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  • What platform to use for browser based turn based strategy game

    - by sunwukung
    I want to write a browser based strategy game that can be played by two players in separate locations. The game itself is predominantly turn based. To that end, I want to determine the correct platform on which to build this game. To prevent gamers "gaming" the system, the business logic needs to reside in the server. I could arguably use AJAX for a large part of the games functionality, but at two key points in the game loop, the opposing player can "counter" the current players move. In addition, when it's time for the players to swap, AJAX polling is likely to fall short, so it's starting to look like WebSockets is going to be a requirement to pull this off smoothly. So, the remaining question is regarding the back end. I'd kinda like to build this in Python/Flask - but this is primarily out of wanting to tackle a project with that language, not neccessarily because it's the appropriate tool for the job. The next most likely candidate has got to be NodeJS given it's (apparently) tighter integration with the WebSockets protocol. My question, then, is regarding the best platform on which to pursue this objective.

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  • Threads are facing deadlock in socket program [migrated]

    - by ankur.trapasiya
    I am developing one program in which a user can download a number of files. Now first I am sending the list of files to the user. So from the list user selects one file at a time and provides path where to store that file. In turn it also gives the server the path of file where does it exist. I am following this approach because I want to give stream like experience without file size limitation. Here is my code.. 1) This is server which gets started each time I start my application public class FileServer extends Thread { private ServerSocket socket = null; public FileServer() { try { socket = new ServerSocket(Utils.tcp_port); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } @Override public void run() { try { System.out.println("request received"); new FileThread(socket.accept()).start(); } catch (IOException ex) { ex.printStackTrace(); } } } 2) This thread runs for each client separately and sends the requested file to the user 8kb data at a time. public class FileThread extends Thread { private Socket socket; private String filePath; public String getFilePath() { return filePath; } public void setFilePath(String filePath) { this.filePath = filePath; } public FileThread(Socket socket) { this.socket = socket; System.out.println("server thread" + this.socket.isConnected()); //this.filePath = filePath; } @Override public void run() { // TODO Auto-generated method stub try { ObjectInputStream ois=new ObjectInputStream(socket.getInputStream()); try { //************NOTE filePath=(String) ois.readObject(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } File f = new File(this.filePath); byte[] buf = new byte[8192]; InputStream is = new FileInputStream(f); BufferedInputStream bis = new BufferedInputStream(is); ObjectOutputStream oos = new ObjectOutputStream( socket.getOutputStream()); int c = 0; while ((c = bis.read(buf, 0, buf.length)) > 0) { oos.write(buf, 0, c); oos.flush(); // buf=new byte[8192]; } oos.close(); //socket.shutdownOutput(); // client.shutdownOutput(); System.out.println("stop"); // client.shutdownOutput(); ois.close(); // Thread.sleep(500); is.close(); bis.close(); socket.close(); } catch (IOException ex) { ex.printStackTrace(); } } } NOTE: here filePath represents the path of the file where it exists on the server. The client who is connecting to the server provides this path. I am managing this through sockets and I am successfully receiving this path. 3) FileReceiverThread is responsible for receiving the data from the server and constructing file from this buffer data. public class FileReceiveThread extends Thread { private String fileStorePath; private String sourceFile; private Socket socket = null; public FileReceiveThread(String ip, int port, String fileStorePath, String sourceFile) { this.fileStorePath = fileStorePath; this.sourceFile = sourceFile; try { socket = new Socket(ip, port); System.out.println("receive file thread " + socket.isConnected()); } catch (IOException ex) { ex.printStackTrace(); } } @Override public void run() { try { ObjectOutputStream oos = new ObjectOutputStream( socket.getOutputStream()); oos.writeObject(sourceFile); oos.flush(); // oos.close(); File f = new File(fileStorePath); OutputStream os = new FileOutputStream(f); BufferedOutputStream bos = new BufferedOutputStream(os); byte[] buf = new byte[8192]; int c = 0; //************ NOTE ObjectInputStream ois = new ObjectInputStream( socket.getInputStream()); while ((c = ois.read(buf, 0, buf.length)) > 0) { // ois.read(buf); bos.write(buf, 0, c); bos.flush(); // buf = new byte[8192]; } ois.close(); oos.close(); // os.close(); bos.close(); socket.close(); //Thread.sleep(500); } catch (IOException ex) { ex.printStackTrace(); } } } NOTE : Now the problem that I am facing is at the first time when the file is requested the outcome of the program is same as my expectation. I am able to transmit any size of file at first time. Now when the second file is requested (e.g. I have sent file a,b,c,d to the user and user has received file a successfully and now he is requesting file b) the program faces deadlock at this situation. It is waiting for socket's input stream. I put breakpoint and tried to debug it but it is not going in FileThread's run method second time. I could not find out the mistake here. Basically I am making a LAN Messenger which works on LAN. I am using SWT as UI framework.

