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You can reach the person managing the list at beginners-ow...@haskell.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Beginners digest..." Today's Topics: 1. Re: Two questions for a production project... (Yitzchak Gale) 2. Re: Fwd: Implementing a spellchecker - problem with Data.HashTable performance (Chadda? Fouch?) 3. Is it only one data structure per ST monad? (KC) 4. Re: Is it only one data structure per ST monad? (Edward Z. Yang) 5. (no subject) (KC) 6. The last statement in a 'do' construct must be an expression: a <- readArray arr (1, 1) (KC) 7. Re: [Haskell-cafe] The last statement in a 'do' construct must be an expression: a <- readArray arr (1, 1) (KC) ---------------------------------------------------------------------- Message: 1 Date: Mon, 23 Apr 2012 17:46:07 +0300 From: Yitzchak Gale <g...@sefer.org> Subject: Re: [Haskell-beginners] Two questions for a production project... To: umptious <umpti...@gmail.com> Cc: beginners@haskell.org Message-ID: <CAOrUaLZ28v+H0R-8G-4vQoidP+Tncp2J_Kf9dKz=xTr1n=z...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 umptious wrote: > ...I can't find a list of real world users for > Yesod etc. There are a number of companies doing web development using each of the various Haskell web frameworks, as well as freelancers. Since you mentioned Yesod specifically, yes, some of them use Yesod. I wont' speak for any them, though. Instead, join the web-devel mailing list to keep up with what's happening in the Haskell web development world: http://www.haskell.org/mailman/listinfo/web-devel Or see the home pages of the three main web frameworks for framework-specific community resources: http://www.happstack.com/ http://snapframework.com/ http://www.yesodweb.com/ Regards, Yitz ------------------------------ Message: 2 Date: Mon, 23 Apr 2012 17:38:37 +0200 From: Chadda? Fouch? <chaddai.fou...@gmail.com> Subject: Re: [Haskell-beginners] Fwd: Implementing a spellchecker - problem with Data.HashTable performance To: Rados?aw Szymczyszyn <lav...@gmail.com> Cc: beginners@haskell.org Message-ID: <CANfjZRYm=yz5w8mscclyytqzcqzrqnauk4016_dr85betr8...@mail.gmail.com> Content-Type: text/plain; charset=UTF-8 On Sun, Apr 22, 2012 at 4:58 PM, Rados?aw Szymczyszyn <lav...@gmail.com> wrote: > Thank you all for thoughts and suggestions. I've been tracking them as > they appeared, but being busy with university assignments, couldn't > try them out yet. > > In the meantime, however, Karol Samborski investigated the issue > further and found the cause of poor performance -- somehow using > HashTable.newHint doesn't play well with HashTable.update. Simply > changing newHint to hint gives me execution time of about 12s (on my > rather slowish AMD Fusion 1.6GHz laptop) with a dataset of ~1.35mln > words. > While it's good that you have found a bug that explain the very poor performance you got, I must reiterate Brent Yorgey's advice to use Data.HashMap from unordered-containers or some other performance oriented implementation : Data.HashTable is a legacy datastructure that was mainly introduced to have a hashtable in Haskell core libraries, it ran into some performance problem of GHC (only reduced in very recent release I believe) and was never written to be very fast in the first place... Avoiding it is generally a very good idea ! Using another structure (HashMap or some trie implementation) would probably get you much better performance without hassle. I must admit that having Data.HashTable in the base library without warning as to its unsuitability is very misleading to the beginner coming from Perl or Python. -- Jeda? ------------------------------ Message: 3 Date: Mon, 23 Apr 2012 11:32:57 -0700 From: KC <kc1...