[Haskell-cafe] ghc-mod and cabal targets
Hi, I have been using ghc-mod for a long time and I can’t give it up now, but I have an annoying problem. When I have a cabal file with a library and an executable depending on the library (for example here https://github.com/bitonic/kant/blob/master/kant.cabal), ghc-mod is not happy, complaining in every file that Error:command line: cannot satisfy -package kant Where ‘kant’ is the package that the cabal file defines with the library that the executable needs. Note that if I issue ‘cabal configure; cabal build’, everything goes smoothly. Did anybody stumble on the same problem? Thanks, Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
Hi Francesco, To keep ghc-mod happy, you also have to keep ghci happy. What you probably need is a .ghci file in the directory with a :set -isrc line in it. You may also need to add other stuff to .ghci such as language extensions and whatever else is needed to load your project with ghci. Regards, CJ On 08/02/13 11:00, Francesco Mazzoli wrote: Hi, I have been using ghc-mod for a long time and I can’t give it up now, but I have an annoying problem. When I have a cabal file with a library and an executable depending on the library (for example here https://github.com/bitonic/kant/blob/master/kant.cabal), ghc-mod is not happy, complaining in every file that Error:command line: cannot satisfy -package kant Where ‘kant’ is the package that the cabal file defines with the library that the executable needs. Note that if I issue ‘cabal configure; cabal build’, everything goes smoothly. Did anybody stumble on the same problem? Thanks, Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- CJ van den Berg mailto:c...@vdbonline.com xmpp:neuroc...@gmail.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 11:11:06 +0100, CJ van den Berg wrote: Hi Francesco, To keep ghc-mod happy, you also have to keep ghci happy. What you probably need is a .ghci file in the directory with a :set -isrc line in it. You may also need to add other stuff to .ghci such as language extensions and whatever else is needed to load your project with ghci. Hi CJ, Thanks for your answer. I had tried to do that (actually I had modified ‘ghc-ghc-options’, but the result should be the same), but it doesn’t fix the issue - and I don’t see why it should, since the problem here is about not satisfying a package dependency. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
On 08/02/13 11:20, Francesco Mazzoli wrote: At Fri, 08 Feb 2013 11:11:06 +0100, CJ van den Berg wrote: To keep ghc-mod happy, you also have to keep ghci happy. What you probably need is a .ghci file in the directory with a :set -isrc line in it. You may also need to add other stuff to .ghci such as language extensions and whatever else is needed to load your project with ghci. I had tried to do that (actually I had modified ‘ghc-ghc-options’, but the result should be the same), but it doesn’t fix the issue - and I don’t see why it should, since the problem here is about not satisfying a package dependency. I downloaded your package and tried it. It does work. Kant.REPL, which it is trying to load, is in the kant package. So it is looking for either the installed kant package, or the source files for the kant package modules. How is that not a package dependency? Telling it where to find the source files will remove the need to find an installed kant package. -- CJ van den Berg mailto:c...@vdbonline.com xmpp:neuroc...@gmail.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Extensible Type Unification
It finally occurred to me how to get most of what I want, at least from a functional perspective.Here's a sample GADT, with four categories of constructor: data Foo :: Bool - Bool - Bool - Bool - * where A :: Foo True b c d B :: Foo True b c d C :: Foo a True c d D :: Foo a b True d E :: Foo a b c True Given an Eq instance, we can easily compare two constructors for equality; we can put some constructors in a list and tell which categories appear in the list, and it plays reasonably nicely with the case coverage analyzer, which I think is important from a software engineering standpoint.For example, this function will compile without warning: fooVal :: Foo a b False False - Int fooVal x = case x of A - 0 B - 1 C - 2 The only thing this doesn't do that I wish it did is infer the type of fooVal above.Rather, GHC infers the type :: Foo a b c d - Int, and then warns me that I'm missing cases. But this is admittedly a strange form of type inference, completely alien to the Haskell landscape, which I realized only shortly after sending my original email. My original description of ranges of sets of types wasn't sufficient to fully capture my intention. That said, this solution falls rather flat in several software engineering respects. It doesn't scale with complexity; types quickly become overbearing even with modest numbers of categories.If you want to add additional categories, you have to modify every type constructor instance you've ever written down.You could mitigate some of this via the existing type-level machinery, but it seems a band-aid, not a solution. For comparison, here is the best I had when I wrote my original email: data Category = W | X | Y | Z data Foo :: [Category] - * where A :: (Member W ub) = Foo ub B :: (Member W ub) = Foo ub C :: (Member X ub) = Foo ub D :: (Member Y ub) = Foo ub E :: (Member Z ub) = Foo ub class Member (a :: x) (bs :: [x]) instance Member a (a ': bs) instance Member a bs = Member a (b ': bs) The code is closer to what I want, in terms of expression, though it mostly fails