value.h.svn-base

这是基于jsoncpp项目写扩展功能

#ifndef CPPTL_JSON_H_INCLUDED
# define CPPTL_JSON_H_INCLUDED

# include "forwards.h"
# include <string>
# include <vector>

# ifndef JSON_USE_CPPTL_SMALLMAP
#  include <map>
# else
#  include <cpptl/smallmap.h>
# endif
# ifdef JSON_USE_CPPTL
#  include <cpptl/forwards.h>
# endif

/** \brief JSON (JavaScript Object Notation).
 */
namespace Json {

   /** \brief Type of the value held by a Value object.
    */
   enum ValueType
   {
      nullValue = 0, ///< 'null' value
      intValue,      ///< signed integer value
      uintValue,     ///< unsigned integer value
      realValue,     ///< double value
      stringValue,   ///< UTF-8 string value
      booleanValue,  ///< bool value
      arrayValue,    ///< array value (ordered list)
      objectValue    ///< object value (collection of name/value pairs).
   };

   enum CommentPlacement
   {
      commentBefore = 0,        ///< a comment placed on the line before a value
      commentAfterOnSameLine,   ///< a comment just after a value on the same line
      commentAfter,             ///< a comment on the line after a value (only make sense for root value)
      numberOfCommentPlacement
   };

//# ifdef JSON_USE_CPPTL
//   typedef CppTL::AnyEnumerator<const char *> EnumMemberNames;
//   typedef CppTL::AnyEnumerator<const Value &> EnumValues;
//# endif

   /** \brief Lightweight wrapper to tag static string.
    *
    * Value constructor and objectValue member assignement takes advantage of the
    * StaticString and avoid the cost of string duplication when storing the
    * string or the member name.
    *
    * Example of usage:
    * \code
    * Json::Value aValue( StaticString("some text") );
    * Json::Value object;
    * static const StaticString code("code");
    * object[code] = 1234;
    * \endcode
    */
   class JSON_API StaticString
   {
   public:
      explicit StaticString( const char *czstring )
         : str_( czstring )
      {
      }

      operator const char *() const
      {
         return str_;
      }

      const char *c_str() const
      {
         return str_;
      }

   private:
      const char *str_;
   };

   /** \brief Represents a <a HREF="http://www.json.org">JSON</a> value.
    *
    * This class is a discriminated union wrapper that can represents a:
    * - signed integer [range: Value::minInt - Value::maxInt]
    * - unsigned integer (range: 0 - Value::maxUInt)
    * - double
    * - UTF-8 string
    * - boolean
    * - 'null'
    * - an ordered list of Value
    * - collection of name/value pairs (javascript object)
    *
    * The type of the held value is represented by a #ValueType and 
    * can be obtained using type().
    *
    * values of an #objectValue or #arrayValue can be accessed using operator[]() methods. 
    * Non const methods will automatically create the a #nullValue element 
    * if it does not exist. 
    * The sequence of an #arrayValue will be automatically resize and initialized 
    * with #nullValue. resize() can be used to enlarge or truncate an #arrayValue.
    *
    * The get() methods can be used to obtanis default value in the case the required element
    * does not exist.
    *
    * It is possible to iterate over the list of a #objectValue values using 
    * the getMemberNames() method.
    */
   class JSON_API Value 
   {
      friend class ValueIteratorBase;
# ifdef JSON_VALUE_USE_INTERNAL_MAP
      friend class ValueInternalLink;
      friend class ValueInternalMap;
# endif
   public:
      typedef std::vector<std::string> Members;
      typedef int Int;
      typedef unsigned int UInt;
      typedef ValueIterator iterator;
      typedef ValueConstIterator const_iterator;
      typedef UInt ArrayIndex;

      static const Value null;
      static const Int minInt;
      static const Int maxInt;
      static const UInt maxUInt;

   private:
#ifndef JSONCPP_DOC_EXCLUDE_IMPLEMENTATION
# ifndef JSON_VALUE_USE_INTERNAL_MAP
      class CZString 
      {
      public:
         enum DuplicationPolicy 
         {
            noDuplication = 0,
            duplicate,
            duplicateOnCopy
         };
         CZString( int index );
         CZString( const char *cstr, DuplicationPolicy allocate );
         CZString( const CZString &other );
         ~CZString();
         CZString &operator =( const CZString &other );
         bool operator<( const CZString &other ) const;
         bool operator==( const CZString &other ) const;
         int index() const;
         const char *c_str() const;
         bool isStaticString() const;
      private:
         void swap( CZString &other );
         const char *cstr_;
         int index_;
      };

   public:
#  ifndef JSON_USE_CPPTL_SMALLMAP
      typedef std::map<CZString, Value> ObjectValues;
#  else
      typedef CppTL::SmallMap<CZString, Value> ObjectValues;
#  endif // ifndef JSON_USE_CPPTL_SMALLMAP
# endif // ifndef JSON_VALUE_USE_INTERNAL_MAP
#endif // ifndef JSONCPP_DOC_EXCLUDE_IMPLEMENTATION

   public:
      /** \brief Create a default Value of the given type.

        This is a very useful constructor.
        To create an empty array, pass arrayValue.
        To create an empty object, pass objectValue.
        Another Value can then be set to this one by assignment.
	This is useful since clear() and resize() will not alter types.

