[Haskell-cafe] (no subject)
http://maipenarai.com/lindex02.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Input and output of mathematical expressions
On Thu, 9 Jun 2011 16:23:20 +0200 Jacek Generowicz jacek.generow...@cern.ch wrote: Greetings Cafe, What would you recommend as a Haskell-based means of interactively reading and writing mathematical formulae? As a toy example, what might I use to write a program which presents the user with Please simplify the expression: \pi x^2 + 3\pi x^2 (Where the TeX-style expression would be presented with a greek pi and superscript twos on the xs.) The user should then have the ability to reply with something that looks like the result of TeXing 5 \pi x^2 Whatever means the user uses to enter this expression, he should be able to preview the typeset version of his input before submitting. Any ideas? Thanks. Regarding the rendering math formulas on web browsers: you might want to have a look at MathJax (http://www.mathjax.org/). You can use LaTeX or MathML and will work in most browsers (even if when they don't natively support MathML). Pedro ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] YesodAuth documentation
Does exist some simple examples using yesod authentication except code of Haskellers site? Does exist some examples using YesodAuthEmail? For example, can i use third-party mail server instead of Sendmail for YesodAuthEmail? Can i disable registration confirmation? Does passwords stored in a database in an unencrypted form? -- Timofeev N.D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] (no subject)
I'm sorry, somehow my e-mail account got kidnapped. The link is a virus and should NOT be opened. I apologise for any inconvenience. Fernando Henrique Sanches 2011/6/13 Fernando Henrique Sanches fernandohsanc...@gmail.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Input and output of mathematical expressions
Pedro Vasconcelos comments: Regarding the rendering math formulas on web browsers: you might want to have a look at MathJax (http://www.mathjax.org/). You can use LaTeX or MathML and will work in most browsers (even if when they don't natively support MathML). Don't forget two other (which I have been using for years) LaTeXMathML : http://math.etsu.edu/LaTeXMathML/ jsMath : http://www.math.union.edu/~dpvc/jsMath/ The first needs MathML, obviously, but I won't use browser which ignores it... Thios is one script, fairly readable. The second one is much bigger. Used by Planet Math, integrated into Drupal, etc. I confess I tried to write something which displayed math fromHaskell, I gave even a project of that kind to my student. But the solutions exist already and are known, so... See e.g. http://www.twingly.com/haskell/stories/4013ffd773e942fdb4b9cf2cb7c0089e Jerzy Karczmarczuk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] YesodAuth documentation
Does exist some simple examples using yesod authentication except code of Haskellers site? Does exist some examples using YesodAuthEmail? For example, can i use third-party mail server instead of Sendmail for YesodAuthEmail? Can i disable registration confirmation? Does passwords stored in a database in an unencrypted form? -- Timofeev N.D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] ANNOUNCE: Parallel and Concurrent programming in Haskell, a tutorial
On Thu, 19 May 2011, Simon Marlow wrote: I've put together a tutorial on Parallel and Concurrent programming in Haskell, here: http://community.haskell.org/~simonmar/par-tutorial.pdf The main reason for writing this was that I needed some lecture notes for a course at the CEFP summer school next month, but I hope the material is useful to the Haskell community in general. Thank you a lot for this overview! Concerning the parallelisation of K-means: It seems to be difficult to choose a size for the pieces of points. Since the 'combine' function is associative something map-reduce-like seems to be applicable. That is, if there is a library function for a parallelised 'reduce' and I promise, that I call it with an associative function as argument, then the library could choose an appropriate size for the pieces. Is there already library support for parallelism of this style? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] YesodAuth documentation