on the functional requirements.Case analysis doesn't work, I can't compare two constructors without additional type annotations, and while I can find out which categories of constructors appear in a list, it doesn't seem I can actually turn those contexts into many useful things, automatically. So while I didn't have any trouble computing set operations over unordered lists at the type level, I couldn't figure out out to put it to use in the way I wanted.Perhaps there is a clever way to emulate unification, but I really like the new features that reduce the need to be clever when it comes to type-level computation. Best, Leon ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 11:39:19 +0100, CJ van den Berg wrote: I downloaded your package and tried it. It does work. So, what I have is bitonic@clay ~/src/kant (git)-[master] % cat .ghci :set -isrc And I still get the mentioned error. Did you take any other measures to make things work? I’m using ghc-mod version 1.11.3. Kant.REPL, which it is trying to load, is in the kant package. So it is looking for either the installed kant package, or the source files for the kant package modules. How is that not a package dependency? Telling it where to find the source files will remove the need to find an installed kant package. OK, now I understand what you are doing: instead of making ghc-mod rely on cabal, you simply make it load the files directly. Which is a bit annoying in my case because I have some files that need to be preprocessed (alex/happy), but it would still be better than nothing. I can achieve the same result by simply moving the ‘cabal’ file, or by deleting the target. I guess that the ‘.ghci’ has (or should have) the same effect. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
On 8 February 2013 22:25, Francesco Mazzoli f...@mazzo.li wrote: At Fri, 08 Feb 2013 11:39:19 +0100, CJ van den Berg wrote: I downloaded your package and tried it. It does work. So, what I have is bitonic@clay ~/src/kant (git)-[master] % cat .ghci :set -isrc Try also having :set -isrc/dist and possibly :set -isrc/dist/package name (not on a machine with Haskell so I can't test this); I think I've had to do something like that before. And I still get the mentioned error. Did you take any other measures to make things work? I’m using ghc-mod version 1.11.3. Kant.REPL, which it is trying to load, is in the kant package. So it is looking for either the installed kant package, or the source files for the kant package modules. How is that not a package dependency? Telling it where to find the source files will remove the need to find an installed kant package. OK, now I understand what you are doing: instead of making ghc-mod rely on cabal, you simply make it load the files directly. Which is a bit annoying in my case because I have some files that need to be preprocessed (alex/happy), but it would still be better than nothing. I can achieve the same result by simply moving the ‘cabal’ file, or by deleting the target. I guess that the ‘.ghci’ has (or should have) the same effect. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com http://IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
On 08/02/13 12:25, Francesco Mazzoli wrote: At Fri, 08 Feb 2013 11:39:19 +0100, CJ van den Berg wrote: I downloaded your package and tried it. It does work. So, what I have is bitonic@clay ~/src/kant (git)-[master] % cat .ghci :set -isrc And I still get the mentioned error. Did you take any other measures to make things work? I’m using ghc-mod version 1.11.3. Ah, I only just realised that you’re talking about the flymake error, not the inferior-mode error. The problem is pretty much the same though. flymake uses ghc --make, which can’t import the Kant module because it doesn’t know how to build Parser.y. ghc-ghc-options is the right place for flymake options to ghc. Kant.REPL, which it is trying to load, is in the kant package. So it is looking for either the installed kant package, or the source files for the kant package modules. How is that not a package dependency? Telling it where to find the source files will remove the need to find an installed kant package. OK, now I understand what you are doing: instead of making ghc-mod rely on cabal, you simply make it load the files directly. Which is a bit annoying in my case because I have some files that need to be preprocessed (alex/happy), but it would still be better than nothing. I can achieve the same result by simply moving the ‘cabal’ file, or by deleting the target. I guess that the ‘.ghci’ has (or should have) the same effect. Options in .ghci won’t fix flymake, only inferior-mode. ghc-ghc-options is the place to fix flymake, although it won’t help if the import fails anyway. Can’t you manually preprocess Parser.y so that ghc --make has a .hs file it can use? -- CJ van den Berg mailto:c...@vdbonline.com xmpp:neuroc...@gmail.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
