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  • Is there a better term than "smoothness" or "granularity" to describe this language feature?

    - by Chris
    One of the best things about programming is the abundance of different languages. There are general purpose languages like C++ and Java, as well as little languages like XSLT and AWK. When comparing languages, people often use things like speed, power, expressiveness, and portability as the important distinguishing features. There is one characteristic of languages I consider to be important that, so far, I haven't heard [or been able to come up with] a good term for: how well a language scales from writing tiny programs to writing huge programs. Some languages make it easy and painless to write programs that only require a few lines of code, e.g. task automation. But those languages often don't have enough power to solve large problems, e.g. GUI programming. Conversely, languages that are powerful enough for big problems often require far too much overhead for small problems. This characteristic is important because problems that look small at first frequently grow in scope in unexpected ways. If a programmer chooses a language appropriate only for small tasks, scope changes can require rewriting code from scratch in a new language. And if the programmer chooses a language with lots of overhead and friction to solve a problem that stays small, it will be harder for other people to use and understand than necessary. Rewriting code that works fine is the single most wasteful thing a programmer can do with their time, but using a bazooka to kill a mosquito instead of a flyswatter isn't good either. Here are some of the ways this characteristic presents itself. Can be used interactively - there is some environment where programmers can enter commands one by one Requires no more than one file - neither project files nor makefiles are required for running in batch mode Can easily split code across multiple files - files can refeence each other, or there is some support for modules Has good support for data structures - supports structures like arrays, lists, and especially classes Supports a wide variety of features - features like networking, serialization, XML, and database connectivity are supported by standard libraries Here's my take on how C#, Python, and shell scripting measure up. Python scores highest. Feature C# Python shell scripting --------------- --------- --------- --------------- Interactive poor strong strong One file poor strong strong Multiple files strong strong moderate Data structures strong strong poor Features strong strong strong Is there a term that captures this idea? If not, what term should I use? Here are some candidates. Scalability - already used to decribe language performance, so it's not a good idea to overload it in the context of language syntax Granularity - expresses the idea of being good just for big tasks versus being good for big and small tasks, but doesn't express anything about data structures Smoothness - expresses the idea of low friction, but doesn't express anything about strength of data structures or features Note: Some of these properties are more correctly described as belonging to a compiler or IDE than the language itself. Please consider these tools collectively as the language environment. My question is about how easy or difficult languages are to use, which depends on the environment as well as the language.

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  • Explanation of the definition of interface inheritance as described in GoF book

    - by Geek
    I am reading the first chapter of the Gof book. Section 1.6 discusses about class vs interface inheritance: Class versus Interface Inheritance It's important to understand the difference between an object's class and its type. An object's class defines how the object is implemented.The class defines the object's internal state and the implementation of its operations.In contrast,an object's type only refers to its interface--the set of requests on which it can respond. An object can have many types, and objects of different classes can have the same type. Of course, there's a close relationship between class and type. Because a class defines the operations an object can perform, it also defines the object's type . When we say that an object is an instance of a class, we imply that the object supports the interface defined by the class. Languages like c++ and Eiffel use classes to specify both an object's type and its implementation. Smalltalk programs do not declare the types of variables; consequently,the compiler does not check that the types of objects assigned to a variable are subtypes of the variable's type. Sending a message requires checking that the class of the receiver implements the message, but it doesn't require checking that the receiver is an instance of a particular class. It's also important to understand the difference between class inheritance and interface inheritance (or subtyping). Class inheritance defines an object's implementation in terms of another object's implementation. In short, it's a mechanism for code and representation sharing. In contrast,interface inheritance(or subtyping) describes when an object can be used in place of another. I am familiar with the Java and JavaScript programming language and not really familiar with either C++ or Smalltalk or Eiffel as mentioned here. So I am trying to map the concepts discussed here to Java's way of doing classes, inheritance and interfaces. This is how I think of of these concepts in Java: In Java a class is always a blueprint for the objects it produces and what interface(as in "set of all possible requests that the object can respond to") an object of that class possess is defined during compilation stage only because the class of the object would have implemented those interfaces. The requests that an object of that class can respond to is the set of all the methods that are in the class(including those implemented for the interfaces that this class implements). My specific questions are: Am I right in saying that Java's way is more similar to C++ as described in the third paragraph. I do not understand what is meant by interface inheritance in the last paragraph. In Java interface inheritance is one interface extending from another interface. But I think the word interface has some other overloaded meaning here. Can some one provide an example in Java of what is meant by interface inheritance here so that I understand it better?

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  • Your interesting code tricks/ conventions? [closed]

    - by Paul
    What interesting conventions, rules, tricks do you use in your code? Preferably some that are not so popular so that the rest of us would find them as novelties. :) Here's some of mine... Input and output parameters This applies to C++ and other languages that have both references and pointers. This is the convention: input parameters are always passed by value or const reference; output parameters are always passed by pointer. This way I'm able to see at a glance, directly from the function call, what parameters might get modified by the function: Inspiration: Old C code int a = 6, b = 7, sum = 0; calculateSum(a, b, &sum); Ordering of headers My typical source file begins like this (see code below). The reason I put the matching header first is because, in case that header is not self-sufficient (I forgot to include some necessary library, or forgot to forward declare some type or function), a compiler error will occur. // Matching header #include "example.h" // Standard libraries #include <string> ... Setter functions Sometimes I find that I need to set multiple properties of an object all at once (like when I just constructed it and I need to initialize it). To reduce the amount of typing and, in some cases, improve readability, I decided to make my setters chainable: Inspiration: Builder pattern class Employee { public: Employee& name(const std::string& name); Employee& salary(double salary); private: std::string name_; double salary_; }; Employee bob; bob.name("William Smith").salary(500.00); Maybe in this particular case it could have been just as well done in the constructor. But for Real WorldTM applications, classes would have lots more fields that should be set to appropriate values and it becomes unmaintainable to do it in the constructor. So what about you? What personal tips and tricks would you like to share?

