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  • Pascals Triangle by recursion

    - by Olpers
    Note : My Class Teacher gave me this question as an assignment... I am not asked to do it but please tell me how to do it with recursion Binomial coefficients can be calculated using Pascal's triangle: 1 n = 0 1 1 1 2 1 1 3 3 1 1 4 6 4 1 n = 4 Each new level of the triangle has 1's on the ends; the interior numbers are the sums of the two numbers above them. Task: Write a program that includes a recursive function to produce a list of binomial coefficients for the power n using the Pascal's triangle technique. For example, Input = 2 Output = 1 2 1 Input = 4 Output = 1 4 6 4 1 done this So Far but tell me how to do this with recursion... #include<stdio.h> int main() { int length,i,j,k; //Accepting length from user printf("Enter the length of pascal's triangle : "); scanf("%d",&length); //Printing the pascal's triangle for(i=1;i<=length;i++) { for(j=1;j<=length-i;j++) printf(" "); for(k=1;k<i;k++) printf("%d",k); for(k=i;k>=1;k--) printf("%d",k); printf("\n"); } return 0; }

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  • BinaryFormatter in C# a good way to read files?

    - by mr-pac
    I want to read a binary file which was created outside of my program. One obvious way in C# to read a binary file is to define class representing the file and then use a BinaryReader and read from the file via the Read* methods and assign the return values to the class properties. What I don't like with the approach is that I manually have to write code that reads the file, although the defined structure represents how the file is stored. I also have to keep the order correct when I read. After looking a bit around I came across the BinaryFormatter which can automatically serialize and deserialze object in binary format. One great advantage would be that I can read and also write the file without creating additional code. However I wonder if this approach is good for files created from other programs on not just serialized .NET objects. Take for example a graphics format file like BMP. Would it be a good idea to read the file with a BinaryFormatter or is it better to manually and write via BinaryReader and BinaryWriter? Or are there any other approaches which suit better? I'am not looking for concrete examples but just for an advice what is the best way to implement that.

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  • MS Excel automation without macros in the generated reports. Any thoughts?

    - by ezeki77
    Hello! I know that the web is full of questions like this one, but I still haven't been able to apply the answers I can find to my situation. I realize there is VBA, but I always disliked having the program/macro living inside the Excel file, with the resulting bloat, security warnings, etc. I'm thinking along the lines of a VBScript that works on a set of Excel files while leaving them macro-free. Now, I've been able to "paint the first column blue" for all files in a directory following this approach, but I need to do more complex operations (charts, pivot tables, etc.), which would be much harder (impossible?) with VBScript than with VBA. For this specific example knowing how to remove all macros from all files after processing would be enough, but all suggestions are welcome. Any good references? Any advice on how to best approach external batch processing of Excel files will be appreciated. Thanks! PS: I eagerly tried Mark Hammond's great PyWin32 package, but the lack of documentation and interpreter feedback discouraged me.

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  • C: Global ,Static variables understanding

    - by pavun_cool
    Hi All, In following program . I have one doubt. I have declared one global variable . I am printing the address of the global variable in the function . It is giving me same address when I am not changing the value of global . If I did any changes in the global variables It is giving me different address why...........? Like that it is happening for static also. #include<stdio.h> int global=10 ; // Global variables void function(); main() { global=20; printf ( " %p \n" , global ) ; printf ( " Val: %d\n", global ) ; function(); new(); } void function() { global=30; printf ( " %p \n" , global ) ; printf ( " Val: %d\n", global ) ; } Thanks.

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  • Which isolation level should I use for the following insert-if-not-present transaction?

    - by Steve Guidi
    I've written a linq-to-sql program that essentially performs an ETL task, and I've noticed many places where parallelization will improve its performance. However, I'm concerned about preventing uniquness constraint violations when two threads perform the following task (psuedo code). Record CreateRecord(string recordText) { using (MyDataContext database = GetDatabase()) { Record existingRecord = database.MyTable.FirstOrDefault(record.KeyPredicate()); if(existingRecord == null) { existingRecord = CreateRecord(recordText); database.MyTable.InsertOnSubmit(existingRecord); } database.SubmitChanges(); return existingRecord; } } In general, this code executes a SELECT statement to test for record existance, followed by an INSERT statement if the record doesn't exist. It is encapsulated by an implicit transaction. When two threads run this code for the same instance of recordText, I want to prevent them from simultaneously determining that the record doesn't exist, thereby both attempting to create the same record. An isolation level and explicit transaction will work well, except I'm not certain which isolation level I should use -- Serializable should work, but seems too strict. Is there a better choice?

