source: doc/papers/llheap/examples/Fib3.c@ c3e41cda

#include <stdio.h>

typedef struct {
        int restart, fn1, fn;
} Fib;
#define FibCtor { 0, 1, 0 }

Fib * comain( Fib * f ) {
        static void * states[] = {&&s0, &&s1};
        goto *states[f->restart];
  s0: f->restart = 1;
        for ( ;; ) {
                return f;
          s1:; int fn = f->fn + f->fn1;
                f->fn1 = f->fn; f->fn = fn;
        }
}
int main() {
        Fib f1 = FibCtor, f2 = FibCtor;
        for ( int i = 0; i < 10; i += 1 )
                printf( "%d %d\n", comain( &f1 )->fn, comain( &f2 )->fn );
}

// Local Variables: //
// tab-width: 4 //
// compile-command: "gcc-8 Fib3.c" //
// End: //