[Haskell-cafe] why PArr slower than list ?

Manuel M T Chakravarty chak at cse.unsw.edu.au
Wed Nov 14 23:44:39 EST 2007

Albert Lee:
> I read the GHC/Data Parallel Haskell/GHC.PArr page
> http://haskell.org/haskellwiki/Data_Parallel_Haskell/GHC.PArr
> and make a simple test to compare the speed of PArr against List:

On the wiki page GHC.PArr is described under the heading "Convenience  
without the speed".  You'd usually still expect it not to be slower  
than lists.  However, lists are optimised by GHC (buildr/fold fusion),  
where the implementation of GHC.PArr at this point is complete naive.


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