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  • Organizing Git repositories with common nested sub-modules

    - by André Caron
    I'm a big fan of Git sub-modules. I like to be able to track a dependency along with its version, so that you can roll-back to a previous version of your project and have the corresponding version of the dependency to build safely and cleanly. Moreover, it's easier to release our libraries as open source projects as the history for libraries is separate from that of the applications that depend on them (and which are not going to be open sourced). I'm setting up workflow for multiple projects at work, and I was wondering how it would be if we took this approach a bit of an extreme instead of having a single monolithic project. I quickly realized there is a potential can of worms in really using sub-modules. Supposing a pair of applications: studio and player, and dependent libraries core, graph and network, where dependencies are as follows: core is standalone graph depends on core (sub-module at ./libs/core) network depdends on core (sub-module at ./libs/core) studio depends on graph and network (sub-modules at ./libs/graph and ./libs/network) player depends on graph and network (sub-modules at ./libs/graph and ./libs/network) Suppose that we're using CMake and that each of these projects has unit tests and all the works. Each project (including studio and player) must be able to be compiled standalone to perform code metrics, unit testing, etc. The thing is, a recursive git submodule fetch, then you get the following directory structure: studio/ studio/libs/ (sub-module depth: 1) studio/libs/graph/ studio/libs/graph/libs/ (sub-module depth: 2) studio/libs/graph/libs/core/ studio/libs/network/ studio/libs/network/libs/ (sub-module depth: 2) studio/libs/network/libs/core/ Notice that core is cloned twice in the studio project. Aside from this wasting disk space, I have a build system problem because I'm building core twice and I potentially get two different versions of core. Question How do I organize sub-modules so that I get the versioned dependency and standalone build without getting multiple copies of common nested sub-modules? Possible solution If the the library dependency is somewhat of a suggestion (i.e. in a "known to work with version X" or "only version X is officially supported" fashion) and potential dependent applications or libraries are responsible for building with whatever version they like, then I could imagine the following scenario: Have the build system for graph and network tell them where to find core (e.g. via a compiler include path). Define two build targets, "standalone" and "dependency", where "standalone" is based on "dependency" and adds the include path to point to the local core sub-module. Introduce an extra dependency: studio on core. Then, studio builds core, sets the include path to its own copy of the core sub-module, then builds graph and network in "dependency" mode. The resulting folder structure looks like: studio/ studio/libs/ (sub-module depth: 1) studio/libs/core/ studio/libs/graph/ studio/libs/graph/libs/ (empty folder, sub-modules not fetched) studio/libs/network/ studio/libs/network/libs/ (empty folder, sub-modules not fetched) However, this requires some build system magic (I'm pretty confident this can be done with CMake) and a bit of manual work on the part of version updates (updating graph might also require updating core and network to get a compatible version of core in all projects). Any thoughts on this?

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  • Finding work as a college student

    - by lightburst
    I'm a 3rd year CS student. I'm currently really, really, bored and tired of cheap school programming(I go to a fairly respectable(albeit not top) university in my country, but, really, it's not MIT) so I've been thinking about getting a part-time dev job for a long while now. I'm not some hotshot programmer or anything, but "Add/Delete XYZ class objects to list" or "Do this web feature/pattern in PHP" does get old after a few semesters. I also only learned(heard?) of programming when I entered college, so the duration of me being in contact with any code is short. I can't really apply as an intern as I have not accumulated the necessary credits yet to do that so I was thinking of selling myself as a part-time dev. I still need to go to school, and don't want to subject myself to living two lives. Plus, I think I'd have better chances considering my lack of things to write on the resume. The only language I know at heart is C (I've written several pointer-oriented stuff on my freshman year, which is apparently pretty leet(for some reason), or so Joel says. That sort of boosted my morale a bit) but I've worked with several other languages only for the sake of course work such as C#/Java/PHP/ASM. My only user-worthy project was a recursive quicksort simulator I wrote for class using GTK+ that used a textbox to output the progress. I also have not taken the compiler theory class yet, or my thesis. All that being said, I wonder if any legitimate software company(big or small) would hire somebody like me considering all that. If there are companies that do accept anybody like me, would I be doing programming or maybe just be a tester or something? Would anybody hire me as a dev at all? I know I don't have much(not even a degree) but what I lack in experience, I compensate with interest? I am less interested in websites and 'management' software(no offense or anything. also, most of the places here ONLY have those), and more into 'process driven'(I'm not sure how to call it) and system software. I have my eyes on a startup that sells basically an extension of Google Drive, but I feel like I'm too 'risky' for them. Oh, I'm also 19 if that means anything. We're not K-12 so kids go to college earlier than in the US.

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  • Referencing a picture in another DLL in Silverlight and Windows Phone 7

    - by Laurent Bugnion
    This one has burned me a few times, so here is how it works for future reference: Usually, when I add an Image control into a Silverlight application, and the picture it shows is local (as opposed to loaded from the web), I set the picture’s Build Action to Content, and the Copy to Output Directory to Copy if Newer. What the compiler does then is to copy the picture to the bin\Debug folder, and then to pack it into the XAP file. In XAML, the syntax to refer to this local picture is: <Image Source="/Images/mypicture.jpg" Width="100" Height="100" /> And in C#: return new BitmapImage(new Uri( "/Images/mypicture.jpg", UriKind.Relative)); One of the features of Silverlight is to allow referencing content (pictures, resource dictionaries, sound files, movies etc…) located in a DLL directly. This is very handy because just by using the right syntax in the URI, you can do this in XAML directly, for example with: <Image Source="/MyApplication;component/Images/mypicture.jpg" Width="100" Height="100" /> In C#, this becomes: return new BitmapImage(new Uri( "/MyApplication;component/Images/mypicture.jpg", UriKind.Relative)); Side note: This kind of URI is called a pack URI and they have been around since the early days of WPF. There is a good tutorial about pack URIs on MSDN. Even though it refers to WPF, it also applies to Silverlight Side note 2: With the Build Action set to Content, you can rename the XAP file to ZIP, extract all the files, change the picture (but keep the same name), rezip the whole thing and rename again to XAP. This is not possible if the picture is embedded in an assembly! So what’s the catch? Well the catch is that this does not work if you set the Build Action to Content. It’s actually pretty simple to explain: The pack URI above tells the Silverlight runtime to look within an assembly named MyOtherAssembly for a file named MyPicture.jpg in the Images folder. If the file is included as Content, however, it is not in the assembly. Silverlight does not find it, and silently returns nothing. The image is not displayed. And the fix? The fix, for class libraries, is to set the Build Action to Resource. With this, the picture will gets packed into the DLL itself. Of course, this will increase the size of the DLL, and any change to the picture will require recompiling the class library, which is not ideal. But in the cases where you want to distribute pictures (icons etc) together with a plug-in assembly, well, this is a good way to have everything in the same place Happy coding, Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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  • Basis of definitions

