Re: [Haskell-cafe] Compiler stops at SpecConstr optimization
Yes, that GHC ticket shows that this problem is well known. Thank you. On Fri, Aug 30, 2013 at 2:19 AM, Ben Lippmeier b...@ouroborus.net wrote: On 30/08/2013, at 2:38 AM, Daniel Díaz Casanueva wrote: While hacking in one of my projects, one of my modules stopped to compile for apparently no reason. The compiler just freezes (like if it where in an infinite loop) while trying to compile that particular module. Since I had this problem I have been trying to reduce the problem as much as I could, and I came out with this small piece of code: module Blah (foo) where import Data.Vector (Vector) import qualified Data.Vector as V foo :: (a - a) - Vector a - Vector a foo f = V.fromList . V.foldl (\xs x - f x : xs) [] Probably an instance of this one: http://ghc.haskell.org/trac/ghc/ticket/5550 Ben. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Compiler stops at SpecConstr optimization
Hello. While hacking in one of my projects, one of my modules stopped to compile for apparently no reason. The compiler just freezes (like if it where in an infinite loop) while trying to compile that particular module. Since I had this problem I have been trying to reduce the problem as much as I could, and I came out with this small piece of code: module Blah (foo) where import Data.Vector (Vector) import qualified Data.Vector as V foo :: (a - a) - Vector a - Vector a foo f = V.fromList . V.foldl (\xs x - f x : xs) [] The module I am importing comes from package vector-0.10.0.1. The compiler I am using is ghc-7.6.3. The problem arises when compiling using the following flags: ghc Blah.hs -O1 -fspec-constr If I compile it verbosely (with -v), I can see that the compiler stops in the SpecConstr optimization step. I have tried to reduce the -O1 flag to a particular set of flags, but I didn't manage yet to find the complete set of flags that -O1 translates to (optLevelFlags [1] seems to give not enough information). Since this problem can be OS-dependent, my system is Debian 7 and I didn't try yet to reproduce my problem in other systems (mainly because I don't have access to other systems at the moment). I am posting this here to, with the help of the Haskell Community, check first if this is indeed a bug and, in such case, to find out where that bug comes from (GHC, vector library, something else?). Then, if necessary, I would write a bug report where appropriate. Thank you, Daniel Díaz. -- References [1] - https://github.com/ghc/ghc/blob/ghc-7.6.3-release/compiler/main/DynFlags.hs#L2266 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANN: processing-1.2.0.0. Graphic web applications with processing.js.
Hello readers of Haskell-Cafe. Yesterday I uploaded a new version of the processing library [1]. == What is this library for? == The library is oriented to create graphic applications that run in a web browser, with no need of running a server. It provides the user with a set of functions and combinators that can be used to create an abstract piece code. This code is rendered to the processing language syntax. Once the code is uploaded, using processing.js [2], the output code is runnable from any browser with JavaScript support. To quickly give you a taste of the library, look at this animation, created with a simple recursive function: http://daniel-diaz.github.io/projects/processing/mill.html The code is here: https://github.com/Daniel-Diaz/processing/blob/master/examples/mill.hs == What's new? == After a couple of weeks working hard to have this library properly working, I think it have reached a point of reasonable usability. As a proof, I have written a simplified version of the Pac-Man game [3]. However, although I have implemented some code optimizations, it seems that the game still does not run smoothly in every web browser. I will definitely keep trying to improve the performance of the code generated by the library. I encourage you to try the library if you are interested, but keep in mind that it is still in an early stage, and may contain bugs, lack some important features, have an incomplete documentation or suffer from API changes. == References == [1] Library at Hackage - http://hackage.haskell.org/package/processing-1.2.0.0 [2] Processing.js - http://processingjs.org [3] Pac-Man game - http://daniel-diaz.github.io/projects/processing/pacman.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Does exist something like data-files in Cabal, which works at compile time?
What I have always done to solve this is to create a custom Setup.hs. Something like: Setup.hs - import Distribution.Simple main :: IO () main = doThisBeforeInstall defaultMain - Then you specify in your .cabal file that the Build-Type is Custom. Best regards, Daniel Díaz. On Fri, Aug 16, 2013 at 11:58 AM, Alfredo Di Napoli alfredo.dinap...@gmail.com wrote: Hello guys, I'm pretty sure the answer is no, but I was hoping to get some extra insight / best practices. The problem can be summarised by this SO question (not the OP, but I have the same problem): http://stackoverflow.com/questions/15731170/cabal-how-to-add-text-file-as-a-build-dependency As someone states, data-files in for run-time, whereas I need to tell cabal please copy these files in place before trying to compile, so at compile-time. Does something similar exist? I think the best solution, unless someone prove me wrong, is to create a small startup script which copies the files for me (I *think* yesod is using something similar, namely a script called EmbeddedFiles.hs) and then triggers cabal install the usual way. Can you come up with a better way? Thanks in advance! Alfredo ___ 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
[Haskell-cafe] Automatically test different versions of single dependency
Hello everyone. I would like to check what dependencies is one of my packages compatible with. For example, say I have a package called foo that depends on package bar. Most likely, foo does not build with each version of bar. What I want to do is try to build foo with each single version of bar (not manually). What is the best approach to this? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Automatically test different versions of single dependency
