while (psi_plist_top(input, &entry)) {
/* bail out if exp->op > entry.type */
if (psi_calc_oper(exp->op, entry.type) == -1) {
while (psi_plist_top(input, &entry)) {
/* bail out if exp->op > entry.type */
if (psi_calc_oper(exp->op, entry.type) == -1) {