:-) Thank you for your kindness. I mean... your frankness.
I had another issue in that code which clearly shows that I don't know
how to use parMap or strategies in general. Maybe this is better:
weirdParMap action = sequence_ . map action . parMap rwhnf (\x -> x `seq`
x)
or maybe that's overkill and this is sufficient:
weirdParMap action = sequence_ . map action . parMap rwhnf id
or this:
weirdParMap action list = sequence_ $ map action (list `using` rnf)
(which I guess would require the appropriate NFData instanbe for the
pixel type)
or maybe I still don't know enough about this Parallel Haskell thingy.
In any case... couldn't something like this be what was needed in the
OP?
JCAB
On Tue, 17 Apr 2007 17:56:27 -0700, Stefan O'Rear
On Tue, Apr 17, 2007 at 05:49:11PM -0700, Juan Carlos Arevalo Baeza wrote:
I may be talking out of my other end here, but... if you want something like parMap to calculate all the pixels in parallel, then... can't you use parMap itself?
Something like:
weirdParMap action = sequence_ . map action . parMap (id $!)
This evaluates all the elements of the list using parMap (the expensive part, right?), and then sequentially applies the action on the current thread.
You are. I'm devoting most of my brain cells to automatic deriving of TTypeable atm, but note that id is already strict, so (id $!) is equivalent to id.
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