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  • How important is to sacriface your free time for accomplishing goals? [closed]

    - by Darf Zon
    I was reading a book about XP programming and about agile teams. While I was reading, I saw this scenario. I've never worked with a development team (just in school). So I would like what do you opine on this situation: Your boss has asked you to deliver software in a time that can only be possible to meet the project team asking if you want to work overtime without pay. All team members have young children. Discuss whether it should accept this request from your boss or should persuade the team to give their time to the organization rather than their families. What could be significant factors in the decision? As a programmer, you are offered an upgrade as project manager, but his feeling is that you can have a more effective contribution in a technical role in one administrative. Write when you should accept that promotion. Somethimes, I sacrifice my free time for accomplishing hits at work, so it's very important to me to know your opinion base of your experience.

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  • Best practice for managing dynamic HTML modules?

    - by jt0dd
    I've been building web apps that add and remove lots of dynamic content and even structure within the page, and I'm not impressed by the method I'm using to do it. When I want to add a section or module into a position in the interface, I'm storing the html in the code, and I don't like that: if (rank == "moderator") { $("#header").append('<div class="mod_controls">' + // content, using + to implement line breaks '</div>'); } This seems like such a bad programming practice.. There must be a better way. I thought of building a function to convert a JSON structure to html, but it seems like overkill. For the functionality of the apps I'm using: Node.js JS JQuery AJAX Is there some common way to store HTML modules externally for AJAX importation?

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  • Project development without experience

    - by Raven13
    I'm a web developer who is part of a three-man team that has been tasked with a rather large and complex development project. Other than some direction and impetus from management, we're pretty much on our own to develop the new website. None of us have any project management experience nor do my two coworkers seem like they would be interested in taking on that role, so I feel like it's up to me to implement some kind of structure to the development process in order to avoid issues down the road. My question is: what can I do as a developer without project managment experience to ensure that our project gets developed successfully and avoid the pitfalls of developing a project without a plan?

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  • Noob-Friendly Guides to WSGI?

    - by Johnny McKenzie
    world! I have recently been delving into server-side code web development with python, and I have hit a brick wall; you see, I know little about server side code and HTTP (other than the v. basics with php shudder), and all of the docs for wsgi that I have found seem to be for people already well established in the field. Are there any n00b happy guides for server-side scripting (the theory of), or on wsgi out there. Http would be helpful, video tuts are also greatly appreciated. Thanks in advance.

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  • Java - learning / migrating fast

    - by Yippie-Kai-Yay
    Hello! This is not one of those questions like "How do I learn Java extremely fast, I know nothing about programming, but I heard Java is cool, yo". I have an interview for a Java Software Developer in a couple of weeks and the thing is that I think that I know C++ really good and I am somewhat good at C# (like, here I can probably answer on a lot of questions related to these languages), but I have almost zero experience with Java. I have a lot of projects written in both languages, I participiated in several open-source projects (mostly C++, though). Now, what should I do (in your opinion) to prepare myself for this Java interview. I guess migrating from C# to Java should be kind of fast, especially when you know a lot about programming in global, patterns, modern techniques and have a lot of practical experience behind you. But still two weeks is obviously not enough to get Java in-depth - so what should I focus on to have the best chances to pass the interview? Thank you.

