nom::Value Class Reference

Generic interface for opaque data containers. More...

#include <Value.hpp>

Classes
union	ValueHolder
	Container for the data types able to be held. More...

Public Types
enum	ValueType {   Null = 0 , SignedInteger , UnsignedInteger , RealNumber ,   String , Boolean , ArrayValues , ObjectValues }
	Supported data types able to be held inside the object. More...
typedef Value	SelfType
typedef Value *	RawPtr
typedef Value &	Reference
typedef ValueConstIterator	ConstIterator
typedef ValueIterator	Iterator
typedef std::vector< std::string >	Members

Public Member Functions
	Value ()
	Default constructor; constructs an object with NullValue data type.
	Value (int val)
	Construct an object using a signed integer value.
	Value (uint val)
	Construct an object using an unsigned (non-negative) integer value.
	Value (real64 val)
	Construct an object using a double-precision floating point "real" number value.
	Value (const char *str)
	Construct an object from a C-style string value.
	Value (const std::string &str)
	Construct an object from a C++ string value (std::string).
	Value (bool val)
	Construct an object from a boolean value.
	Value (const Object &obj)
	Construct an object with either array or object node values.
	Value (ValueType type)
	Construct a Value container node of a specified type.
	Value (const Value &rhs)
	Copy constructor.
Value::SelfType &	operator= (const SelfType &rhs)
	Copy assignment operator.
void	swap (Value &rhs)
	Exchange the contents of the container; copy & swap idiom.
bool	operator< (const Value &rhs) const
	Lesser than comparison operator.
bool	operator<= (const Value &rhs) const
	Lesser than or equal to comparison operator.
bool	operator>= (const Value &rhs) const
	Greater than or equal to comparison operator.
bool	operator> (const Value &rhs) const
	Greater than or equal to comparison operator.
bool	operator== (const Value &rhs) const
	Equality comparison operator.
bool	operator!= (const Value &rhs) const
	Not equal comparison operator.
bool	operator! () const
	Returns Value::null.
int	compare (const Value &rhs) const
	Internal helper method for comparing array & object node containers.
Value::RawPtr	get ()
	Obtain a pointer to the object.
Value::Reference	ref ()
	Obtain a reference to the object.
enum Value::ValueType	type () const
	Obtain the enumeration type of the object.
const std::string	type_name () const
	Obtain the enumeration type of the object as a std::string.
bool	null_type () const
	Query if the value type type stored in the object is NULL.
bool	int_type () const
	Query if the value type type stored in the object is a signed integer.
bool	uint_type () const
	Query if the value type type stored in the object is an unsigned integer (non-negative.
bool	double_type () const
	Query if the value type type stored in the object is a double- precision floating point real number.
bool	float_type () const
	Query if the value type type stored in the object is a double- precision floating point real number.
bool	string_type () const
	Query if the value type type stored in the object is a string value.
bool	bool_type () const
	Query if the value type type stored in the object is a boolean value.
bool	array_type () const
	Query if the value type type stored in the object are array values.
bool	object_type () const
	Query if the value type type stored in the object are object values.
const std::string	stringify () const
int	get_int () const
	Obtain the signed integer value stored within the container.
uint	get_uint () const
	Obtain the unsigned (non-negative) integer value stored within the container.
real64	get_double () const
	Obtain the double-precision floating point "real" number value stored within the container.
real32	get_float () const
	Obtain the double-precision floating point "real" number value stored within the container.
const char *	get_cstring () const
	Obtain the C style string value stored within the container.
std::string	get_string () const
	Obtain the string value stored within the container.
bool	get_bool () const
	Obtain the boolean value stored within the container.
bool	array_valid () const
bool	object_valid () const
const Object	array () const
	Obtain the array values of the object.
const Object	object () const
	Obtain the object tree of the object.
nom::size_type	size () const
	Obtain the size of the object's contained values.
bool	empty () const
	Obtain boolean response in regards to container's empty status.
void	clear ()
	Remove all array and object members.
Value &	operator[] (ArrayIndex index)
	Obtain a stored element by index number.
Value &	operator[] (int index)
const Value &	operator[] (ArrayIndex index) const
	Obtain a stored element by index number.
const Value &	operator[] (int index) const
Value &	operator[] (const char *key)
	Access an object node's container.
Value &	operator[] (const std::string &key)
const Value &	operator[] (const char *key) const
const Value &	operator[] (const std::string &key) const
Value &	push_back (const Value &val)
	Insert array elements.
const Value &	find (const std::string &key) const
	Search the object for an existing member.
Value	erase (const std::string &key)
	Remove the named member.
Members	member_names () const
	Remove an array object.
Value::ConstIterator	begin () const
Value::ConstIterator	end () const
Value::Iterator	begin ()
	Iterator access to the beginning of the object's tree.
Value::Iterator	end ()
	Iterator access to the end of the object's tree.
const std::string	dump (const Value &object, int depth=0) const
	Dump the object's complete value tree.