    - by Yttrill
    Let us suppose we have a set of functions which characterise something: in the OO world methods characterising a type. In mathematics these are propositions and we have two kinds: axioms and lemmas. Axioms are assumptions, lemmas are easily derived from them. In C++ axioms are pure virtual functions. Here's the problem: there's more than one way to axiomatise a system. Given a set of propositions or methods, a subset of the propositions which is necessary and sufficient to derive all the others is called a basis. So too, for methods or functions, we have a desired set which must be defined, and typically every one has one or more definitions in terms of the others, and we require the programmer to provide instance definitions which are sufficient to allow all the others to be defined, and, if there is an overspecification, then it is consistent. Let me give an example (in Felix, Haskell code would be similar): class Eq[t] { virtual fun ==(x:t,y:t):bool => eq(x,y); virtual fun eq(x:t, y:t)=> x == y; virtual fun != (x:t,y:t):bool => not (x == y); axiom reflex(x:t): x == x; axiom sym(x:t, y:t): (x == y) == (y == x); axiom trans(x:t, y:t, z:t): implies(x == y and y == z, x == z); } Here it is clear: the programmer must define either == or eq or both. If both are defined, the definitions must be equivalent. Failing to define one doesn't cause a compiler error, it causes an infinite loop at run time. Defining both inequivalently doesn't cause an error either, it is just inconsistent. Note the axioms specified constrain the semantics of any definition. Given a definition of == either directly or via a definition of eq, then != is defined automatically, although the programmer might replace the default with something more efficient, clearly such an overspecification has to be consistent. Please note, == could also be defined in terms of !=, but we didn't do that. A characterisation of a partial or total order is more complex. It is much more demanding since there is a combinatorial explosion of possible bases. There is an reason to desire overspecification: performance. There also another reason: choice and convenience. So here, there are several questions: one is how to check semantics are obeyed and I am not looking for an answer here (way too hard!). The other question is: How can we specify, and check, that an instance provides at least a basis? And a much harder question: how can we provide several default definitions which depend on the basis chosen?

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  • C++ Accelerated Massive Parallelism

    - by Daniel Moth
    At AMD's Fusion conference Herb Sutter announced in his keynote session a technology that our team has been working on that we call C++ Accelerated Massive Parallelism (C++ AMP) and during the keynote I showed a brief demo of an app built with our technology. After the keynote, I go deeper into the technology in my breakout session. If you read both those abstracts, you'll get some information about what C++ AMP is, without being too explicit since we published the abstracts before the technology was announced. You can find the official online announcement at Soma's blog post. Here, I just wanted to capture the key points about C++ AMP that can serve as an introduction and an FAQ. So, in no particular order… C++ AMP lowers the barrier to entry for heterogeneous hardware programmability and brings performance to the mainstream, without sacrificing developer productivity or solution portability. is designed not only to help you address today's massively parallel hardware (i.e. GPUs and APUs), but it also future proofs your code investments with a forward looking design. is part of Visual C++. You don't need to use a different compiler or learn different syntax. is modern C++. Not C or some other derivative. is integrated and supported fully in Visual Studio vNext. Editing, building, debugging, profiling and all the other goodness of Visual Studio work well with C++ AMP. provides an STL-like library as part of the existing concurrency namespace and delivered in the new amp.h header file. makes it extremely easy to work with large multi-dimensional data on heterogeneous hardware; in a manner that exposes parallelization. introduces only one core C++ language extension. builds on DirectX (and DirectCompute in particular) which offers a great hardware abstraction layer that is ubiquitous and reliable. The architecture is such, that this point can be thought of as an implementation detail that does not surface to the API layer. Stay tuned on my blog for more over the coming months where I will switch from just talking about C++ AMP to showing you how to use the API with code examples… Comments about this post welcome at the original blog.

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  • How Microsoft Market DotNet?

    - by Fendy
    I just read an Joel's article about Microsoft's breaking change (non-backwards compatibility) with dot net's introduction. It is interesting and explicitly reflected the condition during that time. But now almost 10 years has passed. The breaking change It is mainly on how bad is Microsoft introducing non-backwards compatibility development tools, such as dot net, instead of improving the already-widely used asp classic or VB6. As much have known, dot net is not natively embedded in windows XP (yes in vista or 7), so in order to use the .net apps, you need to install the .net framework of over 300mb (it's big that day). However, as we see that nowadays many business use .net as their main development tools, with asp.net or mvc as their web-based applications. C# nowadays be one of tops programming languages (the most questions in stackoverflow). The more interesing part is, win32api still alive even there is newer technology out there (and still widely used). Imagine if microsoft does not introduce the breaking change, there will many corporates still uses asp classic or vb-based applications (there still is, but not that much). There are many corporates use additional services such as azure or sharepoint (beside how expensive is it). Please note that I also know there are many flagships applications (maybe adobe's and blizzard's) still use C-based or older language and not porting to newer high-level language. The question How can Microsoft persuade the users to migrate their old applications into dot net? As we have known it is very hard and give no immediate value when rewrite the applications (netscape story), and it is very risky. I am more interested in Microsoft's way and not opinion such as "because dot net is OOP, or dot net is dll-embedable, etc". This question may be constructive, as the technology is vastly changes over times lately. As we can see, Microsoft changes Asp.Net webform to MVC, winform is legacy now, it is starting to change to use windows store rather than basic-installment, touchscreen and later on we will have see-through applications such as google class. And that will be breaking changes. We will need to account portability as an issue nowadays. We will need other than just mere technology choice, but also migration plans. Even maybe as critical as we might need multiplatform language compiler, as approached by Joel's Wasabi. (hey, I read his articles too much!)

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  • Perl syntax error [closed]

    - by Linny
    I am a beginner taking a Perl programming course. We are trying to write a basic program for counting nucleotides in a DNA string. I'm getting syntax errors on the lines that have a single bracket on lines 28 & 70 and don't know why. It also reads that I have compilation errors. I have no idea where to start figuring that out. # The purpose of this program is to count the number of nucleotides in a strand. Each protein is counted separately # print "/n NOTE: Nucleotide counting /n"; # use strict; # enforce variable declarations use warnings; # enable compiler warnings # Display number of A,a,T,t,G,g,C,c, nucleotides in a word or sequence of letters. # my ($base) = ''; # an extracted letter from a string my ($nuceotide_count) = 0 ; # the current position within the word my ($position) = 0 ; # number of vowels in user-supplied word my ($word) = ''; # word to be processed my ($A_count) = 0 ; # of A nucleotides in the user-supplied sequence my ($a_count) = 0 ; # of A nucleotides in the user-supplied sequence my ($C_count) = 0 ; # of C nucleotides in the user-supplied sequence my ($c_count) = 0 ; # of C nucleotides in the user-supplied sequence my ($G_count) = 0 ; # of G nucleotides in the user-supplied sequence my ($g_count) = 0 ; # of G nucleotides in the user-supplied sequence my ($T_count) = 0 ; # of T nucleotides in the user-supplied sequence my ($t_count) = 0 ; # of T nucleotides in the user-supplied sequence word = (STDIN) for ($position = 0);($position if (($base eq 'a') or ($base eq 'A')) { ++$A_count; } # end if ++$position; if (($base eq 'T') or ($base eq 't')) { ++$T_count; } end if ++$position; if (($base eq 'G') or ($base eq 'g')) { ++$G_count; } # end if ++$position; if (($base eq 'C') or ($base eq 'c')) { ++$C_count; } # end if ++$position; } # end for # Display final results. # print " \n The number of A or a neucleotides is: $A_count"; print " \n The number of T or t neucleotides is: $T_count"; print " \n The number of G or g neucleotides is: $G_count"; print " \n The number of C or c neucleotides is: $C_count"; print " \n\n Program completed successfully. \n" ; exit ;

