Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

Hi Donnie, Any chance of those issues being moved over still? I'd prefer to read the older issues in pdf format, like the new issues. I have gotten permission from (almost) all the authors to move the content to the new wiki. I've started reformatting everything to the MediaWiki format -

Re: [Haskell-cafe] I am new to haskell

On 08/mag/08, at 08:59, Benjamin L. Russell wrote: One hint that is not (at least to my knowledge) listed on haskell.org is that, according to at least one user (see "The Programmers’ Stone » Blog Archive » A First Haskell Experience" at http://the-programmers-stone.com/2008/03/04/a-first-h

[Haskell-cafe] "resource exhausted"

Hello, I am running some monadic code that I have written. I double checked my code and it seems to be ok (no guarantee though). I am getting a "resource exhausted (Message too long)". I just did a google on "resource exhausted" and saw a few posts on the number of open files which is obviousl

Re: [Haskell-cafe] Interesting critique of OCaml

Actually, it's (+) for ints and (+.) for floats. Which kind of proves your point. Mike Tim Docker wrote: | An interesting critique of OCaml. | | http://enfranchisedmind.com/blog/2008/05/07/why-ocaml-sucks/ Interesting to me is that my pet ocaml peeve is not there: namely the lack of conven

RE: [Haskell-cafe] Interesting critique of OCaml

| An interesting critique of OCaml. | | http://enfranchisedmind.com/blog/2008/05/07/why-ocaml-sucks/ Interesting to me is that my pet ocaml peeve is not there: namely the lack of convenient operator overloading. Admittedly I only used ocaml for 6 months, but I never adapted to needing to write (+

Re[2]: [Haskell-cafe] Newbie Question: Using Haskell Functions in a C Program

Hello Philip, Friday, May 9, 2008, 3:09:33 AM, you wrote: > Thanks for all the answers. I'm testing this right now and simples cases > work as expected. However from what I've read it seems it'll get ugly > once I try to pass a C array to a Haskell function. http://haskell.org/haskellwiki/Moder

Re: [Haskell-cafe] Stack vs Heap allocation

Edsko de Vries wrote: sum :: Tree -> Int sum t = sum' [t] 0 where sum' [] acc = acc sum' (Leaf i : ts) acc = sum' ts $! (i + acc) sum' (Node l r : ts) acc = sum' (l : r : ts) acc Because of $!, you should compare the Leaf case to foldl', not foldl. The Node case can be said to mi

Re: [Haskell-cafe] Newbie Question: Using Haskell Functions in a C Program

mail: > Thanks for all the answers. I'm testing this right now and simples > cases work as expected. However from what I've read it seems it'll > get ugly once I try to pass a C array to a Haskell function. Right, passing arrays back and forth is going to get tiring. > Well, maybe arrays in C

Re: [Haskell-cafe] Induction (help!)

On 5/8/08, Daniel Fischer <[EMAIL PROTECTED]> wrote: > No. In the induction step, we prove that > IF p(j) holds, THEN p(j+1) holds, too. > p(j) is the assumption, and we prove that *given that assumption*, p(j+1) > follows. > Then we have proved > (*) p(j) implies p(j+1), for all j. To formalize t

Re: [Haskell-cafe] Newbie Question: Using Haskell Functions in a C Program

Thanks for all the answers. I'm testing this right now and simples cases work as expected. However from what I've read it seems it'll get ugly once I try to pass a C array to a Haskell function. Well, maybe arrays in C have been ugly before trying to pass them to Haskell functions ;) To elab

Re: [Haskell-cafe] Stack vs Heap allocation

On Thu, 2008-05-08 at 23:29 +0100, Edsko de Vries wrote: > Hi, > > How can I know whether something will be stack or heap allocated? For > example, in the standard example of why > > foldl (+) 0 > > will fail to evaluate a long list of integers due to a stack overflow, > but foldl' won't, it is

Re: [Haskell-cafe] Newbie Question: Using Haskell Functions in a C Program

mail: > Is there a way to write some of the functions in Haskell and then use > them in my C code via some kind of interface? Using C just for IO is a bit weird -- perhaps you could illustrate the kind of IO you're doing? Learning how to do IO in Haskell is a much safer solution that linking th

Re: [Haskell-cafe] Newbie Question: Using Haskell Functions in a C Program

Hello Philip, Friday, May 9, 2008, 2:17:41 AM, you wrote: > Is there a way to write some of the functions in Haskell and then use > them in my C code via some kind of interface? http://haskell.org/haskellwiki/IO_inside#Interfacing_with_foreign_evil_.28under_development.29 and then entries 1,6,7