Hi, When I have a cabal file with a library and an executable depending on the library (for example here https://github.com/bitonic/kant/blob/master/kant.cabal), ghc-mod is not happy, complaining in every file that Error:command line: cannot satisfy -package kant Where ‘kant’ is the package that the cabal file defines with the library that the executable needs. Note that if I issue ‘cabal configure; cabal build’, everything goes smoothly. I guess you don't install the kant library, right? If so, I will think how to treat this kind problem. --Kazu ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 21:22:23 +0900 (JST), Kazu Yamamoto (山本和彦) wrote: I guess you don't install the kant library, right? If so, I will think how to treat this kind problem. The ‘kant’ package is the package I’m developing and using ghc-mod on. It includes both a library and an executable. The executable target has ‘kant’ as a dependency. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 12:50:47 +0100, CJ van den Berg wrote: On 08/02/13 12:25, Francesco Mazzoli wrote: At Fri, 08 Feb 2013 11:39:19 +0100, CJ van den Berg wrote: I downloaded your package and tried it. It does work. So, what I have is bitonic@clay ~/src/kant (git)-[master] % cat .ghci :set -isrc And I still get the mentioned error. Did you take any other measures to make things work? I’m using ghc-mod version 1.11.3. Ah, I only just realised that you’re talking about the flymake error, not the inferior-mode error. The problem is pretty much the same though. flymake uses ghc --make, which can’t import the Kant module because it doesn’t know how to build Parser.y. No, that is not the problem, I have a manually preprocessed Parser.hs in place. ghc-ghc-options is the right place for flymake options to ghc. Tried setting ‘ghc-ghc-options’, still no luck. And by the way, running ‘ghc-mod’ manually doesn’t help either: bitonic@clay ~/src/kant (git)-[master] % cat .ghci :set -isrc bitonic@clay ~/src/kant (git)-[master] % ghc-mod check src/Kant/REPL.hs src/Kant/REPL.hs:0:0:Error:command line: cannot satisfy -package kant (use -v for more information) Options in .ghci won’t fix flymake, only inferior-mode. ghc-ghc-options is the place to fix flymake, although it won’t help if the import fails anyway. Can’t you manually preprocess Parser.y so that ghc --make has a .hs file it can use? Well yes I can, but it’s a bit annoying. I think things would be easier if ‘ghc-mod’ just used cabal commands (e.g. ‘cabal build’) to check things. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
The ‘kant’ package is the package I’m developing and using ghc-mod on. Yes. I understand it. It includes both a library and an executable. The executable target has ‘kant’ as a dependency. What I asked is whether or not the kant library is installed by cabal. To edit a Haskell file for the kant executable, the current ghc-mod needs to find the kant library in global or user. I guess this bug does not exist in ghc-mod v1.11.1. --Kazu ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 22:18:20 +0900 (JST), Kazu Yamamoto (山本和彦) wrote: The ‘kant’ package is the package I’m developing and using ghc-mod on. Yes. I understand it. It includes both a library and an executable. The executable target has ‘kant’ as a dependency. What I asked is whether or not the kant library is installed by cabal. Well installing it has the big problem that each time I make a change to the interface I have to manually re-install, and this happens often since I’m in an early stage... To edit a Haskell file for the kant executable, the current ghc-mod needs to find the kant library in global or user. Right, but this is surely doable since cabal handles the situation fine. In general it seems that ghc-mod should work with cabal when it can. I guess this bug does not exist in ghc-mod v1.11.1. I’ll try with that. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
Well installing it has the big problem that each time I make a change to the interface I have to manually re-install, and this happens often since I’m in an early stage... I'm not saying that you should install it. But I just want to know your situation. Right, but this is surely doable since cabal handles the situation fine. In general it seems that ghc-mod should work with cabal when it can. Yes. This is a bug of the current ghc-mod. This behavior change was introduced by another guy, I guess. I need to look into his code. --Kazu ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 22:39:07 +0900 (JST), Kazu Yamamoto (山本和彦) wrote: Well installing it has the big problem that each time I make a change to the interface I have to manually re-install, and this happens often since I’m in an early stage... I'm not saying that you should install it. But I just want to know your situation. Oh OK, I took it as an advice. Yes, it works if I install it. Right, but this is surely doable since cabal handles the situation fine. In general it seems that ghc-mod should work with cabal when it can. Yes. This is a bug of the current ghc-mod. This behavior change was introduced by another guy, I guess. I need to look into his code. Thanks a lot, I’ll downgrade and wait for a fix. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ghc-mod and cabal targets
At Fri, 08 Feb 2013 13:43:12 +, Francesco Mazzoli wrote: At Fri, 08 Feb 2013 22:39:07 +0900 (JST), Kazu Yamamoto (山本和彦) wrote: Well installing it has the big problem that each time I make a change to the interface I have to manually re-install, and this happens often since I’m in an early stage... I'm not saying that you should install it. But I just want to know your situation. Oh OK, I took it as an advice. Yes, it works if I install it. Right, but this is surely doable since cabal handles the situation fine. In general it seems that ghc-mod should work with cabal when it can. Yes. This is a bug of the current ghc-mod. This behavior change was introduced by another guy, I guess. I need to look into his code. Thanks a lot, I’ll downgrade and wait for a fix. Francesco I can confirm that 1.11.1 works. Francesco ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] cabal-dev add-source
