basic_msgpack_cursor.md

jsoncons::msgpack::basic_msgpack_cursor

#include <jsoncons_ext/msgpack/msgpack_cursor.hpp>

template<
    class Source=jsoncons::binary_stream_source,
    class Allocator=std::allocator<char>>
class basic_msgpack_cursor;

A pull parser for reporting MessagePack parse events. A typical application will repeatedly process the current() event and call the next() function to advance to the next event, until done() returns true. In addition, when positioned on a begin_object event, the read_to function can pull a complete object representing the events from begin_object to end_object, and when positioned on a begin_array event, a complete array representing the events from begin_array ro end_array.

basic_msgpack_cursor is noncopyable and nonmoveable.

Aliases for common sources are provided:

Type	Definition
msgpack_stream_cursor	basic_msgpack_cursorjsoncons::binary_stream_source
msgpack_bytes_cursor	basic_msgpack_cursorjsoncons::bytes_source

Implemented interfaces

staj_cursor

Constructors

template <typename Sourceable>
basic_msgpack_cursor(Sourceable&& source,
                     const msgpack_decode_options& options = msgpack_decode_options(),
                     const Allocator& alloc = Allocator()); (1)

template <typename Sourceable>
basic_msgpack_cursor(Sourceable&& source,
                     std::error_code& ec); (2)
template <typename Sourceable>
basic_msgpack_cursor(Sourceable&& source,
                     const msgpack_decode_options& options,
                     std::error_code& ec); (3)

template <typename Sourceable>
basic_msgpack_cursor(std::allocator_arg_t, const Allocator& alloc, 
                     Sourceable&& source,
                     const msgpack_decode_options& options,
                     std::error_code& ec); (4)

Constructor (1) reads from a buffer or stream source and throws a ser_error if a parsing error is encountered while processing the initial event.

Constructors (2)-(4) read from a buffer or stream source and set ec if a parsing error is encountered while processing the initial event.

Note: It is the programmer's responsibility to ensure that basic_msgpack_cursor does not outlive any source passed in the constuctor, as basic_msgpack_cursor holds a pointer to but does not own this object.

Parameters

source - a value from which a source_type is constructible.

Member functions

bool done() const override;

Checks if there are no more events.

const staj_event& current() const override;

Returns the current staj_event.

void read_to(json_visitor& visitor) override

Feeds the current and succeeding staj events through the provided visitor, until the visitor indicates to stop. If a parsing error is encountered, throws a ser_error.

void read_to(json_visitor& visitor, std::error_code& ec) override

Feeds the current and succeeding staj events through the provided visitor, until the visitor indicates to stop. If a parsing error is encountered, sets ec.

void next() override;

Advances to the next event. If a parsing error is encountered, throws a ser_error.

void next(std::error_code& ec) override;

Advances to the next event. If a parsing error is encountered, sets ec.

const ser_context& context() const override;

Returns the current context

void reset();

Reset cursor to read another value from the same source

template <typename Sourceable>
reset(Sourceable&& source)

Reset cursor to read new value from a new sources

Non-member functions

template <typename Source,typename Allocator> staj_filter_view operator|(basic_msgpack_cursor<Source,Allocator>& cursor, std::function<bool(const staj_event&, const ser_context&)> pred);

See also

staj_event

staj_array_iterator

staj_object_iterator