For JSON and XML, mechanisms to generate an in-memory document from an xs:string() exist. For CSV or text inputs, however, I'm unclear on how to do this without declaring options and invoking db:add() -- not ideal when the content being handled is intended only for transient, one-time-only processing.
...just another issue that has already been resolved for a commercial customer. It will soon end up in the open source branch as well.
Christian