jem::util::DictionaryEnumerator Class Reference

Iterates over the key/value pairs in a dictionary. More...

#include <jem/util/DictionaryEnumerator.h>

Inheritance diagram for jem::util::DictionaryEnumerator:

Public Types
typedef Enumerator	Super
typedef DictionaryEnumerator	Self

Public Member Functions
virtual Class *	getClass () const
	Returns the Class instance representing the runtime class of this object. More...
virtual Ref< Object >	get () const
	Returns the current key/value pair as an object. More...
virtual String	getKey () const =0
	Returns the key in the current key/value pair. More...
virtual Ref< Object >	getValue () const =0
	Returns the value in the current key/value pair. More...
Public Member Functions inherited from jem::util::Enumerator
virtual bool	atEnd () const =0
	Checks whether this enumerator points to an end object. More...
virtual void	toNext ()=0
	Advances this enumerator to the next object. More...
Public Member Functions inherited from jem::Object
virtual String	toString () const
	Returns a short textual description of this object. More...
virtual long	hashValue () const
	Returns a hash value for this object. More...
virtual bool	equals (const Ref< Object > &obj) const
	Tests whether two objects are equal. More...
Ref< Object >	clone () const
	Returns a copy of this object. More...

Static Public Member Functions
static Class *	makeClass ()
static Class *	getType ()
Static Public Member Functions inherited from jem::util::Enumerator
static Class *	makeClass ()
static Class *	getType ()
Static Public Member Functions inherited from jem::Object
static Class *	getType ()
	Returns the Class instance representing the Object class. More...

Protected Member Functions
virtual	~DictionaryEnumerator ()
Protected Member Functions inherited from jem::util::Enumerator
virtual	~Enumerator ()
Protected Member Functions inherited from jem::Collectable
	Collectable ()
	Creates an empty Collectable. More...
	~Collectable ()
	Frees resources. More...

Detailed Description

The abstract class DictionaryEnumerator can be used to iterate over all key/value pairs in a Dictionary. It extends the Enumerator class with the member functions getKey() and getValue() that return the key and value, respectively, in a key/value pair.

A DictionaryEnumerator points either to a key/value pair or to an end object that comes right after the last key/value pair. An end object is a conceptual object that can not be accessed. Only the function atEnd() may be called when a DictionaryEnumerator points to an end object.

See also

Dictionary

Member Typedef Documentation

typedef Enumerator jem::util::DictionaryEnumerator::Super

typedef DictionaryEnumerator jem::util::DictionaryEnumerator::Self

Constructor & Destructor Documentation

virtual jem::util::DictionaryEnumerator::~DictionaryEnumerator ( )

protectedvirtual

Member Function Documentation

static Class* jem::util::DictionaryEnumerator::makeClass ( )

static

static Class* jem::util::DictionaryEnumerator::getType ( )

static

virtual Class* jem::util::DictionaryEnumerator::getClass ( ) const

virtual

Returns a pointer to the Class instance representing the runtime class of this object. If T denotes the runtime class of this object, then this function is equivalent with T::getType(). The pointer is valid during the entire lifetime of the program.

Returns

A pointer to the Class instance representing the runtime class of this object.

Reimplemented from jem::util::Enumerator.

virtual Ref<Object> jem::util::DictionaryEnumerator::get ( ) const

virtual

Returns an object containing the key/value pair that this enumerator is currently pointing to. The dynamic type of the returned object is not specified. The only requirement is that the returned object can be passed to the function add() of the dictionary that created this enumerator.

The implementation of this function provided by the DictionaryEnumerator return the key/value pair as an ObjectPair. That is, it executes the following code:

return newInstance<ObjectPair> (
  toObject ( getKey() ),
  getValue ()
);

This function may not be called when this enumerator points to the end object.

Precondition

atEnd() == false

Returns

An object containing the current key/value pair.

Implements jem::util::Enumerator.

virtual String jem::util::DictionaryEnumerator::getKey ( ) const

pure virtual

Returns the key in the current key/value pair. This function may not be called when this enumerator points to the end object.

Precondition

atEnd() == false

Returns

The key in the current key/value pair.

virtual Ref<Object> jem::util::DictionaryEnumerator::getValue ( ) const

pure virtual

Returns a reference to the value in the current key/value pair. This function may not be called when this enumerator points to the end object.

Precondition

atEnd() == fale

Returns

A reference to the value in the current key/value pair.