- Haskell-Cafe - Haskell.org

Bilgi Payla�t�k�a Artar
by info 11 Sep '02

11 Sep '02

1 0

mutable records
by Scott J. 10 Sep '02

10 Sep '02

Hi, Is it possible to define oject types in Haskell and what does one propose to do it? Is it possible to define parts of a record with the help of the ST s monad mutable during the whole program? (As is possible in Ocamel)? Thx Scott

8 11

RE: A problem with haskell-mode
by Simon Marlow 09 Sep '02

09 Sep '02

> I had the same problem, and I found a fix somewhere. > Don't reember what exactly I had to change so I'll just send > you my Haskell section of xemacs init.el. > > By the way I get an error whenever I type "undefined". Anyone > else noticed it? > (1) (error/warning) Error in `post-command-hook' (setting > hook to nil): > (wrong-type-argument listp a ) I'm officially the maintainer of the emacs Haskell mode since Reuben Thomas left, but I deleted the section of my brain that contained my knowledge of emacs lisp in order to make more room for GHC, so I'm not a very effective maintainer I'm afraid :( Offers to take over the maintainership are entirely welcome, but in the meantime I'm happy to add any fixes for these kinds of problems to the web page and/or the source. Cheers, Simon

1 0

A problem with haskell-mode
by Deling Ren 06 Sep '02

06 Sep '02

Hi, all, I installed the latest version of Haskell mode for emacs. Whenever I load haskell major mode by opening a haskell file, Xemacs gives me the following error message: (1) (error/warning) Error in `post-command-hook' (setting hook to nil): (void-variable imenu--index-alist) My Xemacs version is 21.4.8. It works well under GNU emacs though. Anybody has an idea how to get around it? Thanks. Deling

2 1

aide SVP
by fouad ktiri 31 Aug '02

31 Aug '02

Bonjour, Comment faire pour stocker des données dans une liste comme en programmation normale (x=x+1) Merci beaucoup ______________________________________________________ Boîte aux lettres - Caramail - http://www.caramail.com

2 1

help
by yan zhong 31 Aug '02

31 Aug '02

3 2

RE: Question aboutthe use of an inner forall
by Simon Peyton-Jones 30 Aug '02

30 Aug '02

Now fixed in the 5.04 branch. The fix will get into the HEAD when I merge in the Template Haskell stuff. Thanks for the report Simon | -----Original Message----- | From: Simon Peyton-Jones [mailto:simonpj@microsoft.com] | Sent: 28 August 2002 12:21 | To: Ashley Yakeley | Cc: Haskell Cafe List | Subject: RE: Question aboutthe use of an inner forall | | | No, this is a bug, thank you. Will fix. | | Simon | | | -----Original Message----- | | From: Ashley Yakeley [mailto:ashley@semantic.org] | | Sent: 19 August 2002 11:31 | | To: Jay Cox; Haskell Cafe List | | Subject: Re: Question aboutthe use of an inner forall | | | | | | At 2002-08-18 20:19, Jay Cox wrote: | | | | >#ST> runST (newSTRef (3::Prelude.Int)) | | ># | | >#Ambiguous type variable(s) `a' in the constraint `PrelShow.Show a' | | >#arising from use of `PrelIO.print' at <No locn> #In a 'do' | | expression | | >pattern binding: PrelIO.print it | | | | I don't understand this either, actually: | | | | $ ghci -fglasgow-exts -package lang | | ___ ___ _ | | / _ \ /\ /\/ __(_) | | / /_\// /_/ / / | | GHC Interactive, version 5.04, | | for Haskell | | 98. | | / /_\\/ __ / /___| | http://www.haskell.org/ghc/ | | \____/\/ /_/\____/|_| Type :? for help. | | | | Loading package base ... linking ... done. | | Loading package haskell98 ... linking ... done. | | Loading package lang ... linking ... done. | | Prelude> :module ST | | Prelude ST> :type runST | | | | Inferred type is less polymorphic than expected | | Quantified type variable `s' escapes | | Expected type: ST s a -> t | | Inferred type: (forall s1. ST s1 a) -> a | | Prelude ST> | | | | What's up with that? Can't I even look at the type? Is this the | | monomorphism restriction or something? | | | | -- | | Ashley Yakeley, Seattle WA | | | | _______________________________________________ | | Haskell-Cafe mailing list | | Haskell-Cafe(a)haskell.org | | http://www.haskell.org/mailman/listinfo/haskell-cafe | | | _______________________________________________ | Haskell-Cafe mailing list | Haskell-Cafe(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe |

2 1

Say�n haskell-cafe ,
by Green Card 30 Aug '02

30 Aug '02

1 0

RE: Question aboutthe use of an inner forall
by Simon Peyton-Jones 28 Aug '02

28 Aug '02

No, this is a bug, thank you. Will fix. Simon | -----Original Message----- | From: Ashley Yakeley [mailto:ashley@semantic.org] | Sent: 19 August 2002 11:31 | To: Jay Cox; Haskell Cafe List | Subject: Re: Question aboutthe use of an inner forall | | | At 2002-08-18 20:19, Jay Cox wrote: | | >#ST> runST (newSTRef (3::Prelude.Int)) | ># | >#Ambiguous type variable(s) `a' in the constraint `PrelShow.Show a' | >#arising from use of `PrelIO.print' at <No locn> #In a 'do' | expression | >pattern binding: PrelIO.print it | | I don't understand this either, actually: | | $ ghci -fglasgow-exts -package lang | ___ ___ _ | / _ \ /\ /\/ __(_) | / /_\// /_/ / / | | GHC Interactive, version 5.04, | for Haskell | 98. | / /_\\/ __ / /___| | http://www.haskell.org/ghc/ | \____/\/ /_/\____/|_| Type :? for help. | | Loading package base ... linking ... done. | Loading package haskell98 ... linking ... done. | Loading package lang ... linking ... done. | Prelude> :module ST | Prelude ST> :type runST | | Inferred type is less polymorphic than expected | Quantified type variable `s' escapes | Expected type: ST s a -> t | Inferred type: (forall s1. ST s1 a) -> a | Prelude ST> | | What's up with that? Can't I even look at the type? Is this the | monomorphism restriction or something? | | -- | Ashley Yakeley, Seattle WA | | _______________________________________________ | Haskell-Cafe mailing list | Haskell-Cafe(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe |

1 0

N queens problem
by Jonata Goulart 26 Aug '02

26 Aug '02

This is the problem to figure out the n queens problem but I didn't understand it very well. Somebody can help me ? how legal and queens functions work? attack (l,c) (ll,cc) = l ==ll || (l+c==ll+cc) || (l-c==ll-cc) legal p m = and [not (attack (l,c) (m, length p +1)) | (l,c) <- zip p [1..]] queens n = r n n where r 0 n = [[]] r m n = [p ++ [m] | p <- r (m-1) n, m <-[1..n], legal p m] _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com

1 0