jsonv::extraction_context::path_scope Class Reference

An RAII guard naming one step of the extraction path while it is alive. More...

#include <jsonv/serialization/extract.hpp>

Public Member Functions
	path_scope (extraction_context &context, std::size_t index) noexcept
	path_scope (extraction_context &context, std::string_view key) noexcept
	path_scope (extraction_context &context, path_element elem)
	path_scope (extraction_context &context, const jsonv::path &subpath) noexcept
	Push every element of subpath at once. subpath must outlive the scope.
	path_scope (const path_scope &)=delete
path_scope &	operator= (const path_scope &)=delete

Friends
class	extraction_context

Detailed Description

An RAII guard naming one step of the extraction path while it is alive.

A reader knows where the reader is, which is not always where the extractor is: an adapter which re-roots onto a subtree gets a reader whose reader::current_path is relative to that subtree, and an adapter which renames a member wants the name the caller declared rather than the one the document used. Pushing a scope says where the extractor is, and takes precedence over the reader's own answer.

Scopes are kept on the C++ stack and linked into a chain, so a push is two stores and a pop is one. No jsonv::path is built until something calls extraction_context::path, which happens only when a problem is recorded.

The std::size_t and std::string_view overloads allocate nothing; the key of the latter must outlive the scope, which is why an owning path_element overload exists for the callers that cannot promise it (a key decoded from an ast_node_type::key_escaped node, for instance).

Definition at line 574 of file extract.hpp.

Friends And Related Symbol Documentation

extraction_context

friend class extraction_context

friend

Definition at line 590 of file extract.hpp.

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

• jsonv/serialization/extract.hpp