Does exist some simple examples using yesod authentication except code of Haskellers site? Does exist some examples using YesodAuthEmail? Another example is Orangeroster [1]. For example, can i use third-party mail server instead of Sendmail for YesodAuthEmail? No. Email handling is done through the mime-mail package, which uses sendmail to do it's work. Can i disable registration confirmation? Does passwords stored in a database in an unencrypted form? The stock email plugin does not let you disable these features, but it should be easy to write your own. [1] : http://github.com/snoyberg/orangeroster 2011/6/13 Тимофеев Никита Дмитриевич ndtimof...@gmail.com Does exist some simple examples using yesod authentication except code of Haskellers site? Does exist some examples using YesodAuthEmail? For example, can i use third-party mail server instead of Sendmail for YesodAuthEmail? Can i disable registration confirmation? Does passwords stored in a database in an unencrypted form? -- Timofeev N.D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- -- Michael Steele ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] GHC handles badly with math formulas
I've noted several times that GHC doesn't evaluate formulas for Double values during compilation. That is using 4.2326514735445615 instead of (512 / 0.844)**(1/3) or 0.906179845938664 instead of (1/3) * sqrt(5 + 2 * sqrt(10 / 7)) This can lead to significant slowdown if such values are called often. It's not always convenient to use where or let to reduce the number of calculations of such constants so I wonder how to force GHC to evaluate them during compilation? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] ANNOUNCE: Parallel and Concurrent programming in Haskell, a tutorial
On 13/06/2011 15:23, Henning Thielemann wrote: On Thu, 19 May 2011, Simon Marlow wrote: I've put together a tutorial on Parallel and Concurrent programming in Haskell, here: http://community.haskell.org/~simonmar/par-tutorial.pdf The main reason for writing this was that I needed some lecture notes for a course at the CEFP summer school next month, but I hope the material is useful to the Haskell community in general. Thank you a lot for this overview! Concerning the parallelisation of K-means: It seems to be difficult to choose a size for the pieces of points. In practice it's not too sensitive - as long as the value is much larger than the number of cores, but less than the spark pool size (4096), you should be ok. Since the 'combine' function is associative something map-reduce-like seems to be applicable. That is, if there is a library function for a parallelised 'reduce' and I promise, that I call it with an associative function as argument, then the library could choose an appropriate size for the pieces. Is there already library support for parallelism of this style? Not really, but there ought to be. Various people have looked at this problem, but not much in Haskell (look at Lazy Tree Splitting for example). In practice you usually want to add a cut-off point to the tree below which you stop trying to parallelise. Cheers, Simon ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC handles badly with math formulas
On Monday 13 June 2011, 17:46:23, Grigory Sarnitskiy wrote: I've noted several times that GHC doesn't evaluate formulas for Double values during compilation. That is using 4.2326514735445615 instead of (512 / 0.844)**(1/3) or 0.906179845938664 instead of (1/3) * sqrt(5 + 2 * sqrt(10 / 7)) This can lead to significant slowdown if such values are called often. It's not always convenient to use where or let to reduce the number of calculations of such constants so I wonder how to force GHC to evaluate them during compilation? http://hackage.haskell.org/trac/ghc/ticket/4101 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC handles badly with math formulas
On Mon, 2011-06-13 at 19:46 +0400, Grigory Sarnitskiy wrote: I've noted several times that GHC doesn't evaluate formulas for Double values during compilation. That is using 4.2326514735445615 instead of (512 / 0.844)**(1/3) or 0.906179845938664 instead of (1/3) * sqrt(5 + 2 * sqrt(10 / 7)) Yep, looks that way. It's the square roots and powers that GHC is not applying. Where you've got divisions between constants, those are getting applied at compile time. This can lead to significant slowdown if such values are called often. If you assign them to a global name, then lazy evaluation will take care of it. It looks like GHC is even throwing in a specialization for Double when I give the global name a polymorphic type. -- Chris Smith ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] question about interruptable state runner