Static Public Attributes
static const Value &	null
	Declared value of Null for this object.

Private Member Functions
const std::string	dump_key (const Value &key) const
	Internal helper method for nom::Value::dump.
const std::string	dump_value (const Value &val) const
	Internal helper method for nom::Value::dump.
const std::string	print_key (const std::string &type, uint size) const
	Internal helper method for nom::Value::dump_key.
const std::string	print_value (const std::string &val) const
	Internal helper method for nom::Value::dump_value.

Private Attributes
enum ValueType	type_
	The type of stored value in this instance.
ValueHolder	value_
	The stored value in this instance.

Detailed Description

Generic interface for opaque data containers.

Inspired by Apple's PropertyList API & made possible by JSONCPP, ...

[STUB]

References (class design & inspiration):

JSON RFC json_spirit jsoncpp cijson (of the Cinder engine) Boost::PropertyTree Apple's PropertyList (.plist)

Todo

Implement support for (un)-signed 64-bit integers

Todo

Implement support for comments (XML & JSON style)

Definition at line 42 of file Value.hpp.

Member Typedef Documentation

ConstIterator

typedef ValueConstIterator nom::Value::ConstIterator

Definition at line 50 of file Value.hpp.

Iterator

typedef ValueIterator nom::Value::Iterator

Definition at line 53 of file Value.hpp.

Members

typedef std::vector<std::string> nom::Value::Members

Definition at line 55 of file Value.hpp.

RawPtr

typedef Value* nom::Value::RawPtr

Definition at line 46 of file Value.hpp.

Reference

typedef Value& nom::Value::Reference

Definition at line 47 of file Value.hpp.

SelfType

typedef Value nom::Value::SelfType

Definition at line 45 of file Value.hpp.

Member Enumeration Documentation

ValueType

enum nom::Value::ValueType

Supported data types able to be held inside the object.

Remarks

ValueType::ObjectValue type is a singly-list of key / value pairs; this allows one to use this class to serialize and unserialize many common file formats, such as: JSON, XML, INI & plist.

Note

Borrowed over from the wonderful JsonCpp API.

Definition at line 66 of file Value.hpp.

Constructor & Destructor Documentation

Value() [1/7]

nom::Value::Value

(

int

val

)

Construct an object using a signed integer value.

Note

Type 1

Value() [2/7]

nom::Value::Value

(

uint

val

)

Construct an object using an unsigned (non-negative) integer value.

Remarks

It may be necessary to append the 'u' symbol after the number in order to have the compiler recognize the request and route to the correct constructor.

Note

Type 2

Value() [3/7]

nom::Value::Value

(

real64

val

)

Construct an object using a double-precision floating point "real" number value.

Note

Type 3

Value() [4/7]

nom::Value::Value

(

const char *

str

)

Construct an object from a C-style string value.

Remarks

A duplicate copy of the passed C string value is made upon construction.

Note

This constructor makes construction using string literals possible:

Note

Without defining this constructor, string literals were being overloaded by the boolean constructor.

Note

Type 4

Value() [5/7]

nom::Value::Value

(

const std::string &

str

)

Construct an object from a C++ string value (std::string).

Note

Type 4

Value() [6/7]

nom::Value::Value

(

bool

val

)

Construct an object from a boolean value.

Note

Type 5

Value() [7/7]

nom::Value::Value

(

const Object &

obj

)

Construct an object with either array or object node values.

Note

Type 6 or 7

Member Function Documentation

array()

const Object nom::Value::array

(

)

const

Obtain the array values of the object.

Returns

Return-by-value cloned copy of the nom::Array pointer held by this object.

array_type()

bool nom::Value::array_type

(

)

const

Query if the value type type stored in the object are array values.

Remarks

nom::Value object may be either an array OR object type at any given time.

begin()

Value::Iterator nom::Value::begin

(

)

Iterator access to the beginning of the object's tree.