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  • Unit Tests as a learning tool - a good idea?

    - by Ekkehard.Horner
    I'm interested in ways and means for learning (a) programming language(s) efficiently. I believe that using Unit Test concepts and infrastructure early in that process is a good thing, even better than starting with "Hello world". Why: To write a decent program even for a toy/restricted problem in a new language, you'll have to master many heterogenous concepts (control flow & variables & IO ...), you are tempted to glance over details just to get your program 'to work'. Putting (your understanding of) the facts about the new language in assertions with good descriptions (=success messages) enforces thinking thru/clearness/precision. Grouping topics and adding assertions to such groups is much easier than incorporation features from the 2. chapter of your "Learning X" book to your chapter 1 program. Why not: 'Real' Unit Tests are meant to output "1234 tests ok; 1 failure: saveWorld() chokes on negative input"; 'didactic' Unit Tests should output relevant facts about the new language like perl6 10-string.t # ### p5chop ... ok 13 - p5chop( "cbä" ) returns "ä" ok 14 - after that, victim is changed to "cb" # ### (p6) chop ... ok 27 - (p6) chop( "cbä" ) returns chopped copy: "cb" ok 18 - after that, victim is unchanged: "cbä" # ### chomp ... So (mis?)using Unit Tests may be counterproductive - practicing actions while learning you wouldn't use professionally. How: Writing 'didactic' Unit Tests in languages with lightweight testing systems (Perl 5/6) is easy; (mis?)using more elaborate systems (JUnit, CppUnit) may be not worth the effort or not suitable for a person just starting with a new language. So Is using Unit Tests as a learning tool a bad idea? Can the Unit Test tool(s) of your favourite language(s) used didactically? Should implementation details (eventually) be discussed here or over at stackoverflow.com?

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  • Question about SDLC. How to answer this?

    - by pirzada
    I have seen this asked many times in job interviews but I am still not sure how to answer this. I am a web developer for quite some time but I still have problem with explaining OOP and SDLC (Familiar with system development life cycle) . How to prepare for above 2 topics for an interview point of view. Still I use both all the time during development. I am not clear on OOP SDLC Is there any simplest answer to both of these? Thanks

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  • What quality standards to consider for software development process?

    - by Ron-Damon
    Hi, i'm looking for metrics/standards/normatives to evaluate a given "Software Development Process". I'm NOT looking to evaluate the SOFTWARE itself (trough SQUARE and such), i'm trying to evaluate software development PROCESS. So, my question is if you could give me some pointers to find this standard, considering that "evaluation objetives" would be documentation quality, how good is the customer relation, how efective is the process, etc. Very much like a ISO 9000, and like CMMI on a sense, but much lightweight and concrete and process oriented, not company oriented. Please help, i'm trying to stablish the advantages of our development process as formal as i can.

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  • C-Objective Function

    - by nimbus
    I'm unsure about how to make MWE with C-Obective, so if you need anything else let me know. I am trying running through a tutorial on building an iPhone app and have gotten stuck defining a function. I keep getting an error message saying "use of undeclared indentifer." However I believe I have initiated the function. In the view controller I have: if (scrollAmount > 0) { moveViewUp = YES; [scrollTheView:YES]; } else{ moveViewUp = NO; } with the function under it - (void)scrollTheView:(BOOL)movedUp { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.3]; CGRect rect = self.view.frame; if (movedUp){ rect.origin.y -= scrollAmount; } else { rect.origin.y += scrollAmount; } self.view.frame = rect; [UIView commitAnimations]; } I have initiated the function in the header file (that I have imported). - (void)scrollTheView:(BOOL)movedUp; Any help would be appreciated, thank you in advanced

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  • Recent programming language for AI?