On 11-06-09 04:14 PM, Alexander V Vershilov wrote: Hello. I'm writing a small tcp server with that can handle connections and answer by rules writen in a small script that can be interpreted by server. For this purpose I've written an interpreter that has type ErrorT MyError (StateT ScriptState IO) so I can call native IO function in that script, and define new one. I can run this script with runState (runErrorT (...)) oldState. But there is one problem: in script i should be able to call functions that will stop script interpretation and wait for some server event. To continue interpretation. Can smb give an advice what is the best way to do it? It appears you've already settled on operational, and that's a good choice. I just wanted to point out the monad-coroutine as a possible alternative. The two packages have lots of similarities, the main difference appears to be in the way the monad suspension is seen: Prompt vs. Functor. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Unexpected type error
On Sun, Jun 12, 2011 at 7:12 PM, Antoine Latter aslat...@gmail.com wrote: Types from differing versions of the same module are specifically not compatible - even if they are defined identically (in this case they are different, though). You can do one of two things: 1. Edit the package description of the package that wants the older version of parsec to allow to use the new one. Also, it helps to slightly bump the version number of the package when you do this. 2. Use the older version of parsec in your software. You already have it installed (or else the package you want to use wouldn't be able to load!). If you're using ghci you can start it with the option '-package parsec-2.1.0.1'. I understand that types from different versions of a module are incompatible. What I don't understand is why one module is using a new version of Parsec when it is constrained to use the old one (I control both modules. Their package descriptions contain the same line). Is this a cabal-dev bug? I'll try the -package parsec-2.1.0.1 tip, but this is /not/ a long term solution to my problem. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Unexpected type error
On Mon, Jun 13, 2011 at 12:34 PM, Alexander Solla alex.so...@gmail.com wrote: On Sun, Jun 12, 2011 at 7:12 PM, Antoine Latter aslat...@gmail.com wrote: Types from differing versions of the same module are specifically not compatible - even if they are defined identically (in this case they are different, though). You can do one of two things: 1. Edit the package description of the package that wants the older version of parsec to allow to use the new one. Also, it helps to slightly bump the version number of the package when you do this. 2. Use the older version of parsec in your software. You already have it installed (or else the package you want to use wouldn't be able to load!). If you're using ghci you can start it with the option '-package parsec-2.1.0.1'. I understand that types from different versions of a module are incompatible. What I don't understand is why one module is using a new version of Parsec when it is constrained to use the old one (I control both modules. Their package descriptions contain the same line). Is this a cabal-dev bug? I'll try the -package parsec-2.1.0.1 tip, but this is /not/ a long term solution to my problem. I think I might be mus-understanding your problem. Which module is producing the error message? In which package? How are you compiling this module? What should be constraining it to the older version of parsec? I'd been assuming that you were getting this message from compiling your own modules by hand, or in GHCi. Take care, Antoine ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Unexpected type error
On Mon, Jun 13, 2011 at 10:45 AM, Antoine Latter aslat...@gmail.com wrote: On Mon, Jun 13, 2011 at 12:34 PM, Alexander Solla alex.so...@gmail.com wrote: On Sun, Jun 12, 2011 at 7:12 PM, Antoine Latter aslat...@gmail.com wrote: Types from differing versions of the same module are specifically not compatible - even if they are defined identically (in this case they are different, though). You can do one of two things: 1. Edit the package description of the package that wants the older version of parsec to allow to use the new one. Also, it helps to slightly bump the version number of the package when you do this. 2. Use the older version of parsec in your software. You already have it installed (or else the package you want to use wouldn't be able to load!). If you're using ghci you can start it with the option '-package parsec-2.1.0.1'. I understand that types from different versions of a module are incompatible. What I don't understand is why one module is using a new version of Parsec when it is constrained to use the old one (I control both modules. Their package descriptions contain the same line). Is this a cabal-dev bug? I'll try the -package parsec-2.1.0.1 