text: // Copyright 2007-2010 Baptiste Lepilleur
  // 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
  
  /*
  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.
  */
  
  
  #ifndef CPPTL_JSON_READER_H_INCLUDED
  # define CPPTL_JSON_READER_H_INCLUDED
  
  # include "features.h"
  # include "value.h"
  # include <deque>
  # include <stack>
  # include <string>
  # include <iostream>
  
  namespace Json {
  
     /** \brief Unserialize a <a HREF="http://www.json.org">JSON</a> document into a Value.
      *
      */
     class JSON_API Reader
     {
     public:
        typedef char Char;
        typedef const Char *Location;
  
        /** \brief Constructs a Reader allowing all features
         * for parsing.
         */
        Reader();
  
        /** \brief Constructs a Reader allowing the specified feature set
         * for parsing.
         */
        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 root [out] 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 document UTF-8 encoded string containing the document to read.
         * \param root [out] 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( std::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.
         */
        std::string getFormatedErrorMessages() 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_;
           std::string message_;
           Location extra_;
        };
  
        typedef std::deque<ErrorInfo> Errors;
  
        bool expectToken( TokenType type, Token &token, const char *message );
        bool readToken( Token &token );
        void skipSpaces();
        bool match( Location 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 decodeString( Token &token );
        bool decodeString( Token &token, std::string &decoded );
        bool decodeDouble( Token &token );
        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 std::string &message,
                       Token &token,
                       Location extra = 0 );
        bool recoverFromError( TokenType skipUntilToken );
        bool addErrorAndRecover( const std::string &message,
                                 Token &token,
                                 TokenType skipUntilToken );
        void skipUntilSpace();
        Value &currentValue();
        Char getNextChar();
        void getLocationLineAndColumn( Location location,
                                       int &line,
                                       int &column ) const;
        std::string getLocationLineAndColumn( Location location ) const;
        void addComment( Location begin,
                         Location end,
                         CommentPlacement placement );
        void skipCommentTokens( Token &token );
  
        typedef std::stack<Value *> Nodes;
        Nodes nodes_;
        Errors errors_;
        std::string document_;
        Location begin_;
        Location end_;
        Location current_;
        Location lastValueEnd_;
        Value *lastValue_;
        std::string commentsBefore_;
        Features features_;
        bool collectComments_;
     };
  
     /** \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<<()
     */
     std::istream& operator>>( std::istream&, Value& );
  
  } // namespace Json
  
  #endif // CPPTL_JSON_READER_H_INCLUDED
  