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  • How to make a plot from summaryRprof?

    - by ThorDivDev
    This is a question for an university assignment. I was given three algorithms to calculate the GCD that I already did. My problem is getting the Rprof results to a plot so I can compare them side by side. From what little understanding I have about Rprof, summaryRprof and plot is that Rprof is used like this: Rprof() #To start #functions here Rprof(NULL) #TO end summaryRprof() # to print results I understand that plot has many different types of inputs, x and y values and something called a data frame which I assume is a fancy word for table. and to draw different lines and things I need to use this: http://www.harding.edu/fmccown/r/ what I cant figure out is how to get the summaryRprof results to the plot() function. > Rprof(filename="RProfOut2.out", interval=0.0001) > gcdBruteForce(10000, 33) [1] 1 > gcdEuclid(10000, 33) [1] 1 > gcdPrimeFact(10000, 33) [1] 1 > Rprof(NULL) > summaryRprof() ?????plot???? I have been reading on stack overflow that and other sites that I can also try to use profr and proftools although I am not very clear on the usage. The only graph I have been able to make is one using plot(system.time(gcdFunction(10,100))) As always any help is appreciated.

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  • Tree iterator, can you optimize this any further?

    - by Ron
    As a follow up to my original question about a small piece of this code I decided to ask a follow up to see if you can do better then what we came up with so far. The code below iterates over a binary tree (left/right = child/next ). I do believe there is room for one less conditional in here (the down boolean). The fastest answer wins! The cnt statement can be multiple statements so lets make sure this appears only once The child() and next() member functions are about 30x as slow as the hasChild() and hasNext() operations. Keep it iterative <-- dropped this requirement as the recursive solution presented was faster. This is C++ code visit order of the nodes must stay as they are in the example below. ( hit parents first then the children then the 'next' nodes). BaseNodePtr is a boost::shared_ptr as thus assignments are slow, avoid any temporary BaseNodePtr variables. Currently this code takes 5897ms to visit 62200000 nodes in a test tree, calling this function 200,000 times. void processTree (BaseNodePtr current, unsigned int & cnt ) { bool down = true; while ( true ) { if ( down ) { while (true) { cnt++; // this can/will be multiple statesments if (!current->hasChild()) break; current = current->child(); } } if ( current->hasNext() ) { down = true; current = current->next(); } else { down = false; current = current->parent(); if (!current) return; // done. } } }

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  • Zend Framework-where do calls to my methods go? Controller of Model?

    - by Joel
    Hi guys, I'm confused about exactly what I should have in my controller and what in my method. Specifically, I have this in the action method: public function upcomingshowsAction() { $gcal = $this->_validateCalendarConnection(); $uncleanedFeedArray = $this->_getCalendarFeed($gcal); $finishedFeedArray = $this->_cleanFeed($uncleanedFeedArray); $this->view->googleArray = $finishedFeedArray; } And then (incorrectly I know), I have my methods still in the bottom of my controller. So what I'm wondering, is for those methods in the upcomingshowsAction method, should all the actual methods just be in one model and then I'd have something like this: public function upcomingshowsAction() { $finishedFeedArray = new Application_Model_calendarModelPage(); $this->view->googleArray = $finishedFeedArray; } And then something like this in the model: class Application_Model_CalendarModelPage { $gcal = $this->_validateCalendarConnection(); $uncleanedFeedArray = $this->_getCalendarFeed($gcal); $finishedFeedArray = $this->_cleanFeed($uncleanedFeedArray); public functions { ... ... ... } } Am I on the right track here? Thanks!

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  • using threads in menu options