Hello, Alp. Thank you for your response. Currently, I am extracting the information from the 00-index.tar.gz, and planning to use cabal-dev for the builds. Using the cabal tool directly looks like a very bad idea to me. I am still interested in knowing if there is some related job already done, or any other clever ideas that I didn't manage to think of. However, this looks like the best approach right now. Thank you, Daniel Díaz. On Thu, Jul 4, 2013 at 2:36 PM, Alp Mestanogullari alpmes...@gmail.comwrote: You can just write a bash script that will do: cabal install --constraint='bar == v' for all the values of 'v' (0.1, 0.2, 1.2.5.1, ...) you are interested in. You can be aware of all the existing versions just using the directory listing in http://hackage.haskell.org/packages/archive/containers/ (for the 'containers' package in this case) or by using cabal-install cleverly maybe? I just saw 'cabal info containers' gives a list of available versions, up to a point... after which it says (and 4 others). So maybe go see how 'cabal info' does this? But all in all, this should give you enough to work out a nice solution. On Thu, Jul 4, 2013 at 12:56 PM, Daniel Díaz Casanueva dhelta.d...@gmail.com wrote: Hello everyone. I would like to check what dependencies is one of my packages compatible with. For example, say I have a package called foo that depends on package bar. Most likely, foo does not build with each version of bar. What I want to do is try to build foo with each single version of bar (not manually). What is the best approach to this? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Alp Mestanogullari ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Custom Setup.hs and Paths module
Hello Erik. Yes, that solution may work, but seems ad-hoc to me. I would like to see a way to actually import the Paths module. In the meanwhile, I will be using your idea. Thank you for the response. Anybody knows how to hack the Setup.hs so I can use the real Paths module? On Wed, Jul 3, 2013 at 3:39 AM, Erik de Castro Lopo mle...@mega-nerd.comwrote: Daniel Díaz Casanueva wrote: Hi everyone. I am writing a package where I am using the Paths module that cabal generates automatically. After adding the Paths module to the other-modules section in my cabal file everything worked just fine, until I wanted to write a custom Setup.hs. This Setup.hs just writes a couple of files in the system and then calls defaultMain. The thing is that now cabal install does not find the Paths module, so the package is broken. I ran into the same problem. I ended up fixing it by *not* using the auto generated Paths module and instead parsing the cabal file in Setup.hs. This is not has horrible as it sounds as I used the Cabal insfrastructure to do it. Basically something like this: import Distribution.Simple import Distribution.PackageDescription import Distribution.PackageDescription.Parse (readPackageDescription) import Distribution.Verbosity (silent) version - fmap (showVersion . pkgVersion . package . packageDescription) $ readPackageDescription silent my-package.cabal and then used that version String to write a trivial 5 line file Version.hs. HTH, Erik -- -- Erik de Castro Lopo http://www.mega-nerd.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
[Haskell-cafe] Custom Setup.hs and Paths module
Hi everyone. I am writing a package where I am using the Paths module that cabal generates automatically. After adding the Paths module to the other-modules section in my cabal file everything worked just fine, until I wanted to write a custom Setup.hs. This Setup.hs just writes a couple of files in the system and then calls defaultMain. The thing is that now cabal install does not find the Paths module, so the package is broken. Any thoughts? I need your help, people! Thank you, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANN: HaTeX 3.6. Now with Babel, TikZ and more!
Hello everyone! It is time for a new release of HaTeX, the Haskell LaTeX library. http://hackage.haskell.org/package/HaTeX-3.6 == What is HaTeX? == HaTeX contains numerous types and functions that will assist you in the process of creating a LaTeX document within Haskell. You can also include your manually created LaTeX code in HaTeX, so you can choose the more convenient tool you want to use for each case. == What's new in this release? == A lot of changes have been made since the last release! The most important changes are explained in the blog post I just wrote: http://deltadiaz.blogspot.com.es/2013/06/hatex-36-texy-class-babel-fontenc-tikz.html However, the new feature I am more excited with is the TikZ script generator. Using a very intuitive interface, you will be able to generate high quality graphics for LaTeX documents. It is still far from be complete, but next releases will fill the gaps that you may find right now. Just to give you a taste, consider the following code: myFigure :: Figure myFigure = Scale 2 $ Figures [ RectangleFilled (0,0) 1 1 , Colored Green $ RectangleFilled (-1,1) 1 1 , Colored Red $ RectangleFilled ( 0,2) 1 1 , Colored Blue $ RectangleFilled ( 1,1) 1 1 ] With this simple construction you already have the following picture ready to be inserted in your LaTeX file output. http://daniel-diaz.github.com/projects/hatex/tikzsimple.png In the examples directory contained in the source distribution there is also an example (tikz.hs) that includes the plotting of a Haskell function (sine). However, the interface it uses may be less comfortable than the one shown in the example above. If you are a HaTeX user, don't miss this update, because it also contains some very important bug fixes. Any feedback gladly accepted. Good luck, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: standalone-haddock-1.0
Hello Roman! Thank you, this is a great contribution. I found myself several times modifying the html output by hand in order to do exactly this. Nice! On Fri, Jun 7, 2013 at 2:15 PM, Roman Cheplyaka r...@ro-che.info wrote: I am happy to announce the first release of standalone-haddock. http://feuerbach.github.io/standalone-haddock/ standalone-haddock generates standalone haddock Haskell documentation. When you simply run `cabal haddock`, the resulting HTML documentation contains hyperlinks to other packages on your system. As a result, you cannot publish it on the internet (well, you can, but the links will be broken). standalone-haddock takes several packages for which you want to publish documentation. It generates documentation for them with proper links: * links to identifiers inside this package set are relative * links to identifiers from external packages lead to hackage Thus the resulting directory with HTML is relocatable and publishable. **TL;DR**: it just works. See the [haskell-suite][] documentation for an example output. [haskell-suite]: http://haskell-suite.github.io/docs Usage - Usage: standalone-haddock [--package-db DB-PATH] -o OUTPUT-PATH [PACKAGE-PATH] Available options: -h,--helpShow this help text --package-db DB-PATH Additional package database -o OUTPUT-PATH Directory where html files will be placed `PACKAGE-PATH` is the path to the (unpacked) package — i.e. a directory with a `.cabal` file. For example: standalone-haddock -o doc haskell-names haskell-packages haskell-src-exts hse-cpp cabal/Cabal **NOTE**: dependencies of every package need to be already installed in the system with documentation (even those dependencies that themselves belong to the current package set). If they are installed in a non-standard package database (e.g. if you use sandboxes), use the `--package-db` option. Cabal dependency The program only builds with (unreleased) Cabal 1.17 which you can get from [github](https://github.com/haskell/cabal). I spent some time trying to make it compatible with Cabal 1.16 (see [Cabal-1.16][] branch), but the API seems to have changed too much. If you seriously care about this, feel free to send a patch, but it's really easier just to install Cabal HEAD. [Cabal-1.16]: https://github.com/feuerbach/standalone-haddock/tree/Cabal-1.16 Roman ___ 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