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  • Subterranean IL: Exception handling 1

    - by Simon Cooper
    Today, I'll be starting a look at the Structured Exception Handling mechanism within the CLR. Exception handling is quite a complicated business, and, as a result, the rules governing exception handling clauses in IL are quite strict; you need to be careful when writing exception clauses in IL. Exception handlers Exception handlers are specified using a .try clause within a method definition. .try <TryStartLabel> to <TryEndLabel> <HandlerType> handler <HandlerStartLabel> to <HandlerEndLabel> As an example, a basic try/catch block would be specified like so: TryBlockStart: // ... leave.s CatchBlockEndTryBlockEnd:CatchBlockStart: // at the start of a catch block, the exception thrown is on the stack callvirt instance string [mscorlib]System.Object::ToString() call void [mscorlib]System.Console::WriteLine(string) leave.s CatchBlockEnd CatchBlockEnd: // method code continues... .try TryBlockStart to TryBlockEnd catch [mscorlib]System.Exception handler CatchBlockStart to CatchBlockEnd There are four different types of handler that can be specified: catch <TypeToken> This is the standard exception catch clause; you specify the object type that you want to catch (for example, [mscorlib]System.ArgumentException). Any object can be thrown as an exception, although Microsoft recommend that only classes derived from System.Exception are thrown as exceptions. filter <FilterLabel> A filter block allows you to provide custom logic to determine if a handler block should be run. This functionality is exposed in VB, but not in C#. finally A finally block executes when the try block exits, regardless of whether an exception was thrown or not. fault This is similar to a finally block, but a fault block executes only if an exception was thrown. This is not exposed in VB or C#. You can specify multiple catch or filter handling blocks in each .try, but fault and finally handlers must have their own .try clause. We'll look into why this is in later posts. Scoped exception handlers The .try syntax is quite tricky to use; it requires multiple labels, and you've got to be careful to keep separate the different exception handling sections. However, starting from .NET 2, IL allows you to use scope blocks to specify exception handlers instead. Using this syntax, the example above can be written like so: .try { // ... leave.s EndSEH}catch [mscorlib]System.Exception { callvirt instance string [mscorlib]System.Object::ToString() call void [mscorlib]System.Console::WriteLine(string) leave.s EndSEH}EndSEH:// method code continues... As you can see, this is much easier to write (and read!) than a stand-alone .try clause. Next time, I'll be looking at some of the restrictions imposed by SEH on control flow, and how the C# compiler generated exception handling clauses.

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  • What are some reasonable stylistic limits on type inference?

    - by Jon Purdy
    C++0x adds pretty darn comprehensive type inference support. I'm sorely tempted to use it everywhere possible to avoid undue repetition, but I'm wondering if removing explicit type information all over the place is such a good idea. Consider this rather contrived example: Foo.h: #include <set> class Foo { private: static std::set<Foo*> instances; public: Foo(); ~Foo(); // What does it return? Who cares! Just forward it! static decltype(instances.begin()) begin() { return instances.begin(); } static decltype(instances.end()) end() { return instances.end(); } }; Foo.cpp: #include <Foo.h> #include <Bar.h> // The type need only be specified in one location! // But I do have to open the header to find out what it actually is. decltype(Foo::instances) Foo::instances; Foo() { // What is the type of x? auto x = Bar::get_something(); // What does do_something() return? auto y = x.do_something(*this); // Well, it's convertible to bool somehow... if (!y) throw "a constant, old school"; instances.insert(this); } ~Foo() { instances.erase(this); } Would you say this is reasonable, or is it completely ridiculous? After all, especially if you're used to developing in a dynamic language, you don't really need to care all that much about the types of things, and can trust that the compiler will catch any egregious abuses of the type system. But for those of you that rely on editor support for method signatures, you're out of luck, so using this style in a library interface is probably really bad practice. I find that writing things with all possible types implicit actually makes my code a lot easier for me to follow, because it removes nearly all of the usual clutter of C++. Your mileage may, of course, vary, and that's what I'm interested in hearing about. What are the specific advantages and disadvantages to radical use of type inference?

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  • cloud programming for OpenStack in C / C++

    - by Basile Starynkevitch
    (Sorry for such a fuzzy question, I am very newbie to cloud programming) I am interested in designing (and developing) a (free software) program in C or C++ (probably, most of it being meta-programmed, i.e. part of the C code code being generated). I am still in the thinking / designing phase. And I might perhaps give up. For reference, I am the main architect and implementor of GCC MELT, a domain specific language to extend the GCC compiler (the MELT language is translated to C/C++ and is bootstrapped: the MELT to C/C++ translator being written in MELT). And I am dreaming of extending it with some cloud computing abilities. But I am a newbie in cloud computing. (I am only interested in free-software, GPLv3 friendly, based cloud computing, which probably means openstack). I believe that "compiling on the cloud with some enhanced GCC" could make sense (for super-optimizations or static analysis of e.g. an entire Linux distribution, or at least a massive GCC compiled free software like Qt, GCC itself, or the Linux kernel). I'm dreaming of a MELT specific monitoring program which would store, communicate, and and enhance GCC compilation (extended by MELT). So the picture would be that each GCC process (actually the cc1 or cc1plus started by the gcc driver, suitably extended by some MELT extension) would communicate with some monitor. That "monitoring/persisting" program would run "on the cloud" (and probably manage some information produced by GCC e.g. on NoSQL bases). So, how should some (yet to be written) C program (some Linux daemon) be designed to be cloud-friendly? So far, I understood that it should provide some Web service, probably thru a RESTful service, so should use an HTTP server library like onion. And that OpenStack is able to start (e.g. a dozen of) such services. But I don't have a clear picture of what OpenStack brings. So far, I noticed the ability to manage (and distribute) virtual machines (with some Python API). It is less clear how can it distribute some ELF executable, how can it start it, etc. Do you have any references or examples of C / C++ programming on the cloud? How should a "cloud-friendly" (actually, OpenStack friendly) C/C++ server application be designed?