Returns

nom::ValueIterator object pointing to the beginning of the array or object. On err, an invalid, empty nom::ValueIterator is returned.

Remarks

The nom::Value object must be initialized as a nom::ArrayValue or nom::ObjectValue type.

clear()

void nom::Value::clear

(

)

Remove all array and object members.

Remarks

The object's value type is unchanged.

Note

This method has no effect unless the object's container is one of two node types: array or object.

compare()

int nom::Value::compare

(

const Value &

rhs

)

const

Internal helper method for comparing array & object node containers.

Note

Borrowed from JsonCpp library – thanks!

dump()

const std::string nom::Value::dump	(	const Value &	object,
		int	depth = 0 ) const

Dump the object's complete value tree.

Remarks

This is a useful method for debugging.

Note

This method is used by the << overload function for nom::Value objects.

empty()

bool nom::Value::empty

(

)

const

Obtain boolean response in regards to container's empty status.

Remarks

The object's type is not modified.

Note

This method will fail with an assert if the container type is not either: null, array or object node type.

end()

Value::Iterator nom::Value::end

(

)

Iterator access to the end of the object's tree.

Returns

nom::ValueIterator object pointing to the beginning of the array or object. On err, an invalid, empty nom::ValueIterator is returned.

Remarks

The nom::Value object must be initialized as a nom::ArrayValue or nom::ObjectValue type.

erase()

Value nom::Value::erase

(

const std::string &

key

)

Remove the named member.

Returns

Removed member upon success, or Value::null upon failure.

Remarks

The object is unchanged if the referenced key does not exist.

Note

The object's type is not modified.

find()

const Value & nom::Value::find

(

const std::string &

key

)

const

Search the object for an existing member.

Returns

The found member key upon success, or Value::null upon failure.

Note

The object's type is not modified.

This method will fail with an assert if the container type is not either a null or object node type.

get()

Value::RawPtr nom::Value::get

(

)

Obtain a pointer to the object.

Returns

A raw pointer to the object. No transfer of ownership is made.

get_bool()

bool nom::Value::get_bool

(

)

const

Obtain the boolean value stored within the container.

Returns

On err, boolean false is returned.

get_cstring()

const char * nom::Value::get_cstring

(

)

const

Obtain the C style string value stored within the container.

Returns

On err, nullptr is returned.

Remarks

A copy of the stored C string is made, therefore no ownership transfers occur; you are responsible for freeing the returned C string.

get_double()

real64 nom::Value::get_double

(

)

const

Obtain the double-precision floating point "real" number value stored within the container.

Returns

On err, zero (0) is returned.

get_float()

real32 nom::Value::get_float

(

)

const

Obtain the double-precision floating point "real" number value stored within the container.

Returns

On err, zero (0) is returned.

Remarks

Conversion from the internally stored double variable to a float type is done.

get_int()

int nom::Value::get_int

(

)

const

Obtain the signed integer value stored within the container.

Returns

On err, zero (0) is returned.

get_string()

std::string nom::Value::get_string

(

)

const

Obtain the string value stored within the container.

Remarks

Conversion from the internally stored char* variable to a std::string is done.

Returns

On err, a null-terminated std::string – "\0" is returned.

get_uint()

uint nom::Value::get_uint

(

)

const

Obtain the unsigned (non-negative) integer value stored within the container.

Returns

On err, zero (0) is returned.

member_names()

Members nom::Value::member_names

(

)

const

Remove an array object.

Returns

The removed array object upon success, or Value::null on failure, such as when you specify an invalid position index.

Remarks

The object is unchanged if the referenced key does not exist.

Note

The object's type is not modified.

This method will fail with an assert if the container type is not either a null or object node type.

Todo

Verify working state of method.

Obtain the member names (keys) of each pair in this container.

Returns

A vector of strings upon success, or an empty vector upon failure.

Note

This method will fail with an assert if the container type is not either a null or object node type.

object()

const Object nom::Value::object

(

)

const

Obtain the object tree of the object.

Returns

Return-by-value cloned copy of the nom::Object pointer held by this object.

object_type()

bool nom::Value::object_type

(

)

const

Query if the value type type stored in the object are object values.

Remarks

nom::Value object may be either an array OR object type at any given time.

operator!()

bool nom::Value::operator!

(

)

const

Returns Value::null.

Note

Borrowed from JsonCpp library – thanks!

operator!=()

bool nom::Value::operator!=

(

const Value &

rhs

)

const

Not equal comparison operator.