    - by vbNewbie
    I have an app that has a console menu with 2/3 selections. One process involves uploading a file and performing a lengthy search process on its contents, whilst another process involves SQL queries and is an interactive process with the user. I wish to use threads to allow one process to run and the menu to offer the option for the second process to run. However you cannot run the first process twice. I have created threads and corrected some compilation errors but the threading options are not working correctly. Any help appreciated. main... Dim tm As Thread = New Thread(AddressOf loadFile) Dim ts As Thread = New Thread(AddressOf reports) .... While Not response.Equals("3") Try Console.Write("Enter choice: ") response = Console.ReadLine() Console.WriteLine() If response.Equals("1") Then Console.WriteLine("Thread 1 doing work") tm.SetApartmentState(ApartmentState.STA) tm.IsBackground = True tm.Start() response = String.Empty ElseIf response.Equals("2") Then Console.WriteLine("Starting a second Thread") ts.Start() response = String.Empty End If ts.Join() tm.Join() Catch ex As Exception errormessage = ex.Message End Try End While I realize that a form based will be easier to implement with perhaps just calling different forms to handle the processes.But I really dont have that option now since the console app will be added to api later. But here are my two processes from the menu functions. Also not sure what to do with the boolean variabel again as suggested below. Private Sub LoadFile() Dim dialog As New OpenFileDialog Dim response1 As String = Nothing Dim filepath As String = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) dialog.InitialDirectory = filepath If dialog.ShowDialog() = DialogResult.OK Then fileName = dialog.FileName ElseIf DialogResult.Cancel Then Exit Sub End If Console.ResetColor() Console.Write("Begin Search -- Discovery Search, y or n? ") response1 = Console.ReadLine() If response1 = "y" Then Search() ElseIf response1 = "n" Then Console.Clear() main() End If isRunning = False End Sub and the second one Private Shared Sub report() Dim rptGen As New SearchBlogDiscovery.rptGeneration Console.WriteLine("Tread Process started") rptGen.main() Console.WriteLine("Thread Process ended") isRunning = False End Sub

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  • Blocking HTML and Javascript from being displayed on my site

    - by Tim Powell
    I am working on this new social networking site. One of it's various functions is posting. You can post to Facebook and my site, or Twitter and my site. That being said, I couldn't help but try and post HTML as I was testing sql injection. When I did, I noticed that there where ways to manipulate the site to, for instance, using a element to completely screw up the CSS design, or redirect a user to another site using javascript. That being said, I want to make my site a safe environment for my users... not a site that is used to distribute computer viruses, porn, and other things that might make someone tend to stay off of my site. When I searched this topic, I found ways to "strip" the HTML out of the $post variable before submitting it to the database. However, I would just like to make it so you can post any text, including HTML and Javascript, without the browser interpreting it as "run this..." code: I want to display it as plane text. I've seen it on Facebook, and when I looked at it the source code of a post, it showed <, /, and as regular text. I tried "dissecting" Facebook's source code, but found nothing. I have tried using tags such as <pre> and <code>, but because of the lack of ability to style and control them, I gave up and went back to just allowing HTML. Please, anyone who knows how to do this, please help me out. Thanks in advance, TP

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  • Jquery + Prototype Question

    - by mikeyhill
    I recently inherited a site which is botched in all sorts of ways. I'm more of a php guy and initially the js was working just fine. I made no changes to the javascript or the any of the include files but after making a few content edits I'm getting errors from firebug. a.dispatchEvent is not a function emptyFunction()protot...ects.js (line 2) emptyFunction()protot...ects.js (line 2) fireContentLoadedEvent()protot...ects.js (line 2) [Break on this error] var Prototype={Version:'1.6.0.2',Brows...pe,Enumerable);Element.addMethods(); protot...ects.js (line 2) this.m_eTarget.setStyle is not a function [Break on this error] this.m_eTarget.setStyle( { position: 'relative', overflow:'hidden'} ); protot...ects.js (line 43) uncaught exception: [Exception... "Component returned failure code: 0x80070057 (NS_ERROR_ILLEGAL_VALUE)" nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)" location: "JS frame :: js/prototype_effects.js :: anonymous :: line 2" data: no] Googling around I found several posts that sometimes jquery+prototype don't play well and rearranging the scripts could fix this issue, however being that I didn't touch these sections I'm not sure where I even need to begin to debug. The previous developer incorporated a head.inc file which loads up prototype, scriptaculous and then many of the pages are in a sub-template loading up jquery for functions like lightbox. The site is temp housed at http://dawn.mikeyhill.com Any help is appreciated.