[Haskell-cafe] Fwd: Cabal config file Guide
Thank you, Albert, what you wrote is very useful. Why the Cabal Guide is lacking this kind of information? Maybe I should start gathering information in one place myself! Thank you, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Cabal config file Guide
Hello Cafe! As you already know, cabal-install is configured in the file config. It has a lot of fields, but I didn't find a single place where each field is explained with detail. Most of the options are trivial enough to understand what they do without previous explanation, but some of them aren't. Therefore, in order to know what these options do, you have to search info about that one specifically, when it would be much more convenient to have all the information together. So, is there any place like this out there in the web? Thank you, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Good to find you on LinkedIn
LinkedIn Daniel Díaz Casanueva requested to add you as a connection on LinkedIn: -- Minh Thu, I'd like to add you to my professional network on LinkedIn. - Daniel Accept invitation from Daniel Díaz Casanueva http://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/XvIdBwmueHfd6vFMPXXdLaqreCbl5oOSpPTFPU/blk/I790933864_20/3wOtCVFbmdxnSVFbm8JrnpKqlZJrmZzbmNJpjRQnOpBtn9QfmhBt71BoSd1p65Lr6lOfP0OnPgSe3cPej0VdQALl4EOm5kPtSALdz8PcPwNdP0PcP4LrCBxbOYWrSlI/eml-comm_invm-b-in_ac-inv28/?hs=falsetok=0mY1dMLBAo4lM1 View profile of Daniel Díaz Casanueva http://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/rso/255311896/LIky/name/22724543_I790933864_20/?hs=falsetok=2n9H_NXUco4lM1 -- You are receiving Invitation emails. This email was intended for Minh Thu Vo. Learn why this is included: http://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/plh/http%3A%2F%2Fhelp%2Elinkedin%2Ecom%2Fapp%2Fanswers%2Fdetail%2Fa_id%2F4788/-GXI/?hs=falsetok=0pRQwEVKAo4lM1 (c) 2012, LinkedIn Corporation. 2029 Stierlin Ct, Mountain View, CA 94043, USA. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Good to find you on LinkedIn
My apologies, I don't know how this e-mail has reached the Haskell-Cafe. Sincerely, Daniel Díaz. On Wed, May 15, 2013 at 11:44 PM, Daniel Díaz Casanueva mem...@linkedin.com wrote: [image: LinkedIn Logo] http://www.linkedin.com/ Minh Thu, ** Daniel Díaz Casanueva wants to connect with you on LinkedIn. Daniel Díaz Casanueva Computer Software Professional View Profile » http://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/rso/255311896/LIky/name/22724543_I790933864_20/eml-comm_invm-b-pro_txt-inv28/?hs=falsetok=3xtaBEOiMo4lM1 Accepthttp://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/XvIdBwmueHfd6vFMPXXdLaqreCbl5oOSpPTFPU/blk/I790933864_20/3wOtCVFbmdxnSVFbm8JrnpKqlZJrmZzbmNJpjRQnOpBtn9QfmhBt71BoSd1p65Lr6lOfP0OnPgSe3cPej0VdQALl4EOm5kPtSALdz8PcPwNdP0PcP4LrCBxbOYWrSlI/eml-comm_invm-b-in_ac-inv28/?hs=falsetok=0mY1dMLBAo4lM1 ** You are receiving Invitation emails. Unsubscribehttps://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/XvIdBwmueHfd6vFMPXXdLaqreCbl5oOSpPTFPU/uns/20008/22724543/jh9ot6gkko1pkl7/haskell-cafe%40haskell%2Eorg/uc6lxc-hgr1egm6-6q/eml-comm_invm-f-unsub-inv28/?hs=falsetok=3-VEVqVyAo4lM1. This email was intended for Minh Thu Vo (Core/Server Lead Developer at OpenERP). Learn why we included thishttp://www.linkedin.com/e/uc6lxc-hgr1egm6-6q/plh/http%3A%2F%2Fhelp%2Elinkedin%2Ecom%2Fapp%2Fanswers%2Fdetail%2Fa_id%2F4788/-GXI/?hs=falsetok=0pRQwEVKAo4lM1. © 2013, LinkedIn Corporation. 2029 Stierlin Ct. Mountain View, CA 94043, USA ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] list comprehension doesn't work
You can always write it like this: listPairs = [ (x,y) | x - [6 .. 499] , y - [0 .. 1000] , isProduct x , isSqrt y , mod y x == 0 ] So you have the bounds for x and y, and then the conditions. You then need to define isProduct and isSqrt with types isProduct :: Int - Bool isSqrt :: Int - Bool Hopefully, these problems will look easier separately. Well, it's just an idea. Good luck, Daniel Díaz. On Tue, May 14, 2013 at 4:57 PM, John knowledge1...@gmail.com wrote: Hi, I have to write a function which returns a list of all pairs (x,y) where x, y ∈ N AND: – x is the product of two natural numbers (x = a · b, where a, b ∈ N) AND – x is really bigger than 5 but really smaller than 500, AND – y is a squer number (y = c² where c ∈ N) NOT greater than 1000, AND – x is a divisor of y. My attempt is as follows: listPairs :: [(Int, Int)] listPairs = [(x,y) | x-[0..], y-[0..], x-[0..]*[0..], x 5, x 500, (y*y) 1001, mod y x == 0] However it doesn't work unfortunatly Could anyone tell me where my mistake is? Thanks. -- View this message in context: http://haskell.1045720.n5.nabble.com/list-comprehension-doesn-t-work-tp5730158.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] list comprehension doesn't work
Well, definitely, isSqrt should be called isSquare. On Tue, May 14, 2013 at 5:22 PM, Daniel Díaz Casanueva dhelta.d...@gmail.com wrote: You can always write it like this: listPairs = [ (x,y) | x - [6 .. 499] , y - [0 .. 1000] , isProduct x , isSqrt y , mod y x == 0 ] So you have the bounds for x and y, and then the conditions. You then need to define isProduct and isSqrt with types isProduct :: Int - Bool isSqrt :: Int - Bool Hopefully, these problems will look easier separately. Well, it's just an idea. Good luck, Daniel Díaz. On Tue, May 14, 2013 at 4:57 PM, John knowledge1...@gmail.com wrote: Hi, I have to write a function which returns a list of all pairs (x,y) where x, y ∈ N AND: – x is the product of two natural numbers (x = a · b, where a, b ∈ N) AND – x is really bigger than 5 but really smaller than 500, AND – y is a squer number (y = c² where c ∈ N) NOT greater than 1000, AND – x is a divisor of y. My attempt is as follows: listPairs :: [(Int, Int)] listPairs = [(x,y) | x-[0..], y-[0..], x-[0..]*[0..], x 5, x 500, (y*y) 1001, mod y x == 0] However it doesn't work unfortunatly Could anyone tell me where my mistake is? Thanks. -- View this message in context: http://haskell.1045720.n5.nabble.com/list-comprehension-doesn-t-work-tp5730158.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] list comprehension doesn't work
Hi John,
On Tue, May 14, 2013 at 5:41 PM, John knowledge1...@gmail.com wrote:
Danny Gratzer wrote
Well you've deleted the portion of the code referring to x and y.
