Re: [Haskell-cafe] FFI - Approaches to C/C++
I'd object to your implication that Haskell is completely ready for use in general soft real-time systems. I was unable to implement a multi-threaded application which does a some IO-work in background threads in a way so that its GUI won't die. Worker threads simply starve the GUI, because Haskell doesn't have thread priorities. And even if it had, it would still lag on Windows, due to lack of IO manager. Ezyang had, in fact, made a new scheduler, which seems to address the problem; and joeyadams tries to make IO-manager for windows, but all this isn't going to see the light of day for a while, at least until 7.8.1. 2013/1/31 Ertugrul Söylemez e...@ertes.de: That used to be true, but the reason has nothing to do with the language. The problem was that the libraries weren't there. Nowadays you can write all sorts of interactive applications in Haskell, including GUIs, TUIs, games, simulations and web applications. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
On Tue, Feb 5, 2013 at 1:56 PM, kudah kudahkuka...@gmail.com wrote: I'd object to your implication that Haskell is completely ready for use in general soft real-time systems. I was unable to implement a multi-threaded application which does a some IO-work in background threads in a way so that its GUI won't die. Worker threads simply starve the GUI, because Haskell doesn't have thread priorities. And even if it had, it would still lag on Windows, due to lack of IO manager. Ezyang had, in fact, made a new scheduler, which seems to address the problem; and joeyadams tries to make IO-manager for windows, but all this isn't going to see the light of day for a while, at least until 7.8.1. What did you use for the GUI? WxWidgets? I'm interested in this case because I develop a cross-platform Python GUI application and would like to see how a Haskell implementation would behave. -- Carlo Hamalainen http://carlo-hamalainen.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
kudah kudahkuka...@gmail.com wrote: I'd object to your implication that Haskell is completely ready for use in general soft real-time systems. I was unable to implement a multi-threaded application which does a some IO-work in background threads in a way so that its GUI won't die. Worker threads simply starve the GUI, because Haskell doesn't have thread priorities. And even if it had, it would still lag on Windows, due to lack of IO manager. Ezyang had, in fact, made a new scheduler, which seems to address the problem; and joeyadams tries to make IO-manager for windows, but all this isn't going to see the light of day for a while, at least until 7.8.1. Be sure to compile with -threaded. Also note that GUI libraries often want to run in a bound thread. Greets, Ertugrul -- Key-ID: E5DD8D11 Ertugrul Soeylemez e...@ertes.de FPrint: BD28 3E3F BE63 BADD 4157 9134 D56A 37FA E5DD 8D11 Keysrv: hkp://subkeys.pgp.net/ signature.asc Description: PGP signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
I used gtk2hs, because I couldn't find a free software design tool that was at least as good as glade3. Last time I tried to compile wxHaskell, wxc produced an enormous dynamic library which also linked to every wxWidgets library out there(e.g. wxwebkit), so that the resulting mess couldn't be reasonably distributed in binaries. 2013/2/5 Carlo Hamalainen carlo.hamalai...@gmail.com: On Tue, Feb 5, 2013 at 1:56 PM, kudah kudahkuka...@gmail.com wrote: I'd object to your implication that Haskell is completely ready for use in general soft real-time systems. I was unable to implement a multi-threaded application which does a some IO-work in background threads in a way so that its GUI won't die. Worker threads simply starve the GUI, because Haskell doesn't have thread priorities. And even if it had, it would still lag on Windows, due to lack of IO manager. Ezyang had, in fact, made a new scheduler, which seems to address the problem; and joeyadams tries to make IO-manager for windows, but all this isn't going to see the light of day for a while, at least until 7.8.1. What did you use for the GUI? WxWidgets? I'm interested in this case because I develop a cross-platform Python GUI application and would like to see how a Haskell implementation would behave. -- Carlo Hamalainen http://carlo-hamalainen.net ___ 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] FFI - Approaches to C/C++
I followed dmwit's guide on threaded gtk2hs, all GUI interaction is in the main thread, which is always bounded. This shouldn't really impact the lag, as soon as gtk2hs calls back to haskell, nothing stops the RTS from delaying main thread's peaceful return to C-land for arbitrary amount of time. 2013/2/5 Ertugrul Söylemez e...@ertes.de: Be sure to compile with -threaded. Also note that GUI libraries often want to run in a bound thread. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
