public QueryExpr(Scan s) {
super();
scan = s;
aggregation.addAll(scan.getAggregation());
Schema tmpSchema = scan.getSchema();
type = tmpSchema.getColumn(0).type;
}
@Override
public DataRecord valueExpr(Env env) {
scan.eval(env);
if (scan.hasNext()) {
Record r = scan.next();
return r.getField(0);
} else return Null.getInstance();
}
@Override
public String toString() {
return "@QueryExpr(" + scan.toString() + ")";
}