size()) + return fail("unexpected end of input", (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.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)); + // Check for another object + parser.consume_garbage(); + if (!parser.failed) + 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 diff --git a/ext/json11/json11.hpp b/ext/json11/json11.hpp new file mode 100644 index 0000000..a68394b --- /dev/null +++ b/ext/json11/json11.hpp @@ -0,0 +1,232 @@ +/* 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, typename M::key_type>::value + && std::is_constructible<Json, typename M::mapped_type>::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, typename V::value_type>::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 |