Table looping functoid..what if row count cannot be a fixed value?

I have a source
<person count=3>
 <name1>adam1</name1>
 <age1>gump1</age1>
 <name1>adam1</name1>
 <age1>gump1</age1>
 <name1>adam1</name1>
 <age1>gump1</age1>
</person>

Target should be looked as
<Person>
 <name/>
 <age/>
</Person>

I know table looping functoid deals well for a fixed number of rows in
design time, how can I tell the engine to look for number of rows
going to produced at run time?

thanks for every help!