tip, but this is /not/ a long term solution to my problem. I think I might be mus-understanding your problem. Which module is producing the error message? In which package? How are you compiling this module? What should be constraining it to the older version of parsec? I'd been assuming that you were getting this message from compiling your own modules by hand, or in GHCi. I am working on Lime, an unreleased module. It depends on Lime-Utility, which is also under my control. Lime's package description contains the Build-Depends constraints (among many others): Lime-Utility =0.1 0.2 parsec =2.1 2.2 Lime-Utility's package description contains the Build-depends constraint: parsec =2.1 2.2 I am using cabal-dev to maintain a package database in my Lime.Blah working directory. I get a compilation failure (based on mismatched types, based on different versions of Parsec) when I use: $ cabal-dev ghci :cd src :l Lime.Data.IPAddress Interestingly, if I do: $ cabal-dev clean cabal-dev configure cabal-dev clean Lime.Data.IPAddress compiles. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Profiling with Data.PQueue.Min
I'm having trouble with getting a profiling version of Data.PQueue.Min. I've set the profiling options in ~/.cabal/config and used it to build profiling versions of other packages. When I run cabal install --reinstall pqueue, it runs successfully and properly installs the package...but it isn't building a profiling version. Has anyone else gotten this to work? I'd appreciate some pointers. thanks Lee Short ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] YesodAuth documentation
2011/6/13 Michael Steele mikesteel...@gmail.com: Does exist some simple examples using yesod authentication except code of Haskellers site? Does exist some examples using YesodAuthEmail? Another example is Orangeroster [1]. For example, can i use third-party mail server instead of Sendmail for YesodAuthEmail? No. Email handling is done through the mime-mail package, which uses sendmail to do it's work. Actually, that's not entirely accurate. The Yesod scaffolding tool generates a site that uses mime-mail and sendmail, but there's nothing inherent in yesod-auth requiring either. Additionally, mime-mail includes a function to use the sendmail executable, but it can also be used with other packages, such as Haskellnet. I think we should move in the direction of making these integrations better. In fact, next time I need to set up a project that sends email, I'll likely be doing just that. Can i disable registration confirmation? Does passwords stored in a database in an unencrypted form? The stock email plugin does not let you disable these features, but it should be easy to write your own. You could just copy the email module from yesod-auth and make the modifications there. Or even better if you're so inclined: submit a patch to make these features optional. If you are so inclined, feel free to contact me for some guidance. Michael [1] : http://github.com/snoyberg/orangeroster 2011/6/13 Тимофеев Никита Дмитриевич ndtimof...@gmail.com Does exist some simple examples using yesod authentication except code of Haskellers site? Does exist some examples using YesodAuthEmail? For example, can i use third-party mail server instead of Sendmail for YesodAuthEmail? Can i disable registration confirmation? Does passwords stored in a database in an unencrypted form? -- Timofeev N.D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- -- Michael Steele ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Unexpected type error
On Mon, Jun 13, 2011 at 1:00 PM, Alexander Solla alex.so...@gmail.com wrote: On Mon, Jun 13, 2011 at 10:45 AM, Antoine Latter aslat...@gmail.com wrote: On Mon, Jun 13, 2011 at 12:34 PM, Alexander Solla alex.so...@gmail.com wrote: On Sun, Jun 12, 2011 at 7:12 PM, Antoine Latter aslat...@gmail.com wrote: Types from differing versions of the same module are specifically not compatible - even if they are defined identically (in this case they are different, though). You can do one of two things: 1. Edit the package description of the package that wants the older version of parsec to allow to use the new one. Also, it helps to slightly bump the version number of the package when you do this. 2. Use the older version of parsec in your software. You already have it installed (or else the package you want to use wouldn't be able to load!). If you're using ghci you can start it with the option '-package parsec-2.1.0.1'. I understand that types from different versions of a module are incompatible. What I don't understand is why one module is using a new version of Parsec when it is