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  • How do you search a document for a string in c++?

    - by Jeff
    Here's my code so far: #include<iostream> #include<string> #include<fstream> using namespace std; int main() { int count = 0; string fileName; string keyWord; string word; cout << "Please make sure the document is in the same file as the program, thank you!" << endl << "Please input document name: " ; getline(cin, fileName); cout << endl; cout << "Please input the word you'd like to search for: " << endl; cin >> keyWord; cout << endl; ifstream infile(fileName.c_str()); while(infile.is_open()) { getline(cin,word); if(word == keyWord) { cout << word << endl; count++; } if(infile.eof()) { infile.close(); } } cout << count; } I'm not sure how to go to the next word, currently this infinite loops...any recommendation? Also...how do I tell it to print out the line that that word was on? Thanks in advance!

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  • Modify existing struct alignment in Visual C++

    - by Crend King
    Is there a way to modify the member alignment of an existing struct in Visual C++? Here is the background: I use an 3rd-party library, which uses several structs. To fill up the structs, I pass the address of the struct instance to some functions. Unfortunately, the functions only returns unaligned buffer, so that data of some members are always wrong. /Zp is out of choice, since it breaks the other parts of the program. I know #pragma pack modifies the alignment of the following struct, but I do not want to copy the structs into my code, for the definitions in the library might change in the future. Sample code: test.h: struct am_aligned { BYTE data1[10]; ULONG data2; }; test.cpp: include "test.h" // typedef alignment(1) struct am_aligned am_unaligned int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) { char buffer[20] = {}; for (int i = 0; i < sizeof(unaligned_struct); i++) { buffer[i] = i; } am_aligned instance = *(am_aligned*) buffer; return 0; } instance.data2 is 0x0f0e0d0c, while 0x0d0c0b0a is desired. The commented line does not work of course. Thanks for help!

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  • MVVM and avoiding Monolithic God object

    - by bufferz
    I am in the completion stage of a large project that has several large components: image acquisition, image processing, data storage, factory I/O (automation project) and several others. Each of these components is reasonably independent, but for the project to run as a whole I need at least one instance of each component. Each component also has a ViewModel and View (WPF) for monitoring status and changing things. My question is the safest, most efficient, and most maintainable method of instantiating all of these objects, subscribing one class to an Event in another, and having a common ViewModel and View for all of this. Would it best if I have a class called God that has a private instance of all of these objects? I've done this in the past and regretted it. Or would it be better if God relied on Singleton instances of these objects to get the ball rolling. Alternatively, should Program.cs (or wherever Main(...) is) instantiate all of these components, and pass them to God as parameters and then let Him (snicker) and His ViewModel deal with the particulars of running this projects. Any other suggestions I would love to hear. Thank you!

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  • PHP driven site needs password change.

    - by Drea
    I have inherited a website that needs the password changed that accesses the database. I can see that there are two tables within the database but neither of them have username or password info. The previous web guy moved out of the country and can't be reached. I am not up-to-speed enough to figure this out. I have gone through all the files to try and find the answer but can't get it. It's hosted by goDaddy.com and I have changed the passwords there but it didn't change this login info. www.executivehomerents.com/cpanel <-this brings up the prompt for the username & password which I won't give out but the page only gives you 5 choices and none of them deal with changing the password. They are simply to change the data in the tables. If you go to: http://www.websitedatabases.com/ <=this is the company that the PHPMagic program was purchased from-- They have no contact number. Here is another page that might help: http://www.executivehomerents.com/cpanel/dbinput/setup.php I don't think I'll get an answer to this but it's worth a try... thanks.

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  • Trying to make a plugin system in C++

    - by Pirate for Profit
    I'm making a task-based program that needs to have plugins. Tasks need to have properties which can be easily edited, I think this can be done with Qt's Meta-Object Compiler reflection capabilities (I could be wrong, but I should be able to stick this in a QtPropertyBrowser?) So here's the base: class Task : public QObject { Q_OBJECT public: explicit Task(QObject *parent = 0) : QObject(parent){} virtual void run() = 0; signals: void taskFinished(bool success = true); } Then a plugin might have this task: class PrinterTask : public Task { Q_OBJECT public: explicit PrinterTask(QObject *parent = 0) : Task(parent) {} void run() { Printer::getInstance()->Print(this->getData()); // fictional emit taskFinished(true); } inline const QString &getData() const; inline void setData(QString data); Q_PROPERTY(QString data READ getData WRITE setData) // for reflection } In a nutshell, here's what I want to do: // load plugin // find all the Tasks interface implementations in it // have user able to choose a Task and edit its specific Q_PROPERTY's // run the TASK It's important that one .dll has multiple tasks, because I want them to be associated by their module. For instance, "FileTasks.dll" could have tasks for deleting files, making files, etc. The only problem with Qt's plugin setup is I want to store X amount of Tasks in one .dll module. As far as I can tell, you can only load one interface per plugin (I could be wrong?). If so, the only possible way to do accomplish what I want is to create a FactoryInterface with string based keys which return the objects (as in Qt's Plug-And-Paint example), which is a terrible boilerplate that I would like to avoid. Anyone know a cleaner C++ plugin architecture than Qt's to do what I want? Also, am I safely assuming Qt's reflection capabilities will do what I want (i.e. able to edit an unknown dynamically loaded tasks' properties with the QtPropertyBrowser before dispatching)?

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  • File.Move, why do i get a FileNotFoundException? The file exist...

    - by acidzombie24
    Its extremely weird since the program is iterating the file! outfolder and infolder are both in H:/ my external HD using windows 7. The idea is to move all folders that only contain files with the extention db and svn-base. When i try to move the folder i get an exception. VS2010 tells me it cant find the folder specified in dir. This code is iterating through dir so how can it not find it! this is weird. string []theExt = new string[] { "db", "svn-base" }; foreach (var dir in Directory.GetDirectories(infolder)) { bool hit = false; if (Directory.GetDirectories(dir).Count() > 0) continue; foreach (var f in Directory.GetFiles(dir)) { var ext = Path.GetExtension(f).Substring(1); if(theExt.Contains(ext) == false) { hit = true; break; } } if (!hit) { var dst = outfolder + "\\" + Path.GetFileName(dir); File.Move(dir, outfolder); //FileNotFoundException: Could not find file dir. } } }

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  • Organizing a String based on maxlength of each field

    - by pringlesinn
    I've made a program that makes my life easier by reading a class and creating methods like these below: //Ferramentas Parâmetros acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Pesquisa", "ppaParametrosList", null, TipoAcessoBean.TELA)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Gravar", "ppaParametrosHome", "persist", TipoAcessoBean.ACAO)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Atualizar Dados", "ppaParametrosHome", "update", TipoAcessoBean.ACAO)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Leitura", "ppaParametrosHome", "find", TipoAcessoBean.ACAO)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Excluir", "ppaParametrosHome", "remove", TipoAcessoBean.ACAO)); Don't worry about the language. It won't make it harder to understand what I need to make. I want to organize it to be shown like this: //Ferramentas Parâmetros acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Pesquisa" , "ppaParametrosList", null , TipoAcessoBean.TELA)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Gravar" , "ppaParametrosHome", "persist", TipoAcessoBean.ACAO)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Atualizar Dados", "ppaParametrosHome", "update" , TipoAcessoBean.ACAO)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Leitura" , "ppaParametrosHome", "find" , TipoAcessoBean.ACAO)); acessos.add(new AcessoBean("Ferramentas", "Parâmetros", "Parâmetros", "Excluir" , "ppaParametrosHome", "remove" , TipoAcessoBean.ACAO)); I'm reading the whole class with Scanner, but once I read, I save only the things I want in a Collection containing this things above. How can I make a method to complete with blank to make it organized?

