GenericPointer< ValueType, Allocator > Class Template Reference

Represents a JSON Pointer. Use Pointer for UTF8 encoding and default allocator. More...

#include <pointer.h>

Classes
struct	Token
	A token is the basic units of internal representation. More...

Public Types
typedef ValueType::EncodingType	EncodingType
	Encoding type from Value.
typedef ValueType::Ch	Ch
	Character type from Value.

Public Member Functions
Constructors and destructor.
	GenericPointer (Allocator *allocator=0)
	Default constructor.
	GenericPointer (const Ch *source, Allocator *allocator=0)
	Constructor that parses a string or URI fragment representation. More...
	GenericPointer (const Ch *source, size_t length, Allocator *allocator=0)
	Constructor that parses a string or URI fragment representation, with length of the source string. More...
	GenericPointer (const Token *tokens, size_t tokenCount)
	Constructor with user-supplied tokens. More...
	GenericPointer (const GenericPointer &rhs, Allocator *allocator=0)
	Copy constructor.
	~GenericPointer ()
	Destructor.
GenericPointer &	operator= (const GenericPointer &rhs)
	Assignment operator.

Append token
Allocator *	allocator
Allocator stackAllocator stackAllocator &	document
Allocator stackAllocator stackAllocator T defaultValue	const
GenericPointer	Append (const Token &token, Allocator *allocator=0) const
	Append a token and return a new Pointer. More...
GenericPointer	Append (const Ch *name, SizeType length, Allocator *allocator=0) const
	Append a name token with length, and return a new Pointer. More...
template<typename T >
	RAPIDJSON_DISABLEIF_RETURN ((internal::NotExpr< internal::IsSame< typename internal::RemoveConst< T >::Type, Ch > >),(GenericPointer)) Append(T *name
	Append a name token without length, and return a new Pointer. More...
Allocator stackAllocator	RAPIDJSON_DISABLEIF_RETURN ((internal::OrExpr< internal::IsPointer< T >, internal::IsGenericValue< T > >),(ValueType &)) GetWithDefault(GenericDocument< EncodingType

Set a value
T	value
T ValueType::AllocatorType &allocator	const
stackAllocator &	document
stackAllocator T value	const
ValueType &	Set (ValueType &root, ValueType &value, typename ValueType::AllocatorType &allocator) const
	Set a value in a subtree, with move semantics. More...
ValueType &	Set (ValueType &root, const ValueType &value, typename ValueType::AllocatorType &allocator) const
	Set a value in a subtree, with copy semantics.
ValueType &	Set (ValueType &root, const Ch *value, typename ValueType::AllocatorType &allocator) const
	Set a null-terminated string in a subtree.
template<typename T >
	RAPIDJSON_DISABLEIF_RETURN ((internal::OrExpr< internal::IsPointer< T >, internal::IsGenericValue< T > >),(ValueType &)) Set(ValueType &root
	Set a primitive value in a subtree. More...
template<typename stackAllocator >
ValueType &	Set (GenericDocument< EncodingType, typename ValueType::AllocatorType, stackAllocator > &document, ValueType &value) const
	Set a value in a document, with move semantics.
template<typename stackAllocator >
ValueType &	Set (GenericDocument< EncodingType, typename ValueType::AllocatorType, stackAllocator > &document, const ValueType &value) const
	Set a value in a document, with copy semantics.
template<typename stackAllocator >
ValueType &	Set (GenericDocument< EncodingType, typename ValueType::AllocatorType, stackAllocator > &document, const Ch *value) const
	Set a null-terminated string in a document.
template<typename T , typename stackAllocator >
	RAPIDJSON_DISABLEIF_RETURN ((internal::OrExpr< internal::IsPointer< T >, internal::IsGenericValue< T > >),(ValueType &)) Set(GenericDocument< EncodingType
	Set a primitive value in a document. More...

Swap a value
ValueType &	Swap (ValueType &root, ValueType &value, typename ValueType::AllocatorType &allocator) const
	Swap a value with a value in a subtree. More...
template<typename stackAllocator >
ValueType &	Swap (GenericDocument< EncodingType, typename ValueType::AllocatorType, stackAllocator > &document, ValueType &value) const
	Swap a value with a value in a document.
bool	Erase (ValueType &root) const
	Erase a value in a subtree. More...

