9.8.2 Compatibility between Prolog versions

Great care is taken to ensure binary compatibility of foreign extensions between different Prolog versions. Only the much less frequently used stream interface has been responsible for binary incompatibilities.

Source code that relies on new features of the foreign interface can use the macro PLVERSION to find the version of SWI-Prolog.h and PL_query() using the option PL_QUERY_VERSION to find the version of the attached Prolog system. Both follow the same numbering schema explained with PL_query().