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  • Making alarm clock with NSTimer

    - by Alex G
    I just went through trying to make an alarm clock app with local notifications but that didn't do the trick because I needed an alert to appear instead of it going into notification centre in iOS 5+ So far I've been struggling greatly with nstimer and its functions so I was wondering if anyone could help out. I want when the user selects a time (through UIDatePicker, only time) for an alert to be displayed at exactly this time. I have figured out how to get the time from UIDatePicker but I do not know how to properly set the firing function of nstimer. This is what I have attempted so far, if anyone could help... be much appreciated. Thank you Example (it keeps going into the function every second opposed to a certain time I told it too... not what I want): NSDate *timestamp; NSDateComponents *comps = [[[NSDateComponents alloc] init] autorelease]; [comps setHour:2]; [comps setMinute:8]; timestamp = [[NSCalendar currentCalendar] dateFromComponents:comps]; NSTimer *f = [[NSTimer alloc] initWithFireDate:timestamp interval:0 target:self selector:@selector(test) userInfo:nil repeats:YES]; NSRunLoop *runner = [NSRunLoop currentRunLoop]; [runner addTimer:f forMode: NSDefaultRunLoopMode];

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  • What is a recommended Android utility class collection?

    - by Sebastian Roth
    I often find myself writing very similar code across projects. And more often than not, I copy stuff over from old projects. Things like: Create images with round corners read density into a static variable & re-use. 4 lines.. disable / hide multiple views / remote views at once. Example: } public static void disableViews(RemoteViews views, int... ids) { for (int id : ids) { views.setInt(id, SET_VISIBILITY, View.GONE); } } public static void showViews(RemoteViews views, int... ids) { for (int id : ids) { views.setInt(id, SET_VISIBILITY, View.VISIBLE); } } I'd love to package these kind of functions into 1 letter / 2 letter class names, i.e. V.showViews(RemoteViews views, int... ids) would be easy to write & remember I hope. I'm searching for Github recommendations, links and if nothing is found, I perhaps will start a small project on github to collect.

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  • C++ reference variables

    - by avd
    I have these two functions (with Point2D & LineVector (has 2 Point2D member variables) classes and SQUARE macro predefined) inline float distance(const Point2D &p1,const Point2D &p2) { return sqrt(SQUARE(p2.getX()-p1.getX())+SQUARE(p2.getY()-p1.getY())); } inline float maxDistance(const LineVector &lv1,const LineVector &lv2) { return max(distance(lv1.p1,lv2.p2),distance(lv1.p2,lv2.p1)); } but it gives compilation error in maxDistance() function (line 238) saying: /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator_base_types.h: In instantiation of `std::iterator_traits<Point2D>': quadrilateral.cpp:238: instantiated from here /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator_base_types.h:129: error: no type named `iterator_category' in `class Point2D' /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator_base_types.h:130: error: no type named `value_type' in `class Point2D ' /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator_base_types.h:131: error: no type named `difference_type' in `class Point2D' /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator_base_types.h:132: error: no type named `pointer' in `class Point2D' /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_iterator_base_types.h:133: error: no type named `reference' in `class Point2D' Please suggest what is the error?

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  • Passing System classes as constructor parameters

    - by mcl
    This is probably crazy. I want to take the idea of Dependency Injection to extremes. I have isolated all System.IO-related behavior into a single class so that I can mock that class in my other classes and thereby relieve my larger suite of unit tests of the burden of worrying about the actual file system. But the File IO class I end up with can only be tested with integration tests, which-- of course-- introduces complexity I don't really want to deal with when all I really want to do is make sure my FileIO class calls the correct System.IO stuff. I don't need to integration test System.IO. My FileIO class is doing more than simply wrapping System.IO functions, every now and then it does contain some logic (maybe this is the problem?). So what I'd like is to be able to test my File IO class to ensure that it makes the correct system calls by mocking the System.IO classes themselves. Ideally this would be as easy as having a constructor like so: public FileIO( System.IO.Directory directory, System.IO.File file, System.IO.FileStream fileStream ) { this.Directory = directory; this.File = file; this.FileStream = fileStream; } And then calling in methods like: public GetFilesInFolder(string folderPath) { return this.Directory.GetFiles(folderPath) } But this doesn't fly since the System.IO classes in question are static classes. As far as I can tell they can neither be instantiated in this way or subclassed for the purposes of mocking.

