// 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
#ifndef CPPTL_JSON_READER_H_INCLUDED
#define CPPTL_JSON_READER_H_INCLUDED
#if !defined(JSON_IS_AMALGAMATION)
#include "features.h"
#include "value.h"
#endif // if !defined(JSON_IS_AMALGAMATION)
#include <deque>
#include <iosfwd>
#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)
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 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 {
size_t offset_start;
size_t offset_limit;
std::string message;
};
/** \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 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 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.
* \deprecated Use getFormattedErrorMessages() instead (typo fix).
*/
JSONCPP_DEPRECATED("Use getFormattedErrorMessages instead")
std::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.
*/
std::string getFormattedErrorMessages() const;
/** \brief Returns a vector of structured erros encounted 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 std::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 std::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_;
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 decodeNumber(Token& token, Value& decoded);
bool decodeString(Token& token);
bool decodeString(Token& token, std::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 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<<()
*/
JSON_API std::istream& operator>>(std::istream&, Value&);
} // namespace Json
#if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
#pragma warning(pop)
#endif // if defined(JSONCPP_DISABLE_DLL_INTERFACE_WARNING)
#endif // CPPTL_JSON_READER_H_INCLUDED