[Haskell-cafe] cap 3: stopping thread 3 (stackoverflow)

[Johannes Waldmann]

Here's source and logs:

http://www.imn.htwk-leipzig.de/~waldmann/draft/skpp11/subseqsum/Subseqsum.hs

The program is meant to show an application of the "third homomorphism theorem"
approach (hom-based structural parallel programming).

My observation (for this program) is that there is little speedup,
indeed the threadscope picture shows a peak only at the very end,
but the eventlog contains surprising (for me) stack and heap overflows.

Would this work better with Data.Sequence instead of List?
(Is there a really cheap way (O(1)) to split some Data.Sequence roughly in half?)

PS: I keep telling my students that "structural parallel programming"
is the right thing to do, but I find it surprisingly difficult
to exhibit clear-cut examples that support the claim
(and work with standard ghc, so students can reproduce it).

I appreciate any comments.  - J.W.