Hello, I'm trying to understand cabal-dev, and I seem to be missing some basic point, because I can't get dependencies between projects working properly. I have two projects, let's call them P1 and P2. P2 depends on P1, as indicated by its cabal file build-depends field. I run cabal-dev add-source ..\P1 inside P2 then cabal-dev install Everything works fine, and my project compiles, with modules in P2 calling functions from P1. Then I add a new function if an exposed module of P1. I rerun the cabal-dev add-source and cabal-dev install commands to tell P2 of the change, as per the cabal-dev documentation. I change a file in P2 to use the new function, the compilation fails. If I check into the cabal-dev folder, I see the .hi file for my changed module has not been updated (old date). What am I missing? Thanks -- JP Moresmau http://jpmoresmau.blogspot.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] arrow notation
The proposed changes are described here: http://hackage.haskell.org/trac/ghc/wiki/ArrowNotation ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] cabal-dev add-source
You need to call cabal-dev add-source on P1 again to copy over the sdist, then do a cabal-dev install. See notes under Using a sandbox-local Hackage on https://github.com/creswick/cabal-dev On Feb 8, 2013 2:22 PM, JP Moresmau jpmores...@gmail.com wrote: Hello, I'm trying to understand cabal-dev, and I seem to be missing some basic point, because I can't get dependencies between projects working properly. I have two projects, let's call them P1 and P2. P2 depends on P1, as indicated by its cabal file build-depends field. I run cabal-dev add-source ..\P1 inside P2 then cabal-dev install Everything works fine, and my project compiles, with modules in P2 calling functions from P1. Then I add a new function if an exposed module of P1. I rerun the cabal-dev add-source and cabal-dev install commands to tell P2 of the change, as per the cabal-dev documentation. I change a file in P2 to use the new function, the compilation fails. If I check into the cabal-dev folder, I see the .hi file for my changed module has not been updated (old date). What am I missing? Thanks -- JP Moresmau http://jpmoresmau.blogspot.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] cabal-dev add-source
On Fri, Feb 8, 2013 at 9:53 AM, Blake Rain blake.r...@gmail.com wrote: You need to call cabal-dev add-source on P1 again to copy over the sdist, then do a cabal-dev install. See notes under Using a sandbox-local Hackage on https://github.com/creswick/cabal-dehttps://github.com/creswick/cabal-dev With the new cabal sandboxing (due in 1.18) this won't be necessary as we create a link to the repo, instead of installing a copy. We will rebuild the linked repo as needed. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] cabal-dev add-source
That's exactly what I'm doing, and I was exactly following these notes, but it doesn't work. This google+ post and the answers to it ( https://plus.google.com/102016502921512042165/posts/TGaENqWfubP) lead me to at least one solution that seems to work: you need to unregister the changed package first. So cabal-dev ghc-pkg unregister --force P1 cabal-dev add-source ../P1 cabal-dev install Does the trick. There seems to be a way to pass a --reinstall flag to cabal-dev install but I haven't gotten it to work yet. Thanks JP On Fri, Feb 8, 2013 at 6:53 PM, Blake Rain blake.r...@gmail.com wrote: You need to call cabal-dev add-source on P1 again to copy over the sdist, then do a cabal-dev install. See notes under Using a sandbox-local Hackage on https://github.com/creswick/cabal-dev On Feb 8, 2013 2:22 PM, JP Moresmau jpmores...@gmail.com wrote: Hello, I'm trying to understand cabal-dev, and I seem to be missing some basic point, because I can't get dependencies between projects working properly. I have two projects, let's call them P1 and P2. P2 depends on P1, as indicated by its cabal file build-depends field. I run cabal-dev add-source ..\P1 inside P2 then cabal-dev install Everything works fine, and my project compiles, with modules in P2 calling functions from P1. Then I add a new function if an exposed module of P1. I rerun the cabal-dev add-source and cabal-dev install commands to tell P2 of the change, as per the cabal-dev documentation. I change a file in P2 to use the new function, the compilation fails. If I check into the cabal-dev folder, I see the .hi file for my changed module has not been updated (old date). What am I missing? Thanks -- JP Moresmau http://jpmoresmau.blogspot.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- JP Moresmau http://jpmoresmau.blogspot.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] cabal-dev add-source
Johan, thanks, that brings me to a point that I wanted to raise. I'm playing with cabal-dev because users have asked me to add support for it in EclipseFP (so projects could have their own sandbox and have dependencies between projects without polluting the main package databases). It is worth it, or should I just wait for cabal 1.18 and use the sandboxing facility? Or will the two work similarly enough that supporting both will be easy? Does the sandboxing in cabal means that tools like cabal-dev are going to get deprecated? Thanks JP On Fri, Feb 8, 2013 at 7:02 PM, Johan Tibell johan.tib...@gmail.com wrote: On Fri, Feb 8, 2013 at 9:53 AM, Blake Rain blake.r...@gmail.com wrote: You need to call cabal-dev add-source on P1 again to copy over the sdist, then do a cabal-dev install. See notes under Using a sandbox-local Hackage on https://github.com/creswick/cabal-dehttps://github.com/creswick/cabal-dev With the new cabal sandboxing (due in 1.18) this won't be necessary as we create a link to the repo, instead of installing a copy. We will rebuild the linked repo as needed. -- JP Moresmau http://jpmoresmau.blogspot.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] cabal-dev add-source