    - by Eduard Florinescu
    For a few decades the programming language of choice for AI was either Prolog or LISP, and a few more others that are not so well known. Most of them were designed before the 70's. Changes happens a lot on many other domains specific languages, but in the AI domain it hadn't surfaced so much as in the web specific languages or scripting etc. Are there recent programming languages that were intended to change the game in the AI and learn from the insufficiencies of former languages?

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  • How to Mentor a Junior Developer

    - by Josh Johnson
    This title is a little broad but I may need to give a little background before I can ask my question properly. I know that similar questions have been asked here already. But in my case I'm not asking if I should be mentoring someone or if the person is a good fit for being a software developer. That is not my place to judge. I have not been asked outright, but it is apparent that myself and other fellow senior developers are to mentor the new developers that start here. I have no problem with this whatsoever and, in many cases, it lends me a fresh perspective on things and I end up learning in the process. Also, I remember how beneficial it was in the beginning of my career when someone would take some time to teach me something. When I say "new developer" they could be anywhere from fresh out of college to having a year or two of experience. Recently and in the past we've had people start here who seem to have an attitude toward development/programming which is different from mine and hard for me to reconcile; they seem to extract just enough information to get the task done but not really learn from it. I find myself going over and over the same issues with them. I understand that part of this could be a personality thing, but I feel it's my job to do my best and sort of push them out of the nest while they're under my wing, so to speak. How can I impart just enough information so that they will learn but not give so much as to solve the problem for them? Or perhaps: What's the proper response to questions that are designed to take the path of least resistance and, in essence, force them to learn instead of take the easy way out? These questions are probably more general teaching questions and don't have that much to do specifically with software development. Note: I do not get a say in what tasks they are working on. Management doles the task out and it could be anything from a very simple bug fix to starting an entire application by themselves. While this is not ideal by any means and obviously presents its own gauntlet of challenges, I feel it's a topic best left for another question. So the best I can do is help them with the problem at hand and try to help them break it down into simpler problems and also check their commit logs and point out mistakes that they made. My main objectives are to: Help them out and give them the tools they need to start becoming more self-reliant. Steer them in the right direction and break bad development habits early on. Lessen the amount of time I spend with them (the personality type described above seems to need much more one-on-one time and does not do well over IM or email. While that's generally fine, I can't always stop what I'm working on, break my stride, and help them debug an error on a moments notice; I have my own projects that need to get done).

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  • How do you stay productive when dealing with extremely badly written code?

    - by gaearon
    I don't have much experience in working in software industry, being self-taught and having participated in open source before deciding to take a job. Now that I work for money, I also have to deal with some unpleasant stuff, which is normal of course. Recently I was assigned to add logging to a large SharePoint project which is written by some programmer who obviously was learning to code on the job. After 2 years of collaboration, the client switched to our company, but the damage was done, and now somehow I need to maintain this code. Not that the code was too hard to read. Despite problems - each project has one class with several copy-pasted methods, enormous if nestings, Systems Hungarian, undisposed connections — it's still readable. However, I found myself absolutely unproductive despite working on something as simple as adding logging. Basically, I just need to go through the code step by step and add some trace calls. However, the idiocy of the code is so annoying that I get tired within 10 minutes of starting. In the beginning, I used to add using constructs, reduce nesting by reversing if's, rename the variables to readable names—but the project is large, and eventually I gave up. I know this is not the task I should be doing, but at least reducing the mess gave me some kind of psychological reward so I could keep going. Now the trick stopped working, and I still have 60% of my work to do. I started having headaches after work, and I no longer get the feeling of satisfaction I used to get - which would usually allow me to code for 10 hours straight and still feel fresh. This is not just one big rant, for I really do have an actual question: Is there a way to stay productive and not to fight the windmills? Is there some kind of psychological trick to stay focused on the task, instead of thinking “How stupid is that?” each time I see another clever trick by the previous programmer? The problem with adding logging is that I actually have to understand what the code does, and doing so hurts my brain in an unpleasant fashion.