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  • variables in abstract classes C++

    - by wyatt
    I have an abstract class CommandPath, and a number of derived classes as below: class CommandPath { public: virtual CommandResponse handleCommand(std::string) = 0; virtual CommandResponse execute() = 0; virtual ~CommandPath() {} }; class GetTimeCommandPath : public CommandPath { int stage; public: GetTimeCommandPath() : stage(0) {} CommandResponse handleCommand(std::string); CommandResponse execute(); }; All of the derived classes have the member variable 'stage'. I want to build a function into all of them which manipulates 'stage' in the same way, so rather than defining it many times I thought I'd build it into the parent class. I moved 'stage' from the private sections of all of the derived classes into the protected section of CommandPath, and added the function as follows: class CommandPath { protected: int stage; public: virtual CommandResponse handleCommand(std::string) = 0; virtual CommandResponse execute() = 0; std::string confirmCommand(std::string, int, int, std::string, std::string); virtual ~CommandPath() {} }; class GetTimeCommandPath : public CommandPath { public: GetTimeCommandPath() : stage(0) {} CommandResponse handleCommand(std::string); CommandResponse execute(); }; Now my compiler tells me for the constructor lines that none of the derived classes have a member 'stage'. I was under the impression that protected members are visible to derived classes? The constructor is the same in all classes, so I suppose I could move it to the parent class, but I'm more concerned about finding out why the derived classes aren't able to access the variable. Also, since previously I've only used the parent class for pure virtual functions, I wanted to confirm that this is the way to go about adding a function to be inherited by all derived classes.

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  • How to map keys in vim differently for different kinds of buffers

    - by Yogesh Arora
    The problem i am facing is that i have mapped some keys and mouse events for seraching in vim while editing a file. But those mappings impact the functionality if the quickfix buffer. I was wondering if it is possible to map keys depending on the buffer in which they are used. EDIT - I am adding more info for this question Let us consider a scenario. I want to map <C-F4> to close a buffer/window. Now this behavior could depend on a number of things. If i am editing a buffer it should just close that buffer without changing the layout of the windows. I am using buffkil plugin for this. It does not depend on extension of file but on the type of buffer. I saw in vim documentation that there are unlisted and listed buffer. So if it is listed buffer it should close using bufkill commands. If it is not a listed buffer it should use <c-w>c command to close buffer and changing the window layout. I am new at writing vim functions/scripts, can someone help me getting started on this

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  • Handling large datasets with PHP/Drupal

    - by jo
    Hi all, I have a report page that deals with ~700k records from a database table. I can display this on a webpage using paging to break up the results. However, my export to PDF/CSV functions rely on processing the entire data set at once and I'm hitting my 256MB memory limit at around 250k rows. I don't feel comfortable increasing the memory limit and I haven't got the ability to use MySQL's save into outfile to just serve a pre-generated CSV. However, I can't really see a way of serving up large data sets with Drupal using something like: $form = array(); $table_headers = array(); $table_rows = array(); $data = db_query("a query to get the whole dataset"); while ($row = db_fetch_object($data)) { $table_rows[] = $row->some attribute; } $form['report'] = array('#value' => theme('table', $table_headers, $table_rows); return $form; Is there a way of getting around what is essentially appending to a giant array of arrays? At the moment I don't see how I can offer any meaningful report pages with Drupal due to this. Thanks

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  • calling constructor of the class in the destructor of the same class

    - by dicaprio
    Experts !! I know this question is one of the lousy one , but still I dared to open my mind , hoping I would learn from all. I was trying some examples as part of my routine and did this horrible thing, I called the constructor of the class from destructor of the same class. I don't really know if this is ever required in real programming , I cant think of any real time scenarios where we really need to call functions/CTOR in our destructor. Usually , destructor is meant for cleaning up. If my understanding is correct, why the compiler doesn't complain ? Is this because it is valid for some good reasons ? If so what are they ? I tried on Sun Forte, g++ and VC++ compiler and none of them complain about it. using namespace std; class test{ public: test(){ cout<<"CTOR"<<endl; } ~test() {cout<<"DTOR"<<endl; test(); }};

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  • Why should I abstract my data layer?

    - by Gazillion
    OOP principles were difficult for me to grasp because for some reason I could never apply them to web development. As I developed more and more projects I started understanding how some parts of my code could use certain design patterns to make them easier to read, reuse, and maintain so I started to use it more and more. The one thing I still can't quite comprehend is why I should abstract my data layer. Basically if I need to print a list of items stored in my DB to the browser I do something along the lines of: $sql = 'SELECT * FROM table WHERE type = "type1"';' $result = mysql_query($sql); while($row = mysql_fetch_assoc($result)) { echo '<li>'.$row['name'].'</li>'; } I'm reading all these How-Tos or articles preaching about the greatness of PDO but I don't understand why. I don't seem to be saving any LoCs and I don't see how it would be more reusable because all the functions that I call above just seem to be encapsulated in a class but do the exact same thing. The only advantage I'm seeing to PDO are prepared statements. I'm not saying data abstraction is a bad thing, I'm asking these questions because I'm trying to design my current classes correctly and they need to connect to a DB so I figured I'd do this the right way. Maybe I'm just reading bad articles on the subject :) I would really appreciate any advice, links, or concrete real-life examples on the subject!

