[Pig-user] Accessing fields in Tuple

Hi all,

I have the follwoing data file

(1L,2L,3L)
(4L,2L,1L)
(8L,3L,4L)

I am trying to write a UDF (like sum) that would add the fields in Tuple. This works --

public class SumAll extends EvalFunc<Long> {
public Long exec(Tuple input) {
try {
return sum(input);
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0L;
}

static protected Long sum(Tuple input) throws ExecException, NumberFormatException {
long sum = 0;

List<Object> values = input.getAll();
for (Iterator<Object> it = values.iterator(); it.hasNext();) {
Tuple t = (Tuple)it.next();
sum += (Long)t.get(0);
sum += (Long)t.get(1);
sum += (Long)t.get(2);
}
return sum;
}

}

grunt> A = LOAD 'data2' as aa:bytearray;
grunt> C = FOREACH A GENERATE UDF.SumAll((tuple(long,long,long))aa);
grunt> dump C;
2009-11-05 10:07:09,266 [main] INFO  org.apache.pig.backend.local.executionengine.LocalPigLauncher - Successfully stored result in: "file:/tmp/temp1206478472/tmp-577036369"
2009-11-05 10:07:09,267 [main] INFO  org.apache.pig.backend.local.executionengine.LocalPigLauncher - Records written : 3
2009-11-05 10:07:09,267 [main] INFO  org.apache.pig.backend.local.executionengine.LocalPigLauncher - Bytes written : 0
2009-11-05 10:07:09,267 [main] INFO  org.apache.pig.backend.local.executionengine.LocalPigLauncher - 100% complete!
2009-11-05 10:07:09,267 [main] INFO  org.apache.pig.backend.local.executionengine.LocalPigLauncher - Success!!
(6L)
(7L)
(15L)
grunt>

Initially I thought that such a loop would work

static protected Long sum(Tuple input) throws ExecException, NumberFormatException {
long sum = 0;

List<Object> values = input.getAll(); // Would give all fields in Tuple??
for (Iterator<Object> it = values.iterator(); it.hasNext();) {
sum += (Long)t;
}
return sum;
}

But I get an error that Tuple can't be cast back to Long. So my question is that what is input.getAll() returning? What is the structure of data that gets passed to exec function?

Thanks!