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  • What's the best way to get a bunch of rows from MySQL if you have an array of integer primary keys?

    - by Evan P.
    I have a MySQL table with an auto-incremented integer primary key. I want to get a bunch of rows from the table based on an array of integers I have in memory in my program. The array ranges from a handful to about 1000 items. What's the most efficient query syntax to get the rows? I can think of a few: "SELECT * FROM thetable WHERE id IN (1, 2, 3, 4, 5)" (this is what I do now) "SELECT * FROM thetable where id = 1 OR id = 2 OR id = 3" Multiple queries of the form "SELECT * FROM thetable WHERE id = 1". Probably the most friendly to the query cache, but expensive due to having lots of query parsing. A union, like "SELECT * FROM thetable WHERE id = 1 UNION SELECT * FROM thetable WHERE id = 2 ..." I'm not sure if MySQL caches the results of each query; it's also the most verbose format. I think using the NoSQL interface in MySQL 5.6+ would be the most efficient way to do this, but I'm not yet up to MySQL 5.6.

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  • Does everything after my try statement have to be encompassed in that try statement to access variab

    - by Mithrax
    I'm learning java and one thing I've found that I don't like, is generally when I have code like this: import java.util.*; import java.io.*; public class GraphProblem { public static void main(String[] args) { if (args.length < 2) { System.out.println("Error: Please specify a graph file!"); return; } FileReader in = new FileReader(args[1]); Scanner input = new Scanner(in); int size = input.nextInt(); WeightedGraph graph = new WeightedGraph(size); for(int i = 0; i < size; i++) { graph.setLabel(i,Character.toString((char)('A' + i))); } for(int i = 0; i < size; i++) { for(int j = 0; j < size; j++) { graph.addEdge(i, j, input.nextInt()); } } // .. lots more code } } I have an uncaught exception around my FileReader. So, I have to wrap it in a try-catch to catch that specific exception. My question is does that try { } have to encompass everything after that in my method that wants to use either my FileReader (in) or my Scanner (input)? If I don't wrap the whole remainder of the program in that try statement, then anything outside of it can't access the in/input because it may of not been initialized or has been initialized outside of its scope. So I can't isolate the try-catch to just say the portion that intializes the FileReader and close the try statement immediately after that. So, is it the "best practice" to have the try statement wrapping all portions of the code that are going to access variables initialized in it? Thanks!

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  • How to read the network file.

    - by ungalnanban
    I'm using Net::FTP for getting a remote hosted file. I want to read the file. I don't want to get the file from the remote host to my host (localhost), but I need to read the file content only. Is there any module to do this? use strict; use warnings; use Data::Dumper; use Net::FTP; my $ftp = Net::FTP->new("192.168.8.20", Debug => 0) or die "Cannot connect to some.host.name: $@"; $ftp->login("root",'root123') or die "Cannot login ", $ftp->message; $ftp->cwd("SUGUMAR") or die "Cannot change working directory ", $ftp->message; $ftp->get("Testing.txt") or die "get failed ", $ftp->message; $ftp->quit; In the above sample program, I get the file from 192.168.8.20. Then I will read the file and do the operation. I don't want to place the file in my local system. I need to read the Testing.txt file content.

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  • Haskell Cons Operator (:)

