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• Writing generic code when your target is a C compiler

  - by enobayram

  I need to write some algorithms for a PIC micro controller. AFAIK, the official tools support either assembler or a subset of C. My goal is to write the algorithms in a generic and reusable way without losing any runtime or memory performance. And if possible, I would like to do this without increasing the development time much and compromising the readability and maintainability much either. What I mean by generic and reusable is that I don't want to commit to types, array sizes, number of bits in a bit field etc. All these specifications, IMHO, point to C++ templates, but there's no compiler for it for my target. C macro metaprogramming is another option, but, again my opinion, that greatly reduces readability and increases development time. I believe what I'm looking for is a decent C++ to C translator, but I'd like to hear anything else that satisfies the above requirements. Maybe a translator from another high-level language to C that produces very efficient code, maybe something else. Please note that I have nothing against C, I just wish templates were available in it.

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• The Red Hat Enterprise Linux 6 Kernel: What Is It?

  The enterprise Linux OS vendor goes its own way when it comes to including a Linux kernel in its RHEL 6 release.

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• Using "public" vars or attributes in class calls, functional approach

  - by marw

  I was always wondering about two things I tend to do in my little projects. Sometimes I will have this design: class FooClass ... self.foo = "it's a bar" self._do_some_stuff(self) def _do_some_stuff(self): print(self.foo) And sometimes this one: class FooClass2 ... self.do_some_stuff(foo="it's a bar") def do_some_stuff(self, foo): print(foo) Although I roughly understand the differences between functional and class approaches, I struggle with the design. For example, in FooClass the self.foo is always accessible as an attribute. If there are numerous calls to it, is that faster than making foo a local variable that is passed from method to method (like in FooClass2)? What happens in memory in both cases? If FooClass2 is preferred (ie. I don't need to access foo) and other attributes inside do not change their states (the class is executed once only and returns the result), should the code then be written as a series of functions in a module?

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• Rhythmbox plugin code for hot key not working - why?

  - by Bunny Rabbit

  def activate(self,shell): self.shell = shell self.copy_selected() self.action = gtk.Action ('foo','bar','baz',None) self.activate_id = self.action.connect ('activate', self.call_bk_fn,self.shell) self.action_group = gtk.ActionGroup ('hot_key_action_group') self.action_group.add_action_with_accel (self.action, "<control>E") uim = shell.get_ui_manager () uim.insert_action_group (self.action_group, 0) uim.ensure_update () def call_bk_fn(): print('hello world') I am using the above code in a plugin for Rhythmbox and here I am trying to register the key Ctrl+E so that the call_bk_fn gets called whenever the key combination is pressed but its not working. Why is that so ?

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• How to avoid the GameManager god object?

  - by lorancou

  I just read an answer to a question about structuring game code. It made me wonder about the ubiquitous GameManager class, and how it often becomes an issue in a production environment. Let me describe this. First, there's prototyping. Nobody cares about writing great code, we just try to get something running to see if the gameplay adds up. Then there's a greenlight, and in an effort to clean things up, somebody writes a GameManager. Probably to hold a bunch of GameStates, maybe to store a few GameObjects, nothing big, really. A cute, little, manager. In the peaceful realm of pre-production, the game is shaping up nicely. Coders have proper nights of sleep and plenty of ideas to architecture the thing with Great Design Patterns. Then production starts and soon, of course, there is crunch time. Balanced diet is long gone, the bug tracker is cracking with issues, people are stressed and the game has to be released yesterday. At that point, usually, the GameManager is a real big mess (to stay polite). The reason for that is simple. After all, when writing a game, well... all the source code is actually here to manage the game. It's easy to just add this little extra feature or bugfix in the GameManager, where everything else is already stored anyway. When time becomes an issue, no way to write a separate class, or to split this giant manager into sub-managers. Of course this is a classical anti-pattern: the god object. It's a bad thing, a pain to merge, a pain to maintain, a pain to understand, a pain to transform. What would you suggest to prevent this from happening?