@gmail.com> Subject: [Haskell-beginners] Is it only one data structure per ST monad? To: haskell-cafe <haskell-c...@haskell.org>, beginners@haskell.org Message-ID: <CAMLKXynmZsoVcOyQ4hVCo2kvTq-X48qZdyNN_=p6beqrfbs...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" Is it only one data structure per ST monad? -- -- Regards, KC -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120423/0379a44a/attachment-0001.htm> ------------------------------ Message: 4 Date: Mon, 23 Apr 2012 16:49:33 -0400 From: "Edward Z. Yang" <ezy...@mit.edu> Subject: Re: [Haskell-beginners] Is it only one data structure per ST monad? To: KC <kc1...@gmail.com> Cc: beginners <beginners@haskell.org>, haskell-cafe <haskell-c...@haskell.org> Message-ID: <1335214142-sup-4033@ezyang> Content-Type: text/plain; charset=UTF-8 If you mean, per 'ST s a', no: you can generate as many STRefs as you want. Edward Excerpts from KC's message of Mon Apr 23 14:32:57 -0400 2012: > Is it only one data structure per ST monad? > ------------------------------ Message: 5 Date: Mon, 23 Apr 2012 13:51:03 -0700 From: KC <kc1...@gmail.com> Subject: [Haskell-beginners] (no subject) To: haskell-cafe <haskell-c...@haskell.org>, beginners@haskell.org Message-ID: <CAMLKXynrGaMu8GUMpjCkF4ZuJSegaXXv3YOo-ao7wxw=aT-=d...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" buildPair = do arr <- newArray ((1,1),(1,10)) 37 :: ST s (STArray s (Int,Int) Int) a <- readArray arr (1,1) writeArray arr (1,1) 64 b <- readArray arr (1,1) return (a,b) main = print $ runST buildPair -- -- Regards, KC -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120423/f9ad2a32/attachment-0001.htm> ------------------------------ Message: 6 Date: Mon, 23 Apr 2012 13:52:48 -0700 From: KC <kc1...@gmail.com> Subject: [Haskell-beginners] The last statement in a 'do' construct must be an expression: a <- readArray arr (1, 1) To: haskell-cafe <haskell-c...@haskell.org>, beginners@haskell.org Message-ID: <CAMLKXy=z9yJNJ1X6ceDxoEmyiZFGE4uW=quciizrvvbyr4u...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" I'm getting the above error message and I cannot figure out why? buildPair = do arr <- newArray ((1,1),(1,10)) 37 :: ST s (STArray s (Int,Int) Int) a <- readArray arr (1,1) writeArray arr (1,1) 64 b <- readArray arr (1,1) return (a,b) main = print $ runST buildPair -- -- Regards, KC -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120423/b106eeca/attachment-0001.htm> ------------------------------ Message: 7 Date: Mon, 23 Apr 2012 13:58:21 -0700 From: KC <kc1...@gmail.com> Subject: Re: [Haskell-beginners] [Haskell-cafe] The last statement in a 'do' construct must be an expression: a <- readArray arr (1, 1) To: Ryan Yates <fryguy...@gmail.com>, haskell-cafe <haskell-c...@haskell.org>, beginners@haskell.org Message-ID: <camlkxym0rtxkooac2a0lkaihrwaur-8g9qgso4wgqbpl88k...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" Thank you, that was it. I was mixing up and tabs and spaces. I expected new versions of NotePad++ to keep my old settings. On Mon, Apr 23, 2012 at 1:54 PM, Ryan Yates <fryguy...@gmail.com> wrote: > Perhaps you are mixing tabs and spaces? > > On Mon, Apr 23, 2012 at 4:52 PM, KC <kc1...@gmail.com> wrote: > >> I'm getting the above error message and I cannot figure out why? >> >> >> buildPair = >> do >> arr <- newArray ((1,1),(1,10)) 37 :: ST s (STArray s (Int,Int) Int) >> a <- readArray arr (1,1) >> writeArray arr (1,1) 64 >> b <- readArray arr (1,1) >> return (a,b) >> >> >> main = print $ runST buildPair >> >> >> -- >> -- >> Regards, >> KC >> >> _______________________________________________ >> Haskell-Cafe mailing list >> haskell-c...@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe >> >> > -- -- Regards, KC -------------- next part -------------- An HTML attachment was scrubbed... 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