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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: A "show" error (Adrien Haxaire) 2. Re: A "show" error (Adrien Haxaire) 3. Re: A "show" error (Brandon Allbery) 4. Re: A "show" error (Adrien Haxaire) 5. Re: A "show" error (bahad?r altan) 6. Re: A "show" error (Brandon Allbery) 7. populating a bloom filter; stymied by ST monad (Joey Hess) ---------------------------------------------------------------------- Message: 1 Date: Sun, 11 Mar 2012 20:26:54 +0100 From: Adrien Haxaire <adr...@haxaire.org> Subject: Re: [Haskell-beginners] A "show" error To: beginners@haskell.org Message-ID: <20120311192654.GA4231@arch> Content-Type: text/plain; charset=iso-8859-1 On Sun, Mar 11, 2012 at 07:10:28PM +0000, bahad?r altan wrote: > Hi,? > I'm trying to process on a tree with this function : > > f (Branch x (Branch y y1 y2) (Branch z z1 z2)) = (x,y,y1,y2,z,z1,z2) > > > and my tree declaration is this :? > > data Tree = Empty | Branch Integer Tree Tree deriving (Show) > > And I'm getting this error :? > > Main> f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) > ERROR - Cannot find "show" function for: > *** Expression : f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) > *** Of type ? ?: (Integer,Integer,Tree,Tree,Integer,Tree,Tree) > > I'll be happy if you help me to get rid of this error.. Hello, Dit you try to derive it automatically, by adding 'deriving (Show)' after its declaration? Otherwise you need to define it manually I'm afraid. -- Adrien Haxaire www.adrienhaxaire.org | @adrienhaxaire ------------------------------ Message: 2 Date: Sun, 11 Mar 2012 20:34:13 +0100 From: Adrien Haxaire <adr...@haxaire.org> Subject: Re: [Haskell-beginners] A "show" error To: beginners@haskell.org Message-ID: <20120311193413.GB4231@arch> Content-Type: text/plain; charset=iso-8859-1 Oh sorry I just realized you did ! On Sun, Mar 11, 2012 at 07:10:28PM +0000, bahad?r altan wrote: > Hi,? > I'm trying to process on a tree with this function : > > f (Branch x (Branch y y1 y2) (Branch z z1 z2)) = (x,y,y1,y2,z,z1,z2) > > > and my tree declaration is this :? > > data Tree = Empty | Branch Integer Tree Tree deriving (Show) > > And I'm getting this error :? > > Main> f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) > ERROR - Cannot find "show" function for: > *** Expression : f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) > *** Of type ? ?: (Integer,Integer,Tree,Tree,Integer,Tree,Tree) > > I'll be happy if you help me to get rid of this error.. > _______________________________________________ > Beginners mailing list > Beginners@haskell.org > http://www.haskell.org/mailman/listinfo/beginners -- Adrien Haxaire www.adrienhaxaire.org | @adrienhaxaire ------------------------------ Message: 3 Date: Sun, 11 Mar 2012 15:42:29 -0400 From: Brandon Allbery <allber...@gmail.com> Subject: Re: [Haskell-beginners] A "show" error To: bahad?r altan <doal...@yahoo.co.uk> Cc: "beginners@haskell.org" <beginners@haskell.org> Message-ID: <cakfcl4x7o7u8kdgq6erlm0tee4oynmnt3nqqsqccvvq+23a...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" On Sun, Mar 11, 2012 at 15:10, bahad?r altan <doal...@yahoo.co.uk> wrote: > ERROR - Cannot find "show" function for: > *** Expression : f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty > Empty)) > *** Of type : (Integer,Integer,Tree,Tree,Integer,Tree,Tree) > Hugs apparently doesn't have a Show instance for 7-tuples. Note that Hugs is quite old and not very well supported at this point; you should probably be using ghc / ghci instead. -- brandon s allbery allber...@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120311/1d42d4ce/attachment.html> ------------------------------ Message: 4 Date: Sun, 11 Mar 2012 20:43:13 +0100 From: Adrien Haxaire <adr...@haxaire.org> Subject: Re: [Haskell-beginners] A "show" error To: beginners@haskell.org Message-ID: <20120311194313.GC4231@arch> Content-Type: text/plain; charset=us-ascii On Sun, Mar 11, 2012 at 07:26:02PM +0000, Ozgur Akgun wrote: > Hi again, > > What interpreter do you use? With ghci, I don't get any errors. > > *Main> f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) > (12,15,Empty,Empty,28,Empty,Empty) > Hi, Me neither, no error on GHCi 7.4.1 on ArchLinux. Prelude> data Tree = Empty | Branch Integer Tree Tree deriving (Show) Prelude> let f (Branch x (Branch y y1 y2) (Branch z z1 z2)) = (x,y,y1,y2,z,z1,z2) Prelude> f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) (12,15,Empty,Empty,28,Empty,Empty) HTH, Adrien -- Adrien Haxaire www.adrienhaxaire.org | @adrienhaxaire ------------------------------ Message: 5 Date: Sun, 11 Mar 2012 20:00:34 +0000 (GMT) From: bahad?r altan <doal...