[Haskell-cafe] Stack vs Heap allocation

Hi, How can I know whether something will be stack or heap allocated? For example, in the standard example of why foldl (+) 0 will fail to evaluate a long list of integers due to a stack overflow, but foldl' won't, it is pointed out that foldl starts building up unevaluated thunks. So, apparent

[Haskell-cafe] Re: Newbie Question: Using Haskell Functions in a C Program

Philip Müller <[EMAIL PROTECTED]> wrote: > Is there a way to write some of the functions in Haskell and then use > them in my C code via some kind of interface? > The beast you are looking for is called the FFI: Foreign Function Interface. C doesn't make IO any easier, though. More verbose and

Re: [Haskell-cafe] Induction (help!)

Am Freitag, 9. Mai 2008 00:04 schrieb PR Stanley: > You've got the right idea. > Paul: At long last! :-) > I should point out that it doesn't make sense to say p(Succ n) = > Succ(p(n)), p(x) represents some statement that is either true or > false, so it doesn't make sense to say Succ(

[Haskell-cafe] Newbie Question: Using Haskell Functions in a C Program

Hi, I'm in the process of writing a C program, but I can't stop thinking about how some functions would be much nicer implemented in Haskell. Is there a way to write some of the functions in Haskell and then use them in my C code via some kind of interface? BTW yes, I have been thinking abo

Re: [Haskell-cafe] Induction (help!)

You've got the right idea. Paul: At long last! :-) I should point out that it doesn't make sense to say p(Succ n) = Succ(p(n)), p(x) represents some statement that is either true or false, so it doesn't make sense to say Succ(p(n)). . Paul: okay, da capo: We prove/test through

Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

Speaking of old Monad.Reader issues... the wiki says, "Issues 2 through 5 can be found on the special tmrwiki – they haven't been included here for licensing reasons. I hope to move over most of the content soon." Any chance of those issues being moved over still?

Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

Don Stewart wrote: You should read through every issue ever published though -- there's a lot of interesting lessons in TMR for the practical Haskeller. That would be entertaining sometime, but how many issues have ac... oh, wait... this is issue 11? Hmm, I hadn't realised that this publica

Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

andrewcoppin: > Wouter Swierstra wrote: > > > >On 7 May 2008, at 19:56, Andrew Coppin wrote: > > > >>Wouter Swierstra wrote: > >>>Please consider writing something for the next issue of The > >>>Monad.Reader. > >> > >>You know, I'm actually tempted to do just that... > > > >Please do! We've had lo

Re: [Haskell-cafe] Re: Interesting critique of OCaml

2008/5/8 Donnie Jones <[EMAIL PROTECTED]>: > I would be interested to see an article on Haskell in the same light as this > Ocaml article, aka a constructive criticism of Haskell. > http://www.drmaciver.com/2008/02/tell-us-why-your-language-sucks/ -- Darrin ___

Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

Without reading through every issue ever published, do you have any specific examples of this that I [or anybody else in cafe] could take a look at? The following two articles spring to mind: * Kenneth Hoste wrote a gtk2hs tutorial, after having just started using it: http://www.haskell.

Re: [Haskell-cafe] A Cabal problem

Duncan Coutts wrote: On Tue, 2008-05-06 at 09:43 -0400, Mario Blazevic wrote: Trevor Elliott wrote: Cabal doesn't pass the --main-is option, I believe because it is specific to GHC. What you could do is add this flag in the ghc-options field of your executable in the cabal file, like this:

[Haskell-cafe] Re: I am new to haskell

Bjorn Buckwalter gmail.com> writes: > I found the "Gentle Introduction..." mentioned elsewhere in this thread to be > not-so-gentle as described on the tutorials wiki page. I'd avoid it unless > you're already comfortable with functional programming. Let me modify that statement. I'd avoid it un

[Haskell-cafe] Re: I am new to haskell

Ambrish Bhargava gmail.com> writes: > Hi All,I am new to Haskell. Can anyone guide me how can I start on it (Like getting binaries, some tutorials)?Thanks in advance.-- Regards,Ambrish Bhargava Ambrish, When I started learning Haskell I had no previous exposure to functional programming. The so

Re: [Haskell] [Haskell-cafe] Help with polymorphic functions

Op Thursday 08 May 2008 21:10:08 schreef Wei Yuan Cai: > shift is defined as "a -> Int -> a" It's not. It's defined as "(Bits a) => a -> Int -> a" or something along those lines. So there is a restriction that the type a must be a member of the Bits typeclass. Because "test" is essentially just

