[Haskell-cafe] Parallel interruptible computations

[Gesh]

For what it's worth, Conal Elliott did a series of blog posts on a
similar subject[0]. One use case of the library he wrote for this
is to write zip as lazily as possible[1], i.e. in such a way that, even
if xs=undefined, zip [] xs = zip xs [] = undefined.
Hopefully, this example can help you.

Gesh

[0] - http://conal.net/blog/posts/merging-partial-values
[1] - http://www.haskell.org/pipermail/haskell-cafe/2009-January/053966.html