bwsfree
void bwsfree(struct bwstring *s);
bwsfree(ka->key[i].k);
bwsfree(kv->k);
bwsfree(si->str);
bwsfree(si->str);
bwsfree(s1);
bwsfree(s1);
bwsfree(s2);
bwsfree(s2);
bwsfree(lp->str);
bwsfree(lp.str);