constrained to use the old one (I control both modules. Their package descriptions contain the same line). Is this a cabal-dev bug? I'll try the -package parsec-2.1.0.1 tip, but this is /not/ a long term solution to my problem. I think I might be mus-understanding your problem. Which module is producing the error message? In which package? How are you compiling this module? What should be constraining it to the older version of parsec? I'd been assuming that you were getting this message from compiling your own modules by hand, or in GHCi. I am working on Lime, an unreleased module. It depends on Lime-Utility, which is also under my control. Lime's package description contains the Build-Depends constraints (among many others): Lime-Utility =0.1 0.2 parsec =2.1 2.2 Lime-Utility's package description contains the Build-depends constraint: parsec =2.1 2.2 I am using cabal-dev to maintain a package database in my Lime.Blah working directory. I get a compilation failure (based on mismatched types, based on different versions of Parsec) when I use: $ cabal-dev ghci :cd src :l Lime.Data.IPAddress Interestingly, if I do: $ cabal-dev clean cabal-dev configure cabal-dev clean Lime.Data.IPAddress compiles. The command 'cabal-dev ghci' does not use the cabal package description to figure out which dependencies to pull in - if the module you're loading asks for module 'A.B' it loads the most recent version found in the local cabal-devel packages database - even if that same module, when compiled with cabal, would pull in a different package. In your case I'm guessing that something you do later on with cabal-dev pulls in a package which requires parsec-3, which then causes ghci to pull in parsec-3 as its newest version. Getting a proper 'cabal ghci' that passes command-line flags to ghci (along the lines of the -package parameter I gave you above) is something that the cabal folks know people are interested in, but it isn't something we have today. Does that make sense? Antoine ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Vendettaproject]
I'm sorry, somehow my e-mail account got kidnapped. The link is a virus and should NOT be opened. I apologise for any inconvenience. Peço desculpas, de alguma forma minha conta de e-mail foi invadida. O link é um vírus e NÃO deve ser aberto. Peço desculpas por qualquer transtorno. Fernando Henrique Sanches Em 13 de junho de 2011 04:32, Fernando Henrique Sanches fernandohsanc...@gmail.com escreveu: -- Você está recebendo esta mensagem porque se inscreveu no grupo Vendetta Project dos Grupos do Google. Para postar neste grupo, envie um e-mail para fire-kitsune-anime-et-al-c...@googlegroups.com. Para cancelar a inscrição nesse grupo, envie um e-mail para fire-kitsune-anime-et-al-club+unsubscr...@googlegroups.com. Para obter mais opções, visite esse grupo em http://groups.google.com/group/fire-kitsune-anime-et-al-club?hl=pt-BR. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell-Cafe Digest, Vol 93, Issue 58
On 11-06-08 11:17 PM, Gregory Guthrie wrote:
So the implication of the rules:
1) all IO must start from the top level, and there is only one IO
2) you cannot extract anything from an IO
Seems to be that the whole program structure becomes a series of do... blocks,
which is basically a sequential imperative looking style.
The general advice of Strive to keep as much of the program pure as possible
thus seems difficult.
Suppose you teach Java or C++ or any OOP, and you give out this basic
homework to beginners: write a program to take two complex numbers from
the user, then print their sum. You are assured to receive such flawed
design:
class complex {
double r, i;
public:
complex() {
cout please enter the real part:;
cin r;
cout please enter the imaginary part:;
cin i;
}
}
The urge to do I/O at all the wrong places is a born instinct. Humanity
strives to organize programs (and articles) by stream of consciousness
rather than by separation of concerns. Why do they ask the user in the
constructor? Because that's where the editor cursor was when they
remembered to ask the user. Similarly in Haskell, why do they read input
in the data processing function? Because that's where the editor cursor
was when they remembered to read input. This is universal to FP, OOP,
IP, any P, with or without language restrictions.
For people who organize programs by stream of consciousness, Haskell's
separation of IO does not help, but SML's and C++'s non-separation does
not help either. Nothing helps. Don't worry about them.
For people who organize programs by separation of concerns, such as you
and me: Haskell's separation of IO helps. This is what matters.