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• Kernel Linux : la version stable 2.6.38 est disponible, elle optimise la fonction de résolution de la couche VSF

  Kernel Linux : la version stable 2.6.38 est disponible Elle optimise la fonction de résolution de la couche VSF La version stable 2.6.38 du noyau Linux vient d'être rendue disponible et annoncée officiellement par Linus Torvalds. Cette version apporte des améliorations importantes au niveau des performances. Le Kernel intègre désormais le support transparent des « huge pages » (TPH) qui permet d'obtenir de meilleures performances sur des charges de travail qui nécessitent beaucoup de mémoire (on pense aux serveurs JVM et serveurs de base de données). TPH utilise des pages mémoires de grandes tailles (2 Mb) par opposition aux pages traditionnels de 4 Ko. Une autre nouveauté est l...

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• Why does Scala require functions to have explicit return type?

  - by garbage collection

  I recently began learning to program in Scala, and it's been fun so far. I really like the ability to declare functions within another function which just seems to intuitive thing to do. One pet peeve I have about Scala is the fact that Scala requires explicit return type in its functions. And I feel like this hinders on expressiveness of the language. Also it's just difficult to program with that requirement. Maybe it's because I come from Javascript and Ruby comfort zone. But for a language like Scala which will have tons of connected functions in an application, I cannot conceive how I brainstorm in my head exactly what type the particular function I am writing should return with recursions after recursions. This requirement of explicit return type declaration on functions, do not bother me for languages like Java and C++. Recursions in Java and C++, when they did happen, often were dealt with 2 to 3 functions max. Never several functions chained up together like Scala. So I guess I'm wondering if there is a good reason why Scala should have the requirement of functions having explicit return type?

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• The need for source control software - Team Foundation Server? or something different?

  - by l0Ft

  Recently, Here at the company, more than one programmer was appointed in charge for a LightSwitch(C#) software development project and immediately there was a need of some sort of source control/sync. We have never used Team Foundation Server but we'd gladly use it if it's worth it. Is it the right tool to use for synchronising code between programmers? Does it have the needed features? Do you have any other tool in mind? (I have used TortoiseSVN but it was too simple and 'texty' if you know what I mean, we need a professional tool) What other features does Team Foundation has that we can use? (if you did not understand any of the above please ask me to clarify further)

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• What Shading/Rendering techniques are being used in this image?

  - by Rhakiras

  My previous question wasn't clear enough. From a rendering point of view what kind of techniques are used in this image as I would like to apply a similar style (I'm using OpenGL if that matters): http://alexcpeterson.com/ My specific questions are: How is that sun glare made? How does the planet look "cartoon" like? How does the space around the planet look warped/misted? How does the water look that good? I'm a beginner so any information/keywords on each question would be helpful so I can go off and learn more. Thanks

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• Do first-class methods exist?

  - by gdhoward

  Okay, I know first-class functions are cool, closures even better, etc. But is there any language with first-class methods? In my mind, I see a first-class method as an "object" that has both a function pointer and a pointer to a specific instance of the class/object, but the implementation doesn't matter. I just want to know if there is any language that uses them. And as a bonus, how were they implemented?

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• Expected time for lazy evaluation with nested functions?

  - by Matt_JD

  A colleague and I are doing a free R course, although I believe this is a more general lazy evaluation issue, and have found a scenario that we have discussed briefly and I'd like to find out the answer from a wider community. The scenario is as follows (pseudo code): wrapper => function(thing) { print => function() { write(thing) } } v = createThing(1, 2, 3) w = wrapper(v) v = createThing(4, 5, 6) w.print() // Will print 4, 5, 6 thing. v = create(7, 8, 9) w.print() // Will print 4, 5, 6 because "thing" has now been evaluated. Another similar situation is as follows: // Using the same function as above v = createThing(1, 2, 3) v = wrapper(v) w.print() // The wrapper function incestuously includes itself. Now I understand why this happens but where my colleague and I differ is on what should happen. My colleague's view is that this is a bug and the evaluation of the passed in argument should be forced at the point it is passed in so that the returned "w" function is fixed. My view is that I would prefer his option myself, but that I realise that the situation we are encountering is down to lazy evaluation and this is just how it works and is more a quirk than a bug. I am not actually sure of what would be expected, hence the reason I am asking this question. I think that function comments could express what will happen, or leave it to be very lazy, and if the coder using the function wants the argument evaluated then they can force it before passing it in. So, when working with lazy evaulation, what is the practice for the time to evaluate an argument passed, and stored, inside a function?