listPairs = [(a*b, y) | y - [0..], a - [0..], b - [0..], (a*b) 5,
(a*b) 500, (y*y) 1001, mod y (a*b) == 0]
This will still never terminate however.
oh I see, but as you say it doesn't terminate and I get nothing. Does it
mean, that the function is wrong in this place?
Some questions:
1. Does the order of conditions affect the result at all?
2. The , means AND or , right? So how do you write OR || instead? E.g
z-[1..10] OR z-[100..110].
Ofcourse it doesn't relate to this topic, but I wanted to know it.
Since I'm a very beginner I think the approach of Daniel is slightly
complex
for me to comprehend, right?
Allthough I tried it, but it says isProduct and isSquer are not in Scope,
so
I should define them first in WHERE-Clause right?
Yes. The idea is to reduce a problem to simpler subproblems. It is a common
practice while programming, and often will make your code clearer. Where do
you find the difficulty? The (incomplete) solution I wrote was:
[ (x,y) | x - [6 .. 499] , y - [0 .. 1000] , isProduct x , isSquare y ,
mod y x == 0 ]
which you can read as:
*The list of the pairs of numbers x and y, where x belongs to {6, ... ,
499}, y belongs to {0, ... , 1000}, x is a product of two numbers, y is the
square of a number and y MOD x is 0.*
These look like the conditions you asked for. So you can say that you
solved the problem of generating the list, if you know how to decide if a
number is a product or a square in the first place. You can define these
two functions separately.
isProduct :: Int - Bool
isProduct n = ...
isSquare :: Int - Bool
isSquare n = ...
The question of if a number is a product or not is equivalent to the
question of checking if a number is prime or not. Indeed, If it is prime,
it is not a product of two natural numbers (I am, of course, guessing that
you don't want ones in the product). If it is NOT prime, then you can
factor the number.
To solve the isSquare problem, you can just check if it coincides with
the square of any number below the square root of the number in question.
I think you don't want an explicit solution, but some hints, so you can
explore the problem deeper and learn from it.
I must also note, as other people have already done, that this questions
fits in better in the Haskell-Beginners mailing list.
http://www.haskell.org/mailman/listinfo/beginners
I hope this works for you,
Daniel Díaz.
Thanks again to all
--
View this message in context:
http://haskell.1045720.n5.nabble.com/list-comprehension-doesn-t-work-tp5730158p5730167.html
Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
--
E-mail sent by Daniel Díaz Casanueva
let f x = x in x
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Building the Haskell Platform in Linux
Hello Albert! Oh! I didn't find that one when searching for info! That would have helped me a lot! By the way, a random question, what's the memory of the computer you used to build the Platform? On Sun, Apr 14, 2013 at 6:54 PM, Albert Y. C. Lai tre...@vex.net wrote: On 13-04-13 12:19 AM, Daniel Díaz Casanueva wrote: Hi cafe! Probably you all know how to do this, but I myself found confused when building the Haskell Platform in Linux for my first time. I was using Linux for my first time too! The first problem I encountered was to decide what linux packages install to make the ./configure successful in both GHC binary distribution and the Haskell Platform. So I collected the names of the minimum set of packages that you need to have installed before starting with GHC and the Platform in a small blog post: http://deltadiaz.blogspot.com/**2013/04/haskell-platform-from-** source-in-linux.htmlhttp://deltadiaz.blogspot.com/2013/04/haskell-platform-from-source-in-linux.html Shameless plug: also my http://www.vex.net/~trebla/**haskell/haskell-platform.xhtmlhttp://www.vex.net/~trebla/haskell/haskell-platform.xhtml and it will be yet updated again next version. __**_ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/**mailman/listinfo/haskell-cafehttp://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Announcement] Sparse matrix Conjugate Gradient Solver
Nice! I will look at your implementation to see if I can learn something from this. :) On Sun, Apr 14, 2013 at 9:59 PM, Levent Erkok erk...@gmail.com wrote: I'm happy to announce the first release of conjugateGradient, implementing the Conjugate Gradient algorithm for solving linear systems of equations over sparse matrices: http://hackage.haskell.org/package/conjugateGradient The conjugate gradient algorithm only applies to the cases when the input matrix is symmetric and positive definite. See: http://en.wikipedia.org/wiki/Conjugate_gradient_method The advantage of this method is that it can handle really large sparse systems quite well, when other direct methods (such as LU decomposition) are just not practical due to algorithmic complexity. Such large and sparse systems naturally arise in engineering applications, such as in ASIC placement algorithms and when solving partial differential equations. Bug reports, feedback, and improvements are always welcome. -Levent. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] NaN as Integer value
You can always use the Maybe type as a follows: intDiv :: Integer - Integer - Maybe Integer intDiv _ 0 = Nothing intDiv n m = Just (div n m) This allows you to pattern match results of divisions: example :: Integer - Integer - Maybe Integer example n m = case intDiv 4 n of Nothing - Nothing Just n' - case intDiv 5 m of Nothing - Nothing Just m' - Just (n' + m') Or even better using the do notation: example2 :: Integer - Integer - Maybe Integer example2 n m = do n' - intDiv 4 n m' - intDiv 5 m return (n' + m') Note that example and example2 both do the same thing. I think this is cleaner solution add NaN as a value to the Integer type. Good luck, Daniel Díaz. On Sat, Apr 13, 2013 at 12:16 PM, Алексей Егоров elect...@list.ru wrote: Hello haskellers, is there a reason why Integer doesn't have 'NaN' as value? I think it would be very convenient to be able to handle (1 `div` 0) as regular NaN value and not as exception. Thanks. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Building the Haskell Platform in Linux
Hi cafe! Probably you all know how to do this, but I myself found confused when building the Haskell Platform in Linux for my first time. I was using Linux for my first time too! The first problem I encountered was to decide what linux packages install to make the ./configure successful in both GHC binary distribution and the Haskell Platform. So I collected the names of the minimum set of packages that you need to have installed before starting with GHC and the Platform in a small blog post: http://deltadiaz.blogspot.com/2013/04/haskell-platform-from-source-in-linux.html If I would have to start all over again, forgetting what I have learned so far, I would fine this list very useful! This thought is what brought me here to make it public. Who knows, maybe I am saving somebody of some google searches and trials and errors. With my best intentions, Daniel Díaz. -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell / Functional Programmers Group in Madrid (Spain)?
