Re: [Haskell-cafe] Re: Looking for the fastest Haskell primes

I vaguely remember someone (maybe Duncan Coutts?) saying that this was a commonly held misconception, and that GHC did indeed GC CAFs when optimization is enabled. If I am remembering incorrectly, does anyone have a reference to a ticket outlining this non-GC'ed CAF behavior? Thanks, Dan On Thu, Apr 16, 2009 at 4:57 AM, Eugene Kirpichov wrote:

The parameterless version is a top-level definition and won't get garbage-collected, IIRC. So, if you evaluate primes!!10000000, you'll end up with a 10000000-element list hanging in memory forever. If you evaluate (primes' ()) !! 10000000, you won't.

2009/4/16 Niemeijer, R.A. :

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Heinrich Apfelmus wrote:

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+1 except that exporting the potentially infinite list of primes is problematic in that it may become a memory leak.

I'd suggest to export two versions

  primes  :: [Integer]   primes' :: () -> [Integer]

for casual (i.e. throwaway program to solve a Project Euler problem) and for memory aware use respectively.

I'm afraid I don't quite follow. Would you mind explaining what the first parameter is for and how it would solve the memory leak? _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

-- Eugene Kirpichov Web IR developer, market.yandex.ru _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe