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  • Which is the best non-java, dynamic, programming language to build attractive GUIs?

    - by VeeKay
    I am well acquainted with java and groovy but somehow I am not intrigued by the performance or looks of swing based applications that are developed on the same. So I want to learn and know about THE best alternate dynamic programming language (coz I am looking for little bit of luxury while writing code by not willing to fiddle with pointers, memory handling, static typing difficulties etc) to develop attractive cross platform GUIs. To be precise, when I say attractive I mean support for elegant translucent windows and nicer components (not the flashy adobe stuff). Can you please suggest me a programming language that manages to fit into this?

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  • How to handle failure to release a resource which is contained in a smart pointer?

    - by cj
    How should an error during resource deallocation be handled, when the object representing the resource is contained in a shared pointer? Smart pointers are a useful tool to manage resources safely. Examples of such resources are memory, disk files, database connections, or network connections. // open a connection to the local HTTP port boost::shared_ptr<Socket> socket = Socket::connect("localhost:80"); In a typical scenario, the class encapsulating the resource should be noncopyable and polymorphic. A good way to support this is to provide a factory method returning a shared pointer, and declare all constructors non-public. The shared pointers can now be copied from and assigned to freely. The object is automatically destroyed when no reference to it remains, and the destructor then releases the resource. /** A TCP/IP connection. */ class Socket { public: static boost::shared_ptr<Socket> connect(const std::string& address); virtual ~Socket(); protected: Socket(const std::string& address); private: // not implemented Socket(const Socket&); Socket& operator=(const Socket&); }; But there is a problem with this approach. The destructor must not throw, so a failure to release the resource will remain undetected. A common way out of this problem is to add a public method to release the resource. class Socket { public: virtual void close(); // may throw // ... }; Unfortunately, this approach introduces another problem: Our objects may now contain resources which have already been released. This complicates the implementation of the resource class. Even worse, it makes it possible for clients of the class to use it incorrectly. The following example may seem far-fetched, but it is a common pitfall in multi-threaded code. socket->close(); // ... size_t nread = socket->read(&buffer[0], buffer.size()); // wrong use! Either we ensure that the resource is not released before the object is destroyed, thereby losing any way to deal with a failed resource deallocation. Or we provide a way to release the resource explicitly during the object's lifetime, thereby making it possible to use the resource class incorrectly. There is a way out of this dilemma. But the solution involves using a modified shared pointer class. These modifications are likely to be controversial. Typical shared pointer implementations, such as boost::shared_ptr, require that no exception be thrown when their object's destructor is called. Generally, no destructor should ever throw, so this is a reasonable requirement. These implementations also allow a custom deleter function to be specified, which is called in lieu of the destructor when no reference to the object remains. The no-throw requirement is extended to this custom deleter function. The rationale for this requirement is clear: The shared pointer's destructor must not throw. If the deleter function does not throw, nor will the shared pointer's destructor. However, the same holds for other member functions of the shared pointer which lead to resource deallocation, e.g. reset(): If resource deallocation fails, no exception can be thrown. The solution proposed here is to allow custom deleter functions to throw. This means that the modified shared pointer's destructor must catch exceptions thrown by the deleter function. On the other hand, member functions other than the destructor, e.g. reset(), shall not catch exceptions of the deleter function (and their implementation becomes somewhat more complicated). Here is the original example, using a throwing deleter function: /** A TCP/IP connection. */ class Socket { public: static SharedPtr<Socket> connect(const std::string& address); protected: Socket(const std::string& address); virtual Socket() { } private: struct Deleter; // not implemented Socket(const Socket&); Socket& operator=(const Socket&); }; struct Socket::Deleter { void operator()(Socket* socket) { // Close the connection. If an error occurs, delete the socket // and throw an exception. delete socket; } }; SharedPtr<Socket> Socket::connect(const std::string& address) { return SharedPtr<Socket>(new Socket(address), Deleter()); } We can now use reset() to free the resource explicitly. If there is still a reference to the resource in another thread or another part of the program, calling reset() will only decrement the reference count. If this is the last reference to the resource, the resource is released. If resource deallocation fails, an exception is thrown. SharedPtr<Socket> socket = Socket::connect("localhost:80"); // ... socket.reset();

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  • Is it normal to feel bad when someone insults a programming language? [closed]

    - by iammilind
    Few examples before the question: "A language is just a tool; Better to worry only about the concept." "C++ is just an object oriented language." "Java is more about the libraries and less about programming." "C# is just a Microsoft's version of Java with some extra things from C++." "Python is a scripting language used mainly for testing purpose." ... All these statements are made knowingly or unknowingly from my colleagues/friends and I often get to hear them. I feel bad when someone brings down any programming language. I don't know how to respond. Is there any one liner to enlighten those people?

