SWI-Prolog -- (.)/3

Documentation
- Reference manual
  - SWI-Prolog extensions
    - Dicts: structures with named arguments
      - Functions on dicts
        
        ./3
        
        User defined functions on dicts
        
        Predefined functions on dicts
- Packages

Availability:built-in

.(+Dict, +Function, -Result)

This predicate is called to evaluate ./2 terms found in the arguments of a goal. This predicate evaluates the field extraction described above, raising an exception if Function is an atom (key) and Dict does not contain the requested key. If Function is a compound term, it checks for the predefined functions on dicts described in section 5.4.1.2 or executes a user defined function as described in section 5.4.1.1.