summaryrefslogtreecommitdiffstats
path: root/lib/jsoncpp/include/json/reader.h
blob: ee1d6a2444a8e92d20c98a08643b538923c0d06e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
#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