Casey Basichis caseybasic...@gmail.com wrote: I'm not entirely sure what you mean. I'm intending on using Ogre for GUI - for which there is the Hogre bindings, but after emailing the DEV about it, I didn't get the impression from his advice that I should be using it for production code. Here is what he suggested: It depends, really. Hogre is good for running Ogre from within Haskell, but it has its limitations. The number one thing people have been struggling with is handling input with hogre - there's Hois (Haskell wrapper for OIS) but it's not perfect (it misses input events), and the other option is having to write some C++ glue. Hogre is a solid proof of concept and you can do some demos with it, but if you're e.g. writing a game it might be a bit of a struggle. In the end it's about how much you value being able to write code in Haskell (or how allergic to C++ you are). I'm on iOS so I imagine those difficulties are compounded. I am using several other C++ libraries for which there are no existing bindings and no Haskell alternative packages that are even remotely close. Are you suggesting it would be better to write all my own FFI bindings for all the needed libraries? That's not what I'm suggesting. It was just too little information to properly judge the difficulty of doing everything in Haskell. Binding to Ogre (or C++ in general) is indeed difficult. If Hogre doesn't work or is too limited, your best option might be to write a C wrapper around the Hogre functionality you need. Another option is to use SDL/OpenGL directly, which may be easier or harder depending on your application. However, if you can build the bridge between your rendering library and Haskell, then Haskell is certainly the better choice. Everything I read suggests that Haskells strengths are in transformation and that interaction is not its strong suit. I am interested in your thoughts and I am open to whatever, but you are the first to suggest that the mix is a bad idea. That used to be true, but the reason has nothing to do with the language. The problem was that the libraries weren't there. Nowadays you can write all sorts of interactive applications in Haskell, including GUIs, TUIs, games, simulations and web applications. However, I've long been waiting for useful bindings to Ogre or Irrlicht, but I'm afraid that it's not going to happen any time soon. Ultimately it's your choice. Let me summarize the possiblities: * C wrapper around Ogre. Easy integration, but need to write the rendering code in C/C++. * Full FFI bindings to Ogre. Difficult integration, but you can write your rendering code in Haskell. * Partial FFI bindings to Ogre. Integration may be somewhat easy, if you do the initialization in Haskell and the actual rendering in C/C++. However, this again requires to write the rendering in C/C++. * Using SDL/OpenGL directly: Everything available for Haskell. May be difficult, because you need to write OpenGL code. I hope, this helps. Greets, Ertugrul -- Key-ID: E5DD8D11 Ertugrul Soeylemez e...@ertes.de FPrint: BD28 3E3F BE63 BADD 4157 9134 D56A 37FA E5DD 8D11 Keysrv: hkp://subkeys.pgp.net/ signature.asc Description: PGP signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
Quoth Casey Basichis caseybasic...@gmail.com, ... I am using several other C++ libraries for which there are no existing bindings and no Haskell alternative packages that are even remotely close. Are you suggesting it would be better to write all my own FFI bindings for all the needed libraries? Everything I read suggests that Haskells strengths are in transformation and that interaction is not its strong suit. I've done it, for my own amusement - wrapped a C++ graphics toolkit and used it to write a couple small applications. Most of us would probably object to your transformation/interaction evaluation as presented above ... but it depends on your motivations. In my case, I simply wanted to use Haskell, and in fact I started with a model like yours where the UI was simply written in C++. There were some very cumbersome things about that arrangement though, so I was happy to integrate Haskell into the UI as soon as it became possible. On the other hand ... I'd be lying if I said the Haskell code is cleaner, or really advantageous in any compelling way if we're just talking about the UI. It has its moments - Haskell is always going to pull a few things off pretty well, in a UI or whatever - but of course, this particular UI API is specifically more suited to C++, than Haskell. So given that one can write good, clean code in C++, too, the question is whether Haskell is so vastly advantageous for such applications that it compensates for the sketchy binding. It isn't, I think. Whereupon we come to your original question. Personally, I would just work with the model that's natural to your API. If it's a C++ OO 3D graphics library, then go OO, for the very same reasons discussed above. FP may in principle have all the virtues mentioned in that article, and it's good to be on the lookout for ways you can deploy some of that in a C++ program, but when it comes time to use that OO API, it's what you've got. Donn ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