@yahoo.co.uk> Subject: Re: [Haskell-beginners] A "show" error To: Ozgur Akgun <ozgurak...@gmail.com> Cc: "beginners@haskell.org" <beginners@haskell.org> Message-ID: <1331496034.36410.yahoomail...@web171604.mail.ir2.yahoo.com> Content-Type: text/plain; charset="iso-8859-1" I use Hugs. ?And I must use it... ________________________________ From: Ozgur Akgun <ozgurak...@gmail.com> To: bahad?r altan <doal...@yahoo.co.uk> Cc: "beginners@haskell.org" <beginners@haskell.org> Sent: Sunday, 11 March 2012, 21:26 Subject: Re: [Haskell-beginners] A "show" error Hi again, What interpreter do you use? With ghci, I don't get any errors. *Main> f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) (12,15,Empty,Empty,28,Empty,Empty) On 11 March 2012 19:10, bahad?r altan <doal...@yahoo.co.uk> wrote: Hi,? >I'm trying to process on a tree with this function : > > >f (Branch x (Branch y y1 y2) (Branch z z1 z2)) = (x,y,y1,y2,z,z1,z2) > > > >and my tree declaration is this :? > > >data Tree = Empty | Branch Integer Tree Tree deriving (Show) > > >And I'm getting this error :? > > >Main> f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) >ERROR - Cannot find "show" function for: >*** Expression : f (Branch 12 (Branch 15 Empty Empty) (Branch 28 Empty Empty)) >*** Of type ? ?: (Integer,Integer,Tree,Tree,Integer,Tree,Tree) > > >I'll be happy if you help me to get rid of this error.. -- Ozgur Akgun -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120311/9224ef16/attachment-0001.htm> ------------------------------ Message: 6 Date: Sun, 11 Mar 2012 21:20:49 -0400 From: Brandon Allbery <allber...@gmail.com> Subject: Re: [Haskell-beginners] A "show" error To: bahad?r altan <doal...@yahoo.co.uk> Cc: "beginners@haskell.org" <beginners@haskell.org> Message-ID: <CAKFCL4WB=aicgyrxlfhzwqekavgsupzfmxhzdgz9ylbqgrq...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" On Sun, Mar 11, 2012 at 16:00, bahad?r altan <doal...@yahoo.co.uk> wrote: > I use Hugs. And I must use it... > That's ... unfortunate. Use smaller tuples, then; I believe 6 is the limit for its Show and Read instances. Or define your own result ADT and derive a Show instance for it. -- brandon s allbery allber...@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120311/e8985dda/attachment-0001.htm> ------------------------------ Message: 7 Date: Mon, 12 Mar 2012 02:38:45 -0400 From: Joey Hess <j...@kitenet.net> Subject: [Haskell-beginners] populating a bloom filter; stymied by ST monad To: beginners@haskell.org Message-ID: <20120312063845.ga4...@gnu.kitenet.net> Content-Type: text/plain; charset="us-ascii" I have a potentially very large number of values to feed into a bloom filter. They're coming from IO: getValues :: (v -> k -> k) -> k -> IO k getValues update initial = go initial =<< gen where go v [] = return v go v (f:fs) = do x <- val f go (maybe v (`update` v) x) fs gen = undefined val f = undefined This streams lazily, but if I build a list (getValues (:) []), the laziness is lost; the whole list is constructed and returned before any of it can be used. Which uses too much memory of course. So I can't use Data.BloomFilter.fromListB. Seems I need to do something like this: let filter = newMB (cheapHashes 13) 33554432 --- sized for 1 million items filter' <- unsafeFreezeMB <$> getValues insertMB filter Except this won't work, the mutable bloom filter uses the ST monad. And I cannot see a way to combine the three "MB" functions into a single computation in the same ST monad. Perhaps stToIO to is what I need, but I can't work out how to use it. Help? -- see shy jo -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 828 bytes Desc: Digital signature URL: <http://www.haskell.org/pipermail/beginners/attachments/20120312/445439d8/attachment-0001.pgp> ------------------------------ _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners End of Beginners Digest, Vol 45, Issue 16 *****************************************