Re: [Haskell] [Haskell-cafe] Help with polymorphic functions

Hello Wei, Thursday, May 8, 2008, 11:10:08 PM, you wrote: > test :: a -> Int -> a > shift is defined as "a -> Int -> a" not exactly ;) this type signature is given inside class Bits, where 'a' isn't a free variable (as in standalone signature declaration), but means 'a' from type class header:

Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

Wouter Swierstra wrote: On 7 May 2008, at 19:56, Andrew Coppin wrote: Wouter Swierstra wrote: Please consider writing something for the next issue of The Monad.Reader. You know, I'm actually tempted to do just that... Please do! We've had lots of excellent articles written by people who

[Haskell-cafe] Workshop on Generic Programming: Call for Papers (co-located w/ ICFP08)

CALL FOR PAPERS Workshop on Generic Programming 2008 Victoria, Canada, 20th September 2008 http://www.comlab.ox.ac.uk/ralf.hinze/wgp2008/cfp.{html,pdf,ps,txt} The Workshop on Generic Programming is sponsored by AC

Re: [Haskell-cafe] Re: Interesting critique of OCaml

Hello, I pasted a copy of the article below for those that cannot access the site. I would be interested to see an article on Haskell in the same light as this Ocaml article, aka a constructive criticism of Haskell. Enjoy! __ Donnie ### Begin Article ### Why Ocaml Sucks

Re: [Haskell-cafe] Random numbers / monads - beginner question

Henning Thielemann wrote: On Thu, 8 May 2008, Madoc wrote: minValue = 0::Int maxValue = 1000::Int normalize a | a < minValue = minValue | a > maxValue = maxValue | otherwise = a normalize' = min maxValue . max minValue There is a curiosity here. The functions normal

Re: [Haskell-cafe] Re: Interesting critique of OCaml

Chad Scherrer wrote: PS - the link now gives a "500 server error" - did our traffic overwhelm it? Is the cafe the next slashdot? ;) Hell, I can't even get a TCP SYN-ACK packet out of it... :-/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org

Re: [Haskell-cafe] Re: Interesting critique of OCaml

Achim Schneider wrote: Some years or decades ahead, perhaps Haskell will not be able to avoid being successful anymore, and that is the time where you'll see things that look like Java, feel like Java, work like Java, but still use a Haskell RTS. I'm told they're calling it F#... [No, I can

[Haskell-cafe] Re: Interesting critique of OCaml

Chad Scherrer <[EMAIL PROTECTED]> wrote: > Don Stewart galois.com> writes: > [Stuff where I totally agree] > > Now, I don't know much about lisp, but aren't code transformations > like this the whole point of macros? What makes is difficult to do > the same thing in this context? > Proof of cor

[Haskell-cafe] Re: [Haskell] Re: ANN: Haddock version 2.1.0

2008/5/8 Simon Marlow <[EMAIL PROTECTED]>: > So basically you want to run a lexer over the source again to collect all > the comments? Yes. > You really want to use GHC's lexer, because otherwise you > have to write another lexer. I don't mind writing a lexer that just collects the comments. It

[Haskell-cafe] Re: Interesting critique of OCaml

Don Stewart galois.com> writes: [interesting quote...] > Which I think really captures the joy of being able to write algebraic > and data structure transformations, via rewrite rules, without having to > extend the compiler -- all thanks to purity, laziness, and static > typing. This makes me wo

Re: [Haskell-cafe] Using Template Haskell to make type-safe database access

Hi Wouter, Wouter Swierstra wrote: > Nice! I have to admit, it's much nicer than I expected it to be. Just > out of curiousity, what happens when you write: > > selectTupleList :: Connection -> IO [Integer] > > instead of > > selectTupleList :: Connection -> IO [(Integer, String, String)] >

Re: [Haskell-cafe] I am new to haskell

On Thu, May 8, 2008 at 2:59 AM, Benjamin L. Russell <[EMAIL PROTECTED]> wrote: > * Kees Doets and Jan van Eijck: The Haskell Road to Logic, Maths and > Programming, As someone approaching haskell with very rusty math skills, this book has been invaluable. My haskell skills are (mostly) beyond wh

Re: [Haskell-cafe] IO Help

Thank you all for your help, you have been invaluable Thomas Davie wrote: On 8 May 2008, at 16:31, Mark Wallsgrove wrote: Was there? I have been google'ing that problem for ages.. Just one more thing. I have to make a menu system where the user chooses what functionality they want. Because

Re: [Haskell-cafe] IO Help

On 8 May 2008, at 16:31, Mark Wallsgrove wrote: Was there? I have been google'ing that problem for ages.. Just one more thing. I have to make a menu system where the user chooses what functionality they want. Because you cannot change a value once it is set I have used recursion so that wh

Re: [Haskell-cafe] IO Help

Was there? I have been google'ing that problem for ages.. Just one more thing. I have to make a menu system where the user chooses what functionality they want. Because you cannot change a value once it is set I have used recursion so that when something changes it then calls the menu back up.