Hi Ertugrul, Thank you for the detailed reply. From what you wrote, partial FFI still seems like the way to go. Unfortunately Ogre isn't the only large library I'm using, so difficult several times over sounds like a good way to handicap the project early on. I'm perfectly happy to use Haskell for the strengths that will most benefit my project. I can always go back and try to bring the C++ specific parts into the fold once a prototype is up and running. As it seems there is a great deal of c/c++ to do either way, I would really appreciate so thoughts towards my original question. What practices in C++ are preferred by Haskell users, in the know, for the parts of the app that will not be pure Haskell? Should I be looking to avoid OOP? Dependency Injection? I wont reiterate all the facets of the first post, but it would help me immensely to zero in on a few patterns and strategies that can minimized the damage I inflict in c++ land. Thanks, Casey p.s. With That used to be true, but the reason has nothing to do with the language. The problem was that the libraries weren't there. What do you mean? Which packages should I be looking at? I am on iOS like I said, its a stage 1 GHC compiler so I don't have access to GHCI or template haskell. Casey Basichis caseybasichis at gmail.com wrote: I'm not entirely sure what you mean. I'm intending on using Ogre for GUI - for which there is the Hogre bindings, but after emailing the DEV about it, I didn't get the impression from his advice that I should be using it for production code. Here is what he suggested: It depends, really. Hogre is good for running Ogre from within Haskell, but it has its limitations. The number one thing people have been struggling with is handling input with hogre - there's Hois (Haskell wrapper for OIS) but it's not perfect (it misses input events), and the other option is having to write some C++ glue. Hogre is a solid proof of concept and you can do some demos with it, but if you're e.g. writing a game it might be a bit of a struggle. In the end it's about how much you value being able to write code in Haskell (or how allergic to C++ you are). I'm on iOS so I imagine those difficulties are compounded. I am using several other C++ libraries for which there are no existing bindings and no Haskell alternative packages that are even remotely close. Are you suggesting it would be better to write all my own FFI bindings for all the needed libraries? That's not what I'm suggesting. It was just too little information to properly judge the difficulty of doing everything in Haskell. Binding to Ogre (or C++ in general) is indeed difficult. If Hogre doesn't work or is too limited, your best option might be to write a C wrapper around the Hogre functionality you need. Another option is to use SDL/OpenGL directly, which may be easier or harder depending on your application. However, if you can build the bridge between your rendering library and Haskell, then Haskell is certainly the better choice. Everything I read suggests that Haskells strengths are in transformation and that interaction is not its strong suit. I am interested in your thoughts and I am open to whatever, but you are the first to suggest that the mix is a bad idea. That used to be true, but the reason has nothing to do with the language. The problem was that the libraries weren't there. Nowadays you can write all sorts of interactive applications in Haskell, including GUIs, TUIs, games, simulations and web applications. However, I've long been waiting for useful bindings to Ogre or Irrlicht, but I'm afraid that it's not going to happen any time soon. Ultimately it's your choice. Let me summarize the possiblities: * C wrapper around Ogre. Easy integration, but need to write the rendering code in C/C++. * Full FFI bindings to Ogre. Difficult integration, but you can write your rendering code in Haskell. * Partial FFI bindings to Ogre. Integration may be somewhat easy, if you do the initialization in Haskell and the actual rendering in C/C++. However, this again requires to write the rendering in C/C++. * Using SDL/OpenGL directly: Everything available for Haskell. May be difficult, because you need to write OpenGL code. I hope, this helps. Greets, Ertugrul -- Casey James Basichis Composer - Cartoon Network http://www.caseyjamesbasichis.com caseybasic...@gmail.com 310.387.7540 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
