This is a fork of encoding/json with the following features added:
- Context support: MarshalContext() accepts a context that can be accessed by implementing a variant of MarshalJSON()
- Groups: it is possible to have methods returning groups of values
Objects can now implement a MarshalContextJSON(context.Context) method that will be called over the usual MarshalJSON() with
the context of the encoding. Marshal(v) will use context.Background() by default, and the new MarshalContext(ctx, v) receives
a context that will be passed to all objects encoded in the process.
Objects can implement a GroupMarshalerJSON(ctx context.Context, st *pjson.GroupState) ([]byte, error) method that will be
called upon marshaling and can use GroupState to specify it needs to gather specific data in batches before rending is possible.
This can be useful when data returned from a json encoding is taken from a database, and many objects access elements from a given list. These can be grouped in a single SELECT (or similar) from the database, greatly reducing the time needed for render.