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  • Why would I learn C++11, having known C and C++?

    - by Shahbaz
    I am a programmer in C and C++, although I don't stick to either language and write a mixture of the two. Sometimes having code in classes, possibly with operator overloading, or templates and the oh so great STL is obviously a better way. Sometimes use of a simple C function pointer is much much more readable and clear. So I find beauty and practicality in both languages. I don't want to get into the discussion of "If you mix them and compile with a C++ compiler, it's not a mix anymore, it's all C++" I think we all understand what I mean by mixing them. Also, I don't want to talk about C vs C++, this question is all about C++11. C++11 introduces what I think are significant changes to how C++ works, but it has introduced many special cases that change how different features behave in different circumstances, placing restrictions on multiple inheritance, adding lambda functions, etc. I know that at some point in the future, when you say C++ everyone would assume C++11. Much like when you say C nowadays, you most probably mean C99. That makes me consider learning C++11. After all, if I want to continue writing code in C++, I may at some point need to start using those features simply because my colleagues have. Take C for example. After so many years, there are still many people learning and writing code in C. Why? Because the language is good. What good means is that, it follows many of the rules to create a good programming language. So besides being powerful (which easy or hard, almost all programming languages are), C is regular and has few exceptions, if any. C++11 however, I don't think so. I'm not sure that the changes introduced in C++11 are making the language better. So the question is: Why would I learn C++11? Update: My original question in short was: "I like C++, but the new C++11 doesn't look good because of this and this and this. However, deep down something tells me I need to learn it. So, I asked this question here so that someone would help convince me to learn it." However, the zealous people here can't tolerate pointing out a flaw in their language and were not at all constructive in this manner. After the moderator edited the question, it became more like a "So, how about this new C++11?" which was not at all my question. Therefore, in a day or too I am going to delete this question if no one comes up with an actual convincing argument. P.S. If you are interested in knowing what flaws I was talking about, you can edit my question and see the previous edits.

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  • Fixing a NoClassDefFoundError

    - by Chris Okyen
    I have some code: package ftc; import java.util.Scanner; public class Fer_To_Cel { public static void main(String[] argv) { // Scanner object to get the temp in degrees Farenheit Scanner keyboard = new Scanner(System.in); boolean isInt = true; // temporarily put as true in case the user enters a valid int the first time int degreesF = 0; // initialy set to 0 do { try { // Input the temperature text. System.out.print("\nPlease enter a temperature (integer number, no fractional part) in degrees Farenheit: "); degreesF = Integer.parseInt(keyboard.next()); // Get user input and Assign the far. temperature variable, which is casted from String to int. } // Let the user know in a user friendly notice that the value entered wasnt an int ( give int value range ) , and then give error log catch(java.lang.Exception e) { System.out.println("Sorry but you entered a non-int value ( needs to be between ( including ) -2,147,483,648 and 2,147,483,647 ).. \n"); e.printStackTrace(); isInt = false; } } while(!isInt); System.out.println(""); // print a new line. final int degreesC = (5*(degreesF-32)/9); // convert the degrees from F to C and store the resulting expression in degreesC // Print out a newline, then print what X degrees F is in Celcius. System.out.println("\n" + degreesF + " degrees Farenheit is " + degreesC + " degrees Celcius"); } } And The following error: C:\Program Files\Java\jdk1.7.0_06\bin>java Fer_To_Cel Exception in thread "main" java.lang.NoClassDefFoundError: Fer_To_Cel (wrong name: ftc/Fer_To_Cel) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:791) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:14 at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:423) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:356) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:480) The code compiled without compile errors, but presented errors during execution. Which leads me to two questions. I know Errors can be termed Compiler, Runtime and Logic Errors, but the NoClassDefFoundError inherits java.lang.LinkageError. Does that make it a Linker error, being niether of the three types of errors I listed, If I am right this is the answer. For someone else who obtains the singular .java file and compiles it, would this be the only way to solve this problem? Or can I (should I ) do/have done something to fix this problem? Basically, based on a basis of programming, is this a fault of me as the writer? Could this be done once on, my half and be distributed and not needed be done again?

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  • Monitoring C++ applications

    - by Scott A
    We're implementing a new centralized monitoring solution (Zenoss). Incorporating servers, networking, and Java programs is straightforward with SNMP and JMX. The question, however, is what are the best practices for monitoring and managing custom C++ applications in large, heterogenous (Solaris x86, RHEL Linux, Windows) environments? Possibilities I see are: Net SNMP Advantages single, central daemon on each server well-known standard easy integration into monitoring solutions we run Net SNMP daemons on our servers already Disadvantages: complex implementation (MIBs, Net SNMP library) new technology to introduce for the C++ developers rsyslog Advantages single, central daemon on each server well-known standard unknown integration into monitoring solutions (I know they can do alerts based on text, but how well would it work for sending telemetry like memory usage, queue depths, thread capacity, etc) simple implementation Disadvantages: possible integration issues somewhat new technology for C++ developers possible porting issues if we switch monitoring vendors probably involves coming up with an ad-hoc communication protocol (or using RFC5424 structured data; I don't know if Zenoss supports that without custom Zenpack coding) Embedded JMX (embed a JVM and use JNI) Advantages consistent management interface for both Java and C++ well-known standard easy integration into monitoring solutions somewhat simple implementation (we already do this today for other purposes) Disadvantages: complexity (JNI, thunking layer between native C++ and Java, basically writing the management code twice) possible stability problems requires a JVM in each process, using considerably more memory JMX is new technology for C++ developers each process has it's own JMX port (we run a lot of processes on each machine) Local JMX daemon, processes connect to it Advantages single, central daemon on each server consistent management interface for both Java and C++ well-known standard easy integration into monitoring solutions Disadvantages: complexity (basically writing the management code twice) need to find or write such a daemon need a protocol between the JMX daemon and the C++ process JMX is new technology for C++ developers CodeMesh JunC++ion Advantages consistent management interface for both Java and C++ well-known standard easy integration into monitoring solutions single, central daemon on each server when run in shared JVM mode somewhat simple implementation (requires code generation) Disadvantages: complexity (code generation, requires a GUI and several rounds of tweaking to produce the proxied code) possible JNI stability problems requires a JVM in each process, using considerably more memory (in embedded mode) Does not support Solaris x86 (deal breaker) Even if it did support Solaris x86, there are possible compiler compatibility issues (we use an odd combination of STLPort and Forte on Solaris each process has it's own JMX port when run in embedded mode (we run a lot of processes on each machine) possibly precludes a shared JMX server for non-C++ processes (?) Is there some reasonably standardized, simple solution I'm missing? Given no other reasonable solutions, which of these solutions is typically used for custom C++ programs? My gut feel is that Net SNMP is how people do this, but I'd like other's input and experience before I make a decision.