Hi Alejandro! It would be great if Spain would have a Haskell Group in the capital city. I am from Spain and I always begged for something like this. Unfortunately, I find myself in the United States and unable to help. But if, for any circumstances, I end up in Madrid, I'll be there to support this. Saludos de un malagueño, Daniel Díaz. On Wed, Apr 10, 2013 at 3:50 AM, Alejandro Serrano Mena trup...@gmail.comwrote: Hi, Is there any Haskell or functional programmers user group in the region of Madrid? If not, I think it could be a great idea to get to know each other, and share experiences. Furthermore, we could try to organize some meetings with presentations, hackatons and so on (my personal ambition is to be able to organize another ekmett Workshop as the Japanese one - http://comonad.com/reader/2013/japanese-workshop-1/). I know there is some locations along Madrid dedicated to open source promotion, like http://madridonrails.com/, and which we could use for these meetings. I'm really looking forward to hearing from you! PS: Maybe a bare Haskell group is not big enough (at least according to Haskellers.com), but a functional programmers one may well be. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: HaTeX-3.5 - New version of the LaTeX library
Hi readers! A new version of HaTeX has just been released. More math symbols and utilities and a new attoparsec-based parser. This new version also includes a new matrix renderer. A summary of the changes: http://deltadiaz.blogspot.com/2013/03/hatex-35.html The package in Hackage: http://hackage.haskell.org/package/HaTeX-3.5 For those who don't know, HaTeX is a combinator library for LaTeX code. Read more in the manual: https://github.com/downloads/Daniel-Diaz/HaTeX-Guide/HaTeX-Guide.pdf I recommend to HaTeX users to upgrade to this new version. Good luck, Daniel Díaz. -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Some aggregation of Haskell content
I'm totally with this. Also, it is exhausting to check in so many places to see what's going on. I have been looking for this for a while. On Sun, Feb 10, 2013 at 10:41 AM, Christopher Done chrisd...@gmail.comwrote: Is there a page somewhere that aggregates all of Haskell's community output into one place? As a consumer of Haskell content I neither have the time nor inclination to follow haskell-cafe and other various mailing lists, the reddits, the google+ community, planet haskell, hackage releases, twitter, youtube and whatever other submission places I haven't heard of. I made this page for the Lojban community some years ago: http://jbotcan.org/hub/ Lojban doesn't have much community activity (tho this doesn't include mailing list posts), but Haskell's community is much larger and more active, it would be far more useful. I may write such a page for Haskell content, if not for the community then at least for myself, as I keep missing out on cool things because I didn't happen to check out that particular medium of exchange. For example, even this message will be lost on a thousand people who doesn't follow the mailing list but maybe follows G+ or reddit. Kind of like a Haskell Weekly news, except more like Haskell news right now or in some adjustable time frame. And the option to toggle between chronological order or categorized. Ciao! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Sequence and replicateM
Yes, you're right about the type context. I always forget that Functor is not a superclass of Monad. Anyway, the `fmap` can be done only with `Monad` in the context. About the list fusion, I'm compiling with optimizations enabled (-O2), but I do not know how it works with fusions. Is it the optimization omitting the step of creating the list? How can I know it with certainty? On Fri, Jan 25, 2013 at 7:23 AM, Thomas Horstmeyer horst...@mathematik.uni-marburg.de wrote: Hi, isn't the correct type context for f the following? f :: (Functor m, Monad m) = Int - m a - m (Seq a) So your f really is a kind of specialization of g. Could the reason for f performing better be list fusion? Anything happening inside Control.Monad.replicateM should be subject to it. Cheers, Thomas Am 24.01.2013 15:31, schrieb Daniel Díaz Casanueva: Hi Cafe, I was coding this morning when I suddenly found something that surprised me. It's been a short time since I am really caring about the performance of my programs. Before, I was just caring about their correctness. So I am trying different things and profiling to see differences. One difference I have found surprising is that the function f is MUCH faster and less space consuming than the function g: import Control.Monad import qualified Data.Sequence as Seq type Seq = Seq.Seq f :: Monad m = Int - m a - m (Seq a) f n = fmap Seq.fromList . replicateM n g :: Monad m = Int - m a - m (Seq a) g = Seq.replicateM Maybe is just in my test case, where the Int argument is big and the monadic action short, but it looks to me that Data.Sequence.replicateM can be faster than it is right now. Regards, Daniel Díaz. -- E-mail sent by Daniel Díaz Casanueva let f x = x in x __**_ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/**mailman/listinfo/haskell-cafehttp://www.haskell.org/mailman/listinfo/haskell-cafe __**_ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/**mailman/listinfo/haskell-cafehttp://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Data.Sequence and replicateM
Hi Cafe, I was coding this morning when I suddenly found something that surprised me. It's been a short time since I am really caring about the performance of my programs. Before, I was just caring about their correctness. So I am trying different things and profiling to see differences. One difference I have found surprising is that the function f is MUCH faster and less space consuming than the function g: import Control.Monad import qualified Data.Sequence as Seq type Seq = Seq.Seq f :: Monad m = Int - m a - m (Seq a) f n = fmap Seq.fromList . replicateM n g :: Monad m = Int - m a - m (Seq a) g = Seq.replicateM Maybe is just in my test case, where the Int argument is big and the monadic action short, but it looks to me that Data.Sequence.replicateM can be faster than it is right now. Regards, Daniel Díaz. -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Data.Sequence and replicateM