    - by Carson Myers
    I am really new to Haskell (Actually I saw "Real World Haskell" from O'Reilly and thought "hmm, I think I'll learn functional programming" yesterday) and I am wondering: I can use the construct operator to add an item to the beginning of a list: 1 : [2,3] [1,2,3] I tried making an example data type I found in the book and then playing with it: --in a file data BillingInfo = CreditCard Int String String | CashOnDelivery | Invoice Int deriving (Show) --in ghci $ let order_list = [Invoice 2345] $ order_list [Invoice 2345] $ let order_list = CashOnDelivery : order_list $ order_list [CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, ...- etc... it just repeats forever, is this because it uses lazy evaluation? -- EDIT -- okay, so it is being pounded into my head that let order_list = CashOnDelivery:order_list doesn't add CashOnDelivery to the original order_list and then set the result to order_list, but instead is recursive and creates an infinite list, forever adding CashOnDelivery to the beginning of itself. Of course now I remember that Haskell is a functional language and I can't change the value of the original order_list, so what should I do for a simple "tack this on to the end (or beginning, whatever) of this list?" Make a function which takes a list and BillingInfo as arguments, and then return a list? -- EDIT 2 -- well, based on all the answers I'm getting and the lack of being able to pass an object by reference and mutate variables (such as I'm used to)... I think that I have just asked this question prematurely and that I really need to delve further into the functional paradigm before I can expect to really understand the answers to my questions... I guess what i was looking for was how to write a function or something, taking a list and an item, and returning a list under the same name so the function could be called more than once, without changing the name every time (as if it was actually a program which would add actual orders to an order list, and the user wouldn't have to think of a new name for the list each time, but rather append an item to the same list).

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  • Timeout Exceptions

    - by Raihan Jamal
    This is my below code, I am confuse why this thing is happening. In this code getLocationByIpTimeout is a method in which I am passing two things- one is the ip address and second is the timeout. So I will get the timeout exception if the response is not getting back in under 5 ms. So when I ran this below code, I am getting few timeout exceptions but the most important thing that I am confuse is if I am getting timeout exceptions (time taken to get the response is greater than 5 ms) then why the program is entering in that if loop in which I am having difference 5. What can be the possible reason for this? It is because of catch block?? Any suggestions will be appreciated. long runs =10000; long difference = 0; while(runs > 0) { String ipAddress = generateIPAddress(); long start_time = System.nanoTime(); try { resp = PersonalizationGeoLocationServiceClientHelper.getLocationByIpTimeout(ipAddress, 5); } catch (TimeoutException e) { System.out.println("Timeout Exception"); } long end_time = System.nanoTime(); if(resp == null || (resp.getLocation() == null)) { difference = 0; } else if(resp.getLocation() != null) { difference = (end_time - start_time)/1000000; } if(difference> 5) { System.out.println("Debug"); } }

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  • are C functions declared in <c____> headers gauranteed to be in the global namespace as well as std?

    - by Evan Teran
    So this is something that I've always wondered but was never quite sure about. So it is strictly a matter of curiosity, not a real problem. As far as I understand, what you do something like #include <cstdlib> everything (except macros of course) are declared in the std:: namespace. Every implementation that I've ever seen does this by doing something like the following: #include <stdlib.h> namespace std { using ::abort; // etc.... } Which of course has the effect of things being in both the global namespace and std. Is this behavior guaranteed? Or is it possible that an implementation could put these things in std but not in the global namespace? The only way I can think of to do that would be to have your libstdc++ implement every c function itself placing them in std directly instead of just including the existing libc headers (because there is no mechanism to remove something from a namespace). Which is of course a lot of effort with little to no benefit. The essence of my question is, is the following program strictly conforming and guaranteed to work? #include <cstdio> int main() { ::printf("hello world\n"); }

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  • C# Linq to SQL connection string (newbie)

    - by Chris'o
    i am a new linq to sql learner and this is my very first attempt to create a data viewer program. The idea is simple, i'd like to create a software that is able to view content of a table in a database. That's it. I got an early problem here already and i have seen many tutes and articles online but I still cant fix the bug. Here is my code: static void Main(string[] args) { string cs = "Data Source=localhost;Initial Catalog=somedb;Integrated Security=SSPI;"; var db = new DataClasses1DataContext(cs); db.Connection.Open(); foreach (var b in db.Mapping.GetTables()) Console.WriteLine(b.TableName); Console.ReadKey(true); } When I tried to check db.connection.equals(null); it returns false, so i thought i have connected successfully to the database since there is no error at all. But the code above doesn't print anything out to the screen. I kind of lost and don't know what's going on here. Does anyone know what is going wrong here?

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  • How to add a gwt widget to a gwt Composite already visible at runtime using MVP?