From my experience, these things are needed to get solid (i.e. not flaky software) results. This is not what normal Haskell bindings look like though: 1. Create an interface over the Haskell RTS if you are going to use any of it from C++, and use dependency injection to choose between mock and real implementations. 2. Create a mock implementation of the Haskell side if it is accessed from C++. 3. Create comprehensive C++ only tests (using mock Haskell) that runs cleanly through valgrind. 4. Create as small an interface between C++ and Haskell as possible. 5. If you have a wide API that has little performance implications between Haskell and C++, consider not using the FFI directly, but a higher-level abstraction such as protocol buffers for this part of your API. Alexander On Thu, Jan 31, 2013 at 9:53 AM, Casey Basichis caseybasic...@gmail.comwrote: Hi Ertugrul, Thank you for the detailed reply. From what you wrote, partial FFI still seems like the way to go. Unfortunately Ogre isn't the only large library I'm using, so difficult several times over sounds like a good way to handicap the project early on. I'm perfectly happy to use Haskell for the strengths that will most benefit my project. I can always go back and try to bring the C++ specific parts into the fold once a prototype is up and running. As it seems there is a great deal of c/c++ to do either way, I would really appreciate so thoughts towards my original question. What practices in C++ are preferred by Haskell users, in the know, for the parts of the app that will not be pure Haskell? Should I be looking to avoid OOP? Dependency Injection? I wont reiterate all the facets of the first post, but it would help me immensely to zero in on a few patterns and strategies that can minimized the damage I inflict in c++ land. Thanks, Casey p.s. With That used to be true, but the reason has nothing to do with the language. The problem was that the libraries weren't there. What do you mean? Which packages should I be looking at? I am on iOS like I said, its a stage 1 GHC compiler so I don't have access to GHCI or template haskell. Casey Basichis caseybasichis at gmail.com wrote: I'm not entirely sure what you mean. I'm intending on using Ogre for GUI - for which there is the Hogre bindings, but after emailing the DEV about it, I didn't get the impression from his advice that I should be using it for production code. Here is what he suggested: It depends, really. Hogre is good for running Ogre from within Haskell, but it has its limitations. The number one thing people have been struggling with is handling input with hogre - there's Hois (Haskell wrapper for OIS) but it's not perfect (it misses input events), and the other option is having to write some C++ glue. Hogre is a solid proof of concept and you can do some demos with it, but if you're e.g. writing a game it might be a bit of a struggle. In the end it's about how much you value being able to write code in Haskell (or how allergic to C++ you are). I'm on iOS so I imagine those difficulties are compounded. I am using several other C++ libraries for which there are no existing bindings and no Haskell alternative packages that are even remotely close. Are you suggesting it would be better to write all my own FFI bindings for all the needed libraries? That's not what I'm suggesting. It was just too little information to properly judge the difficulty of doing everything in Haskell. Binding to Ogre (or C++ in general) is indeed difficult. If Hogre doesn't work or is too limited, your best option might be to write a C wrapper around the Hogre functionality you need. Another option is to use SDL/OpenGL directly, which may be easier or harder depending on your application. However, if you can build the bridge between your rendering library and Haskell, then Haskell is certainly the better choice. Everything I read suggests that Haskells strengths are in transformation and that interaction is not its strong suit. I am interested in your thoughts and I am open to whatever, but you are the first to suggest that the mix is a bad idea. That used to be true, but the reason has nothing to do with the language. The problem was that the libraries weren't there. Nowadays you can write all sorts of interactive applications in Haskell, including GUIs, TUIs, games, simulations and web applications. However, I've long been waiting for useful bindings to Ogre or Irrlicht, but I'm afraid that it's not going to happen any time soon. Ultimately it's your choice. Let me summarize the possiblities: * C wrapper around Ogre. Easy integration, but need to write the rendering code in C/C++. * Full FFI bindings to Ogre. Difficult integration, but you can write your rendering code in Haskell. * Partial FFI bindings to Ogre. Integration may be somewhat easy,