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  • What are the licensing terms for the Swift Programming Language?

    - by 200_success
    What are the licensing terms of the Swift Programming Language, the API, and runtime? The only mention I have been able to find is from the Copyright and Notices section of Apple's The Swift Programming Language iBook: No licenses, express or implied, are granted with respect to any of the technology described in this document. Apple retains all intellectual property rights associated with the technology described in this document. This document is intended to assist application developers to develop applications only for Apple-branded products. … which suggests that the language is intended to be completely proprietary.

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  • What kind of math should I be expecting in advanced programming?

    - by I_Question_Things_Deeply
    And I don't mean just space shooters and such, because in non-3D environments it's obvious that not much beyond elementary math is needed to implement. Most of the programming in 2D games is mostly going to involve basic arithmetic, algorithms for enemy AI and dimensional worlds, rotation, and maybe some Algebra as well depending on how you want to design. But I ask because I'm not really gifted with math at all. I get frustrated and worn out just by doing Pre-Algebra, so Algebra 2 and Calculus would likely be futile for me. I guess I'm not so "right-brained" when it comes down to pure numbers and math formulas, but the bad part is that I'm no art-expert either. What do you people here suppose I should do? Go along avoiding as much of the extremely difficult maths I can't fathom, or try to ease into more complex math as I excel at programming?

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  • Introducing Programming To a Mathematician

    - by ell
    I currently am a programmer, I'm almost 16 years of age and have pretty much narrowed my careers down to something involving a Computer Science degree or Electrical Engineering degree (I know they are quite different but this question is about my friend) but my friend isn't so sure. He is very interested in maths and is very good at it and I think he would enjoy programming but he isn't willing to try it (edit he is willing to try but has never done before). Can anyone give me an suggestions for a language or tool that he could dabble in programming (at a reasonably basic level I assume) to solve maths problems or involve some kind of maths. As I say he enjoys maths a lot but I think he would enjoy programming, the problem is I don't want him to be put off by the stuff that isn't relevant at introductory levels such as memory allocation et al. I know that is very important but the point is that I want him to learn a bit of programming with maths then hopefully if he is interested enough he can start learning programming as programming. Thanks in advance, ell. Edit: Its not that he's completely uninterested - more that he hasn't actively explored the area before, maybe because he isn't informed about it. I wouldn't want to force him to do something he doesn't want to, I see this as more of a little push so that he can learn about programming. If he doesn't like it - fair enough, I can't control that and don't want to but if he turns out to enjoy it - this push will have been the right thing.

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  • Programming in academic environment vs industry environment [closed]

    - by user200340
    Possible Duplicate: Differences between programming in school vs programming in industry? This is a general discussion about programming in the industry environment. The background story is that my colleague sent me a very interesting article called "10 Things Entrepreneurs Don’t Learn in College." The first point in that post is about the author's experience of programming in the academic environment vs industry environment. After finishing a 4 year Computer Science degree course, I am currently working in the academic environment as a developer, mainly writing Java, J2EE, Javascript code. I know there are differences between academic programming and industry programming, but I was shocked after reading that post. Trying to avoid this happening on me in the future, or the others. Can anyone from industry give some general advice about how to program in industry. For example, What exactly happens when a task is received? What is the flow from the beginning to the end? What are the main differences between the programming in industry and academia? Is it more structured? Are more frameworks used? It would be great if some code examples could be given. Thanks.

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  • Are parallel calls to send/recv on the same socket valid?

    - by Jay
    Can we call send from one thread and recv from another on the same socket? Can we call multiple sends parallely from different threads on the same socket? I know that a good design should avoid this, but I am not clear how these system APIs will behave. I am unable to find a good documentation also for the same. Any pointers in the direction will be helpful.