Good point. However, I forced the result to evaluate using `deepseq` and I still got similar results. On Thu, Jan 24, 2013 at 11:41 AM, Gershom Bazerman gersh...@gmail.comwrote: On 1/24/13 9:31 AM, Daniel Díaz Casanueva wrote: import Control.Monad import qualified Data.Sequence as Seq type Seq = Seq.Seq f :: Monad m = Int - m a - m (Seq a) f n = fmap Seq.fromList . replicateM n g :: Monad m = Int - m a - m (Seq a) g = Seq.replicateM Maybe is just in my test case, where the Int argument is big and the monadic action short, but it looks to me that Data.Sequence.replicateM can be faster than it is right now. Are you forcing the full sequence in both cases? In the former case, you'll get all the actions, but have a thunk containing the result of Seq.fromList. In the latter, you're performing the actions as you build the sequence, so the resultant sequence will be fully evaluated. I imagine that this is the reason that the former seems faster to you. --g ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- E-mail sent by Daniel Díaz Casanueva let f x = x in x ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Gloss and relatively expensive computations
Hi Artyom! Thanks for your response. It seems your tactic has worked. I was so focused on programming inside the gloss parameter that I completely forgot about programming in the outside. Here is what I did (I picked MVar's): myprog s = do ... var - newMVar w0 let loop w = do w' - step s w putMVar var w' loop w' forkIO $ loop w0 simulateIO ... (\_ _ w - fmap (fromMaybe w) $ tryTakeMVar var) And it's working just fine! Best regards, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Object Oriented programming for Functional Programmers
Hello, Haskell Cafe folks. My programming life (which has started about 3-4 years ago) has always been in the functional paradigm. Eventually, I had to program in Pascal and Prolog for my University (where I learned Haskell). I also did some PHP, SQL and HTML while building some web sites, languages that I taught to myself. I have never had any contact with JavaScript though. But all these languages were in my life as secondary languages, being Haskell my predominant preference. Haskell was the first programming language I learned, and subsequent languages never seemed so natural and worthwhile to me. In fact, every time I had to use another language, I created a combinator library in Haskell to write it (this was the reason that brought me to start with the HaTeX library). Of course, this practice wasn't always the best approach. But, why I am writing this to you, haskellers? Well, my curiosity is bringing me to learn a new general purpose programming language. Haskellers are frequently comparing Object-Oriented languages with Haskell itself, but I have never programmed in any OO-language! (perhaps this is an uncommon case) I thought it could be good to me (as a programmer) to learn C/C++. Many interesting courses (most of them) use these languages and I feel like limited for being a Haskell programmer. It looks like I have to learn imperative programming (with side effects all over around) in some point of my programming life. So my questions for you all are: * Is it really worthwhile for me to learn OO-programming? * If so, where should I start? There are plenty of functional programming for OO programmers but I have never seen OO programming for functional programmers. * Is it true that learning other programming languages leads to a better use of your favorite programming language? * Will I learn new programming strategies that I can use back in the Haskell world? Thanks in advance for your kind responses, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: haskell-docs - Given a module name and a name, it will find and display the documentation of that name.
This is something I always missed. Thank you! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Gloss and relatively expensive computations
Hello cafe! I'm having some performance issues trying to use gloss to make animations where each model step is relatively time expensive. I'm using the IO.Simulate module because my step function needs to do an IO operation which takes around 1 second (it may vary). I will try to give some details. I have the step function: step :: Model - IO Model step m = do ... p - slowOperation ... return newModel The rest of the program is small and simple. The drawing function (Model - IO Picture -- it is pure though) is as quick as simple. However, the program get stuck after the first iteration. In the other hand, I am using the animateIO function which ask me for an Int value to set up the number of simulation steps to take for each second of real time. But I'm more interested in the animation waiting for the simulation step to end. Does it make sense? I would be really thankful with any pointer here. Thanks in advance, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Problem with forall type in type declaration
If one parameter is not enough, you always can add more:
Test m a b = Test { f :: m IO a - IO b }
This way, if
run :: m IO a - IO a
then
Test run :: Test m a a
But for other type for your run function
run' :: m IO a - IO b
you get
Test run' :: Test m a b
So you can have different types in input and output. Anyway, your type 'm'
is applied to other two types (m IO a), so it cannot be a monad, because
monads have arity 1 as type constructors, i.e. monads have kind (* - *).
Is perhaps 'm' some kind of monad transformer?
Well, that's all I can say from your explanation of the problem! Hope it
helps!