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• Are there any reliable solutions for annotations/reflection/code-metadata in C?

  - by dukeofgaming

  Not all languages support java-like annotations or C#-like attributes or code metadata in general, however that doesn't mean it is not possible to have in languages that don't have this. An example is PHP with Stubbles and the Doctrine annotation library. My question is, is there anything like this for C?, or are there any reliable ways of doing reflection with extended code metadata in C? Ideally, I'm looking for something that reads javadoc-like comments. Edit: The reason for me *needing* as opposed to just wanting, is that I need to generate C code and code-metadata from a database, as well as being able to edit that metadada and update the database. The volume of the work (~15,000 variables/structures/functions to generate from this database) justifies the solution.

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• What type of application is this called?

  - by boatingcow

  I am working on a web-based application which combines elements of what my client would call a CMS (content management system) and CRM (customer relations management) but also adds in many other business-specific features such as bookings management, staff task allocation management, wages calculations, document version control etc. However, I'm struggling to find a catch-all term for this type of application so I can research how other people have gone about creating such an integrated solution. Can anyone recommend a term I can use to refer to this, both internally in our team, for the client so they know what to call the 'system' and also for me personally, so that I can ask the Stack community further questions?

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• Could a singleton type replace static methods and classes?

  - by MKO

  In C# Static methods has long served a purpose allowing us to call them without instantiating classes. Only in later year have we became more aware of the problems of using static methods and classes. They can’t use interfaces They can’t use inheritance They are hard to test because you can’t make mocks and stubs Is there a better way ? Obviously we need to be able to access library methods without instantiated classes all the time otherwise our code would become pretty cluttered One possibly solution is to use a new keyword for an old concept: the singleton. Singleton’s are global instances of a class, since they are instances we can use them as we would normal classes. In order to make their use nice and practical we'd need some syntactic sugar however Say that the Math class would be of type singleton instead of an actual class. The actual class containing all the default methods for the Math singleton is DefaultMath, which implements the interface IMath. The singleton would be declared as singleton Math : IMath { public Math { this = new DefaultMath(); } } If we wanted to substitute our own class for all math operations we could make a new class MyMath that inherits DefaultMath, or we could just inherit from the interface IMath and create a whole new Class. To make our class the active Math class, you'd do a simple assignment Math = new MyMath(); and voilá! the next time we call Math.Floor it will call your method. Note that for a normal singleton we'd have to write something like Math.Instance.Floor but the compiler eliminates the need for the Instance property Another idea would be to be able to define a singletons as Lazy so they get instantiated only when they're first called, like lazy singleton Math : IMath What do you think, would it have been a better solution that static methods and classes? Is there any problems with this approach?

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• Learning to program in the modern era?

  - by BBHorus

  At this time, lets say in the modern era, in which order do you organize a programing course for teaching and/or learning, what should be learned first, what should emphasize: Databases Data structures Design patterns Programing paradigms(Procedural, functional, OOP, ...etc ) Operating System Some specific programing language What about English if you are not native speaker or doesn't know English AI Anything else... I ask this because in the university that I went, the programing course was awful it was not focus on what you were going to see out when you work what you were supposed to learn. PS: Again sorry about my English is not my main language. ...Experts and gurus please share

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• Top X tips to code & debug efficiently [closed]

  - by user1510230

  I'm starting a big Java project and I wanted to have some advices that could benefit us all. What are the X (X could be 5 / 10 / ... or even 100 :) most important tips to code and debug efficiently in general (and in particular with java / javascript) ? I'll start with some basic ones : Use functions everytime a portion of code is used more than twice. Try not to code features with more than 15 lines of code in one shot. Rather write 5 lines of code then check if they work correctly then write 5 more... and so on start with the outcome of the function and then code it backwards (bottom-top approach) ... Thanks everybody

