| // Copyright 2007-2010 Baptiste Lepilleur and The JsonCpp Authors |
| // Distributed under MIT license, or public domain if desired and |
| // recognized in your jurisdiction. |
| // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE |
| |
| #ifndef JSON_READER_H_INCLUDED |
| #define JSON_READER_H_INCLUDED |
| |
| #if !defined(JSON_IS_AMALGAMATION) |
| #include "json_features.h" |
| #include "value.h" |
| #endif // if !defined(JSON_IS_AMALGAMATION) |
| #include <deque> |
| #include <iosfwd> |
| #include <istream> |
| #include <stack> |
| #include <string> |
| |
| // Disable warning C4251: <data member>: <type> needs to have dll-interface to |
| // be used by... |
| #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
| #pragma warning(push) |
| #pragma warning(disable : 4251) |
| #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
| |
| #pragma pack(push, 8) |
| |
| namespace Json { |
| |
| /** \brief Unserialize a <a HREF="http://www.json.org">JSON</a> document into a |
| * Value. |
| * |
| * \deprecated Use CharReader and CharReaderBuilder. |
| */ |
| |
| class JSONCPP_DEPRECATED( |
| "Use CharReader and CharReaderBuilder instead.") JSON_API Reader { |
| public: |
| using Char = char; |
| using Location = const Char*; |
| |
| /** \brief An error tagged with where in the JSON text it was encountered. |
| * |
| * The offsets give the [start, limit) range of bytes within the text. Note |
| * that this is bytes, not codepoints. |
| */ |
| struct StructuredError { |
| ptrdiff_t offset_start; |
| ptrdiff_t offset_limit; |
| String message; |
| }; |
| |
| /** \brief Constructs a Reader allowing all features for parsing. |
| */ |
| JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead") |
| Reader(); |
| |
| /** \brief Constructs a Reader allowing the specified feature set for parsing. |
| */ |
| JSONCPP_DEPRECATED("Use CharReader and CharReaderBuilder instead") |
| Reader(const Features& features); |
| |
| /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a> |
| * document. |
| * |
| * \param document UTF-8 encoded string containing the document |
| * to read. |
| * \param[out] root Contains the root value of the document if it |
| * was successfully parsed. |
| * \param collectComments \c true to collect comment and allow writing |
| * them back during serialization, \c false to |
| * discard comments. This parameter is ignored |
| * if Features::allowComments_ is \c false. |
| * \return \c true if the document was successfully parsed, \c false if an |
| * error occurred. |
| */ |
| bool parse(const std::string& document, Value& root, |
| bool collectComments = true); |
| |
| /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a> |
| * document. |
| * |
| * \param beginDoc Pointer on the beginning of the UTF-8 encoded |
| * string of the document to read. |
| * \param endDoc Pointer on the end of the UTF-8 encoded string |
| * of the document to read. Must be >= beginDoc. |
| * \param[out] root Contains the root value of the document if it |
| * was successfully parsed. |
| * \param collectComments \c true to collect comment and allow writing |
| * them back during serialization, \c false to |
| * discard comments. This parameter is ignored |
| * if Features::allowComments_ is \c false. |
| * \return \c true if the document was successfully parsed, \c false if an |
| * error occurred. |
| */ |
| bool parse(const char* beginDoc, const char* endDoc, Value& root, |
| bool collectComments = true); |
| |
| /// \brief Parse from input stream. |
| /// \see Json::operator>>(std::istream&, Json::Value&). |
| bool parse(IStream& is, Value& root, bool collectComments = true); |
| |
| /** \brief Returns a user friendly string that list errors in the parsed |
| * document. |
| * |
| * \return Formatted error message with the list of errors with their |
| * location in the parsed document. An empty string is returned if no error |
| * occurred during parsing. |
| * \deprecated Use getFormattedErrorMessages() instead (typo fix). |
| */ |
| JSONCPP_DEPRECATED("Use getFormattedErrorMessages() instead.") |
| String getFormatedErrorMessages() const; |
| |
| /** \brief Returns a user friendly string that list errors in the parsed |
| * document. |
| * |
| * \return Formatted error message with the list of errors with their |
| * location in the parsed document. An empty string is returned if no error |
| * occurred during parsing. |
| */ |
| String getFormattedErrorMessages() const; |
| |
| /** \brief Returns a vector of structured errors encountered while parsing. |
| * |
| * \return A (possibly empty) vector of StructuredError objects. Currently |
| * only one error can be returned, but the caller should tolerate multiple |