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  • Inspiring the method of teaching. Example- C++ :)

    - by Ashwin
    A year ago I graduated with a degree in Computer Science and Engineering. Considering C++ as the first choice of programming language I have been in the process of learning C++ in many ways. At first - five years back - I had many conceptions, most of which were so abstract to me. It started when I knew almost everything about Structs in C and nothing about Classes in C++. I went through a great time experimenting them all and learning a lot. I had a hard time evaluating Procedural programming vs Object-Oriented Programming. Deciding when to choose Procedural or Object-Oriented Programming took a great deal of patience for me. I knew that I cannot underestimate any of these Programming styles... Though Procedural programming is often a better choice than simple sequential unstructured programming, when solving problems with procedural programming, we usually divide one problem into several steps in order regarded as functions. Then we call these functions one by one to get the result of the problem. When solving problems with Object Oriented Priciples we divide one problem into several classes and form the interaction between them. Evaluating these two at the beginning (as a learner) required a lot of inspiration and thoughts. Instructing to think step by step. Relative concepts to understand deeply. Intensive interests to contrast both solving in both POP and OOP. If you were ever a mentor: What ideas/methods would you teach to students in which it will Inspire them to learn a programming language (in general, computer sciences)?

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  • How to maintain a persistant network-connection between two applications over a network?

    - by John
    I was recently approached by my management with an interesting problem - where I am pretty sure I am telling my bosses the correct information but I really want to make sure I am telling them the correct stuff. I am being asked to develop some software that has this function: An application at one location is constantly processing real-time data every second and only generates data if the underlying data has changed in any way. On the event that the data has changed send the results to another box over a network Maintains a persistent connection between the both machines, altering the remote box if for some reason the network connection went down From what I understand, I imagine that I need to do some reading on doing some sort of TCP/IP socket-level stuff. That way if the connection is dropped the remote location will be aware that the data it has received may be stale. However management seems to be very convinced that this can be accomplished using SOAP. I was under the impression that SOAP is more or less a way for a client to initiate a procedure from a server and get some results via the HTTP protocol. Am I wrong in assuming this? I haven't been able to find much information on how SOAP might be able to solve a problem like this. I feel like a lot of people around my office are using SOAP as a buzzword and that has generated a bit of confusion over what SOAP actually is - and is capable of. Any thoughts on how to accomplish this task would be appreciated!

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  • Listening Port Permanently. if file is on my stream, Get file. How to?

    - by Phsika
    i writed 2 client and server program. client dend file also server listen port and than get file.But i need My server App must listen on 51124 port permanently. if any file on my stream, show my message "there is a file on your stream" and than show me savefile dialog. But my server app in "Infinite loop". 1) listen 51124 port every time 2) do i have a file on my stream, show me a messagebox. private void Form1_Load(object sender, EventArgs e) { TcpListener Dinle = new TcpListener(51124); try { Dinle.Start(); Socket Baglanti = Dinle.AcceptSocket(); if (!Baglanti.Connected) { MessageBox.Show("No Connection!"); } else { while (true) { byte[] Dizi = new byte[250000]; Baglanti.Receive(Dizi, Dizi.Length, 0); string Yol; saveFileDialog1.Title = "Save File"; saveFileDialog1.ShowDialog(); Yol = saveFileDialog1.FileName; FileStream Dosya = new FileStream(Yol, FileMode.Create); Dosya.Write(Dizi, 0, Dizi.Length - 20); Dosya.Close(); listBox1.Items.Add("dosya indirildi"); listBox1.Items.Add("Dosya Boyutu=" + Dizi.Length.ToString()); listBox1.Items.Add("Indirilme Tarihi=" + DateTime.Now); listBox1.Items.Add("--------------------------------"); } } } catch (Exception) { throw; } } My Algorithm: if(AnyFileonStream()==true) { GetFile() //Also continue to listening 51124 port... } How can i do that?

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  • Socket.ReceiveAsync problem

    - by bartol
    Hi, I have a problem using SocketAsyncEventArgs model with .net sockets. Everything works great until the moment that the server wishes to close a client connection. I use following code for this: try { socket.Shutdown(SocketShutdown.Both); } catch { } // throws if client process has already closed finally { socket.Close(); } socket = null; Each connection is using two SocketAsyncEventArgs (one for send and one for receive) and after closing the connection they are returned to a pool from which they can be later reused. And here the problem starts, because when another connection is established and receive args are reused from the pool we get an exception: System.InvalidOperationException: "An asynchronous socket operation is already in progress using this SocketAsyncEventArgs instance."; at System.Net.Sockets.SocketAsyncEventArgs.StartOperationCommon(Socket socket) at System.Net.Sockets.Socket.ReceiveAsync(SocketAsyncEventArgs e) I've done some debugging and it appears that the connection closing code from the beginning of the question does not cancel Socket.ReceiveAsync operation that is in progress when the connection is closed. I've tried many combinations of Shutdown, Disconnect and Linger options for the socket but nothing worked. Any suggestions? Thanks