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• Entry level engineer question regarding memory management

  - by Ealianis

  It has been a few months since I started my position as an entry level software developer. Now that I am past some learning curves (e.g. the language, jargon, syntax of VB and C#) I'm starting to focus on more esoteric topics, as to write better software. A simple question I presented to a fellow coworker was responded with "I'm focusing on the wrong things." While I respect this coworker I do disagree that this is a "wrong thing" to focus upon. Here was the code (in VB) and followed by the question. Note: The Function GenerateAlert() returns an integer. Dim alertID as Integer = GenerateAlert() _errorDictionary.Add(argErrorID, NewErrorInfo(Now(), alertID)) vs... _errorDictionary.Add(argErrorID, New ErrorInfo(Now(), GenerateAlert())) I originally wrote the latter and rewrote it with the "Dim alertID" so that someone else might find it easier to read. But here was my concern and question: Should one write this with the Dim AlertID, it would in fact take up more memory; finite but more, and should this method be called many times could it lead to an issue? How will .NET handle this object AlertID. Outside of .NET should one manually dispose of the object after use (near the end of the sub). I want to ensure I become a knowledgeable programmer that does not just rely upon garbage collection. Am I over thinking this? Am I focusing on the wrong things?

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• opengl memory issue - quite strange.

  - by user4707

  Hello, I have heard that textures consumes lot of memory but I am surprised how much.... I have 7 textures 1024 16 bit each. And while I will run my app it consumes 57MB of memory. I think that this is "a bit" too much. I am writing 2D application (no cocos or other framework) Strange is that while I will compile my app with disabled rendering methods: glDrawArrays than It uses only 27MB.... which is about 30MB less... Do you have any Idea why? I am creating textures before rendering of course: rendering looks like this: [EAGLContext setCurrentContext:context]; glBindFramebufferOES(GL_FRAMEBUFFER_OES, defaultFramebuffer); glClearColor(0.0f, 0.0f, 0.0f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); glPushMatrix(); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glEnable(GL_TEXTURE_2D); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); TeksturaObrazek *obrazek_klaw =[[AppDirector sharedAppDirector] obrazek_klaw]; glBindTexture(GL_TEXTURE_2D, [[obrazek_klaw image_texture] name] ); glVertexPointer(2, GL_FLOAT, 0,vertex1); glTexCoordPointer(2, GL_FLOAT, 0, vertex2); glColor4f(1,1,1,alpha); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); glDisable(GL_BLEND); glDisable(GL_TEXTURE_2D); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glPopMatrix(); [context presentRenderbuffer:GL_RENDERBUFFER_OES]; It looks like standard routine... I have spent about 2 days looking for for answer and I still have no clue.

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• Is it a good practice to code in English? [closed]

  - by Milox

  Possible Duplicate: Do people in non-English-speaking countries code in English? I have a development comming that is intended to be sold across Latin America (Spanish speakers), but I've heard from some partners that is a good practice to always code in English, I mean just code (methods, classes, pages names, etc), labels on GUI are going to be all in Spanish... Code will be edited in the future by developer of companies across Latin America and just maybe some from outside. What do you think?, any experience with this?

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• boolean operations on meshes

  - by lathomas64

  given a set of vertices and triangles for each mesh. Does anyone know of an algorithm, or a place to start looking( I tried google first but haven't found a good place to get started) to perform boolean operations on said meshes and get a set of vertices and triangle for the resulting mesh? Of particular interest are subtraction and union. Example pictures: http://www.rhino3d.com/4/help/Commands/Booleans.htm

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• Are there new flexible texteditors? [closed]

