The Java code from ‘pragma foreign_proc’ declarations for Java will be placed in the bodies of static member functions of an automatically generated Java class. ‘pragma foreign_code’ can be used to define additional members of this automatically generated class, which can then be referenced by ‘pragma foreign_proc’ declarations for Java from that module.
:- pragma foreign_code("Java", " static int counter = 0; "). :- impure pred incr_counter is det. :- pragma foreign_proc("Java", incr_counter, [will_not_call_mercury], " counter++; "). :- semipure func get_counter = int. :- pragma foreign_proc("Java", get_counter = (Result::out), [will_not_call_mercury, promise_semipure], " Result = counter; ").