SWI-Prolog -- API-function PL

Documentation
- Reference manual
  - Foreign Language Interface
    - The Foreign Include File
      - Calling Prolog from C
        
        Predicate references
        
        PL_pred()
        
        PL_predicate()
        
        PL_predicate_info()
- Packages

Availability:C-language interface function

predicate_t PL_pred(functor_t f, module_t m)

Return a handle to a predicate for the specified name/arity in the given module. If the module argument m is NULL, the current context module is used. If the target predicate does not exist a handle to a new undefined predicate is returned. The predicate may fail, returning (predicate_t)0 after setting a resource exception, if the target module has a limit on the program_space, see set_module/1. Currently aborts the process with a fatal error when out of memory. Future versions may raise a resource exception and return (predicate_t)0.