Re: [Haskell-cafe] IO Help

On Thu, 8 May 2008, Mark Wallsgrove wrote: Thank you very much for your fast response! Ok, that is now changed, but everything else in my program is expecting Catalogue without IO. Is there a way to change IO Catalogue into Catalogue? Btw. there was a nice article precisely about the issue

[Haskell-cafe] List questions

<[EMAIL PROTECTED]> wrote: > Hi I have a bit of a dilemma.I have a list of lists, eg, > [[1,2,3],[4,5,6],[7,8,9]]. Imagine they represent a grid with 0-2 on > the x axis and 0-2 on the y axis, eg, (0,0) is 1, (1,0) is 2, (2,1) > is 6, etc and (2,3) is 9. I want to be able to put in the list of > l

Re: [Haskell-cafe] (no subject)

Am Donnerstag, 8. Mai 2008 15:36 schrieb [EMAIL PROTECTED]: > Hi I have a bit of a dilemma.I have a list of lists, eg, > [[1,2,3],[4,5,6],[7,8,9]]. Imagine they represent a grid with 0-2 on the x > axis and 0-2 on the y axis, eg, (0,0) is 1, (1,0) is 2, (2,1) is 6, etc and > (2,3) is 9. I want to b

Re: [Haskell-cafe] IO Help

On Thu, 8 May 2008, Mark Wallsgrove wrote: Thank you very much for your fast response! Ok, that is now changed, but everything else in my program is expecting Catalogue without IO. Is there a way to change IO Catalogue into Catalogue? Yes, but you do not want that. You will go on writing fu

[Haskell-cafe] Thanks for the help! (Random numbers / monads - beginner question)

Thanks for helping me! Your fast and accurate responses helped me to solve this issue. I am not so angry at IO any more. You showed me more than one way in which I can solve the problem. In addition, the answers to the other thread "IO Help" helped me too. It seems that Mr. Wallsgrove had a very

Re: [Haskell-cafe] Random numbers / monads - beginner question

2008/5/8 Madoc <[EMAIL PROTECTED]>: > Hello, > > I am just learning Haskell. Now, I encountered something that I cannot > solve by myself. Your advice will be greatly appreciated. > > Given a list of numbers, I want to modify each of those numbers by adding a > random offset. However, each such mo

Re: [Haskell-cafe] IO Help

On Thu, May 8, 2008 at 10:59 PM, Mark Wallsgrove <[EMAIL PROTECTED]> wrote: > Thank you very much for your fast response! > > Ok, that is now changed, but everything else in my program is expecting > Catalogue without IO. Is there a way to change IO Catalogue into Catalogue? Suppose I have a funct

[Haskell-cafe] (no subject)

Hi I have a bit of a dilemma.I have a list of lists, eg, [[1,2,3],[4,5,6],[7,8,9]]. Imagine they represent a grid with 0-2 on the x axis and 0-2 on the y axis, eg, (0,0) is 1, (1,0) is 2, (2,1) is 6, etc and (2,3) is 9. I want to be able to put in the list of lists, and the (x,y) coordinate, and

Re: [Haskell-cafe] IO Help

Am Donnerstag, 8. Mai 2008 14:59 schrieb Mark Wallsgrove: > Thank you very much for your fast response! > > Ok, that is now changed, but everything else in my program is expecting > Catalogue without IO. Is there a way to change IO Catalogue into Catalogue? > Not a recommendable way. But there's no

Re: [Haskell-cafe] IO Help

Thank you very much for your fast response! Ok, that is now changed, but everything else in my program is expecting Catalogue without IO. Is there a way to change IO Catalogue into Catalogue? Henning Thielemann wrote: On Thu, 8 May 2008, Mark Wallsgrove wrote: Problem now is reading the dat

Re: [Haskell-cafe] IO Help

On Thu, 8 May 2008, Mark Wallsgrove wrote: Problem now is reading the data back into the program. When I read the data back into the program it comes as IO [Track]. This is the code I have been using to load the data: loadData :: String -> Catalogue loadData fileName = do x <- readFile fileNa