On Fri, Feb 8, 2013 at 10:07 AM, JP Moresmau jpmores...@gmail.com wrote: Johan, thanks, that brings me to a point that I wanted to raise. I'm playing with cabal-dev because users have asked me to add support for it in EclipseFP (so projects could have their own sandbox and have dependencies between projects without polluting the main package databases). It is worth it, or should I just wait for cabal 1.18 and use the sandboxing facility? Or will the two work similarly enough that supporting both will be easy? Does the sandboxing in cabal means that tools like cabal-dev are going to get deprecated? I think they will be similar enough that you could easily port the code. The new cabal sandboxing will work as follows: cabal sandbox --init cabal add-source dir and then you use cabal commands like normal (e.g. configure, build, test). No installing necessary. I cannot speak for the cabal-dev developers. We do intend to support a superset of the cabal-dev functionality eventually. What we're missing now is ghci support. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] cabal-dev add-source
On Friday, February 8, 2013 at 1:19 PM, Johan Tibell wrote: On Fri, Feb 8, 2013 at 10:07 AM, JP Moresmau jpmores...@gmail.com (mailto:jpmores...@gmail.com) wrote: Johan, thanks, that brings me to a point that I wanted to raise. I'm playing with cabal-dev because users have asked me to add support for it in EclipseFP (so projects could have their own sandbox and have dependencies between projects without polluting the main package databases). It is worth it, or should I just wait for cabal 1.18 and use the sandboxing facility? Or will the two work similarly enough that supporting both will be easy? Does the sandboxing in cabal means that tools like cabal-dev are going to get deprecated? I think they will be similar enough that you could easily port the code. The new cabal sandboxing will work as follows: cabal sandbox --init cabal add-source dir and then you use cabal commands like normal (e.g. configure, build, test). No installing necessary. I cannot speak for the cabal-dev developers. We do intend to support a superset of the cabal-dev functionality eventually. What we're missing now is ghci support. Which, thanks to Johan's help yesterday, can still be worked around (for now) by starting ghci with: ghci -package-conf ./cabal-sandbox/your-package-conf-folder-here/ I'm trying to get Emacs haskell-mode and inferior-haskell to play nice with this, but it's not working so far for some reason. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org (mailto: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] ICFP 2013: Call for papers
= 18th ACM SIGPLAN International Conference on Functional Programming ICFP 2013 Boston, MA, USA, 25-27 September 2013 http://www.icfpconference.org/icfp2013 = Important Dates ~~~ Submissions due: Thursday, 28 March 2013 23:59 UTC-11 (Pago Pago, American Samoa, time) Author response: Wednesday, 22 May 0:00 UTC-11 Friday, 24 May 2013 23:59 UTC-11 Notification: Friday, 7 June 2013 Final copy due: Friday, 5 July 2013 Scope ~ ICFP 2013 seeks original papers on the art and science of functional programming. Submissions are invited on all topics from principles to practice, from foundations to features, and from abstraction to application. The scope includes all languages that encourage functional programming, including both purely applicative and imperative languages, as well as languages with objects, concurrency, or parallelism. Topics of interest include (but are not limited to): * Language Design: concurrency and distribution; modules; components and composition; metaprogramming; interoperability; type systems; relations to imperative, object-oriented, or logic programming * Implementation: abstract machines; virtual machines; interpretation; compilation; compile-time and run-time optimization; memory management; multi-threading; exploiting parallel hardware; interfaces to foreign functions, services, components, or low-level machine resources * Software-Development Techniques: algorithms and data structures; design patterns; specification; verification; validation; proof assistants; debugging; testing; tracing; profiling * Foundations: formal semantics; lambda calculus; rewriting; type theory; monads; continuations; control; state; effects; program verification; dependent types * Analysis and Transformation: control-flow; data-flow; abstract interpretation; partial evaluation; program calculation * Applications and Domain-Specific Languages: symbolic computing; formal-methods tools; artificial intelligence; systems programming; distributed-systems and web programming; hardware design; databases; XML processing; scientific and numerical computing; graphical user interfaces; multimedia programming; scripting; system administration; security * Education: teaching introductory programming; parallel programming; mathematical proof; algebra * Functional Pearls: elegant, instructive, and fun essays on functional programming * Experience Reports: short papers that provide evidence that functional programming really works or describe obstacles that have kept it from working If you are concerned about the appropriateness of some topic, do not hesitate to contact the program chair. Abbreviated instructions for authors * By Thursday, 28 March 2013, 23:59 UTC-11 (American Samoa time), submit