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  • What should my "code sample" look like?

    - by thesunneversets
    I've just had quite a good phone interview (for a CakePHP-related position, not that it's especially important to the question). The interviewer seemed to be impressed with my resume and personality. At the end, though, he asked me to email him a code sample from my existing work project, "to check you're not secretly a terrible programmer, ha ha!" I'm not too worried that my code can't stand on its own two feet, but I'm very much an intermediate programmer rather than an expert. What obvious pitfalls should I make sure my code sample doesn't fall into, in case they rule me out on the spot? Secondly, and this is probably the harder part of the question to answer, what features in a code sample would be so impressive that they would instantly make you much more favourably inclined towards the programmer? All ideas or suggestions welcomed!

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  • Improving the running time of Breadth First Search and Adjacency List creation

    - by user45957
    We are given an array of integers where all elements are between 0-9. have to start from the 1st position and reach end in minimum no of moves such that we can from an index i move 1 position back and forward i.e i-1 and i+1 and jump to any index having the same value as index i. Time Limit : 1 second Max input size : 100000 I have tried to solve this problem use a single source shortest path approach using Breadth First Search and though BFS itself is O(V+E) and runs in time the adjacency list creation takes O(n2) time and therefore overall complexity becomes O(n2). is there any way i can decrease the time complexity of adjacency list creation? or is there a better and more efficient way of solving the problem? int main(){ vector<int> v; string str; vector<int> sets[10]; cin>>str; int in; for(int i=0;i<str.length();i++){ in=str[i]-'0'; v.push_back(in); sets[in].push_back(i); } int n=v.size(); if(n==1){ cout<<"0\n"; return 0; } if(v[0]==v[n-1]){ cout<<"1\n"; return 0; } vector<int> adj[100001]; for(int i=0;i<10;i++){ for(int j=0;j<sets[i].size();j++){ if(sets[i][j]>0) adj[sets[i][j]].push_back(sets[i][j]-1); if(sets[i][j]<n-1) adj[sets[i][j]].push_back(sets[i][j]+1); for(int k=j+1;k<sets[i].size();k++){ if(abs(sets[i][j]-sets[i][k])!=1){ adj[sets[i][j]].push_back(sets[i][k]); adj[sets[i][k]].push_back(sets[i][j]); } } } } queue<int> q; q.push(0); int dist[100001]; bool visited[100001]={false}; dist[0]=0; visited[0]=true; int c=0; while(!q.empty()){ int dq=q.front(); q.pop(); c++; for(int i=0;i<adj[dq].size();i++){ if(visited[adj[dq][i]]==false){ dist[adj[dq][i]]=dist[dq]+1; visited[adj[dq][i]]=true; q.push(adj[dq][i]); } } } cout<<dist[n-1]<<"\n"; return 0; }

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  • How to measure the right time to bring a new client?

    - by Byron Sommardahl
    My growing company has a team of developers working on a number of separate projects. Our developers depend on us to keep them working, and we depend on them to make our clients happy. Our projects have differing start and end dates, as you can imagine. The company's responsibility to the developers is to make sure we have clients waiting in the wings so that when one project ends, another can start. For now, finding clients is not a problem and not the topic of this question. What I'm trying to think through right now is, how can I best measure/view/evaluate the end dates of projects so that I know when I need to start courting the next client. Is there a tool that does this? If it's just a spreadsheet, what might it look like?

