Random questions after a long haskell coding day

[Ketil Z. Malde]

"Simon Marlow" <simonmar@microsoft.com> writes:

>> Any thumb rule for using arrays? I'm expecting access to be 
>> O(1), it is right?

> In GHC, yes.

(Shouldn't this really be required?  I mean, the whole *point* of using
arrays is to have O(1) random access, isn't it?)

Can we also rely on destructive updates for the monadic arrays?

On a different note, I have some nice SMP machinery here (eight CPU
Sun, and possibly 192 CPU IBM :-).  It appears from the documentation
that Concurrent Haskell will only support one OS thread, and thus
treat these machines as their one-CPU workstation equivalents.
Parallell Haskell doesn't, but uses PVM, which seems like an
unnecessary abstraction since I'm in a shared memory (even if
non-uniformly so) setting.  

Is the cost of PVM insignificant enough to not care?  Or are there
plans or projects of which I need to be aware, that target Haskell for
these kinds of architectures?

-kzm
-- 
If I haven't seen further, it is by standing in the footprints of giants