Daniel Díaz.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Cabal try to install a package I already have
Hi Cafe, today I opened the command prompt and typed cabal install ftphs. Then I read: Resolving dependencies... Configuring network-2.3.0.5... And I started to feel confused. Because I already have installed that package with that version! I continued reading: cabal: The package has a './configure' script. This requires a Unix compatibility toolchain such as MinGW+MSYS or Cygwin. Yes, I knew this would happen! (thought I don't like it with a so common-used library) But I can't understand why cabal is trying to install network-2.3.0.5. If I type ghc-pkg list I can see precisely network-2.3.0.5 is installed. In fact, 2.3.0.5 is the version that comes with the Haskell Platform I recently installed (2011.4.0.0) as you can see here: http://code.haskell.org/haskell-platform/haskell-platform.cabal. Could someone, please, explain me this? I will be very glad. I was working with ghc-7.4 but I needed the network package so I switched to the Haskell Platform, because install network in Windows is painful. Yes, I read the Mitchell guide (found in http://neilmitchell.blogspot.com.es/2010/12/installing-haskell-network-library-on.html), but once I installed the library I was having compile time error with unknown symbol errors. I felt very odd so I switched this machine to the Haskell Platform. I hope someone could help me. Thanks in advance, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal try to install a package I already have
Indeed, it seems to be for parsec: ? ghc-pkg latest bytestring bytestring-0.9.1.10 ? ghc-pkg latest parsec parsec-3.1.2 Haskell Platform versions: bytestring-0.9.1.10, parsec-3.1.1. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cabal try to install a package I already have
I have spent some time and, when I unregistered (with ghc-pkg unregister) all dependencies (even indirect dependencies) I have installed since I have the Haskell Platform, then the cabal install ftphs worked. Now I feel I understand the problem, but still seems annoying. Thanks for the pointer, Jeff. I didn't know the reason of your question, but then I saw dependencies of network and thought: eureka!. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Announce: HaTeX 3.3
Greetings Haskellers! A new version of HaTeX is ready to use in Hackage: http://hackage.haskell.org/package/HaTeX-3.3 == Description == HaTeX is a heavily maintained LaTeX code parser/generator. Write LaTeX documents with all the advantages you already have in Haskell (recursion, type system, high order functions, ...), create a LaTeX backend for your own program, make analysis of LaTeX code through its Abstract Syntax Tree (AST), find another way to pretty-printing values, ... == Release notes == Please, to read the release notes go to the following blog post: http://deltadiaz.blogspot.com.es/2012/04/hatex-33-release-notes.html Thanks and good luck, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] [ANNOUNCE] HaTeX 3.2
Hello, A new version (3.2) of HaTeX has been released today to Hackage: http://hackage.haskell.org/package/HaTeX-3.2 HaTeX is the LaTeX language syntax implementation done in Haskell. Key changes in this version are: + LaTeX parser implemented (so new dependency on parsec). + Greek alphabet added to AMSMath module. + New LaTeX package implemented: graphicx. + Function 'documentclass' changed. Further information on this release: http://deltadiaz.blogspot.com/2012/02/hatex-chapter-32.html Library homepage: http://dhelta.net/hprojects/HaTeX Thanks for reading, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] [ANNOUNCE] JuicyPixels 1.0 - image loading library
Thanks for this upload! I searched something like this a time ago. I'll test it soon and, if I have any issue, send you some feedback. Thanks again for the work. I made a library to work with PPM images (not released to Hackage), but I'm glad to see a Haskell implementation of PNG and JPG. Good luck, Daniel Díaz. On Fri, Jan 13, 2012 at 6:26 PM, Vincent Berthoux vincent.berth...@gmail.com wrote: Hello, I'd like to announce the first release of JuicyPixels, an image loading library written entirely in Haskell. The focus of this library is ease of use and correct loading. In this first version the library is capable of the following actions : - PNG(.png) * Reading - 1,2,4,8 bits loading, Grayscale, 24bits, 24 bits with alpha, interleaved filtered (fully compliant with the standard, tested against png suite). * Writing - 8bits RGB (non interleaved) - 8bits RGBA (non interleaved) - 8bits greyscale (non interleaved) - Bitmap (.bmp) (mainly used as a debug output format) * Reading - 24bits (RGB) images * Writing - 32bits (RGBA) per pixel images - 24bits (RGB) per pixel images - 8 bits greyscale (with palette) - Jpeg (.jpg, .jpeg) * Reading non-interlaced baseline DCT image, seems to be OK * Writing : none yet I'm interested on any feedback regarding ease of use, performance and bugs. GitHub : https://github.com/Twinside/Juicy.Pixels Hackage : http://hackage.haskell.org/package/JuicyPixels Thanks Vincent Berthoux ___ Haskell mailing list hask...@haskell.org http://www.haskell.org/mailman/listinfo/haskell ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: HaTeX 3.1.0 (and HaTeX-meta 1.1.0)
Hello Cafe! Today I released to Hackage a new version of the HaTeX package ( http://hackage.haskell.org/package/HaTeX-3.1.0 ). If you don't know HaTeX, it is a combinator library of the LaTeX syntax. Visit the homepage for more information: http://dhelta.net/hprojects/HaTeX Highlights: + Added warnings (See Text.LaTeX.Base.Warnings). Still very experimental. + Added an Examples directory, with a simple example inside to get started. + Num instance for LaTeX and LaTeXT. + New package implemented AMSThm (See Text.LaTeX.Packages.AMSThm). See the ReleaseNotes in the source tarball for more details in release changes. With it, I released an update of HaTeX-meta (version 1.1.0), which produces part of the HaTeX code. An important change here is the addition of the HATEX pragma (explained in http://deltadiaz.blogspot.com/2011/11/hatex-pragma.html ). If you need something more, feel free to contact me or send me a patch. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Overloaded Strings as default
Hi Cafe, I only feel curious about what would be the consequences of becoming the Overloaded Strings feature (currently, an extension) to be default in Haskell. This is not a proposal. I just want to know what pros and cons there are. Thanks! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Hackage feature request: E-mail author when a package breaks
How about to a new optional Cabal field like mail-report? (don't bother about this name, I chose it randomly) If a build failure happens, or there is some relevant information about your package, Hackage will send a mail to the direction specified in that field. A field which content will NOT appear in the package page, so internet bots can't record so easily your mail direction to send you real spam. This is the reason because I write my direction in the name at domine dot com form (since a while ago), in spite of I would really like to receive mails about fails in those packages I maintain. Furthermore, since the field would be optional, you still can avoid to receive these mails. -- Daniel Díaz ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Hackage feature request: E-mail author when a package breaks
Then, the mailing list seems to be an option. But then I will receive mails for every package, and there is a lot of packages! Is not a lot of mails this? There is another work around? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] SpecConstr message while compiling
Hi, cafe!
I wrote a program and had the following message while compiling (with -O2):
SpecConstr
Function `addOc{v s6RL} [lid]'
has four call patterns, but the limit is 3
Use -fspec-constr-count=n to set the bound
Use -dppr-debug to see specialisations
What it means? Is it bad? It only happens when compiling with -O2.
addOc is a local function (defined in a where clause). If it helps, here is
the definition:
addOc x [] = [(x,1)]
addOc x ((y,n):ys) = if x == y then (y,n+1) : ys
else (y,n) : addOc x ys
I want to know if there is something wrong or a I don't need to take care
about this.
Thanks in advance,
Daniel Díaz.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] SpecConstr message while compiling
Thank you, good response!
Anyway, I'm not specially aware about the speed in that section of the
program. The really big work is done in other places. Also, addOc runs in
lists of 300~400 as maximum (but only in special inputs, average is under
200), so the time difference can't be improved notoriously, and I won't see
changes in performance.