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  • Algorithm for Shortest Job First with Preemption

    - by Shray
    I want to implement a shortest job first routine using C# or C++. Priority of Jobs are based on their processing time. Jobs are processed using a binary (min) heap. There are three types of jobs. Type 1 is when jobs come in between every 4-6 seconds, with processing times between 4-6. Type 2 job comes in between 8-12 seconds, with processing times between 8-12. Type 3 job comes in between 24-26 seconds, with processing times between 14-16. So far, I have written the binary heap functionality, but Im kinda confused on how to start processing spawn and also the processor. #include <iostream> #include <stdlib.h> #include <time.h> using namespace std; int timecounting = 20; struct process{ int atime; int ptime; int type; }; class pque{ private: int count; public: process pheap[100]; process type1[100]; process type2[100]; process type3[100]; process type4[100]; pque(){ count = 0; } void swap(int a, int b){ process tempa = pheap[a]; process tempb = pheap[b]; pheap[b] = tempa; pheap[a] = tempb; } void add(process c){ int current; count++; pheap[count] = c; if(count > 0){ current = count; while(pheap[count/2].ptime > pheap[current].ptime){ swap(current/2, current); current = current/2; } } } void remove(){ process temp = pheap[1]; // saves process to temporary pheap[1] = pheap[count]; //takes last process in heap, and puts it at the root int n = 1; int leftchild = 2*n; int rightchild = 2*n + 1; while(leftchild < count && rightchild < count) { if(pheap[leftchild].ptime > pheap[rightchild].ptime) { if(pheap[leftchild].ptime > pheap[n].ptime) { swap(leftchild, n); n = leftchild; int leftchild = 2*n; int rightchild = 2*n + 1; } } else { if(pheap[rightchild].ptime > pheap[n].ptime) { swap(rightchild, n); n = rightchild; int leftchild = 2*n; int rightchild = 2*n + 1; } } } } void spawn1(){ process p; process p1; p1.atime = 0; int i = 0; srand(time(NULL)); while(i < timecounting) { p.atime = rand()%3 + 4 + p1.atime; p.ptime = rand()%5 + 1; p1.atime = p.atime; p.type = 1; type1[i+1] = p; i++; } } void spawn2(){ process p; process p1; p1.atime = 0; srand(time(NULL)); int i = 0; while(i < timecounting) { p.atime = rand()%3 + 9 + p1.atime; p.ptime = rand()%5 + 6; p1.atime = p.atime; p.type = 2; type2[i+1] = p; i++; } } void spawn3(){ process p; process p1; p1.atime = 0; srand(time(NULL)); int i = 0; while(i < timecounting) { p.atime = rand()%3 + 25 + p1.atime; p.ptime = rand()%5 + 11; p1.atime = p.atime; p.type = 3; type3[i+1] = p; i++; } } void spawn4(){ process p; process p1; p1.atime = 0; srand(time(NULL)); int i = 0; while(i < timecounting) { p.atime = rand()%6 + 30 + p1.atime; p.ptime = rand()%5 + 8; p1.atime = p.atime; p.type = 4; type4[i+1] = p; i++; } } void processor() { process p; process p1; p1.atime = 0; int n = 1; int n1 = 1; int n2 = 1; for(int i = 0; i<timecounting;i++) { if(type1[n].atime == i) { add(type1[n]); n++; } if(type2[n1].atime == i) { add(type1[n1]); n1++; } if(type3[n2].atime == i) { add(type1[n2]); n2++; } /* if(pheap[1].atime <= i) { while(pheap[1].atime != 0){ pheap[1].atime--; i++; } remove(); }*/ } } };

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  • There is any reason for which a delete method/field/function refactoring doesn't exist?

    - by raisercostin
    An operation in an interface is obsolete so I decided to delete it. It seems that there is no automatic support for such a "refactoring". For me is a refactoring operation since the behavior of the code will be preserved since nobody(tests, client apis) will notice that the operation was removed. In eclipse, in java code, on an method in an interface I have the following options: rename, move, change method signature, inline, extract interface, extract superclass, use supertype when possible, pull up, push down, introduce parameter objet, introduce indirection, generate declared type. There is any reason for which a delete method/field/function refactoring doesn't exist?