a full paper of at most 12 pages (6 pages for an Experience Report), including bibliography and figures. The deadlines will be strictly enforced and papers exceeding the page limits will be summarily rejected. * Authors have the option to attach supplementary material to a submission, on the understanding that reviewers may choose not to look at it. * Each submission must adhere to SIGPLAN's republication policy, as explained on the web at http://www.acm.org/sigplan/republicationpolicy.htm * Authors of resubmitted (but previously rejected) papers have the option to attach an annotated copy of the reviews of their previous submission(s), explaining how they have addressed these previous reviews in the present submission. If a reviewer identifies him/herself as a reviewer of this previous submission and wishes to see how his/her comments have been addressed, the program chair will communicate to this reviewer the annotated copy of his/her previous review. Otherwise, no reviewer will read the annotated copies of the previous reviews. Overall, a submission will be evaluated according to its relevance, correctness, significance, originality, and clarity. It should explain its contributions in both general and technical terms, clearly identifying what has been accomplished, explaining why it is significant, and comparing it with previous work. The technical content should be accessible to a broad audience. Functional Pearls and Experience Reports are separate categories of papers that need not report original research results and must be marked as such at the time of submission. Detailed guidelines on both categories are on the conference web site. Proceedings will be published by ACM Press. Authors of accepted submissions are expected to transfer the copyright to the ACM. Presentations will be videotaped and released online if the presenter consents. Formatting:
Re: [Haskell-cafe] cabal-dev add-source
On Fri, Feb 8, 2013 at 10:24 AM, Ozgun Ataman ozata...@gmail.com wrote: Which, thanks to Johan's help yesterday, can still be worked around (for now) by starting ghci with: ghci -package-conf ./cabal-sandbox/your-package-conf-folder-here/ You can indeed do this. For real ghci support in cabal we need to also pass -package flags, C libraries, etc to ghci. That's why it's not done yet. -- Johan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] performance question
Hi list, I wrote a script that reads matrix elements from standard input, parses the input using a regular expression, and then bins the matrix elements by magnitude. I wrote the same script in python (just to be sure :) ) and find that the python version vastly outperforms the Haskell script. To be concrete: $ time ./createMatrixDump.py -N 128 | ./printMatrixDecay real0m2.655s user0m2.677s sys 0m0.095s $ time ./createMatrixDump.py -N 128 | ./printMatrixDecay.py - real0m0.445s user0m0.615s sys 0m0.032s The Haskell script was compiled with ghc --make printMatrixDecay.hs. Could you have a look at the script and give me some pointers as to where I could improve it, both in terms of performance and also generally, as I am very new to Haskell. Thanks already, nick printMatrixDecay.hs Description: Binary data ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] performance question
On 08.02.2013 23:26, Nicolas Bock wrote: Hi list, I wrote a script that reads matrix elements from standard input, parses the input using a regular expression, and then bins the matrix elements by magnitude. I wrote the same script in python (just to be sure :) ) and find that the python version vastly outperforms the Haskell script. General performance hints 1) Strings are slow. Fast alternatives are text[1] for textual data and bytestrings[2] for binary data. I can't say anything about performance of Text.Regex.Posix. 2) Appending list wrong operation to do in performance sensitive code. (++) traverses its first argument so it's O(n) in its length. What exactly are you tryeing to do? Create a histogram? The Haskell script was compiled with ghc --make printMatrixDecay.hs. If you want performance you absolutely should use -O2. [1] http://hackage.haskell.org/package/text [2] http://hackage.haskell.org/package/bytestring ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] performance question
Do you mind posting createMatrixDump.py and printMatrixDecay.py? That would certainly make it easier to help you. On Fri, Feb 8, 2013 at 11:26 AM, Nicolas Bock nicolasb...@gmail.com wrote: Hi list, I wrote a script that reads matrix elements from standard input, parses the input using a regular expression, and then bins the matrix elements by magnitude. I wrote the same script in python (just to be sure :) ) and find that the python version vastly outperforms the Haskell script. To be concrete: $ time ./createMatrixDump.py -N 128 | ./printMatrixDecay real0m2.655s user0m2.677s sys 0m0.095s $ time ./createMatrixDump.py -N 128 | ./printMatrixDecay.py - real0m0.445s user0m0.615s sys 0m0.032s The Haskell script was compiled with ghc --make printMatrixDecay.hs. Could you have a look at the script and give me some pointers as to where I could improve it, both in terms of performance and also generally, as I am very new to Haskell. Thanks already, nick ___ 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] performance question
