Calc once allows to performe a one time calculation on the give query.
The query ownership is taken so it can not be used after. This allows
the get a better performance if there is a need to calculate the query
only once.
Create a PathCalculator object. The path calculator can be re-used
to calculate json paths on different jsons.
/// ```rust
extern crate jsonpath_rs
#[macro_use] extern crate serde_json;
Create a PathCalculator object. The path calculator can be re-used
to calculate json paths on different jsons.
Unlike create(), this function will return results with full path as PTracker object.
It is possible to create your own path tracker by implement the PTrackerGenerator triat.