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  • Software Tuned to Humanity

    - by Phil Factor
    I learned a great deal from a cynical old programmer who once told me that the ideal length of time for a compiler to do its work was the same time it took to roll a cigarette. For development work, this is oh so true. After intently looking at the editing window for an hour or so, it was a relief to look up, stretch, focus the eyes on something else, and roll the possibly-metaphorical cigarette. This was software tuned to humanity. Likewise, a user’s perception of the “ideal” time that an application will take to move from frame to frame, to retrieve information, or to process their input has remained remarkably static for about thirty years, at around 200 ms. Anything else appears, and always has, to be either fast or slow. This could explain why commercial applications, unlike games, simulations and communications, aren’t noticeably faster now than they were when I started programming in the Seventies. Sure, they do a great deal more, but the SLAs that I negotiated in the 1980s for application performance are very similar to what they are nowadays. To prove to myself that this wasn’t just some rose-tinted misperception on my part, I cranked up a Z80-based Jonos CP/M machine (1985) in the roof-space. Within 20 seconds from cold, it had loaded Wordstar and I was ready to write. OK, I got it wrong: some things were faster 30 years ago. Sure, I’d now have had all sorts of animations, wizzy graphics, and other comforting features, but it seems a pity that we have used all that extra CPU and memory to increase the scope of what we develop, and the graphical prettiness, but not to speed the processes needed to complete a business procedure. Never mind the weight, the response time’s great! To achieve 200 ms response times on a Z80, or similar, performance considerations influenced everything one did as a developer. If it meant writing an entire application in assembly code, applying every smart algorithm, and shortcut imaginable to get the application to perform to spec, then so be it. As a result, I’m a dyed-in-the-wool performance freak and find it difficult to change my habits. Conversely, many developers now seem to feel quite differently. While all will acknowledge that performance is important, it’s no longer the virtue is once was, and other factors such as user-experience now take precedence. Am I wrong? If not, then perhaps we need a new school of development technique to rival Agile, dedicated once again to producing applications that smoke the rear wheels rather than pootle elegantly to the shops; that forgo skeuomorphism, cute animation, or architectural elegance in favor of the smell of hot rubber. I struggle to name an application I use that is truly notable for its blistering performance, and would dearly love one to do my everyday work – just as long as it doesn’t go faster than my brain.

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  • Keep coding the wrong way to remain consistent? [closed]

    - by bwalk2895
    Possible Duplicate: Code maintenance: keeping a bad pattern when extending new code for being consistent, or not? To keep things simple let's say I am responsible for maintaining two applications, AwesomeApp and BadApp (I am responsible for more and no that is not their actual names). AwesomeApp is a greenfield project I have been working on with other members on my team. It was coded using all the fancy buzzwords, Multilayer, SOA, SOLID, TDD, and so on. It represents the direction we want to go as a team. BadApp is a application that has been around for a long time. The architecture suffers from many sins, namely everything is tightly coupled together and it is not uncommon to get a circular dependency error from the compiler, it is almost impossible to unit test, large classes, duplicate code, and so on. We have a plan to rewrite the application following the standards established by AwesomeApp, but that won't happen for a while. I have to go into BadApp and fix a bug, but after spending months coding what I consider correctly, I really don't want do continue perpetuate bad coding practices. However, the way AwesomeApp is coded is vastly different from the way BadApp is coded. I fear implementing the "correct" way would cause confusion for other developers who have to maintain the application. Question: Is it better to keep coding the wrong way to remain consistent with the rest of the code in the application (knowing it will be replaced) or is it better to code the right way with an understanding it could cause confusion because it is so much different? To give you an example. There is a large class (1000+ lines) with several functions. One of the functions is to calculate a date based on an enumerated value. Currently the function handles all the various calculations. The function relies on no other functionality within the class. It is self contained. I want to break the function into smaller functions (at the very least) and put them into their own classes and hide those classes behind an interface (at the most) and use the factory pattern to instantiate the date classes. If I just broke it out into smaller functions within the class it would follow the existing coding standard. The extra steps are to start following some of the SOLID principles.

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  • Frame rate on one of two machines running same code seems to be capped at 60 for no reason

    - by dennmat
    ISSUE I recently moved a project from my laptop to my desktop(machine info below). On my laptop the exact same code displays the fps(and ms/f) correctly. On my desktop it does not. What I mean by this is on the laptop it will display 300 fps(for example) where on my desktop it will show only up to 60. If I add 100 objects to the game on the laptop I'll see my frame rate drop accordingly; the same test on the desktop results in no change and the frames stay at 60. It takes a lot(~300) entities before I'll see a frame drop on the desktop, then it will descend. It seems as though its "theoretical" frames would be 400 or 500 but will never actually get to that and only do 60 until there's too much to handle at 60. This 60 frame cap is coming from no where. I'm not doing any frame limiting myself. It seems like something external is limiting my loop iterations on the desktop, but for the last couple days I've been scratching my head trying to figure out how to debug this. SETUPS Desktop: Visual Studio Express 2012 Windows 7 Ultimate 64-bit Laptop: Visual Studio Express 2010 Windows 7 Ultimate 64-bit The libraries(allegro, box2d) are the same versions on both setups. CODE Main Loop: while(!abort) { frameTime = al_get_time(); if (frameTime - lastTime >= 1.0) { lastFps = fps/(frameTime - lastTime); lastTime = frameTime; avgMspf = cumMspf/fps; cumMspf = 0.0; fps = 0; } /** DRAWING/UPDATE CODE **/ fps++; cumMspf += al_get_time() - frameTime; } Note: There is no blocking code in the loop at any point. Where I'm at My understanding of al_get_time() is that it can return different resolutions depending on the system. However the resolution is never worse than seconds, and the double is represented as [seconds].[finer-resolution] and seeing as I'm only checking for a whole second al_get_time() shouldn't be responsible. My project settings and compiler options are the same. And I promise its the same code on both machines. My googling really didn't help me much, and although technically it's not that big of a deal. I'd really like to figure this out or perhaps have it explained, whichever comes first. Even just an idea of how to go about figuring out possible causes, because I'm out of ideas. Any help at all is greatly appreciated.