Sorry, should have done this right away. Here are the other two scripts. On Fri, Feb 8, 2013 at 1:45 PM, Bob Ippolito b...@redivi.com wrote: Do you mind posting createMatrixDump.py and printMatrixDecay.py? That would certainly make it easier to help you. On Fri, Feb 8, 2013 at 11:26 AM, Nicolas Bock nicolasb...@gmail.comwrote: Hi list, I wrote a script that reads matrix elements from standard input, parses the input using a regular expression, and then bins the matrix elements by magnitude. I wrote the same script in python (just to be sure :) ) and find that the python version vastly outperforms the Haskell script. To be concrete: $ time ./createMatrixDump.py -N 128 | ./printMatrixDecay real0m2.655s user0m2.677s sys 0m0.095s $ time ./createMatrixDump.py -N 128 | ./printMatrixDecay.py - real0m0.445s user0m0.615s sys 0m0.032s The Haskell script was compiled with ghc --make printMatrixDecay.hs. Could you have a look at the script and give me some pointers as to where I could improve it, both in terms of performance and also generally, as I am very new to Haskell. Thanks already, nick ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe createMatrixDump.py Description: Binary data printMatrixDecay.py Description: Binary data ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] performance question
On Fri, Feb 8, 2013 at 1:23 PM, Aleksey Khudyakov alexey.sklad...@gmail.com wrote: On 08.02.2013 23:26, Nicolas Bock wrote: Hi list, I wrote a script that reads matrix elements from standard input, parses the input using a regular expression, and then bins the matrix elements by magnitude. I wrote the same script in python (just to be sure :) ) and find that the python version vastly outperforms the Haskell script. General performance hints 1) Strings are slow. Fast alternatives are text[1] for textual data and bytestrings[2] for binary data. I can't say anything about performance of Text.Regex.Posix. Thanks for the suggestion, I will try that. 2) Appending list wrong operation to do in performance sensitive code. (++) traverses its first argument so it's O(n) in its length. What exactly are you tryeing to do? Create a histogram? Yes, a histogram. The binning code is really a little awkward. I haven't gotten used to thinking in terms of inmutable objects yet and this list appending is really a pretty bad hack to kind of allow me to increment the bin counts. How would one do this more haskellishish? The Haskell script was compiled with ghc --make printMatrixDecay.hs. If you want performance you absolutely should use -O2. I'll try that. [1] http://hackage.haskell.org/**package/texthttp://hackage.haskell.org/package/text [2] http://hackage.haskell.org/**package/bytestringhttp://hackage.haskell.org/package/bytestring __**_ 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-cafe
Re: [Haskell-cafe] performance question
On 09.02.2013 01:02, Nicolas Bock wrote: Yes, a histogram. The binning code is really a little awkward. I haven't gotten used to thinking in terms of inmutable objects yet and this list appending is really a pretty bad hack to kind of allow me to increment the bin counts. How would one do this more haskellishish? Histogramming is a bit awkward in haskell. If we want to stick to immutable data types best choice is to have map bin → number of entries. For every new entry select bin and add 1 to its content. But if we want to store data in array we have to deal with mutable state. It's not realistic to copy array on every update. For that case I wrote I library histogram-fill[1]. Below is program which does approximately same thing. import Data.Histogram.Fill import Data.Histogram (Histogram) hb :: HBuilder String (Histogram LogBinD Int) hb = forceInt - mkSimple (logBinDN 1e-8 10 10) - read main :: IO () main = do l - getContents print $ fillBuilder hb $ lines l I cheated and used sed to strip unused data. It uses String so it's still slower than python. $ time (python gen.py -N 300 | sed 's/.*=//' | ./printMatrixDecay ) real0m0.958s user0m2.096s sys 0m0.052s $ time (python gen.py -N 300 | python printMatrixDecay.py -) real0m0.590s user0m0.952s sys 0m0.016s [1] http://hackage.haskell.org/package/histogram-fill ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] xml conduit
Hi, Is there a nice way to update xml. I want to be able to use xml-conduit to find a location in the xml and then add/update that node. eg xpath from //d/e/f and then change the content at 'f' or add a new node a ... d e fsome data to change /f /e /d ... /a Thanks for any help, Grant ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] performance question
Heh, I have wrote c++ version and that is much faster than python ;)
bmaxa@maxa:~/haskell$ time ./createMatrixDump.py -N 128 output.txt
real0m0.041suser0m0.040ssys 0m0.000sbmaxa@maxa:~/haskell$ time
./printMatrixDecay.py - output.txt(-) read 16384 matrix elements (128x128 =
16384)[0.00e+00, 1.00e-08) = 0 (0.00%) 0[1.00e-08, 1.00e-07) = 0 (0.00%)
0[1.00e-07, 1.00e-06) = 0 (0.00%) 0[1.00e-06, 1.00e-05) = 0 (0.00%) 0[1.00e-05,
1.00e-04) = 1 (0.00%) 1[1.00e-04, 1.00e-03) = 15 (0.00%) 16[1.00e-03, 1.00e-02)
= 149 (0.00%) 165[1.00e-02, 1.00e-01) = 1425 (0.00%) 1590[1.00e-01, 1.00e+00) =
14794 (0.00%) 16384[1.00e+00, 2.00e+00) = 0 (0.00%) 16384
real0m0.081suser0m0.072ssys 0m0.008sbmaxa@maxa:~/haskell$ time
./printMatrixDecay output.txtread 16384 matrix elements (128x128 =
16384)[0.00e+00, 1.00e-08) = 0 (0.00%) 0[1.00e-08, 1.00e-07) = 0 (0.00%)
0[1.00e-07, 1.00e-06) = 0 (0.00%) 0[1.00e-06, 1.00e-05) = 0 (0.00%) 0[1.00e-05,
1.00e-04) = 1 (0.01%) 1[1.00e-04, 1.00e-03) = 15 (0.09%) 16[1.00e-03, 1.00e-02)
= 149 (0.91%) 165[1.00e-02, 1.00e-01) = 1425 (8.70%) 1590[1.00e-01, 1.00e+00) =
14794 (90.30%) 16384[1.00e+00, 2.00e+00) = 0 (0.00%) 16384
real0m0.018suser0m0.012ssys 0m0.004s
unfortunately g++ does not have regex implemented yet so I used libpcre ...