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  • No feedback from Socket.SendAsync

    - by BowserKingKoopa
    I'm creating a socket and I'm trying to send data through it using SendAsync. My socket isn't connected to anything so I expected to get an error of some sort. However I get nothing. I get no indication that the send didn't work. If I use the synchronous Send method instead of the asynchronous SendAsync method I get an Exception stating that the socket isn't connected to anything. That makes sense to me. When using SendAsync the completed event doesn't ever fire and I get no indication that the send didn't work. So basically my question is how can I tell when SendAsync fails? Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); SocketAsyncEventArgs args = new SocketAsyncEventArgs(); args.SetBuffer(new byte[0], 0, 0); args.Completed += delegate(object sender, SocketAsyncEventArgs e) { Debug.WriteLine("async send complete"); Debug.WriteLine("SOCKET ERROR: " + e.SocketError); }; bool completedSynchronously = socket.SendAsync(args); if (completedSynchronously) { Debug.WriteLine("sync send complete"); Debug.WriteLine("socket error: " + args.SocketError); }

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  • Why is my emit not getting called?

    - by cRaZiRiCaN
    The client and server connect just fine. For some reason the emit on my client is not firing correctly. I am trying to get the testEmit and testEmit2 working. This is my server: express = require 'express' mongo = require 'mongodb' app = express() server = (require 'http').createServer(app) io = (require 'socket.io').listen(server) server.listen(8080) app.use(express.static(__dirname + '/public')) # db = new mongo.Db("documentsdb", new mongo.Server("localhost", 27017, auto_reconnect: true), {safe:true}) io.sockets.on 'connection', (socket) -> console.log 'Socket.io is connected!' #This returns an array of documents sorted via date by decreasing order. (Most recent documents first.) socket.on 'loadRecentDocuments', -> console.log 'Loading most recent documents.' db.collection 'documents', (err, collection) -> collection.find().sort(dateAdded: -1).toArray (err, documents) -> #This emit is recieved at index.html where a javascript function sendDocuments manages the documents. socket.emit 'sendDocuments', documents return #The index.html provides the code data from the search box via a javascript. io.sockets.on 'findDocuments', (code) -> #Returns an array of documents with the corresponding class code. documentCodeToSearch = code console.log 'Retreaving documents with code: ' + documentCodeToSearch db.collection 'documents', (err, collection) -> collection.find(code:documentCodeToSearch).toArray (err, documents) -> socket.emit 'sendDocuments', documents return #Uploads a document to the server. documentData is sent via javascript from submit.html io.sockets.on 'addDocument', (documentData) -> console.log 'Adding document: ' + documentData db.collection 'documents', (err, collection) -> collection.insert documentData, safe: true return #Test socket.io io.sockets.on 'testEmit', -> console.log('Emit recieved.') socket.emit 'testEmit2', 'caca' return app.listen 1337 console.log "Listening on port 1337..." This is my client: <!doctype HTML> <html> <head> <title>ProjectShare</title> <script src="http://localhost:8080/socket.io/socket.io.js"></script> <script src = "http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script> <script> //Make sure DOM is ready before mucking around. $(document).ready(function() { console.log('jQuery entered!'); var socket = io.connect('http://localhost:8080'); socket.emit('testEmit'); socket.on('testEmit2', function(data) { console.log('Emit recieved at browser.'); console.log(data); }); console.log('jQuery exit.'); }); </script> </head> <body> <ol> <li><a href="index.html">ProjectShare</a></li> <li><a href="guidelines.html">Guidelines</a></li> <li><a href="upload.html">Upload</a></li> <li> <form> <input type = "search" placeholder = "enter class code"/> <input type = "submit" value = "Go"/> </form> </li> </ol> <ol id = "documentList"> </ol> </body> </html>

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  • How to Calculate TCP Socket Buffer Sizes for Data Guard Environments

    - by alejandro.vargas
    The MAA best practices contains an example of how to calculate the optimal TCP socket buffer sizes, that is quite important for very busy Data Guard environments, this document Formula to Calculate TCP Socket Buffer Sizes.pdf contains an example of using the instructions provided on the best practices document. In order to execute the calculation you need to know which is the band with or your network interface, usually will be 1Gb, on my example is a 10Gb network; and the round trip time, RTT, that is the time it takes for a packet to make a travel to the other end of the network and come back, on my example that was provided by the network administrator and was 3 ms (1000/seconds)

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  • Undocumented Secrets of MATLAB-Java Programming, un livre de Yair Altman, critique par Jérôme Briot

    Undocumented Secrets of MATLAB-Java Programming de Yair Altman D'après l'éditeur : Citation: For a variety of reasons, the MATLAB®-Java interface was never fully documented. This is really quite unfortunate: Java is one of the most widely used programming languages, having many times the number of programmers and programming resources as MATLAB. Also unfortunate is the popular claim that while MATLAB is a fine programming platform for prototyping...

