Re: [Haskell-cafe] Need some advice around lazy IO
Hi Kashyap I am not sure if this solution to your problem but try using Bytestring rather than String in parseXML' :: String - XMLAST parseXML' str = f ast where ast = parse (spaces xmlParser) str f (Right x) = x f (Left x) = CouldNotParse Also see this post[1] My Space is Leaking.. Regards, Mukesh Tiwari [1] http://www.mega-nerd.com/erikd/Blog/ On Sat, Mar 23, 2013 at 11:11 AM, C K Kashyap ckkash...@gmail.com wrote: Oops...I sent out the earlier message accidentally. I got some profiling done and got this pdf generated. I see unhealthy growths in my XML parser. https://github.com/ckkashyap/haskell-perf-repro/blob/master/RSXP.hs I must be not using parsec efficiently. Regards, Kashyap On Sat, Mar 23, 2013 at 11:07 AM, C K Kashyap ckkash...@gmail.com wrote: I got some profiling done and got this pdf generated. I see unhealthy growths in my XML parser. On Fri, Mar 22, 2013 at 8:12 PM, C K Kashyap ckkash...@gmail.com wrote: Hi folks, I've run into more issues with my report generation tool I'd really appreciate some help. I've created a repro project on github to demonstrate the problem. git://github.com/ckkashyap/haskell-perf-repro.git There is a template xml file that needs to be replicated several times (3000 or so) under the data directory and then driver needs to be run. The memory used by driver keeps growing until it runs out of memory. Also, I'd appreciate some tips on how to go about debugging this situation. I am on the windows platform. Regards, Kashyap On Tue, Mar 19, 2013 at 1:11 PM, Kim-Ee Yeoh k...@atamo.com wrote: On Tue, Mar 19, 2013 at 2:01 PM, Konstantin Litvinenko to.darkan...@gmail.com wrote: Yes. You (and Dan) are totally right. 'Let' just bind expression, not evaluating it. Dan's evaluate trick force rnf to run before hClose. As I said - it's tricky part especially for newbie like me :) To place this in perspective, one only needs to descend one or two more layers before the semantics starts confusing even experts. Whereas the difference between seq and evaluate shouldn't be too hard to grasp, that between evaluate and (return $!) is considerably more subtle, as Edward Yang notified us 10 days ago. See the thread titled To seq or not to seq. -- Kim-Ee ___ 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 mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Compiled code
They are used: any library installed with e.g. cabal-install is kept around not in source form but with .hi and .o files (and perhaps some metadata as well.) Best regards, Krzysztof Skrzętnicki On Fri, Mar 22, 2013 at 11:04 PM, MigMit miguelim...@yandex.ru wrote: Suppose I compiled some module and kept it's .hi and .o files. Is it possible to use this module in my program if the source code was deleted for some reason? Seems like the answer is yes — by creating a fake .hs file (with no real content) and touch-in .hi and .o files I tricked ghc so that it didn't attempt to recompile the module, so the information in .hi and .o files is sufficient. But ghc insists on having the .hs file around, and I didn't find a way to turn it off. Is there any? Or there is a specific reason not to allow this? ___ 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] Announcement - HGamer3D - 0.2.1 - why netwire
Peter Althainz wrote: Heinrich Apfelmus wrote: Of course, I have to ask: what influenced your choice of FRP library in favor of netwire instead of reactive-banana ? good question, actually I need to thank you for your excellent tutorials on FRP and GUI on the WEB. I tried the version of reactive-banana without switches as the first FRP framework to have contact with and I liked its simplicity and the cool introduction around Excel cells you gave on the Web. My pleasure. :) I have to thank Peter Minten for writing the tutorial with Excel cells, though. HGamer3D is my personal way to get more insight into FP and Haskell especially and from the beginning I wanted to have a FRP API to try it with game examples. So your intro on FRP and the examples were very helpful with that. After reading a lot on the web it became clear, that currently reactive-banana and netwire are good candidates to start with. So why in the end I decided to use netwire for the binding? It's some personal things and I do not claim to have done a proper evaluation or comparison. I also cannot judge on performance or other relevant topics. Having said that, I can give you some points why I choosed netwire: - The cool simplicity of reactive-banana API seems to have suffered a little bit after the introduction of the switch functionality. - After getting around Monads and Applicative by great help of Learning a Haskell for great good I was shocked to see, there is even more to learn, when I detected Arrows. So I started to look at it and discovered some nice tutorials for Arrows. - What struck me was introduction of netwire author Ertugrul Söylemez on Arrows and the explanations of local state, which can be kept into an arrow. Since I was also curious on OOP and FP and game state handling, actually this raised some interest. So I think this Arrows keep local state argument was the killer feature. But also behaviours keep local state and maybe I got misguided here. - I then did some trials with netwire and I felt it's a quite comprehensive and nice API, so I got started with that. I'm mainly asking because it helps me learn about issues with reactive-banana that could be fixed. Looking at other FRP libraries for fun and learning is definitely something that should be encouraged and not something that should be fixed, so that's cool. :) You said that reactive-banana didn't feel as simple after the introduction of dynamic event switching, though. Could you pinpoint some particular thing that made you feel like that? Maybe a type signature or a tutorial or something else? I took great care trying to make the dynamic event switching stuff entirely optional, so you can use reactive-banana without understanding it at all, but I'm not sure if I succeeded. Best regards, Heinrich Apfelmus -- http://apfelmus.nfshost.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ticking time bomb
Marc Weber marco-owe...@gmx.de writes: The only safe way is acceptnig keys from people you know don't view pdf using adobe reader, I don’t… who don't browse the web (neither use flash) etc. I only browse the web (in general) from a diskless virtual machine. And then still you also have to know that their email account password is reasonable strong .. I don’t think you need to know that: you need to know that their signing key password is strong, that they’ve never entered it into a machine with a keylogger running, and no-one has shoulder surfed them. Oh, and that no-one can blackmail or torture them :-P -- Jón Fairbairn jon.fairba...@cl.cam.ac.uk ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Announcement - HGamer3D - 0.2.1 - why netwire