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  • Flowcharting functional programming languages

    - by Sadface
    Flowcharting. This ancient old practice that's been in use for over 1000 years now, being forced upon us poor students, without any usefulness (or so do I think). It might work well with imperative, sequentially running languages, but what about my beloved functional programming? Sadly, I'm forced to create a flow chart for my programm (that is written in Haskell). I imagine it being easy for something like this: main :: IO () main = do someInput <- getLine let upped = map toUpper someInput putStrLn upped Which is just 3 sequenced steps, fetching data, uppercasing it, outputting it. Things look worse this time: main :: IO () main = do someInput <- fmap toUpper getLine putStrLn someInput Or like this: main :: IO () main = interact (map toUpper) Okay, that was IO, you can handle that like an imperative language. What about pure functions? An actual example: onlyMatching :: String -> [FilePath] -> [FilePath] onlyMatching ext = filter f where f name = lower ('.' : ext) == (lower . takeExtension $ name) lower = map toLower How would you flowchart that last one?

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  • session timeout prompt asp.net

    - by renathy
    The application I am using is implementing some session timeout prompt using jquery. There is a timer that counts and if there is no user activity after predefined X minutes it shows user prompt (Your session will end soon... Continue or Logout). It uses the approach found here - http://www.codeproject.com/Articles/227382/Alert-Session-Time-out-in-ASP-Net. However, this doesn't work if user opens new tab: 1) User logs in, timer starts counting user inactivity's. 2) User clicks some link that opens in new window (for example, in our case it is a long report running). Second tab is active, there is some response (crossbacks / postbacks that doesn't end session). 3) Second browser tab is active, there is some activity that doesn't end session. 4) However, first browser tab is inactive and counter is "thinking" that session should be closed, it displays appropriate message and then logout user. This is not what we want. So the given approach is just some session timeout fix, but if user is active in another tab, then application will logout user anyway. That is not the desired thing. We have a Report Page. It functions so that it opens report in a new tab/window. And it could be run quite long. Report section take care of some callbacks, so session wont end in this tab. However, it would end in the second tab.

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  • How to Store and Retrieve Images Using SQL Server (Server Management Studio)

    - by Joe Majewski
    I am having difficulties when trying to insert files into a SQL Server database. I'll try to break this down as best as I can: What data type should I be using to store image files (jpeg/png/gif/etc)? Right now my table is using the image data type, but I am curious if varbinary would be a better option. How would I go about inserting the image into the database? Does Microsoft SQL Server Management Studio have any built in functions that allow insertions of files into tables? If so, how is that done? Also, how could this be done through the use of an HTML form with PHP handling the input data and placing it into the table? How would I fetch the image from the table and display it on the page? I understand how to SELECT the cell's contents, but how would I go about translating that into a picture. Would I have to have a header(Content type: image/jpeg)? I have no problem doing any of these things with MySQL, but the SQL Server environment is still new to me, and I am working on a project for my job that requires the use of stored procedures to grab various data. Any and all help is appreciated.

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  • Programmatically setup a PEAP connection in Windows Mobile

    - by tomlog
    I have been working on this for a few days and this is doing my head in: Our application is built using the .NET Compact Framework 2.0 and running on Windows Mobile 5 & 6 devices. We can set the WLAN connection of the device programmatically using the Wireless Zero Config functions (described here: msdn.microsoft.com/en-us/library/ms894771.aspx), most notably the WZCSetInterface function which we pinvoke from our application. This works fine for WEP and WPA-PSK connections. In a recent effort to add support for WPA2 networks we decided to modify the code. We have successfully added support for WPA2 which uses a certificate for the 802.1x authentication by setting the correct registry settings before calling WZCSetInterface. Now we want to do the same for WPA2 using PEAP (MS-CHAPv2) authentication. When manually creating such a connection in Windows Mobile the user will be prompted to enter the domain/user/password details. In our application we will have those details stored locally and want to do this all programmatically without any user intervention. So I thought going along the same route as the certificate authentication, setting the correct registry entries before calling WZCSetInterface. The registry settings we set are: \HKCU\Comm\EAP\Config\[ssid name] Enable8021x = 1 (DWORD) LastAuthSuccessful = 1 (DWORD) EapTypeId = 25 (DWORD) Identity = "domain\username" (string) Password = binary blob containing the password that is encrypted using the CryptProtectData function (described here: msdn.microsoft.com/en-us/library/ms938309.aspx) But when these settings are set and I call WZCSetInterface with the correct parameters, it still prompts me with the User Logon dialog asking for the domain/username/password. Has anyone got an idea what I need to do to prevent the password dialog from appearing and connect straight away with the settings stored in the registry?

