SWI-Prolog -- API-function PL_foreign

Documentation
- Reference manual
  - Foreign Language Interface
    - The Foreign Include File
      - Argument Passing and Control
        
        Non-deterministic Foreign Predicates
        
        PL_retry()
        
        PL_retry_address()
        
        PL_foreign_control()
        
        PL_foreign_context()
        
        PL_foreign_context_address()
        
        PL_foreign_context_predicate()
- Packages

Availability:C-language interface function

intptr_t PL_foreign_context(control_t)

Extracts the context from the context argument. If the call type is PL_FIRST_CALL the context value is 0L. Otherwise it is the value returned by the last PL_retry() associated with this goal (both if the call type is PL_REDO or PL_PRUNED).