#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 ¤t,
Location end,
unsigned int &unicode );
bool decodeUnicodeEscapeSequence( Token &token,
Location ¤t,
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 ¤tValue();
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
