XI 3.0: "Flattening" hierarchical structures

Does anybody have a "generalized" method to flatten a hierarchical structure?

In other words, given a XML-typical structure with trees and leaves, how can i generate a old-style-cobol-like flat file using mapping?

H-
 |_A1_
     |_B1   ----->     HA1B1
     |_B2   ----->     HA1B2
 |_A2_                 HA2B3
     |_B3

I've been able to do that using a recursive manipulation of the context (via custom and standard functions), but this seems very dumb because you need to put a function in fron of each field...

Maybe some XSLT-guru knows a better method....

thanks in advance.

Alessandro