Standard set of hooks weepickle uses to traverse over a structured data. A superset of the JSON, MessagePack, and Scala object hierarchies, since it needs to support efficiently processing all of them.
Note that some parameters are un-set (-1) when not available; e.g. visitArray's length is not set when parsing JSON input (since it cannot be known up front) and the various index parameters are not set when traversing Scala object hierarchies.
When expecting to deal with a subset of the methods; it is common to forward the ones you don't care about to the ones you do; e.g. JSON visitors would forward all visitFloat32/visitInt/etc. methods to visitFloat64
Type parameters
J
the result of visiting elements (e.g. a json AST or side-effecting writer)
T
the result of ObjArrVisitor.subVisitor which is passed back into a ArrVisitor and ObjVisitor via ObjArrVisitor.visitValue. For example, this might be a weejson.Str that gets passed into an ObjVisitor that's building up a weejson.Obj to be returned on ObjVisitor.visitEnd. Often T will be the same type as J for visitors that return things, or else Any by visitors that do their work by side-effecting instead of returning J.
Optional handler for raw double values; can be overriden for performance in cases where you're translating directly between numbers to avoid the overhead of stringifying and re-parsing your numbers (e.g. the WebJson transformer gets raw doubles from the underlying Json.parse).
Optional handler for raw double values; can be overriden for performance in cases where you're translating directly between numbers to avoid the overhead of stringifying and re-parsing your numbers (e.g. the WebJson transformer gets raw doubles from the underlying Json.parse).
Delegates to visitFloat64StringParts if not overriden
==Responsibility== Generally, whoever creates the visitor should be responsible for closing it, i.e. not intermediate transform(v: Visitor) methods themselves.
==Responsibility== Generally, whoever creates the visitor should be responsible for closing it, i.e. not intermediate transform(v: Visitor) methods themselves.
==Self Closing== Given that common usage is most often single-valued (e.g. "{}"), rather than multi-valued (e.g. "{} {} {}"), Visitors may self-close (e.g. visitor.map{v => Try(v.close); v)} after a single value to prevent resource leaks, but are encouraged to expose both forms (i.e. single/multiple), if supportable.
==Multiple close() calls/Idempotency== Visitors are encouraged to respond gracefully if close() is called multiple times. If an underlying resource would throw if already closed, this may mean adding a private var isClosed: Boolean field to prevent multiple calls.