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Re: [Haskell-cafe] Haskell-Cafe Digest, Vol 93, Issue 58
The urge to do I/O at all the wrong places is a born instinct. The original poster was well aware how to factor out IO out of his program, as made apparent by his initial comment: An option I suppose would be to read the dictionary at the top level, and then pass it all the way down to the analysis routine that uses it, but that exposes the details of how the analysis is done, and couples the top and bottom levels of the previously modular functions. His original argument was a genuine observation that IO sometimes seems to be adverse to the loose coupling of modules. Dissing that argument away as: you are doing IO at the wrong place, doesn't convince me the least. Cheers, Marco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)? Michael___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell-Cafe Digest, Vol 93, Issue 58
On Mon, Jun 13, 2011 at 4:45 PM, M.C.A. (Marco) Devillers marco.devill...@gmail.com wrote: The urge to do I/O at all the wrong places is a born instinct. The original poster was well aware how to factor out IO out of his program, as made apparent by his initial comment: An option I suppose would be to read the dictionary at the top level, and then pass it all the way down to the analysis routine that uses it, but that exposes the details of how the analysis is done, and couples the top and bottom levels of the previously modular functions. His original argument was a genuine observation that IO sometimes seems to be adverse to the loose coupling of modules. Dissing that argument away as: you are doing IO at the wrong place, doesn't convince me the least. There are ways to decouple IO from pure code. I often have a Main datatype which constructs a pure context (based on command line arguments, files and their contents, etc) which is then interpreted by pure code. In other words, this is a pure control structure, which is computed by IO (sometimes in an applicative style, sometimes in a monadic one), and then passed into the pure world for processing. This can be as tightly or loosely coupled as we like, assuming we understand that if a value is even partially based on the results of an IO computation, then IO is going to drive the computation of that value. There's no way around that. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
On Mon, Jun 13, 2011 at 4:56 PM, michael rice nowg...@yahoo.com wrote: Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)? Michael This is as close as I have gotten, but it is only probabilistically true. take_n_unique_randoms_in_range :: ( Ord random , Random random , MonadIO io ) = Int - (random, random) - io [random] take_n_unique_randoms_in_range n (a,b) = liftM ((take n) . nub) . (replicateM (3*n)) . liftIO $ randomRIO (a,b) I'm going to put making an iteratee-based solution on my agenda. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
On Mon, 2011-06-13 at 16:56 -0700, michael rice wrote: Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)? Does anything from random-extras look like it'll work? http://hackage.haskell.org/packages/archive/random-extras/0.17/doc/html/Data-Random-Extras.html Shuffle [1..20], then take 5? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
On Mon, Jun 13, 2011 at 8:56 PM, michael rice nowg...@yahoo.com wrote: Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)? Yes, already implemented in the monte-carlo package as sampleSubset [1], sampleSubset :: MonadMC m = [a] - Int - m [a] Complete example code for your example: evalMC (sampleSubset [1..20] 5) (mt19937 0) Cheers! [1] http://hackage.haskell.org/packages/archive/monte-carlo/0.4.1/doc/html/Control-Monad-MC-Class.html#v:sampleSubset -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