Detailed Description

template<typename ValueType, typename Allocator = CrtAllocator>
class GenericPointer< ValueType, Allocator >

Represents a JSON Pointer. Use Pointer for UTF8 encoding and default allocator.

This class implements RFC 6901 "JavaScript Object Notation (JSON) Pointer" (https://tools.ietf.org/html/rfc6901).

A JSON pointer is for identifying a specific value in a JSON document (GenericDocument). It can simplify coding of DOM tree manipulation, because it can access multiple-level depth of DOM tree with single API call.

After it parses a string representation (e.g. "/foo/0" or URI fragment representation (e.g. "#/foo/0") into its internal representation (tokens), it can be used to resolve a specific value in multiple documents, or sub-tree of documents.

Contrary to GenericValue, Pointer can be copy constructed and copy assigned. Apart from assignment, a Pointer cannot be modified after construction.

Although Pointer is very convenient, please aware that constructing Pointer involves parsing and dynamic memory allocation. A special constructor with user- supplied tokens eliminates these.

GenericPointer depends on GenericDocument and GenericValue.

Template Parameters

ValueType	The value type of the DOM tree. E.g. GenericValue<UTF8<> >
Allocator	The allocator type for allocating memory for internal representation.

Note

GenericPointer uses same encoding of ValueType. However, Allocator of GenericPointer is independent of Allocator of Value.

Constructor & Destructor Documentation

GenericPointer() [1/3]

template<typename ValueType , typename Allocator = CrtAllocator>

GenericPointer< ValueType, Allocator >::GenericPointer ( const Ch *  source, Allocator *  allocator = 0  )

inlineexplicit

Constructor that parses a string or URI fragment representation.

Parameters

source	A null-terminated, string or URI fragment representation of JSON pointer.
allocator	User supplied allocator for this pointer. If no allocator is provided, it creates a self-owned one.

GenericPointer() [2/3]

template<typename ValueType , typename Allocator = CrtAllocator>

GenericPointer< ValueType, Allocator >::GenericPointer ( const Ch *  source, size_t  length, Allocator *  allocator = 0  )

inline

Constructor that parses a string or URI fragment representation, with length of the source string.

Parameters

source	A string or URI fragment representation of JSON pointer.
length	Length of source.
allocator	User supplied allocator for this pointer. If no allocator is provided, it creates a self-owned one.

Note

Slightly faster than the overload without length.

GenericPointer() [3/3]

template<typename ValueType , typename Allocator = CrtAllocator>

GenericPointer< ValueType, Allocator >::GenericPointer ( const Token *  tokens, size_t  tokenCount  )

inline

Constructor with user-supplied tokens.

This constructor let user supplies const array of tokens. This prevents the parsing process and eliminates allocation. This is preferred for memory constrained environments.

Parameters

tokens	An constant array of tokens representing the JSON pointer.
tokenCount	Number of tokens.

Example

#define NAME(s) { s, sizeof(s) / sizeof(s[0]) - 1, kPointerInvalidIndex }
#define INDEX(i) { #i, sizeof(#i) - 1, i }
 
static const Pointer::Token kTokens[] = { NAME("foo"), INDEX(123) };
static const Pointer p(kTokens, sizeof(kTokens) / sizeof(kTokens[0]));
// Equivalent to static const Pointer p("/foo/123");
 
#undef NAME
#undef INDEX

Member Function Documentation

Append() [1/2]

template<typename ValueType , typename Allocator = CrtAllocator>

GenericPointer GenericPointer< ValueType, Allocator >::Append ( const Ch *  name, SizeType  length, Allocator *  allocator = 0  ) const

inline

Append a name token with length, and return a new Pointer.

Parameters

name	Name to be appended.
length	Length of name.
allocator	Allocator for the newly return Pointer.

Returns

A new Pointer with appended token.

Append() [2/2]

template<typename ValueType , typename Allocator = CrtAllocator>

GenericPointer GenericPointer< ValueType, Allocator >::Append ( const Token &  token, Allocator *  allocator = 0  ) const

inline

Append a token and return a new Pointer.

Parameters

token	Token to be appended.
allocator	Allocator for the newly return Pointer.