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  • Does the use of mongodb enhance extending/changing database driven applications?

    - by developer10214
    When an application is created which need to store data, an SQL database is used very often. So did I in a lot of asp.net applications. The resulting applications have often an ORM like the entity framework and maybe a business layer. So when such an application needs to be extended(let's say you have to add a comment property to an object), you have to change/extend the database, then the ORM and the business layer and so on. To deploy the changes you have to update the target database and the application. I know that things like code first and fluent can make this approach easier. I tried mongodb, I only used the standard driver and I had to extend some objects and all I had to do was changing the code. So it feels that such approaches are much easier to realize when using mongodb. I don't have much experience with larger applications an mongodb. I know that a SQL database or mongodb doesn't fit for all needs and both have their pros and cons. I want to know if my feeling is right, if yes I would choose rather choose mongodb than SQL database.

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  • What's the relationship between meta-circular interpreters, virtual machines and increased performance?

    - by Gomi
    I've read about meta-circular interpreters on the web (including SICP) and I've looked into the code of some implementations (such as PyPy and Narcissus). I've read quite a bit about two languages which made great use of metacircular evaluation, Lisp and Smalltalk. As far as I understood Lisp was the first self-hosting compiler and Smalltalk had the first "true" JIT implementation. One thing I've not fully understood is how can those interpreters/compilers achieve so good performance or, in other words, why is PyPy faster than CPython? Is it because of reflection? And also, my Smalltalk research led me to believe that there's a relationship between JIT, virtual machines and reflection. Virtual Machines such as the JVM and CLR allow a great deal of type introspection and I believe they make great use it in Just-in-Time (and AOT, I suppose?) compilation. But as far as I know, Virtual Machines are kind of like CPUs, in that they have a basic instruction set. Are Virtual Machines efficient because they include type and reference information, which would allow language-agnostic reflection? I ask this because many both interpreted and compiled languages are now using bytecode as a target (LLVM, Parrot, YARV, CPython) and traditional VMs like JVM and CLR have gained incredible boosts in performance. I've been told that it's about JIT, but as far as I know JIT is nothing new since Smalltalk and Sun's own Self have been doing it before Java. I don't remember VMs performing particularly well in the past, there weren't many non-academic ones outside of JVM and .NET and their performance was definitely not as good as it is now (I wish I could source this claim but I speak from personal experience). Then all of a sudden, in the late 2000s something changed and a lot of VMs started to pop up even for established languages, and with very good performance. Was something discovered about the JIT implementation that allowed pretty much every modern VM to skyrocket in performance? A paper or a book maybe?

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  • How to depict Import a file action in the Sequence diagram

    - by user970696
    Everyone says sequence diagrams are so easy but I just cannot figure this out. Basically user clicks on an 'Import from temp folder' button, the program opens a window with a list populated with filenames, user clicks on a filename, clicks on OK and the document is imported. I know the order of the actions but how to depict e.g. populating a list, or selecting an item from a list? So I assume the objects would be like: [USER] [ImportDialogWindow] [ListOfFiles:STRING] [?where to go with selected file]

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  • Segmentation fault 11 in MacOS X- C++ [migrated]

