ktnext
for (ktwalk(&ts, t); (ap = ktnext(&ts)); ) {
for (ktwalk(&ts, tp); (te = ktnext(&ts)); ) {
for (ktwalk(&ts, &taliases); (tp = ktnext(&ts)) != NULL; )
while ((te = ktnext(&ts))) {
struct tbl * ktnext(struct tstate *);