        Examples:
	\code
	Json::Value null_value; // null
	Json::Value arr_value(Json::arrayValue); // []
	Json::Value obj_value(Json::objectValue); // {}
	\endcode
      */
      Value( ValueType type = nullValue );
      Value( Int value );
      Value( UInt value );
      Value( double value );
      Value( const char *value );
      /** \brief Constructs a value from a static string.

       * Like other value string constructor but do not duplicate the string for
       * internal storage. The given string must remain alive after the call to this
       * constructor.
       * Example of usage:
       * \code
       * Json::Value aValue( StaticString("some text") );
       * \endcode
       */
      Value( const StaticString &value );
      Value( const std::string &value );
# ifdef JSON_USE_CPPTL
      Value( const CppTL::ConstString &value );
# endif
      Value( bool value );
      Value( const Value &other );
      ~Value();

      Value &operator=( const Value &other );
      /// Swap values.
      /// \note Currently, comments are intentionally not swapped, for
      /// both logic and efficiency.
      void swap( Value &other );

      ValueType type() const;

      bool operator <( const Value &other ) const;
      bool operator <=( const Value &other ) const;
      bool operator >=( const Value &other ) const;
      bool operator >( const Value &other ) const;

      bool operator ==( const Value &other ) const;
      bool operator !=( const Value &other ) const;

      int compare( const Value &other );

      const char *asCString() const;
      std::string asString() const;
# ifdef JSON_USE_CPPTL
      CppTL::ConstString asConstString() const;
# endif
      Int asInt() const;
      UInt asUInt() const;
      double asDouble() const;
      bool asBool() const;

      bool isNull() const;
      bool isBool() const;
      bool isInt() const;
      bool isUInt() const;
      bool isIntegral() const;
      bool isDouble() const;
      bool isNumeric() const;
      bool isString() const;
      bool isArray() const;
      bool isObject() const;

      bool isConvertibleTo( ValueType other ) const;

      /// Number of values in array or object
      UInt size() const;

      /// \brief Return true if empty array, empty object, or null;
      /// otherwise, false.
      bool empty() const;

      /// Return isNull()
      bool operator!() const;

      /// Remove all object members and array elements.
      /// \pre type() is arrayValue, objectValue, or nullValue
      /// \post type() is unchanged
      void clear();

      /// Resize the array to size elements. 
      /// New elements are initialized to null.
      /// May only be called on nullValue or arrayValue.
      /// \pre type() is arrayValue or nullValue
      /// \post type() is arrayValue
      void resize( UInt size );

      /// Access an array element (zero based index ).
      /// If the array contains less than index element, then null value are inserted
      /// in the array so that its size is index+1.
      Value &operator[]( UInt index );
      /// Access an array element (zero based index )
      const Value &operator[]( UInt index ) const;
      /// If the array contains at least index+1 elements, returns the element value, 
      /// otherwise returns defaultValue.
      Value get( UInt index, 
                 const Value &defaultValue ) const;
      /// Return true if index < size().
      bool isValidIndex( UInt index ) const;
      /// \brief Append value to array at the end.
      ///
      /// Equivalent to jsonvalue[jsonvalue.size()] = value;
      Value &append( const Value &value );

      /// Access an object value by name, create a null member if it does not exist.
      Value &operator[]( const char *key );
      /// Access an object value by name, returns null if there is no member with that name.
      const Value &operator[]( const char *key ) const;
      /// Access an object value by name, create a null member if it does not exist.
      Value &operator[]( const std::string &key );
      /// Access an object value by name, returns null if there is no member with that name.
      const Value &operator[]( const std::string &key ) const;
      /** \brief Access an object value by name, create a null member if it does not exist.

       * If the object as no entry for that name, then the member name used to store
       * the new entry is not duplicated.
       * Example of use:
       * \code
       * Json::Value object;
       * static const StaticString code("code");
       * object[code] = 1234;
       * \endcode
       */
      Value &operator[]( const StaticString &key );
# ifdef JSON_USE_CPPTL
      /// Access an object value by name, create a null member if it does not exist.
      Value &operator[]( const CppTL::ConstString &key );
      /// Access an object value by name, returns null if there is no member with that name.
      const Value &operator[]( const CppTL::ConstString &key ) const;
# endif
      /// Return the member named key if it exist, defaultValue otherwise.
      Value get( const char *key, 
                 const Value &defaultValue ) const;
      /// Return the member named key if it exist, defaultValue otherwise.
      Value get( const std::string &key,
                 const Value &defaultValue ) const;
# ifdef JSON_USE_CPPTL
      /// Return the member named key if it exist, defaultValue otherwise.
      Value get( const CppTL::ConstString &key,
                 const Value &defaultValue ) const;
# endif
      /// \brief Remove and return the named member.  
      ///
      /// Do nothing if it did not exist.
      /// \return the removed Value, or null.
      /// \pre type() is objectValue or nullValue
      /// \post type() is unchanged
      Value removeMember( const char* key );
      /// Same as removeMember(const char*)
      Value removeMember( const std::string &key );

      /// Return true if the object has a member named key.
      bool isMember( const char *key ) const;
      /// Return true if the object has a member named key.
      bool isMember( const std::string &key ) const;
# ifdef JSON_USE_CPPTL
      /// Return true if the object has a member named key.
      bool isMember( const CppTL::ConstString &key ) const;
# endif

      /// \brief Return a list of the member names.
      ///
      /// If null, return an empty list.
      /// \pre type() is objectValue or nullValue
      /// \post if type() was nullValue, it remains nullValue
      Members getMemberNames() const;