Note

Borrowed from JsonCpp library – thanks!

operator<()

bool nom::Value::operator<

(

const Value &

rhs

)

const

Lesser than comparison operator.

Note

Borrowed from JsonCpp library – thanks!

Todo

Unit testing of the operator overload logic for lesser than equality.

operator<=()

bool nom::Value::operator<=

(

const Value &

rhs

)

const

Lesser than or equal to comparison operator.

Note

Borrowed from JsonCpp library – thanks!

operator==()

bool nom::Value::operator==

(

const Value &

rhs

)

const

Equality comparison operator.

Note

Borrowed from JsonCpp library – thanks!

Todo

Unit testing of the operator overload logic for equality.

operator>()

bool nom::Value::operator>

(

const Value &

rhs

)

const

Greater than or equal to comparison operator.

Note

Borrowed from JsonCpp library – thanks!

operator>=()

bool nom::Value::operator>=

(

const Value &

rhs

)

const

Greater than or equal to comparison operator.

Note

Borrowed from JsonCpp library – thanks!

operator[]() [1/5]

Value & nom::Value::operator[]

(

ArrayIndex

index

)

Obtain a stored element by index number.

Parameters

val	Unsigned integer of the element's index to return.

Remarks

It may be necessary to append the 'u' symbol after the number in order to have the compiler recognize the request and route to the correct constructor.

Note

In contrast to the standard STL method overloads for ::operator[](int), nom::Value should always perform bounds checking.

operator[]() [2/5]

const Value & nom::Value::operator[]

(

ArrayIndex

index

)

const

Obtain a stored element by index number.

Parameters

val	Unsigned integer of the element's index to return.

Remarks

It may be necessary to append the 'u' symbol after the number in order to have the compiler recognize your request properly. (Signed integers are the "default" literal integer type, at least on my development system).

Todo

Fix index methods – VString, ValueBaseIterator & co; this method call relies on our half-finished implementation stemming from the VString class.

Note

In contrast to the standard STL method overloads for ::operator[](int), nom::Value should always perform bounds checking.

operator[]() [3/5]

Value & nom::Value::operator[]

(

const char *

key

)

Access an object node's container.

Remarks

This method call requires an object node container type, and will immediately initialize one, if one is not found to be valid at the time of the call – existing value(s) in the object will be lost.

Note

In contrast to the standard STL method overloads for ::operator[](int), nom::Value should always perform bounds checking.

operator[]() [4/5]

Value & nom::Value::operator[]

(

int

index

)

Note

In contrast to the standard STL method overloads for ::operator[](int), nom::Value should always perform bounds checking.

operator[]() [5/5]

const Value & nom::Value::operator[]

(

int

index

)

const

Note

In contrast to the standard STL method overloads for ::operator[](int), nom::Value should always perform bounds checking.

ref()

Value::Reference nom::Value::ref

(

)

Obtain a reference to the object.

Returns

A reference to the object.

size()

nom::size_type nom::Value::size

(

)

const

Obtain the size of the object's contained values.

Returns

Size of the array or object, or one (1) when not said type. On err – when the object is ValueType::NullValue – zero (0).

swap()

void nom::Value::swap

(

Value &

rhs

)

Exchange the contents of the container; copy & swap idiom.

Remarks

In particular, one must be careful to keep track of copying our char* strings as necessary.

Note

This method is used in the implementation of the copy assignment operator.

type()

enum Value::ValueType nom::Value::type

(

)

const

Obtain the enumeration type of the object.

Remarks

The type is defined by the value type(s) set at construction. See also: Value::ValueType enumeration.

type_name()

const std::string nom::Value::type_name

(

)

const

Obtain the enumeration type of the object as a std::string.

Remarks

The type is defined by the value type(s) set at construction. See also: Value::ValueType enumeration.

Todo

Rename to stringify_type?

Member Data Documentation

null

const Value& nom::Value::null

static

Declared value of Null for this object.

Remarks

Value::null is the default constructor's type.

Definition at line 81 of file Value.hpp.

type_

enum ValueType nom::Value::type_

private

The type of stored value in this instance.

Definition at line 525 of file Value.hpp.

value_

ValueHolder nom::Value::value_

private

The stored value in this instance.

Definition at line 528 of file Value.hpp.

---

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

• /home/jeff/Projects/nomlib.git/include/nomlib/ptree/Value.hpp