    - by mary4pfc
    Hi! I'm building an application whose menus depend on user roles. Once user is logged in and, therefore, her roles are known, I want to create the Hyperlinks related to the user and add them to the menu. I'm using MVP. Here's my code for the presenter: public class AdminMenuAreaPresenter extends WidgetPresenter<AdminMenuAreaPresenter.Display> { public interface Display extends WidgetDisplay{ public void addLink(String link); } private DispatchAsync dispatcher; private SessionManager sessionManager; @Inject public AdminMenuAreaPresenter(AdminMenuAreaPresenter.Display display, EventBus bus, DispatchAsync dispatcher, SessionManager sessionManager){ super(display, bus); this.dispatcher = dispatcher; this.sessionManager = sessionManager; this.bind(); } @Override protected void onBind() { super.onBind(); registerHandler(eventBus.addHandler(LoginEvent.TYPE, new LoginEventHandler() { @Override public void onLogin(LoginEvent event) { display.addLink("register user"); } })); } @Override protected void onUnbind() { // TODO Auto-generated method stub } @Override protected void onRevealDisplay() { // TODO Auto-generated method stub } } And here's the View: public class AdminMenuAreaView extends Composite implements AdminMenuAreaPresenter.Display{ private VerticalPanel vPanel; private Hyperlink registerUserLink; public AdminMenuAreaView(){ vPanel = new VerticalPanel(); initWidget(vPanel); } @Override public Widget asWidget() { return this; } public void addLink(String s){ registerUserLink = new Hyperlink(s, "this is new target"); this.vPanel.add(registerUserLink); registerUserLink.setVisible(true); } public HasClickHandlers getRegisterUserLink(){ return registerUserLink; } What am I doing wrong? Flow program goes throgh the addLink() method, but nothing is added to the view either dom document. Thank you.

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  • Parsing: How to make error recovery in grammars like " a* b*"?

    - by Lavir the Whiolet
    Let we have a grammar like this: Program ::= a* b* where "*" is considered to be greedy. I usually implement "*" operator naively: Try to apply the expression under "*" to input one more time. If it has been applied successfully then we are still under current "*"-expression; try to apply the expression under "*" one more time. Otherwise we have reached next grammar expression; put characters parsed by expression under "*" back into input and proceed with next expression. But if there are errors in input in any of "a*" or "b*" part such a parser will "think" that in position of error both "a*" and "b*" have finished ("let's try "a"... Fail! OK, it looks like we have to proceed to "b*". Let's try "b"... Fail! OK, it looks like the string should have been finished...). For example, for string "daaaabbbbbbc" it will "say": "The string must end at position 1, delete superflous characters: daaaabbbbbbc". In short, greedy "*" operator becomes lazy if there are errors in input. How to make "*" operator to recover from errors nicely?

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  • Access denied from another thread

    - by Lobuno
    Hello! In a program I span a thread ("the working thread"). Hera I copy some files write some data to a database and eventually, delete some other files or directories. Everything works fine. The problem is now, that I decided to move the deleting operation to some other thread. So the working thread now copies the files or directories, writes to the database, and , if there is a need to delete some other files this thread spans another thread and that second thread deleted the needed files or directories. The problem is that,the deletion used to work 100% when done in the working thread, now when the same is done in the secondary thread, I sometimes get an "Access denied" error and the files cannot be deleted. And no, the working thread is definitely NOT acceding the files and directories to delete at this moment. Sometimes (but not always) the main thread is impersonating some user, so if needed , the deleting thread is also running under impersonation just to grant the needed permissions to delete the files, so that should not be the problem. Anybody has a clue why this could be happening?

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  • How to achieve interaction between GUI class with logic class