[Haskell-cafe] IO Help

Hey, I am studying Haskell as a unit at University. I find the concept and design idea's of Haskell interesting but I am finding my self struggling to understand the relationship between the normal state and IO state of Haskell. This is my situation: I have created 12 functions for a program whi

Re: [Haskell-cafe] Random numbers / monads - beginner question

On Thu, 8 May 2008, Madoc wrote: Given a list of numbers, I want to modify each of those numbers by adding a random offset. However, each such modified number shall stay within certain bounds, given by the integers minValue and maxValue. After that, I want to continue computation with the resul

[Haskell-cafe] Re: [Haskell] Re: ANN: Haddock version 2.1.0

David Waern wrote: 2008/5/2 Claus Reinke <[EMAIL PROTECTED]>: 2008/5/2 Simon Marlow <[EMAIL PROTECTED]>: David Waern wrote: No it doesn't, but it's on the TODO list. It needs a fix in GHC. By the way, I'm going to experiment with doing the parsing of comments on the Haddock side instead of

Re: [Haskell-cafe] Random numbers / monads - beginner question

2008/5/8 Thomas Dinsdale-Young <[EMAIL PROTECTED]>: > Madoc wrote: > > Given a list of numbers, I want to modify each of those numbers by adding a > > random offset. However, each such modified number shall stay within certain > > bounds, given by the integers minValue and maxValue. After that, I

Re: [Haskell-cafe] Random numbers / monads - beginner question

Madoc wrote: Given a list of numbers, I want to modify each of those numbers by adding a random offset. However, each such modified number shall stay within certain bounds, given by the integers minValue and maxValue. After that, I want to continue computation with the resulting list of type [Int

Re: [Haskell-cafe] Induction (help!)

On Wed, May 7, 2008 at 8:01 PM, PR Stanley <[EMAIL PROTECTED]> wrote: > So, when you apply the function to the first element in the set - e.g. Zero > or Nil in the case of lists - you're actually testing to see the function > works. Then in the inductive step you base everything on the assumption

Re: [Haskell-cafe] help in tree folding

On Wed, May 7, 2008 at 6:28 AM, patrik osgnach <[EMAIL PROTECTED]> wrote: > Daniel Fischer ha scritto: > > Am Dienstag, 6. Mai 2008 22:40 schrieb patrik osgnach: >> >>> Brent Yorgey ha scritto: >>> On Tue, May 6, 2008 at 8:20 AM, patrik osgnach < [EMAIL PROTECTED]> wrote:

Re: [Haskell-cafe] Random numbers / monads - beginner question

Madoc wrote: Given a list of numbers, I want to modify each of those numbers by adding a random offset. However, each such modified number shall stay within certain bounds, given by the integers minValue and maxValue. After that, I want to continue computation with the resulting list of type [Int

[Haskell-cafe] Random numbers / monads - beginner question

Hello, I am just learning Haskell. Now, I encountered something that I cannot solve by myself. Your advice will be greatly appreciated. Given a list of numbers, I want to modify each of those numbers by adding a random offset. However, each such modified number shall stay within certain bounds

Re: [Haskell-cafe] I am new to haskell

Thanks for this list. On Thu, May 8, 2008 at 12:29 PM, Benjamin L. Russell <[EMAIL PROTECTED]> wrote: > One hint that is not (at least to my knowledge) listed on haskell.org is > that, according to at least one user (see "The Programmers' Stone » Blog > Archive » A First Haskell Experience" at >

Re: [Haskell-cafe] Using Template Haskell to make type-safe database access

Hi Mads, Not only pictures, but also code can say more than a thousands words. Therefore, I have been implementing a proof of concept. The code is attached in two files. Nice! I have to admit, it's much nicer than I expected it to be. Just out of curiousity, what happens when you write: se

Re : [Haskell-cafe] I am new to haskell

Hi, Personnaly, I started to learn Haskell with A Gentle Introduction and (from what I recall) really enjoyed it. I find The Haskell School of Expression a bit problematic because it interleaves information about the language with (although nice) large running-through-all-the-chapter examples. A

Re: [Haskell-cafe] The Monad.Reader (11) - Call for Copy

On 7 May 2008, at 19:56, Andrew Coppin wrote: Wouter Swierstra wrote: Please consider writing something for the next issue of The Monad.Reader. You know, I'm actually tempted to do just that... Please do! We've had lots of excellent articles written by people who were just learning Hask