radsel_prefix_remainder
if(!radsel_prefix_remainder(region, addlen+1, r->str,
if(!radsel_prefix_remainder(region, r->len+1, addstr,
if(!radsel_prefix_remainder(region, common_len+1,
if(!radsel_prefix_remainder(region, common_len+1,
if(!radsel_prefix_remainder(rt->region, 1, k, len,