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  • "Whole-team" C++ features?

    - by Blaisorblade
    In C++, features like exceptions impact your whole program: you can either disable them in your whole program, or you need to deal with them throughout your code. As a famous article on C++ Report puts it: Counter-intuitively, the hard part of coding exceptions is not the explicit throws and catches. The really hard part of using exceptions is to write all the intervening code in such a way that an arbitrary exception can propagate from its throw site to its handler, arriving safely and without damaging other parts of the program along the way. Since even new throws exceptions, every function needs to provide basic exception safety — unless it only calls functions which guarantee throwing no exception — unless you disable exceptions altogether in your whole project. Hence, exceptions are a "whole-program" or "whole-team" feature, since they must be understood by everybody in a team using them. But not all C++ features are like that, as far as I know. A possible example is that if I don't get templates but I do not use them, I will still be able to write correct C++ — or will I not?. I can even call sort on an array of integers and enjoy its amazing speed advantage wrt. C's qsort (because no function pointer is called), without risking bugs — or not? It seems templates are not "whole-team". Are there other C++ features which impact code not directly using them, and are hence "whole-team"? I am especially interested in features not present in C. Update: I'm especially looking for features where there's no language-enforced sign you need to be aware of them. The first answer I got mentioned const-correctness, which is also whole-team, hence everybody needs to learn about it; however, AFAICS it will impact you only if you call a function which is marked const, and the compiler will prevent you from calling it on non-const objects, so you get something to google for. With exceptions, you don't even get that; moreover, they're always used as soon as you use new, hence exceptions are more "insidious". Since I can't phrase this as objectively, though, I will appreciate any whole-team feature. Appendix: Why this question is objective (if you wonder) C++ is a complex language, so many projects or coding guides try to select "simple" C++ features, and many people try to include or exclude some ones according to mostly subjective criteria. Questions about that get rightfully closed regularly here on SO. Above, instead, I defined (as precisely as possible) what a "whole-team" language feature is, provide an example (exceptions), together with extensive supporting evidence in the literature about C++, and ask for whole-team features in C++ beyond exceptions. Whether you should use "whole-team" features, or whether that's a relevant concept, might be subjective — but that only means the importance of this question is subjective, like always.

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  • Best Practice Method for Including Images in a DataGrid using MVVM

    - by Killercam
    All, I have a WPF DataGrid. This DataGrid shows files ready for compilation and should also show the progress of my compiler as it compiles the files. The format of the DataGrid is Image|File Path|State -----|---------|----- * |C:\AA\BB |Compiled & |F:PP\QQ |Failed > |G:HH\LL |Processing .... The problem is the image column (the *, &, and are for representation only). I have a ResourceDictionary that contains hundreds of vector images as Canvas objects: <ResourceDictionary xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"> <Canvas x:Key="appbar_acorn" Width="48" Height="48" Clip="F1 M 0,0L 48,0L 48,48L 0,48L 0,0"> <Path Width="22.3248" Height="25.8518" Canvas.Left="13.6757" Canvas.Top="11.4012" Stretch="Fill" Fill="{DynamicResource BlackBrush}" Data="F1 M 16.6309,18.6563C 17.1309,8.15625 29.8809,14.1563 29.8809,14.1563C 30.8809,11.1563 34.1308,11.4063 34.1308,11.4063C 33.5,12 34.6309,13.1563 34.6309,13.1563C 32.1309,13.1562 31.1309,14.9062 31.1309,14.9062C 41.1309,23.9062 32.6309,27.9063 32.6309,27.9062C 24.6309,24.9063 21.1309,22.1562 16.6309,18.6563 Z M 16.6309,19.9063C 21.6309,24.1563 25.1309,26.1562 31.6309,28.6562C 31.6309,28.6562 26.3809,39.1562 18.3809,36.1563C 18.3809,36.1563 18,38 16.3809,36.9063C 15,36 16.3809,34.9063 16.3809,34.9063C 16.3809,34.9063 10.1309,30.9062 16.6309,19.9063 Z "/> </Canvas> </ResourceDictionary> Now, I want to be able to include these in my image column and change them at run-time. I was going to attempt to do this by setting up a property in my View Model that was of type Image and binding this to my View via: <DataGrid.Columns> <DataGridTemplateColumn Header="" Width="SizeToCells" IsReadOnly="True"> <DataGridTemplateColumn.CellTemplate> <DataTemplate> <Image Source="{Binding Canvas}"/> </DataTemplate> </DataGridTemplateColumn.CellTemplate> </DataGridTemplateColumn> </DataGrid.Columns> Where in the View Model I have the appropriate property. Now, I was told this is not 'pure' MVVM. I don't fully accept this, but I want to know if there is a better way of doing this. Say, binding to an enum and using a converter to get the image? Any advice would be appreciated.

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  • Why can't Java/C# implement RAII?

    - by mike30
    Question: Why can't Java/C# implement RAII? Clarification: I am aware the garbage collector is not deterministic. So with the current language features it is not possible for an object's Dispose() method to be called automatically on scope exit. But could such a deterministic feature be added? My understanding: I feel an implementation of RAII must satisfy two requirements: 1. The lifetime of a resource must be bound to a scope. 2. Implicit. The freeing of the resource must happen without an explicit statement by the programmer. Analogous to a garbage collector freeing memory without an explicit statement. The "implicitness" only needs to occur at point of use of the class. The class library creator must of course explicitly implement a destructor or Dispose() method. Java/C# satisfy point 1. In C# a resource implementing IDisposable can be bound to a "using" scope: void test() { using(Resource r = new Resource()) { r.foo(); }//resource released on scope exit } This does not satisfy point 2. The programmer must explicitly tie the object to a special "using" scope. Programmers can (and do) forget to explicitly tie the resource to a scope, creating a leak. In fact the "using" blocks are converted to try-finally-dispose() code by the compiler. It has the same explicit nature of the try-finally-dispose() pattern. Without an implicit release, the hook to a scope is syntactic sugar. void test() { //Programmer forgot (or was not aware of the need) to explicitly //bind Resource to a scope. Resource r = new Resource(); r.foo(); }//resource leaked!!! I think it is worth creating a language feature in Java/C# allowing special objects that are hooked to the stack via a smart-pointer. The feature would allow you to flag a class as scope-bound, so that it always is created with a hook to the stack. There could be a options for different for different types of smart pointers. class Resource - ScopeBound { /* class details */ void Dispose() { //free resource } } void test() { //class Resource was flagged as ScopeBound so the tie to the stack is implicit. Resource r = new Resource(); //r is a smart-pointer r.foo(); }//resource released on scope exit. I think implicitness is "worth it". Just as the implicitness of garbage collection is "worth it". Explicit using blocks are refreshing on the eyes, but offer no semantic advantage over try-finally-dispose(). Is it impractical to implement such a feature into the Java/C# languages? Could it be introduced without breaking old code?