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  • Scaling Literate Programming?

    - by Tetha
    Greetings. I have been looking at Literate Programming a bit now, and I do like the idea behind it: you basically write a little paper about your code and write down as much of the design decisions, the code probably surrounding the module, the inner workins of the module, assumptions and conclusions resulting from the design decisions, potential extension, all this can be written down in a nice way using tex. Granted, the first point: it is documentation. It must be kept up-to-date, but that should not be that bad, because your change should have a justification and you can write that down. However, how does Literate Programming Scale to a larger degree? Overall, Literate Programming is still just text. Very human readable text, of course, but still text, and thus, it is hard to follow large systems. For example, I reworked large parts of my compiler to use and some magic to chain compile steps together, because some "x.register_follower(y); y.register_follower(z); y.register_follower(a);..." got really unwieldy, and changing that to x y z a made it a bit better, even though this is at its breaking point, too. So, how does Literate Programming scale to larger systems? Does anyone try to do that? My thought would be to use LP to specify components that communicate with each other using event streams and chain all of these together using a subset of graphviz. This would be a fairly natural extension to LP, as you can extract a documentation -- a dataflow diagram -- from the net and also generate code from it really well. What do you think of it? -- Tetha.

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  • How to establish a socket connection from iPhone to a Apache server and communicate via PHP?

    - by candoyo
    Hi, I am working on an iPhone game which is depended on a LAMP server. I want to create a "event" based system where the apache server sends an event to the iphone. For this, I am thinking of using "CFStreamCreatePairWithSocketToHost" to connect to port 80 of the apache server. I am able to successfully connect to the server and open a read and write stream via the iPhone, but I am not sure how to send data to the iphone using PHP running from the LAMP server to the iPhone. I think I can use fsockopen in php to open a socket connection and write data to that socket. I tired running this code $fp = fsockopen("tcp://localhost", 80, $errno, $errstr); if (!$fp) { echo "ERROR: $errno - $errstr<br />\n"; } else { echo"writing to socket "; fwrite($fp, "wwqeqweqw eqwe qwe \n"); //echo fread($fp, 26); fclose($fp); echo "done"; } But, I dont see anything being read on the iphone.. Any idea what's going on, or how to accomplish this? Thanks!

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  • Different programming languages possibilities

    - by b-gen-jack-o-neill
    Hello. This should be very simple question. There are many programming languages out there, compiled into machine code or managed code. I first started with ASM back in high school. Assembler is very nice, since you know what exactly CPU does. Next, (as you can see from my other questions here) I decided to learn C and C++. I choosed C becouse from what I read it is the language with output most close to assembler-written programs. But, what I want to know is, can any other Windows programming language out there call win32 API? To be exact, like C has its special header and functions for win32 api interactions, is this assumed to be some important part of programming language? Or are there any languages that have no support for calling win32 API, or just use console to IO and some functions for basic file IO? Becouse, for Windows programming with graphic output, it is essential to have acess to win32 API. I know this question might seem silly, but still please, help me, I ask for study porposes. Thanks.

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  • How can I make video games if I don't like programming?

    - by hoper
    I am studying C++ code in my school (my major is computer programming). Honestly, my grades are not so good, and assignments are really hard. Sometimes I feel sad that I will spend 8-10 hours per day coding (which is stressful) in the future for my job. But I still want to make video games. Maybe this is the only reason why I am taking all of these stressful courses. I always write down plots, stories, characters, fictional gaming worlds... Once, I thought I should study artistic technology such as game design and not computer technology such as C++, C#, etc. However, most of popular game designers (or directors) such as Kojima, Miyamoto, etc. used to be good programmers. Companies actaully assign programmers to directors because they understand how to make a game. I've try to find other colleges or universities where they teach game design programs. However, one article that lists rank 10 game design schools in North America seems untrustful because the survey company only scores it from intervews of students. Once, I tried to attend Art Institute of Vancouver which is rank 7 according to that article. However, one programmer who used to be an instructor in there told me the truth: the employement rate of graduated students is low. How can I have a future making games if I don't like programming?

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