#include pcre.h#include sstream#include cstdio#include cmath#include
iostream#include stdexcept#include vector
template class Fvoid regex(const std::string in, const std::string
pattern,int n,F f){int ovec[3*n],position;const char* error; int
errorpos;
pcre* pe = pcre_compile(pattern.c_str(),0,error,errorpos,0);
if(!pe)throw std::runtime_error(error);
pcre_extra* extra=pcre_study(pe,0,error);
for(position = 0;
pcre_exec(pe,extra,in.c_str(),in.size(),position,0,ovec,3*n)=0;
position = ovec[1])f(position,ovec);f(position,ovec);pcre_free(extra);
pcre_free(pe); }
int main(){ std::ios::sync_with_stdio(false); std::ostringstream oss; oss
std::cin.rdbuf(); const std::string in = oss.str(); std::vectordouble
strataBounds = { 0.0, 1.0e-8, 1.0e-7, 1.0e-6, 1.0e-5, 1.0e-4, 1.0e-3, 1.0e-2,
1.0e-1, 1.0, 2.0 }; std::vectorint strataCounts(strataBounds.size());
unsigned N = 0; auto f = [](int position,int* ovec) {if(int(position)
ovec[0])return;++N;double aij = 0.0;std::istringstream
iss(in.substr(ovec[2],ovec[3]-ovec[2]));iss aij;aij=fabs(aij);
for(unsigned i = 0; i strataBounds.size() - 1; ++i){ if(aij =
strataBounds[i] aij strataBounds[i+1]) {++strataCounts[i];
break; }} }; regex(in,matrix.*= ([0-9.eE+-]+)\n,2,f);
printf(read %d matrix elements (%dx%d = %d)\n,N,int(sqrt(N)),int(sqrt(N)),N);
int total = 0; for(unsigned i = 0; i strataBounds.size()-1;++i) {total
+= strataCounts[i];printf([%1.2e, %1.2e) = %d (%1.2f%%) %d\n,
strataBounds[i], strataBounds[i+1],strataCounts[i],
100*(double(strataCounts[i])/N), total); }}
From: nicolasb...@gmail.com
Date: Fri, 8 Feb 2013 12:26:09 -0700
To: haskell-cafe@haskell.org
Subject: [Haskell-cafe] performance question
Hi list,
I wrote a script that reads matrix elements from standard input, parses the
input using a regular expression, and then bins the matrix elements by
magnitude. I wrote the same script in python (just to be sure :) ) and find
that the python version vastly outperforms the Haskell script.
To be concrete:
$ time ./createMatrixDump.py -N 128 | ./printMatrixDecayreal0m2.655s
user0m2.677ssys 0m0.095s
$ time ./createMatrixDump.py -N 128 | ./printMatrixDecay.py -
real0m0.445suser0m0.615ssys 0m0.032s
The Haskell script was compiled with ghc --make printMatrixDecay.hs.
Could you have a look at the script and give me some pointers as to where I
could improve it, both in terms of performance and also generally, as I am very
new to Haskell.
Thanks already,
nick
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Re: [Haskell-cafe] xml conduit
I don't know about xml-conduit but I know that such thing is possible in HXT. See the `Modifying a Node' section at [1] for a trivial example. You probably will have to read the whole page to somewhat understand what's going on though. [1] - http://adit.io/posts/2012-04-14-working_with_HTML_in_haskell.html On 08/02/13 23:31, grant wrote: Hi, Is there a nice way to update xml. I want to be able to use xml-conduit to find a location in the xml and then add/update that node. eg xpath from //d/e/f and then change the content at 'f' or add a new node a ... d e fsome data to change /f /e /d ... /a Thanks for any help, Grant ___ 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] CoArbitrary
Hello, In the QuickCheck library, there is a type-class called CoArbitrary. It is defined like so: class CoArbitrary a where coarbitrary :: a - Gen b - Gen b -- Gen is a monad Its purpose is to allow generation of functions. In other words, for taking Gen x - Gen (a - x), which could be done rather degenerately (fmap const) but QuickCheck constrains with (CoArbitrary a) to perturb the resulting value instead of ignoring (const) it. It has always puzzled me in the general sense of thinking about the scenario: f x - f (a - x) and whether the CoArbitrary is a good/general solution, perhaps for the specific case of f=Gen or maybe even more generally. -- approximate (a - f x - f x) -- e.g. CoArbitrary to perturb the result - f x -- e.g. Gen x - f (a - x) -- e.g. Gen (a - x) So I often wonder about what might be a better (and perhaps more general) constraint to produce functions f x - f (a - x) for a given Monad f. I was wondering if there is an existing abstraction (or paper) that might point me in that direction. It is a problem that I encounter on occasion in general programming and I am using Arbitrary/CoArbitrary as an example to help make my point, but I am dissatisfied (for reasons that I am unsure about) with the solution provided by CoArbitrary. What about other monads? For example, what is a general constraint to be placed to permit a function Maybe x - Maybe (a - x) that does not simply const away the argument. I hope I have phrased this in a way to make the point. I found it a bit difficult to articulate and I do wonder (hope!) that others encounter similar scenarios. Thanks for any tips! -- Tony Morris http://tmorris.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