    - by volting
    Im new to GUI programming, and haven't done much OOP. Im working on a basic calculator app to help me learn GUI design and to brush up on OOP. I understand that anything GUI related should be kept seperate from the logic, but Im unsure how to implement interaction between logic an GUI classes when needed i.e. basically passing variables back and forth... Im using TKinter and when I pass a tkinter variable to my logic it only seems to hold the string PY_VAR0. def on_equal_btn_click(self): self.entryVariable.set(self.entryVariable.get() + "=") calculator = Calc(self.entryVariable) self.entryVariable.set(calculator.calculate()) Im sure that im probably doing something fundamentally wrong and probabaly really stupid, I spent a considerable amount of time experimenting (and searching for answers online) but Im getting no where. Any help would be appreciated. Thanks, V The Full Program (well just enough to show the structure..) import Tkinter class Gui(Tkinter.Tk): def __init__(self,parent): Tkinter.Tk.__init__(self,parent) self.parent = parent self.initialize() def initialize(self): self.grid() self.create_widgets() """ grid config """ #self.grid_columnconfigure(0,weight=1,pad=0) self.resizable(False, False) def create_widgets(self): """row 0 of grid""" """Create Text Entry Box""" self.entryVariable = Tkinter.StringVar() self.entry = Tkinter.Entry(self,width=30,textvariable=self.entryVariable) self.entry.grid(column=0,row=0, columnspan = 3 ) self.entry.bind("<Return>", self.on_press_enter) """create equal button""" equal_btn = Tkinter.Button(self,text="=",width=4,command=self.on_equal_btn_click) equal_btn.grid(column=3, row=0) """row 1 of grid""" """create number 1 button""" number1_btn = Tkinter.Button(self,text="1",width=8,command=self.on_number1_btn_click) number1_btn.grid(column=0, row=1) . . . def on_equal_btn_click(self): self.entryVariable.set(self.entryVariable.get() + "=") calculator = Calc(self.entryVariable) self.entryVariable.set(calculator.calculate()) class Calc(): def __init__(self, equation): self.equation = equation def calculate(self): #TODO: parse string and calculate... return self.equation if __name__ == "__main__": app = Gui(None) app.title('Calculator') app.mainloop()

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  • An algo for generating code callgraphs

    - by Shrey
    I am working on a project which requires generating some metrices of a code (it can be C/C++/Java/Python). One of the metrices can be that I create a callgraph after parsing the code entered (the programs are expected to be small - probably under 1000L). As of now, I am looking for a way to create a program (it can be C/Python) which can take as input a file (C/C++/Python/Java) and then create a textual output containing approximate calling sequence as well as tokens in the code file. As of now, I have looked at some other tools which do the same thing - like splint, pylint, codeviz etc. So, I have two ways of solving my problem: Read and understand the algorithm these tools use (tokenization-graph generation etc) Or, have a basic algo (something like very high level steps) and then sit down to create each of them as I want them to be. I know, re-inventing the wheel is not a good idea, but, I would still like to give option (2) a shot. Only issue is, currently I am a blank. My question: Does any one have any knowhow about how to create code graphs? Any hints as to what I should do? Any top levels steps which I can follow? Thanks a lot.

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  • C++ Namespaces & templates question

    - by Kotti
    Hi! I have some functions that can be grouped together, but don't belong to some object / entity and therefore can't be treated as methods. So, basically in this situation I would create a new namespace and put the definitions in a header file, the implementation in cpp file. Also (if needed) I would create an anonymous namespace in that cpp file and put all additional functions that don't have to be exposed / included to my namespace's interface there. See the code below (probably not the best example and could be done better with another program architecture, but I just can't think of a better sample...) Sample code (header) namespace algorithm { void HandleCollision(Object* object1, Object* object2); } Sample code (cpp) #include "header" // Anonymous namespace that wraps // routines that are used inside 'algorithm' methods // but don't have to be exposed namespace { void RefractObject(Object* object1) { // Do something with that object // (...) } } namespace algorithm { void HandleCollision(Object* object1, Object* object2) { if (...) RefractObject(object1); } } So far so good. I guess this is a good way to manage my code, but I don't know what should I do if I have some template-based functions and want to do basically the same. If I'm using templates, I have to put all my code in the header file. Ok, but how should I conceal some implementation details then? Like, I want to hide RefractObject function from my interface, but I can't simply remove it's declaration (just because I have all my code in a header file)... The only approach I came up with was something like: Sample code (header) namespace algorithm { // Is still exposed as a part of interface! namespace impl { template <typename T> void RefractObject(T* object1) { // Do something with that object // (...) } } template <typename T, typename Y> void HandleCollision(T* object1, Y* object2) { impl::RefractObject(object1); // Another stuff } } Any ideas how to make this better in terms of code designing?

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