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  • Intelligent search and generation of Java code, preferrably using Python?

    - by Ipsquiggle
    Basically, I do lots of one-off code generation, large-scale refactorings, etc. etc. in Java. My tool language of choice is Python, but I'll take whatever solutions you can offer. Here is a simplified illustration of what I would like, in a pseudocode Generating an implementation for an interface search within my project: for each Interface as iName: write class(name=iName+"Impl", implements=iName) search within the body of iName: for each Method as mName: write method(name=mName, body="// TODO implement this...") Basically, the tool I'm searching for would allow me to: parse files according to their Java structure ("search for interfaces") search for words contextualized by language elements and types ("variables of type SomeClass", "doStuff() method calls on SomeClass instances") to run searches with structural context ("within the body of the current result") easily replace or generate code (with helpers to generate, as above, or functions for replacing, "rename the interface to Foo", "insert the line Blah.Blah()", etc.) The point is, I don't want to spend a lot of time writing these things, as they are usually throwaway. But sometimes I need something just a little smarter than what grep offers. It wouldn't be too hard to write up a simplistic version of this, but if I'm going to use something like this at all, I'd expect it to be robust. Any suggestions of a tool/library that will help me accomplish this?

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  • Within a DLL, how is the function table structured?

    - by Willi Ballenthin
    I've been looking into the implementation of a device library that doesn't explicitly support my operating system. In particular, I have a disassembled DLL, and a fair amount of supporting source code. Now, how is the function table/export table structured? My understanding is that the first structure of the .data section is a table of VRAs. Next is a table of strings linked by index to that first address table. This makes sense to me, as a linker could translate between symbols and addresses. How do functions referenced by ordinals fit into this picture? How does one know which function has such and such ordinal number, and how does the linker resolve this? In other words, given that some other DLL imports SOME_LIBRARY_ordinal_7, how does the linker know which function to work with? Thanks, all! edit More information... Im working with the FTDI libraries, and would like to resolve which function is being invoked. In particular, I see something like: extern FTD2XX_Ordinal_28: near how might I go about determining which function is being referenced, and how does the linker do this?

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  • MySQL Datefields: duplicate or calculate?

    - by Konerak
    We are using a table with a structure imposed upon us more than 10 years ago. We are allowed to add columns, but urged not to change existing columns. Certain columns are meant to represent dates, but are put in different format. Amongst others: * CHAR(6): YYMMDD * CHAR(6): DDMMYY * CHAR(8): YYYYMMDD * CHAR(8): DDMMYYYY * DATE * DATETIME Since we now would like to do some more complex queries, using advanced date functions, my manager proposed to d*uplicate those problem columns* to a proper FORMATTED_OLDCOLUMNNAME column using a DATE or DATETIME format. Is this the way to go? Couldn't we just use the STR_TO_DATE function each time we accessed the columns? To avoid every query having to copy-paste the function, I could still work with a view or a stored procedure, but duplicating data to avoid recalculation sounds wrong. Solutions I see (I guess I prefer 2.2.1) 1. Physically duplicate columns 1.1 In the same table 1.1.1 Added by each script that does a modification (INSERT/UPDATE/REPLACE/...) 1.1.2 Maintained by a trigger on each modification 1.2 In a separate table 1.2.1 Added by each script that does a modification (INSERT/UPDATE/REPLACE/...) 1.2.2 Maintained by a trigger on each modification 2. On-demand transformation 2.1 Each query has to perform the transformation 2.1.1 Using copy-paste in the source code 2.1.2 Using a library 2.1.3 Using a STORED PROCEDURE 2.2 A view performs the transformation 2.2.1 A separate table replacing the entire table 2.2.2 A separate table just adding the date-fields for the primary keys Am I right to say it's better to recalculate than to store? And would a view be a good solution?