Returns

A new Pointer with appended token.

Erase()

template<typename ValueType , typename Allocator = CrtAllocator>

bool GenericPointer< ValueType, Allocator >::Erase ( ValueType &  root ) const

inline

Erase a value in a subtree.

Parameters

root	Root value of a DOM sub-tree to be resolved. It can be any value other than document root.

Returns

Whether the resolved value is found and erased.

Note

Erasing with an empty pointer Pointer(""), i.e. the root, always fail and return false.

RAPIDJSON_DISABLEIF_RETURN() [1/3]

template<typename ValueType , typename Allocator = CrtAllocator>

template<typename T >

GenericPointer< ValueType, Allocator >::RAPIDJSON_DISABLEIF_RETURN	(	(internal::NotExpr< internal::IsSame< typename internal::RemoveConst< T >::Type, Ch > >)	,
		(GenericPointer< ValueType, Allocator >)
	)

Append a name token without length, and return a new Pointer.

Parameters

name	Name (const Ch*) to be appended.
allocator	Allocator for the newly return Pointer.

Returns

A new Pointer with appended token.

RAPIDJSON_DISABLEIF_RETURN() [2/3]

template<typename ValueType , typename Allocator = CrtAllocator>

template<typename T , typename stackAllocator >

GenericPointer< ValueType, Allocator >::RAPIDJSON_DISABLEIF_RETURN	(	(internal::OrExpr< internal::IsPointer< T >, internal::IsGenericValue< T > >)	,
		(ValueType &)
	)

Set a primitive value in a document.

Template Parameters

T	Either Type, int, unsigned, int64_t, uint64_t, bool

RAPIDJSON_DISABLEIF_RETURN() [3/3]

template<typename ValueType , typename Allocator = CrtAllocator>

template<typename T >

GenericPointer< ValueType, Allocator >::RAPIDJSON_DISABLEIF_RETURN	(	(internal::OrExpr< internal::IsPointer< T >, internal::IsGenericValue< T > >)	,
		(ValueType &)
	)		&

Set a primitive value in a subtree.

Template Parameters

T	Either Type, int, unsigned, int64_t, uint64_t, bool

Set()

template<typename ValueType , typename Allocator = CrtAllocator>

ValueType& GenericPointer< ValueType, Allocator >::Set ( ValueType &  root, ValueType &  value, typename ValueType::AllocatorType &  allocator  ) const

inline

Set a value in a subtree, with move semantics.

It creates all parents if they are not exist or types are different to the tokens. So this function always succeeds but potentially remove existing values.

Parameters

root	Root value of a DOM sub-tree to be resolved. It can be any value other than document root.
value	Value to be set.
allocator	Allocator for creating the values if the specified value or its parents are not exist.

See also

Create()

Swap()

template<typename ValueType , typename Allocator = CrtAllocator>

ValueType& GenericPointer< ValueType, Allocator >::Swap ( ValueType &  root, ValueType &  value, typename ValueType::AllocatorType &  allocator  ) const

inline

Swap a value with a value in a subtree.

It creates all parents if they are not exist or types are different to the tokens. So this function always succeeds but potentially remove existing values.

Parameters

root	Root value of a DOM sub-tree to be resolved. It can be any value other than document root.
value	Value to be swapped.
allocator	Allocator for creating the values if the specified value or its parents are not exist.

See also

Create()

Member Data Documentation

const [1/3]

template<typename ValueType , typename Allocator = CrtAllocator>

Allocator stackAllocator stackAllocator T defaultValue GenericPointer< ValueType, Allocator >::const

Initial value:

{
        return GetWithDefault(document, defaultValue, document.GetAllocator())

const [2/3]

template<typename ValueType , typename Allocator = CrtAllocator>

T ValueType::AllocatorType& allocator GenericPointer< ValueType, Allocator >::const

Initial value:

{
        return Create(root, allocator) = ValueType(value).Move()

const [3/3]

template<typename ValueType , typename Allocator = CrtAllocator>

stackAllocator T value GenericPointer< ValueType, Allocator >::const

Initial value:

{
            return Create(document) = value

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The documentation for this class was generated from the following files:

• fwd.h
• pointer.h