    - by Marcos Cesar Vargas Magana
    all. I have a "segmentation fault 11" error when I run the following code. The code actually compiles but I get the error at run time. //** Terror.h ** #include <iostream> #include <string> #include <map> using std::map; using std::pair; using std::string; template<typename Tsize> class Terror { public: //Inserts a message in the map. static Tsize insertMessage(const string& message) { mErrorMessages.insert( pair<Tsize, string>(mErrorMessages.size()+1, message) ); return mErrorMessages.size(); } private: static map<Tsize, string> mErrorMessages; } template<typename Tsize> map<Tsize,string> Terror<Tsize>::mErrorMessages; //** error.h ** #include <iostream> #include "Terror.h" typedef unsigned short errorType; typedef Terror<errorType> error; errorType memoryAllocationError=error::insertMessage("ERROR: out of memory."); //** main.cpp ** #include <iostream> #include "error.h" using namespace std; int main() { try { throw error(memoryAllocationError); } catch(error& err) { } } I have kind of debugging the code and the error happens when the message is being inserted in the static map member. An observation is that if I put the line: errorType memoryAllocationError=error::insertMessage("ERROR: out of memory."); inside the "main()" function instead of at global scope, then everything works fine. But I would like to extend the error messages at global scope, not at local scope. The map is defined static so that all instances of "error" share the same error codes and messages. Do you know how can I get this or something similar. Thank you very much.

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  • Somewhere to get inspiration - Pair up the creative with the tech

    - by Morten Bergfall
    I am a somewhat green developer; some work experience, last year of school. As most of you, I am constantly working on an assortment of personal projects. Since my mind often has a somewhat drifting characteristic; I am not always able to keep the projects in check. After some time they all exhibit the moral fiber of Vikings, harlots and chain-letter-knitters. This includes constant forking, round-abouting, eating of school assignments of rather mundane, and hence pretty yawn-inducing, specifications, and of course quite a bit of gathering of folder dust. Well, on to my question....is there a place, forum... or something with the purpose of linking people with ideas to the people actually being able to bring said ideas to life? Of course, I know of the professional ones, like rent-a-coder and such. And there seem to be a lot of open source projects available for participation. What I'm looking for doesn't really fit into any of those categories....the form would be somewhat like rent-a-coder, but this is ideas&inspiration, not bubble-sort-my-quarterly-for-a-buck. The possibilities for developing bonds, spicy code, and plain old fun seem quite possible.As I see it, the main benefit would be that we (that is the tech-flipside of the proverbial eCoin) get something worthwhile to do, rather than squeeze the last creative grain out of our code-heavy brains.To give it some perspective...: My last project consists of an absurd jQuery-plugin that includes animated png-robots migrating from Google Earth to drag a html-element of your choosing onto the map, where it gets color, for so to be dragged back by this poorly animated robot.... Often, the line between the creative and the tech is blurred, to say the least. I wouldn't think that would be a problem. Think someone who has developed a nifty little windows application, then sees possibility for a broader use, perhaps some sort of networking functionality. This fellow sadly lacks the skill to implememet this. So he, she or it would then seek a developer with the know-how and they could complete this project together. So, do any of you know of such a place, or can nudge in the right direction? And yes, I understand completely that I should be dedicating myself to doing school work, or applying for mundane developer positions, so please.... :-) UPDATE Sadly, I'm situated in Oslo, Norway, and the number of developers are somewhat limited...and I have had quite some ahem personality issues with the ones who are available ;-) So I feel I must go deeper; search the multitude of the web...

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  • Game Trees Conceptual Question

    - by Chris Corbin
    I am struggling to conceptually understand a question in a programming assignment for an algorithms class. The problem is dealing with a fictitious 2 player game, named Easy. The rules of the game are simple; each player may chose one of 4 integers {0-3} after which that integer is not available for the other player. The catch is, a player picks {0} it means they quit. The objective is for Player 1 to get {1} and Player 2 to get {2}, in which case they may win, however if both or neither succeed, then the game ends in a draw. I have been asked to draw the game tree for Easy, showing all nodes, which they explained as 4! = 24. Labeling the edges, which represent moves (selecting a number) and the leaves with who won (1 means Player 1 won, -1 means Player 2 won, and 0 means a tie). I have drawn out a game tree, which I believe is correct, however I am not 100% certain hence I am asking the question. My game tree only has 16 leaves. I am thinking that when a player picks {0}, and then quits, the game tree stops there? I don't see how it is possible to get to 24 leaves? Any help would be greatly appreciate, and if you need more information I would be happy to provide it. Thanks

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