  - by RParadox

  Vi(m) and Emacs are almost 40 years old. Why are they still the standard, and what attempts have been made at coming up with a new flexible editor? Are there any features which can not be built into vim/emacs? My question is similar to this one: Time to drop Emacs and vi? No one had a suggestion, which surprises me. I would have thought that the core of a texteditor is very small and that people brew their own. Perhaps nobody wants to deal with supporting all the modes? Edit to clarify my question: Instead of writing modes and scripts I ask myself, why there is not a much lightweight project, which lets people custom the editor more directly? Vim has 365395 LOC (C lines all included), Emacs 1.5 million LOC. Why is there a project with say 50k LOC, which is the core, why people can use more freely? Perhaps there is such project, I haven't looked very far. I thought about putting together modules from Vim myself and experimenting with some ideas. The core of editing shouldn't be more than 10k? Vim has a lot optimizations which is really an overkill nowadays. Basically I'm looking for a code base for my own editor and Vi/Emacs are I believe not intended to be used in this way. Bill Joy said the following about vi. http://web.cecs.pdx.edu/~kirkenda/joy84.html The fundamental problem with vi is that it doesn't have a mouse and therefore you've got all these commands. In some sense, its backwards from the kind of thing you'd get from a mouse-oriented thing. I think multiple levels of undo would be wonderful, too. But fundamentally, vi is still ed inside. You can't really fool it. Its like one of those pinatas - things that have candy inside but has layer after layer of paper mache on top. It doesn't really have a unified concept. I think if I were going to go back - I wouldn't go back, but start over again.

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• Isn't Java a quite good choice for desktop applications?

  - by tactoth

  At present most applications are still developed with C++, painfully. Lack of portability, in compatible libraries, memory leaks, slow compilation, and poor productivity. Even if you pick only a single from these shortages, it's still a big headache. However the surprising truth is that C++ remains the first choice for desktop applications. Compared to C++ Java has lots of advantages. The success in server side development shows that the language itself is good, Swing is also thought to be as programmer friendly as the highly recognized QT framework (No, never say even a single word about MFC!). All the disadvantages of C++ listed above has a solution in Java. "Performance!", Well that might still be the problem but to my experience it's a slight problem. I'd been using Java to decode some screen video and generate key frames. The video has a duration of more than 1 hour. The time spent on an average machine is just 1 minute. With C++ I don't expect even faster speed. In recent days there are many news on the JIT performance improvements, that make us feel Java is gradually becoming very suitable for desktop development, without people realizing it. Isn't it?

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• What do you feel are characteristics of a mature programmer?

  - by blparker

  Hey all. As part of ongoing research that I am conducting, I would like to ask a crowd, that I feel is the most qualified, to answer a question. What does the community feel are characteristics of a mature programmer? I'm not asking the question because I'm looking to hire or anything of that nature. A colleague and I repeatedly hear a trend throughout universities and specifically computer science departments. The students generally ask questions of the form: How can I become a mature programmer? How can I become a world class programmer? What steps should a new programmer take to become more skilled? So, with that, we are conducting research to attempt to identify an optimized path that would allow an introductory programmer to advance to that of a skilled/mature programmer. Now, I understand that there are many "it depends" out there depending on what vertical industry one works in, but I feel we can determine many common characteristics irrespective of the industry. Any thing you can offer is greatly appreciated. Thanks.

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• Should I use events in this case?

  - by joon

  I'm creating a video player, like a custom YouTube player. All of the GUI elements (progress bar, video player, play button, ...) are different classes, but I obviously need them to communicate. When the progress bar is clicked, or the slider is moved, it needs to send a "seek(x)" command to the video player. Similarly, the video player needs to update the progressbar every frame. Currently I'm doing this by having almost all elements have a link to each other. So when I create the progress bar, I'm telling it where the video player is. But after a while this becomes more and more complicated, and I'm wondering if events would be a better way to do this. Or a main controller class that has all the connections. What should I do?

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• Writing and Understanding code

  - by Kitex

  I can write code. I can read code but I can't implement good code. How to develop deep understanding of any framework or stuff that we are working on? Is it looking into documentation and working on it? I have seen in this form that people that have great understanding of things they are working on. How is this possible? How to not scrape on the surface only? How to manage time vs learning vs productivity?

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