Module edit 

Edits of a key’s state from outside its handlers.

An edit is an exclusive call to the reserved handler EDIT_HANDLER, which every object type has: it waits for the key like any exclusive call, and its changes commit with its result in the UpdateDone record a handler’s writes make, so it replays, deduplicates by call ID and is sealed by the codec as they are. The handler’s code in each SDK is one call to the engine, which applies the edit below.

The edit is a JSON object, applied in this order:

Field
ifVersion	refuse the edit unless the state’s version is this
clearAll	true: empty the state
clear	fields to remove (absent ones are ignored)
set	fields to set, {field: value}; null removes one
patch	a JSON Patch (RFC 6902) over the state as one JSON object
by	who asked, recorded with the edit (the HTTP API and CLI set it)

The answer is {"version": the new version, "changed": [fields]}.

Constants

EDIT_HANDLER

The handler every object type has that applies an edit.

STALE

How the refusal of an edit whose ifVersion is stale begins.

Functions

apply

The changes edit makes to state (None removes a field) and the edit’s answer. Changes nothing on a refusal.

patch

Applies a JSON Patch (RFC 6902) to doc: all of it, or none of it.

version

The state’s version: a hash of its JSON, so an editor that read one version can refuse to overwrite another (ifVersion, HTTP If-Match).