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. <r.a.niemei...@tue.nl>: > Heinrich Apfelmus wrote: >> +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