Re: [Haskell-cafe] FFI - Approaches to C/C++
On Thu, Jan 31, 2013 at 11:11 AM, Casey Basichis caseybasic...@gmail.comwrote: Hi, I'm working on a project in Haskell and C++ where the former is the brains and the latter is for UI, interaction etc. I've read this http://www.altdevblogaday.com/2012/04/26/functional-programming-in-c/ and a number of other haskell posts suggesting the OOP is not the way to go. Without trying to emulate functional programming through templates or boost::phoenix, what approaches do you all favor when designing parts of an application in C++? Patterns to embrace or avoid? Should I just use functions and handle things with name spaces? I was thinking about handling the callbacks with boosts signals and slots 2 I know this is not entirely haskell centric, but it is a question for haskell users. Thanks, Casey And then I'm on iOS so I imagine those difficulties are compounded. If you can tolerate the view that Haskell is more of an ideology than a technology, and are willing to explore areas that are technologically disparate but conceptually similar to Haskell maybe you should look at ocaml: http://web.yl.is.s.u-tokyo.ac.jp/~tosh/ocaml-on-iphone/index.html http://psellos.com/ocaml/compile-to-iphone.html Rusi -- http://www.the-magus.in http://blog.languager.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] FFI - Approaches to C/C++
Hi, I'm working on a project in Haskell and C++ where the former is the brains and the latter is for UI, interaction etc. I've read this http://www.altdevblogaday.com/2012/04/26/functional-programming-in-c/ and a number of other haskell posts suggesting the OOP is not the way to go. Without trying to emulate functional programming through templates or boost::phoenix, what approaches do you all favor when designing parts of an application in C++? Patterns to embrace or avoid? Should I just use functions and handle things with name spaces? I was thinking about handling the callbacks with boosts signals and slots 2 I know this is not entirely haskell centric, but it is a question for haskell users. Thanks, Casey -- Casey James Basichis Composer - Cartoon Network http://www.caseyjamesbasichis.com caseybasic...@gmail.com 310.387.7540 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
Casey Basichis caseybasic...@gmail.com wrote: I'm working on a project in Haskell and C++ where the former is the brains and the latter is for UI, interaction etc. That's a rather odd choice. Not exactly answering your question, but questioning your project decisions, why would you do UI and interaction in C++? You have the necessary Haskell bindings and libraries to write everything cleanly in Haskell. Greets, Ertugrul -- Not to be or to be and (not to be or to be and (not to be or to be and (not to be or to be and ... that is the list monad. signature.asc Description: PGP signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] FFI - Approaches to C/C++
Hi Ertugrul, I'm not entirely sure what you mean. I'm intending on using Ogre for GUI - for which there is the Hogre bindings, but after emailing the DEV about it, I didn't get the impression from his advice that I should be using it for production code. Here is what he suggested: It depends, really. Hogre is good for running Ogre from within Haskell, but it has its limitations. The number one thing people have been struggling with is handling input with hogre - there's Hois (Haskell wrapper for OIS) but it's not perfect (it misses input events), and the other option is having to write some C++ glue. Hogre is a solid proof of concept and you can do some demos with it, but if you're e.g. writing a game it might be a bit of a struggle. In the end it's about how much you value being able to write code in Haskell (or how allergic to C++ you are). I'm on iOS so I imagine those difficulties are compounded. I am using several other C++ libraries for which there are no existing bindings and no Haskell alternative packages that are even remotely close. Are you suggesting it would be better to write all my own FFI bindings for all the needed libraries? Everything I read suggests that Haskells strengths are in transformation and that interaction is not its strong suit. I am interested in your thoughts and I am open to whatever, but you are the first to suggest that the mix is a bad idea. Thanks, Casey * I'm working on a project in Haskell and C++ where the former is the** brains and the latter is for UI, interaction etc.* That's a rather odd choice. Not exactly answering your question, but questioning your project decisions, why would you do UI and interaction in C++? You have the necessary Haskell bindings and libraries to write everything cleanly in Haskell. Greets, Ertugrul ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
