[Haskell-cafe] Code review: efficiency question

Brian Hulley brianh at metamilk.com
Wed May 3 02:23:41 EDT 2006

Bulat Ziganshin wrote:
> [ideas including reverseMapM_]
> you will laugh, but speed of your two solutions depends on so many
> factors (including size of CPU cache) that noone can say that is
> better in general. although for small lists reverseMapM_ should be
> faster than reverse+mapM. what will be faster - using of higher-order
> function or direct recursion, i can't say, it's a really
> counter-intuitive area of ghc optimizer :)
> of course, i don't think that all that really matters for your program
> (drawing should anyway need much more time than looping). just use
> higher-level approach (that makes code simpler to write, understand
> and maintain) and don't bother your mind :)

Hi Bulat!
Thanks for the suggestions about reverseMapM_ etc.
It seems that since the speeds of the two solutions can be relatively 
faster/slower on different platforms/CPUs I might as well just use the 
combination of existing functions mapM_ and reverse at the moment to get 
readable code with the least amount of effort :-)

Best regards, Brian. 

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