Thanks, all. It seemed like something like this should exist in a prob/stat package, and if so, didn't want to reinvent the wheel. Shuffle [1..20], then take 5? Yes, so simple, I'm embarrassed I didn't think of it. Michael --- On Mon, 6/13/11, Felipe Almeida Lessa felipe.le...@gmail.com wrote: From: Felipe Almeida Lessa felipe.le...@gmail.com Subject: Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints To: michael rice nowg...@yahoo.com Cc: haskell-cafe@haskell.org Date: Monday, June 13, 2011, 9:38 PM On Mon, Jun 13, 2011 at 8:56 PM, michael rice nowg...@yahoo.com wrote: Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)? Yes, already implemented in the monte-carlo package as sampleSubset [1], sampleSubset :: MonadMC m = [a] - Int - m [a] Complete example code for your example: evalMC (sampleSubset [1..20] 5) (mt19937 0) Cheers! [1] http://hackage.haskell.org/packages/archive/monte-carlo/0.4.1/doc/html/Control-Monad-MC-Class.html#v:sampleSubset -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
Reason why this doesn't work? Michael == [michael@sabal ~]$ cabal install monte-carloResolving dependencies...Downloading primitive-0.3.1...Configuring primitive-0.3.1...Preprocessing library primitive-0.3.1...Building primitive-0.3.1...[1 of 7] Compiling Data.Primitive.MachDeps ( Data/Primitive/MachDeps.hs, dist/build/Data/Primitive/MachDeps.o )[2 of 7] Compiling Control.Monad.Primitive ( Control/Monad/Primitive.hs, dist/build/Control/Monad/Primitive.o ) Control/Monad/Primitive.hs:24:1: Warning: Module `GHC.IOBase' is deprecated: use GHC.IO instead[3 of 7] Compiling Data.Primitive.Types ( Data/Primitive/Types.hs, dist/build/Data/Primitive/Types.o ) Data/Primitive/Types.hs:39:30: Warning: In the use of `mkNorepType' (imported from Data.Data): Deprecated: Use mkNoRepType instead[4 of 7] Compiling Data.Primitive.Array ( Data/Primitive/Array.hs, dist/build/Data/Primitive/Array.o ) Data/Primitive/Array.hs:27:30: Warning: In the use of `mkNorepType' (imported from Data.Data): Deprecated: Use mkNoRepType instead[5 of 7] Compiling Data.Primitive.ByteArray ( Data/Primitive/ByteArray.hs, dist/build/Data/Primitive/ByteArray.o ) Data/Primitive/ByteArray.hs:36:30: Warning: In the use of `mkNorepType' (imported from Data.Data): Deprecated: Use mkNoRepType instead[6 of 7] Compiling Data.Primitive.Addr ( Data/Primitive/Addr.hs, dist/build/Data/Primitive/Addr.o )[7 of 7] Compiling Data.Primitive ( Data/Primitive.hs, dist/build/Data/Primitive.o )Registering primitive-0.3.1...Installing library in /home/michael/.cabal/lib/primitive-0.3.1/ghc-7.0.2Registering primitive-0.3.1...Downloading vector-0.7.0.1...Configuring vector-0.7.0.1...Preprocessing library vector-0.7.0.1...Building vector-0.7.0.1...[ 1 of 19] Compiling Data.Vector.Storable.Internal ( Data/Vector/Storable/Internal.hs, dist/build/Data/Vector/Storable/Internal.o )[ 2 of 19] Compiling Data.Vector.Fusion.Util ( Data/Vector/Fusion/Util.hs, dist/build/Data/Vector/Fusion/Util.o )[ 3 of 19] Compiling Data.Vector.Fusion.Stream.Size ( Data/Vector/Fusion/Stream/Size.hs, dist/build/Data/Vector/Fusion/Stream/Size.o ) Data/Vector/Fusion/Stream/Size.hs:25:10: Warning: No explicit method nor default method for `*' In the instance declaration for `Num Size' Data/Vector/Fusion/Stream/Size.hs:25:10: Warning: No explicit method nor default method for `abs' In the instance declaration for `Num Size' Data/Vector/Fusion/Stream/Size.hs:25:10: Warning: No explicit method nor default method for `signum' In the instance declaration for `Num Size'[ 4 of 19] Compiling Data.Vector.Internal.Check ( Data/Vector/Internal/Check.hs, dist/build/Data/Vector/Internal/Check.o )[ 5 of 19] Compiling Data.Vector.Fusion.Stream.Monadic ( Data/Vector/Fusion/Stream/Monadic.hs, dist/build/Data/Vector/Fusion/Stream/Monadic.o )Loading package ghc-prim ... linking ... done.Loading package integer-gmp ... linking ... done.Loading package base ... linking ... done.Loading package primitive-0.3.1 ... linking ... done.