| * errors. This can occur if the parser recovers from a non-fatal parse |
| * error and then encounters additional errors. |
| */ |
| std::vector<StructuredError> getStructuredErrors() const; |
| |
| /** \brief Add a semantic error message. |
| * |
| * \param value JSON Value location associated with the error |
| * \param message The error message. |
| * \return \c true if the error was successfully added, \c false if the Value |
| * offset exceeds the document size. |
| */ |
| bool pushError(const Value& value, const String& message); |
| |
| /** \brief Add a semantic error message with extra context. |
| * |
| * \param value JSON Value location associated with the error |
| * \param message The error message. |
| * \param extra Additional JSON Value location to contextualize the error |
| * \return \c true if the error was successfully added, \c false if either |
| * Value offset exceeds the document size. |
| */ |
| bool pushError(const Value& value, const String& message, const Value& extra); |
| |
| /** \brief Return whether there are any errors. |
| * |
| * \return \c true if there are no errors to report \c false if errors have |
| * occurred. |
| */ |
| bool good() const; |
| |
| private: |
| enum TokenType { |
| tokenEndOfStream = 0, |
| tokenObjectBegin, |
| tokenObjectEnd, |
| tokenArrayBegin, |
| tokenArrayEnd, |
| tokenString, |
| tokenNumber, |
| tokenTrue, |
| tokenFalse, |
| tokenNull, |
| tokenArraySeparator, |
| tokenMemberSeparator, |
| tokenComment, |
| tokenError |
| }; |
| |
| class Token { |
| public: |
| TokenType type_; |
| Location start_; |
| Location end_; |
| }; |
| |
| class ErrorInfo { |
| public: |
| Token token_; |
| String message_; |
| Location extra_; |
| }; |
| |
| using Errors = std::deque<ErrorInfo>; |
| |
| bool readToken(Token& token); |
| void skipSpaces(); |
| bool match(const Char* pattern, int patternLength); |
| bool readComment(); |
| bool readCStyleComment(); |
| bool readCppStyleComment(); |
| bool readString(); |
| void readNumber(); |
| bool readValue(); |
| bool readObject(Token& token); |
| bool readArray(Token& token); |
| bool decodeNumber(Token& token); |
| bool decodeNumber(Token& token, Value& decoded); |
| bool decodeString(Token& token); |
| bool decodeString(Token& token, String& decoded); |
| bool decodeDouble(Token& token); |
| bool decodeDouble(Token& token, Value& decoded); |
| bool decodeUnicodeCodePoint(Token& token, Location& current, Location end, |
| unsigned int& unicode); |
| bool decodeUnicodeEscapeSequence(Token& token, Location& current, |
| Location end, unsigned int& unicode); |
| bool addError(const String& message, Token& token, Location extra = nullptr); |
| bool recoverFromError(TokenType skipUntilToken); |
| bool addErrorAndRecover(const String& message, Token& token, |
| TokenType skipUntilToken); |
| void skipUntilSpace(); |
| Value& currentValue(); |
| Char getNextChar(); |
| void getLocationLineAndColumn(Location location, int& line, |
| int& column) const; |
| String getLocationLineAndColumn(Location location) const; |
| void addComment(Location begin, Location end, CommentPlacement placement); |
| void skipCommentTokens(Token& token); |
| |
| static bool containsNewLine(Location begin, Location end); |
| static String normalizeEOL(Location begin, Location end); |
| |
| using Nodes = std::stack<Value*>; |
| Nodes nodes_; |
| Errors errors_; |
| String document_; |
| Location begin_{}; |
| Location end_{}; |
| Location current_{}; |
| Location lastValueEnd_{}; |
| Value* lastValue_{}; |
| String commentsBefore_; |
| Features features_; |
| bool collectComments_{}; |
| }; // Reader |
| |
| /** Interface for reading JSON from a char array. |
| */ |
| class JSON_API CharReader { |
| public: |
| virtual ~CharReader() = default; |
| /** \brief Read a Value from a <a HREF="http://www.json.org">JSON</a> |
| * document. The document must be a UTF-8 encoded string containing the |
| * document to read. |
| * |
| * \param beginDoc Pointer on the beginning of the UTF-8 encoded string |
| * of the document to read. |
| * \param endDoc Pointer on the end of the UTF-8 encoded string of the |
| * document to read. Must be >= beginDoc. |
| * \param[out] root Contains the root value of the document if it was |
| * successfully parsed. |
| * \param[out] errs Formatted error messages (if not NULL) a user |
| * friendly string that lists errors in the parsed |
| * document. |
| * \return \c true if the document was successfully parsed, \c false if an |
| * error occurred. |
| */ |
| virtual bool parse(char const* beginDoc, char const* endDoc, Value* root, |
| String* errs) = 0; |
| |
| class JSON_API Factory { |