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  • Do functional generics exist and what is the correct name for them if they do?

    - by voroninp
    Consider the following generic class: public class EntityChangeInfo<EntityType,TEntityKey> { ChangeTypeEnum ChangeType {get;} TEntityKeyType EntityKey {get;} } Here EntityType unambiguously defines TEntityKeyType. So it would be nice to have some kind of types' map: public class EntityChangeInfo<EntityType,TEntityKey> with map < [ EntityType : Person -> TEntityKeyType : int] [ EntityType : Car -> TEntityKeyType : CarIdType ]> { ChangeTypeEnum ChangeType {get;} TEntityKeyType EntityKey {get;} } Another one example is: public class Foo<TIn> with map < [TIn : Person -> TOut1 : string, TOut2 : int, ..., TOutN : double ] [TIn : Car -> TOut1 : int, TOut2 :int, ..., TOutN : Price ] > { TOut1 Prop1 {get;set;} TOut2 Prop2 {get;set;} ... TOutN PropN {get;set;} } The reasonable question: how can this be interpreted by the compiler? Well, for me it is just the shortcut for two structurally similar classes: public sealed class Foo<Person> { string Prop1 {get;set;} int Prop2 {get;set;} ... double PropN {get;set;} } public sealed class Foo<Car> { int Prop1 {get;set;} int Prop2 {get;set;} ... Price PropN {get;set;} } But besides this we could imaging some update of the Foo<>: public class Foo<TIn> with map < [TIn : Person -> TOut1 : string, TOut2 : int, ..., TOutN : double ] [TIn : Car -> TOut1 : int, TOut2 :int, ..., TOutN : Price ] > { TOut1 Prop1 {get;set;} TOut2 Prop2 {get;set;} ... TOutN PropN {get;set;} public override string ToString() { return string.Format("prop1={0}, prop2={1},...propN={N-1}, Prop1, Prop2,...,PropN); } } This all can seem quite superficial but the idea came when I was designing the messages for our system. The very first class. Many messages with the same structure should be discriminated by the EntityType. So the question is whether such construct exists in any programming language?

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  • Do functional generics exist or what is the correct name for them if they do?

    - by voroninp
    Consider the following generic class public class EntityChangeInfo<EntityType,TEntityKey> { ChangeTypeEnum ChangeType {get;} TEntityKeyType EntityKey {get;} } Here EntityType unambiguously defines TEntityKeyType. So it would be nice to have some kind of types' map public class EntityChangeInfo<EntityType,TEntityKey> with map < [ EntityType : Person -> TEntityKeyType : int] [ EntityType : Car -> TEntityKeyType : CarIdType ]> { ChangeTypeEnum ChangeType {get;} TEntityKeyType EntityKey {get;} } Another one example is: public class Foo<TIn> with map < [TIn : Person -> TOut1 : string, TOut2 : int, ..., TOutN : double ] [TIn : Car -> TOut1 : int, TOut2 :int, ..., TOutN : Price ] > { TOut1 Prop1 {get;set;} TOut2 Prop2 {get;set;} ... TOutN PropN {get;set;} } The reasonable question how this can be interpreted by the compiler? Well, for me it is just the sortcut for two structurally similar classes: public sealed class Foo<Person> { string Prop1 {get;set;} int Prop2 {get;set;} ... double PropN {get;set;} } public sealed class Foo<Car> { int Prop1 {get;set;} int Prop2 {get;set;} ... Price PropN {get;set;} } But besides this we could imaging some update of the Foo<: public class Foo<TIn> with map < [TIn : Person -> TOut1 : string, TOut2 : int, ..., TOutN : double ] [TIn : Car -> TOut1 : int, TOut2 :int, ..., TOutN : Price ] > { TOut1 Prop1 {get;set;} TOut2 Prop2 {get;set;} ... TOutN PropN {get;set;} public override string ToString() { return string.Format("prop1={0}, prop2={1},...propN={N-1}, Prop1, Prop2,...,PropN); } } This all can seem quite superficial but the idea came when I was designing the messages for our system. The very first class. Many messages with the same structrue should be discriminated by the EntityType. So the question is whether such construct exist in any programming language?

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  • Fix ACPI DSDT of Amilo Pa 1538

    - by kayahr
    I have a Fujitsu-Siemens Amilo Pa 1538 laptops and installed Ubuntu 10.04 on it (Kernel 2.6.32). Main problem is that the fans of the notebook are always on even when the temperature is low. Another problem is that the display brightness can not be adjusted. Since some years I use Dell laptops and never experienced any ACPI problems so I thought that it is no longer needed to fix ACPI tables but now I have this crap of a laptop and I think I have to do it. Unfortunately I need some help repairing the DSDT. The dsdt.dat and dsdt.dsl of the laptop can be found here: http://www.ailis.de/~k/permdata/20100420/dsdt/ Compiling the DSDT gives the following output: # iasl -sa dsdt.dsl Intel ACPI Component Architecture ASL Optimizing Compiler version 20090521 [Jun 30 2009] Copyright (C) 2000 - 2009 Intel Corporation Supports ACPI Specification Revision 3.0a dsdt.dsl 81: Method (\_WAK, 1, NotSerialized) Warning 1080 - ^ Reserved method must return a value (_WAK) dsdt.dsl 207: Method (_L10, 0, NotSerialized) Warning 1087 - ^ Not all control paths return a value (_L10) dsdt.dsl 2861: Method (NVIF, 3, NotSerialized) Warning 1087 - ^ Not all control paths return a value (NVIF) dsdt.dsl 4551: Store (\_SB.PCI0.LPC0.PMRD (0xFA), Local0) Warning 1099 - Statement is unreachable ^ ASL Input: dsdt.dsl - 4962 lines, 162828 bytes, 2300 keywords AML Output: dsdt.aml - 17627 bytes, 591 named objects, 1709 executable opcodes Compilation complete. 0 Errors, 4 Warnings, 0 Remarks, 519 Optimizations Anyone here with DSDT experience who can help me fixing the DSDT?

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