[ 6 of 19] Compiling Data.Vector.Fusion.Stream ( Data/Vector/Fusion/Stream.hs, dist/build/Data/Vector/Fusion/Stream.o )[ 7 of 19] Compiling Data.Vector.Generic.Mutable ( Data/Vector/Generic/Mutable.hs, dist/build/Data/Vector/Generic/Mutable.o )[ 8 of 19] Compiling Data.Vector.Generic.Base ( Data/Vector/Generic/Base.hs, dist/build/Data/Vector/Generic/Base.o )[ 9 of 19] Compiling Data.Vector.Generic.New ( Data/Vector/Generic/New.hs, dist/build/Data/Vector/Generic/New.o )[10 of 19] Compiling Data.Vector.Generic ( Data/Vector/Generic.hs, dist/build/Data/Vector/Generic.o ) Data/Vector/Generic.hs:185:36: Warning: In the use of `mkNorepType' (imported from Data.Data): Deprecated: Use mkNoRepType instead[11 of 19] Compiling Data.Vector.Primitive.Mutable ( Data/Vector/Primitive/Mutable.hs, dist/build/Data/Vector/Primitive/Mutable.o )[12 of 19] Compiling Data.Vector.Primitive ( Data/Vector/Primitive.hs, dist/build/Data/Vector/Primitive.o )[13 of 19] Compiling Data.Vector.Storable.Mutable ( Data/Vector/Storable/Mutable.hs, dist/build/Data/Vector/Storable/Mutable.o )[14 of 19] Compiling Data.Vector.Storable ( Data/Vector/Storable.hs, dist/build/Data/Vector/Storable.o )[15 of 19] Compiling Data.Vector.Unboxed.Base ( Data/Vector/Unboxed/Base.hs, dist/build/Data/Vector/Unboxed/Base.o )[16 of 19] Compiling Data.Vector.Unboxed ( Data/Vector/Unboxed.hs, dist/build/Data/Vector/Unboxed.o )[17 of 19] Compiling Data.Vector.Unboxed.Mutable ( Data/Vector/Unboxed/Mutable.hs, dist/build/Data/Vector/Unboxed/Mutable.o )[18 of 19] Compiling Data.Vector.Mutable ( Data/Vector/Mutable.hs, dist/build/Data/Vector/Mutable.o )[19 of 19] Compiling Data.Vector ( Data/Vector.hs, dist/build/Data/Vector.o )Registering vector-0.7.0.1...Installing library in /home/michael/.cabal/lib/vector-0.7.0.1/ghc-7.0.2Registering
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
On Mon, Jun 13, 2011 at 11:44 PM, michael rice nowg...@yahoo.com wrote: Downloading gsl-random-0.4.3... [1 of 1] Compiling Main ( /tmp/gsl-random-0.4.32479/gsl-random-0.4.3/Setup.lhs, /tmp/gsl-random-0.4.32479/gsl-random-0.4.3/dist/setup/Main.o ) Linking /tmp/gsl-random-0.4.32479/gsl-random-0.4.3/dist/setup/setup ... Configuring gsl-random-0.4.3... setup: The program gsl-config is required but it could not be found. cabal: Error: some packages failed to install: gsl-random-0.4.3 failed during the configure step. The exception was: ExitFailure 1 You have to install GSL development packages on your system. Cheers, -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints
And then reinstall the monte-carlo? Michael --- On Mon, 6/13/11, Felipe Almeida Lessa felipe.le...@gmail.com wrote: From: Felipe Almeida Lessa felipe.le...@gmail.com Subject: Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints To: michael rice nowg...@yahoo.com Cc: haskell-cafe@haskell.org Date: Monday, June 13, 2011, 10:45 PM On Mon, Jun 13, 2011 at 11:44 PM, michael rice nowg...@yahoo.com wrote: Downloading gsl-random-0.4.3... [1 of 1] Compiling Main ( /tmp/gsl-random-0.4.32479/gsl-random-0.4.3/Setup.lhs, /tmp/gsl-random-0.4.32479/gsl-random-0.4.3/dist/setup/Main.o ) Linking /tmp/gsl-random-0.4.32479/gsl-random-0.4.3/dist/setup/setup ... Configuring gsl-random-0.4.3... setup: The program gsl-config is required but it could not be found. cabal: Error: some packages failed to install: gsl-random-0.4.3 failed during the configure step. The exception was: ExitFailure 1 You have to install GSL development packages on your system. Cheers, -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] YesodAuth documentation
Actually, that's not entirely accurate. The Yesod scaffolding tool generates a site that uses mime-mail and sendmail, but there's nothing inherent in yesod-auth requiring either. My apologies for adding to the confusion. I see now that Yesod.Auth.Email handles database interactions, generates verify URLs for new accounts to use, and provides forms to embed in HTML. It doesn't actually create email messages or handle any kind of email delivery. I saw the mime-mail dependency, and then forgot where I had seen Network.Mail.Mime.renderSendMail actually being called. The stock email plugin does not let you disable these features, but it should be easy to write your own. You could just copy the email module from yesod-auth and make the modifications there. Or even better if you're so inclined: submit a patch to make these features optional. If you are so inclined, feel free to contact me for some guidance. My understanding is that none of the plugins included in yesod-auth are magic in any way. New ones can be created outside of the official package as long as their associated AuthPlugin has a Text value unique among any others being used. Is this all correct? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
