basic_json_pointer.md

jsoncons::jsonpointer::basic_json_pointer

#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>

template <typename CharT>
class basic_json_pointer

Two specializations for common character types are defined:

Type	Definition
json_pointer	basic_json_pointer<char> (since 0.159.0)
json_ptr	basic_json_pointer<char> (until 0.159.0)
wjson_pointer	basic_json_pointer<wchar_t> (since 0.159.0)
wjson_ptr	basic_json_pointer<wchar_t> (unitl 0.159.0)

Objects of type basic_json_pointer represent a JSON Pointer.

Member types

Type	Definition
char_type	CharT
string_type	std::basic_string<char_type>
string_view_type	jsoncons::basic_string_view<char_type>
const_iterator	A constant LegacyRandomAccessIterator with a value_type of std::basic_string<char_type>
iterator	An alias to const_iterator

Constructors

basic_json_pointer();                                      (1)

explicit basic_json_pointer(const string_view_type& str);  

explicit basic_json_pointer(const string_view_type& str, 
                            std::error_code& ec);          (2)

basic_json_pointer(const basic_json_pointer&);             (3)

basic_json_pointer(basic_json_pointer&&) noexcept;         (4)

(1) Constructs an empty basic_json_pointer.

(2) Constructs a basic_json_pointer from a string representation or a URI fragment identifier (starts with #).

operator=

basic_json_pointer& operator=(const basic_json_pointer&);

basic_json_pointer& operator=(basic_json_pointer&&);

Modifiers

basic_json_pointer& append(const string_type& s);     (since 0.172.0)

Appends the token s.

template <typename IntegerType>
basic_json_pointer& append(IntegerType index)         (since 0.172.0)

Appends the token index. This overload only participates in overload resolution if IntegerType is an integer type.

basic_json_pointer& operator/=(const string_type& s)

Appends the token s.

template <typename IntegerType>
basic_json_pointer& operator/=(IntegerType index) 

Appends the token index. This overload only participates in overload resolution if IntegerType is an integer type.

basic_json_pointer& operator+=(const basic_json_pointer& ptr)

Concatenates the current pointer and the specified pointer ptr.

Iterators

iterator begin() const;
iterator end() const;

Iterator access to the tokens in the pointer.

Accessors

bool empty() const

Checks if the pointer is empty

string_type to_string() const Returns a JSON Pointer represented as a string value, escaping any / or ~ characters.

Static member functions

static parse(const string_view_type& str); static parse(const string_view_type& str, std::error_code& ec); Constructs a basic_json_pointer from a string representation or a URI fragment identifier (starts with #).

Non-member functions

basic_json_pointer<CharT> operator/(const basic_json_pointer<CharT>& lhs, const basic_string<CharT>& s);

Concatenates a JSON Pointer pointer and a string. Effectively returns basic_json_pointer(lhs) /= s.

template <typename CharT,class IntegerType>
basic_json_pointer<CharT> operator/(const basic_json_pointer<CharT>& lhs, IntegerType index);

Concatenates a JSON Pointer pointer and an index. Effectively returns basic_json_pointer(lhs) /= index. This overload only participates in overload resolution if IntegerType is an integer type.

template <typename CharT,class IntegerType>
basic_json_pointer<CharT> operator+( const basic_json_pointer<CharT>& lhs, const basic_json_pointer<CharT>& rhs );

Concatenates two JSON Pointers. Effectively returns basic_json_pointer(lhs) += rhs.

template <typename CharT,class IntegerType>
bool operator==(const basic_json_pointer<CharT>& lhs, const basic_json_pointer<CharT>& rhs);

template <typename CharT,class IntegerType>
bool operator!=(const basic_json_pointer<CharT>& lhs, const basic_json_pointer<CharT>& rhs);

std::string to_string(const json_pointer& ptr);      (since 0.172.0)

std::wstring to_wstring(const wjson_pointer& ptr);   (since 0.172.0)

template <typename CharT>
std::basic_ostream<CharT>& operator<<(std::basic_ostream<CharT>& os, const basic_json_pointer<CharT>& ptr);

Performs stream output

Examples

Iterate over the tokens in a JSON Pointer

#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>

// for brevity
namespace jsonpointer = jsoncons::jsonpointer;

int main()
{
    jsonpointer::json_pointer ptr("/store/book/1/author");

    std::cout << "(1) " << ptr << "\n\n";

    std::cout << "(2)\n";
    for (const auto& token : ptr)
    {
        std::cout << token << "\n";
    }

    std::cout << "\n";
}

Output:

(1) /store/book/1/author

(2)
store
book
1
author

Append tokens to a JSON Pointer

#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>

namespace jsonpointer = jsoncons::jsonpointer;

int main()
{
    jsonpointer::json_pointer ptr;

    ptr /= "a/b";
    ptr /= "";
    ptr /= "m~n";

    std::cout << "(1) " << ptr << "\n\n";

    std::cout << "(2)\n";
    for (const auto& token : ptr)
    {
        std::cout << token << "\n";
    }

    std::cout << "\n";
}

Output:

(1) /a~1b//m~0n

(2)
a/b

m~n

Concatentate two JSONPointers

#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>

namespace jsonpointer = jsoncons::jsonpointer;

int main()
{
    jsonpointer::json_pointer ptr("/a~1b");

    ptr += jsonpointer::json_pointer("//m~0n");

    std::cout << "(1) " << ptr << "\n\n";

    std::cout << "(2)\n";
    for (const auto& token : ptr)
    {
        std::cout << token << "\n";
    }

    std::cout << "\n";
}

Output:

(1) /a~1b//m~0n

(2)
a/b

m~n