Heinrich Apfelmus apfel...@quantentunnel.de wrote: You said that reactive-banana didn't feel as simple after the introduction of dynamic event switching, though. Could you pinpoint some particular thing that made you feel like that? Maybe a type signature or a tutorial or something else? I took great care trying to make the dynamic event switching stuff entirely optional, so you can use reactive-banana without understanding it at all, but I'm not sure if I succeeded. I think this is less of an issue with reactive-banana than with classic FRP in general. The type signatures of Netwire can be scary at first sight, but they are consistent throughout the entire library. Once you understand one of these type signatures you understand all of them. Once you know how to use one wire, you know how to use all others. Let me pinpoint something in particular: events. In reactive-banana events are special, in Netwire they are not. This makes dynamic switching special in reactive-banana and natural in Netwire. Let me show you an example: You want to dispaly one for ten seconds, then two for twelve seconds, then start over: myWire = one . for 10 -- two . for 12 -- myWire Events and particularly dynamic event switching is one of the main problems Netwire solves elegantly. You can add this to reactive-banana, too, but it would require changing almost the entire event interface. 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] A question about data declaration
On Mar 22, 2013 2:58 AM, C K Kashyap ckkash...@gmail.com wrote: Thanks Eric and Brent, Even with GADT, it appears that I'd need extra data definitions. I'll go without GADT then ... Brent, my use case is not particularly complicated. I am trying to model the pdf spec - which says that pdf contains Objects that could of of types Number, String, Name, Array and Dictionary - while array is list of objects, the Disctionary is a list of tuples (Name, Object) not (Object, Object) - hence my situation. Regards, Kashyap You could have a look at how the aeson package represents JavaScript values, which have a similar structure to your requirement, e.g. http://hackage.haskell.org/packages/archive/aeson/0.6.1.0/doc/html/Data-Aeson-Types.html#t:Value Doug ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] ANN: pdf-toolbox
Hello, I have uploaded the first release of my pdf toolbox, a collection of tools for processing PDF files. It supports both parsing and generating of pdf files. It consists of two libraries: - core ( http://hackage.haskell.org/package/pdf-toolbox-core ) contains low level tools. - document ( http://hackage.haskell.org/package/pdf-toolbox-document ) contains pretty limited set of middle level tools. (Also there is the 3d library, pdf-toolbox-content. It contains tools for processing pdf page content, e.g. text extraction. It is not released yet, but you can find it on github.) The initial plan was to create higher level tools before releasing on hackage, but I found it hard to design good high level API without wide rage on use cases. So I decided to release it earlier in order to receive feedback. You can find few examples here: https://github.com/Yuras/pdf-toolbox/tree/master/examples Thanks, Yuras ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] A question about data declaration
Brent, my use case is not particularly complicated. I am trying to model the pdf spec - which says that pdf contains Objects that could of of types Number, String, Name, Array and Dictionary - while array is list of objects, the Disctionary is a list of tuples (Name, Object) not (Object, Object) - hence my situation. The WASH web framework used a trick to type HTML. If I recall correctly, they had a couple of phantom type parameters and then wrote MPTC instances for only the allowed combinations. So you'd have HTML InXContext OrderedList and HTML InXContext UnorderedList, etc. Then the constructor for an X would have a type signature that required 'HTML InXContext a' of its argument. Or something like that. See if you can dig up any old WASH docs for more details. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Enumerating functions at runtime
I'm curious about using Haskell for metaprogramming. It looks like I can dynamically compile, load and run some Haskell with the plugins package. Actually I've briefly tried this and it seems to work for some simple cases at least. Now I would like to be able to enumerate precompiled public functions in modules that I might use as building blocks in such dynamic compilation. So far I'm not seeing anything that does this directly. Can anyone provide some pointers? If it's just not possible to introspect on compiled modules, then I suppose I could use external metadata of my own, or even perhaps haddock info if it exists, to attempt to generate this info. Clearly though, that's nowhere near as good as extracting the info from something the compiler built directly. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Enumerating functions at runtime
On Sat, Mar 23, 2013 at 11:26 PM, Luke Evans l...@eversosoft.com wrote: I'm curious about using Haskell for metaprogramming. It looks like I can dynamically compile, load and run some Haskell with the plugins package. Actually I've briefly tried this and it seems to work for some simple cases at least. Now I would like to be able to enumerate precompiled public functions in modules that I might use as building blocks in such dynamic compilation. So far I'm not seeing anything that does this directly. Can anyone provide some pointers? I'm not aware of any canned solutions, but one way you could do it is to enumerate the symbol table of a compiled module and z-decode symbols; functions get their types z-encoded into their symbol table names. A more likely useful way is to extract them from the .hi file; there should be functions in ghc-api and likely in hint to do this, since the compiler must do so as part of importing a module; or at worst, you can use ghc -print-iface to decode a .hi file to text and extract the information that way. -- brandon s allbery kf8nh sine nomine associates allber...@gmail.com ballb...@sinenomine.net unix, openafs, kerberos, infrastructure, xmonadhttp://sinenomine.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
