#include <fstream.hfa>
#include <thread.hfa>

int num_links = 10;

exception unwind { int num; };
vtable(unwind) unwind_vt;


coroutine Node { int cnt;  unwind except; };
void ?{}( Node & this, int cnt ) { this.cnt = cnt; }

// builds a list of Node coroutines linked by their last resumer field
// the (num_links + 1)th node then triggers unwinding of the list by throwing resumtions at the last resumer
void main( Node & this ) with( this ) {
    sout | cnt;
    if ( cnt == 0 ) {
        except{ &unwind_vt, cnt };
        resumeAt( resumer( this ), except );
        return;
    }
    Node next{ cnt - 1 };
    resume( next );
    try {
        poll();
    } catch( unwind * e ) {
        e->num++;
        if ( e->num != cnt ) {
            sout | "exception count and thread count should be consistent!";
            abort();
        }
        sout | e->num;
        except{ &unwind_vt, e->num };
        resumeAt( resumer( this ), except );
    }

}

int main() {
	sout | "main start";
    Node n{ num_links };
    try {
        resume( n );
        poll();
    } catch( unwind * e ) {}
    
	sout | "main end";
}