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  • C++ Design Question on template types

    - by user231536
    I have a templated class template <typename T> class MyContainerClass For types to be substituted for T, it has to satisfy many requirements: for example, get_id(), int data(), etc. Obviously none of the fundamental types (PODs) are substitutable. One way I can provide this is via wrappers for the PODs that provide these functions. Is this an acceptable way? Another way would be to change the template to: template < typename T, typename C=traits<T> > class MyContainerClass and inside MyContainerClass, call traits::data() instead of data() on T objects. I will specialize traits<int>, traits<const char *> etc. Is this good design ? How do I design such a traits class (completely static methods or allow for inheritance) ? Or are the wrapper classes a good solution? What other alternatives are there?

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  • Fortran pointer as an argument to interface procedure

    - by icarusthecow
    Im trying to use interfaces to call different subroutines with different types, however, it doesnt seem to work when i use the pointer attribute. for example, take this sample code MODULE ptr_types TYPE, abstract :: parent INTEGER :: q END TYPE TYPE, extends(parent) :: child INTEGER :: m END TYPE INTERFACE ptr_interface MODULE PROCEDURE do_something END INTERFACE CONTAINS SUBROUTINE do_something(atype) CLASS(parent), POINTER :: atype ! code determines that this allocation is correct from input ALLOCATE(child::atype) WRITE (*,*) atype%q END SUBROUTINE END MODULE PROGRAM testpass USE ptr_types CLASS(child), POINTER :: ctype CALL ptr_interface(ctype) END PROGRAM This gives error Error: There is no specific subroutine for the generic 'ptr_interface' at (1) however if i remove the pointer attribute in the subroutine it compiles fine. Now, normally this wouldnt be a problem, but for my use case i need to be able to treat that argument as a pointer, mainly so i can allocate it if necessary. Any suggestions? Mind you I'm new to fortran so I may have missed something edit: forgot to put the allocation in the parents subroutine, the initial input is unallocated EDIT 2 this is my second attempt, with caller side casting MODULE ptr_types TYPE, abstract :: parent INTEGER :: q END TYPE TYPE, extends(parent) :: child INTEGER :: m END TYPE TYPE, extends(parent) :: second INTEGER :: meow END TYPE CONTAINS SUBROUTINE do_something(this, type_num) CLASS(parent), POINTER :: this INTEGER type_num IF (type_num == 0) THEN ALLOCATE (child::this) ELSE IF (type_num == 1) THEN ALLOCATE (second::this) ENDIF END SUBROUTINE END MODULE PROGRAM testpass USE ptr_types CLASS(child), POINTER :: ctype SELECT TYPE(ctype) CLASS is (parent) CALL do_something(ctype, 0) END SELECT WRITE (*,*) ctype%q END PROGRAM however this still fails. in the select statement it complains that parent must extend child. Im sure this is due to restrictions when dealing with the pointer attribute, for type safety, however, im looking for a way to convert a pointer into its parent type for generic allocation. Rather than have to write separate allocation functions for every type and hope they dont collide in an interface or something. hopefully this example will illustrate a little more clearly what im trying to achieve, if you know a better way let me know

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  • How can I write a function template for all types with a particular type trait?

    - by TC
    Consider the following example: struct Scanner { template <typename T> T get(); }; template <> string Scanner::get() { return string("string"); } template <> int Scanner::get() { return 10; } int main() { Scanner scanner; string s = scanner.get<string>(); int i = scanner.get<int>(); } The Scanner class is used to extract tokens from some source. The above code works fine, but fails when I try to get other integral types like a char or an unsigned int. The code to read these types is exactly the same as the code to read an int. I could just duplicate the code for all other integral types I'd like to read, but I'd rather define one function template for all integral types. I've tried the following: struct Scanner { template <typename T> typename enable_if<boost::is_integral<T>, T>::type get(); }; Which works like a charm, but I am unsure how to get Scanner::get<string>() to function again. So, how can I write code so that I can do scanner.get<string>() and scanner.get<any integral type>() and have a single definition to read all integral types? Update: bonus question: What if I want to accept more than one range of classes based on some traits? For example: how should I approach this problem if I want to have three get functions that accept (i) integral types (ii) floating point types (iii) strings, respectively.

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