fill_proc         497 ext/vport/vport.c     ScmObj fill_proc;           /* (U8vector) -> Maybe Int*/
fill_proc         513 ext/vport/vport.c     if (SCM_FALSEP(data->fill_proc)) {
fill_proc         518 ext/vport/vport.c     r = Scm_Apply(data->fill_proc, SCM_LIST1(vec));
fill_proc         620 ext/vport/vport.c     data->fill_proc  = SCM_FALSE;