But I will follow your pointers when necessary in the future.
On Sun, Oct 23, 2011 at 7:50 PM, Daniel Fischer
daniel.is.fisc...@googlemail.com wrote:
On Sunday 23 October 2011, 19:33:55, Daniel Díaz Casanueva wrote:
Hi, cafe!
I wrote a program and had the following message while compiling (with
-O2):
SpecConstr
Function `addOc{v s6RL} [lid]'
has four call patterns, but the limit is 3
Use -fspec-constr-count=n to set the bound
Use -dppr-debug to see specialisations
What it means? Is it bad? It only happens when compiling with -O2.
It's nothing serious.
It's just a message (that accidentally was output by default in the 7.0.*
series) that the spec-constr pass could have done more specialising, but
the limit forbade it.
More specialising on constructors means
- certainly bigger code
- potentially faster code
but it could also become slower (most likely because of worse cache
locality).
It's not even a warning, just a notification.
addOc is a local function (defined in a where clause). If it helps, here
is the definition:
addOc x [] = [(x,1)]
addOc x ((y,n):ys) = if x == y then (y,n+1) : ys
else (y,n) : addOc x ys
I want to know if there is something wrong or a I don't need to take
care about this.
You need not take care of it, but you can try out and pass
-fspec-constr-count=N
on the command line (here, N = 4 is a good start) to see if the generated
code is faster.
Thanks in advance,
Daniel Díaz.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] SSH in community.haskell.org
Hi Cafe! This is not actually a question about Haskell, but it is related. I sent my request and I have now an account in community.haskell.org. When I was going to use my project, I read these instructions: http://community.haskell.org/admin/using_project.html But I stopped in the first step If you need to use a shell, SSH to community.haskell.org. OK, I don't have too knowledge in SSH, so I searched the web and found putty as an SSH client. I downloaded it and tried it. But, sadly, without success. I put this configuration: Host name: community.haskell.org Port: 22 Connection type: SSH And it connects! Then, server asks me for an user name, and, after I put my user name, it throws the following error: Disconnected: No supported authentication methods available (server sent: publickey). Uh... I have no idea of how to avoid this error. Wrong client? Wrong configuration? Well, I have a public key I didn't put anywhere yet (but in the community registration). I guess I'm lacking some authentication, but I don't know how to solve it. I hope someone can give me some pointers! Thanks in advance! And sorry if this is not a strictly-related Haskell question. Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] SSH in community.haskell.org
Thanks JP and Ivan for the quick response! Anyway, it seems I lack the private key mentioned (all I have is the public key), and that sounds bad. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANNOUNCE: HaTeX 3 - First release
Hello, folks! I have just released HaTeX 3 to Hackage: http://hackage.haskell.org/HaTeX It is a first version, not well documented yet, but now you can test it with a simple cabal install hatex. What is HaTeX? HaTeX consists in a set of combinators which allow you to build LaTeX code, following the LaTeX syntax in a type-safe manner. This allows you to build programs which generates LaTeX code automatically for any purpose you can figure out. Further reading about HaTeX 3: * http://deltadiaz.blogspot.com/2011/09/hatex-3-previous-notes.html * http://deltadiaz.blogspot.com/2011/10/hatex-3-two-styles.html I wanted to make the release before end the proper documentation because: 1) This allow people to test the library (and hence, help me to build the documentation if any feedback comes). 2) I am too busy currently and I can't expend to HaTeX the time I'd like. The library may need some improvements, but it worked well for my own tests. With HaTeX, I uploaded the HaTeX-meta package. This package is needed if you want to develope a subset of the HaTeX modules, because they are automatically generated by this application. Anyway, there are notes in the API reference warning this. HaTeX-meta in Hackage: http://hackage.haskell.org/HaTeX-meta A continously updated version of the source code from these packages can be found at: http://dhelta.net/hprojects/HaTeX/code http://dhelta.net/hprojects/HaTeX-meta/code Thanks for reading, Daniel Díaz. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: HaTeX 3 - First release
It seems there is an error in the hackage URL's. Working URL's: http://hackage.haskell.org/package/HaTeX http://hackage.haskell.org/package/HaTeX-meta Sorry! ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Installing Gtk2Hs on Win32
Hi, Dmitri, here is newer guide, with updated links: http://deltadiaz.blogspot.com/2011/03/on-windows-how-to-install-gtk.html Hope it helps! On Fri, Jun 10, 2011 at 5:30 PM, Dmitri O.Kondratiev doko...@gmail.comwrote: Please help to find pre-compiled binary libraries of Gtk+ for Win32. Gtk2Hs insatll instructions at: http://code.haskell.org/gtk2hs/INSTALL tells us: [quote] Building on Windows Installation on Windows is nearly as easy as on Unix platforms. However, you need to download the pre-compiled binary libraries of Gtk+ and all it's dependent libraries. Point your browser to http://www.gtk.org/download-windows.html and download one of the All-in-one bundles. Note that you do *not* need to install MinGW nor MSys (but it does not hurt if they are installed on your system). Install the binaries by unpacking them into a directory without spaces. [/quote] This link (http://www.gtk.org/download-windows.html) is dead. Where to get pre-compiled binary libraries of Gtk+ ? Thanks! ___ 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
[Haskell-cafe] ANNOUNCE: Clipboard-2.2.0. System clipboard interface.
Hi all, I've just uploaded Clipboard-2.2.0 to Hackage [1]. Clipboard [2] is a library that provides an interface for the system clipboard. The API is very simple, so anyone can use it without knowing of low-level Win32 API. Currently, this library only works on a Windows OS, due to its dependency on the Win32 library. Features for 2.2.0 version: * Added compatibility with the unicode character set, while reading the content of the clipboard. * Unicode character set is the new standard for setting the clipboard content. * Fixed the function 'modifyClipboardString'. * Some changes in documentation. I want to give thanks to Artyom Kazak, who sent me the patch of Unicode compatibilty and the fix for 'modifyClipboardString' function. -- References [1] - Hackage site - http://hackage.haskell.org [2] - Clipboard site - http://sites.google.com/site/dheltadiaz/packages/clipboard ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
