reader.h

/*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 * 
 *  JSON Library, originally from http://jsoncpp.sourceforge.net/
 *
 *  Copyright (C) 2011 Stewart Smith
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *      * Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *      * 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.
 *
 *      * The names of its contributors may not be used to endorse or
 *  promote products derived from this software without specific prior
 *  written permission.
 *
 *  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
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 *
 */

#pragma once

#include "features.h"
#include "value.h"
#include <deque>
#include <stack>
#include <string>
#include <iosfwd>

namespace Json {

   class JSON_API Reader
   {
   public:
      typedef char Char;
      typedef const Char *Location;

      Reader();

      Reader( const Features &features );

      bool parse( const std::string &document, 
                  Value &root,
                  bool collectComments = true );

      bool parse( const char *beginDoc, const char *endDoc, 
                  Value &root,
                  bool collectComments = true );

      bool parse( std::istream &is,
                  Value &root,
                  bool collectComments = true );

      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_;
   };

   std::istream& operator>>( std::istream&, Value& );

} // namespace Json