| public: |
| virtual ~Factory() = default; |
| /** \brief Allocate a CharReader via operator new(). |
| * \throw std::exception if something goes wrong (e.g. invalid settings) |
| */ |
| virtual CharReader* newCharReader() const = 0; |
| }; // Factory |
| }; // CharReader |
| |
| /** \brief Build a CharReader implementation. |
| * |
| * Usage: |
| * \code |
| * using namespace Json; |
| * CharReaderBuilder builder; |
| * builder["collectComments"] = false; |
| * Value value; |
| * String errs; |
| * bool ok = parseFromStream(builder, std::cin, &value, &errs); |
| * \endcode |
| */ |
| class JSON_API CharReaderBuilder : public CharReader::Factory { |
| public: |
| // Note: We use a Json::Value so that we can add data-members to this class |
| // without a major version bump. |
| /** Configuration of this builder. |
| * These are case-sensitive. |
| * Available settings (case-sensitive): |
| * - `"collectComments": false or true` |
| * - true to collect comment and allow writing them back during |
| * serialization, false to discard comments. This parameter is ignored |
| * if allowComments is false. |
| * - `"allowComments": false or true` |
| * - true if comments are allowed. |
| * - `"allowTrailingCommas": false or true` |
| * - true if trailing commas in objects and arrays are allowed. |
| * - `"strictRoot": false or true` |
| * - true if root must be either an array or an object value |
| * - `"allowDroppedNullPlaceholders": false or true` |
| * - true if dropped null placeholders are allowed. (See |
| * StreamWriterBuilder.) |
| * - `"allowNumericKeys": false or true` |
| * - true if numeric object keys are allowed. |
| * - `"allowSingleQuotes": false or true` |
| * - true if '' are allowed for strings (both keys and values) |
| * - `"stackLimit": integer` |
| * - Exceeding stackLimit (recursive depth of `readValue()`) will cause an |
| * exception. |
| * - This is a security issue (seg-faults caused by deeply nested JSON), so |
| * the default is low. |
| * - `"failIfExtra": false or true` |
| * - If true, `parse()` returns false when extra non-whitespace trails the |
| * JSON value in the input string. |
| * - `"rejectDupKeys": false or true` |
| * - If true, `parse()` returns false when a key is duplicated within an |
| * object. |
| * - `"allowSpecialFloats": false or true` |
| * - If true, special float values (NaNs and infinities) are allowed and |
| * their values are lossfree restorable. |
| * |
| * You can examine 'settings_` yourself to see the defaults. You can also |
| * write and read them just like any JSON Value. |
| * \sa setDefaults() |
| */ |
| Json::Value settings_; |
| |
| CharReaderBuilder(); |
| ~CharReaderBuilder() override; |
| |
| CharReader* newCharReader() const override; |
| |
| /** \return true if 'settings' are legal and consistent; |
| * otherwise, indicate bad settings via 'invalid'. |
| */ |
| bool validate(Json::Value* invalid) const; |
| |
| /** A simple way to update a specific setting. |
| */ |
| Value& operator[](const String& key); |
| |
| /** Called by ctor, but you can use this to reset settings_. |
| * \pre 'settings' != NULL (but Json::null is fine) |
| * \remark Defaults: |
| * \snippet src/lib_json/json_reader.cpp CharReaderBuilderDefaults |
| */ |
| static void setDefaults(Json::Value* settings); |
| /** Same as old Features::strictMode(). |
| * \pre 'settings' != NULL (but Json::null is fine) |
| * \remark Defaults: |
| * \snippet src/lib_json/json_reader.cpp CharReaderBuilderStrictMode |
| */ |
| static void strictMode(Json::Value* settings); |
| }; |
| |
| /** Consume entire stream and use its begin/end. |
| * Someday we might have a real StreamReader, but for now this |
| * is convenient. |
| */ |
| bool JSON_API parseFromStream(CharReader::Factory const&, IStream&, Value* root, |
| String* errs); |
| |
| /** \brief Read from 'sin' into 'root'. |
| * |
| * Always keep comments from the input JSON. |
| * |
| * This can be used to read a file into a particular sub-object. |
| * For example: |
| * \code |
| * Json::Value root; |
| * cin >> root["dir"]["file"]; |
| * cout << root; |
| * \endcode |
| * Result: |
| * \verbatim |
| * { |
| * "dir": { |
| * "file": { |
| * // The input stream JSON would be nested here. |
| * } |
| * } |
| * } |
| * \endverbatim |
| * \throw std::exception on parse error. |
| * \see Json::operator<<() |
| */ |
| JSON_API IStream& operator>>(IStream&, Value&); |
| |
| } // namespace Json |
| |
| #pragma pack(pop) |
| |
| #if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
| #pragma warning(pop) |
| #endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING) |
| |
| #endif // JSON_READER_H_INCLUDED |