source: doc/papers/concurrency/examples/Fib.sim @ a757ba1

BEGIN
        CLASS Fibonacci;
                HIDDEN fn, main;                                        ! private members;
        BEGIN
                INTEGER fn;                                                     ! communication;

                PROCEDURE main;                                         ! mimic uC++ coroutine main;
                BEGIN
                        INTEGER fn1, fn2;

                        fn := 0; fn1 := fn;
                        Detach;                                                 ! suspend();
                        fn := 1; fn2 := fn1; fn1 := fn;
                        Detach;                                                 ! suspend();
                        WHILE TRUE DO BEGIN
                                fn := fn1 + fn2; fn2 := fn1; fn1 := fn;
                                Detach;                                         ! suspend();
                        END;
                END;

                INTEGER PROCEDURE next;
                BEGIN
                        Call( THIS Fibonacci );                 ! resume();
                        next := fn;
                END;
                ! Fibonacci constructor code;
                Detach;                                                         ! return to declaration;
                main;                                                           ! call main as last line of constructor;
        END Fibonacci;
        ! program main equivalent;
        REF(Fibonacci) f1, f2;                                  ! objects are references;
        INTEGER i;

        f1 :- NEW Fibonacci;
        f2 :- NEW Fibonacci;
        FOR i := 1 STEP 1 UNTIL 10 DO BEGIN
                OutInt( f1.next, 3 );
                OutText( " " );
                OutInt( f2.next, 3 );
                OutImage;
        END
END;

! Local Variables: ;
! tab-width: 4 ;
! compile-command: "cim Fib.sim" ;
! End: ;