Hi, Am Samstag, den 10.03.2012, 15:50 -0300 schrieb Thiago Negri:
I see. Thanks for the answers.
Any data structure or source annotation that would prevent that?
For example, if I try the same program to run on a [1..9999999999999999] list, I'll get an out of memory error for the single-threaded version. Any way to prevent it without declaring two different versions of "list"?
I had real-world applications where I wanted a list rather to be generated over and over again, instead of generated once and then shared. One trick is to add a dummy parameter (of type (), for example) to the list, and instead of passing around the "[Int]", you pass around the "() -> [Int]" and apply it to () very late: module Main where import Data.List (foldl1') import Control.Parallel (par, pseq) import Control.Arrow ((&&&)) f `parApp` (a, b) = a `par` (b `pseq` (f a b)) seqApp = uncurry main = print result where result = (+) `parApp` minMax list minMax = minlist &&& maxlist minlist l = foldl1' min (l ()) maxlist l = foldl1' max (l ()) list _ = [1..19999999] Greetings, Joachim -- Joachim "nomeata" Breitner mail@joachim-breitner.de | nomeata@debian.org | GPG: 0x4743206C xmpp: nomeata@joachim-breitner.de | http://www.joachim-breitner.de/