But like I just showed, sometimes paring them may not be a natural approach though...
Yeah, I understand what you mean. In the examples you give, you could always try to make the appended stuff (the zs, etc) the same length by appending Nothings, but probalby not a general solution.
Yes maybe, I was hoping I could find a more elegant solution though.
I wonder if, given you original function which returns ([Int],[Int]), you couldn't do something really ugly like using unsafeInterleaveIO on writing the first list, and then write the second list "by hand".
Just a thought.
If "consuming" is just writing stuff to files I think Trace (which uses unsafeInterleaveIO) would be just fine, but "consuming" might be more than that. In that case I'd have to fuse the functions that consume each of the streams, with the function that produces them. J.A.