z order - Page 599 - Developer IT

using usort to re-arrange multi-dimension array

- by Thomas Bennett

I have a large array: [0] => stdClass Object ( [products] => Array ( [0] => stdClass Object ( [body_html] => bodyhtml [published_at] => 2012-12-16T23:59:18+00:00 [created_at] => 2012-12-16T11:30:24+00:00 [updated_at] => 2012-12-18T10:52:14+00:00 [vendor] => Name [product_type] => type ) [1] => stdClass Object ( [body_html] => bodyhtml [published_at] => 2012-12-16T23:59:18+00:00 [created_at] => 2012-12-16T10:30:24+00:00 [updated_at] => 2012-12-18T10:52:14+00:00 [vendor] => Name [product_type] => type ) ) ) and I need to arrange each of the products by the date they where created... I've tried and failed all kinds of usort, ksort, uksort techniques to try and get it to be in a specific order (chronological) but failed! any guidance would be most appreciated

Read the article

MySQL query against pseudo-key-value pair data in WordPress custom query

- by andrevr

I'm writing a custom WordPress query to use some of the data which the Woothemes Diarise theme creates. Diarise is an event planner theme with calendar blah, blah... and uses custom fields to store the event start and end dates in WP custom fields in the *wp_postmeta* table, which implements a key-value store. So for each post in the "event" category, there are 2 records in *wp_postmeta*, named *event_start_date* and *event_end_date* that I'm interested in. The task is to compare a tourist's arrival and departure dates with the start and end dates of events, yielding a what's on list of events available. We thought we'd killed it with a grand flash of logic, that goes like this: Disregard any event that ends before the tourist arrives, and any that begin after the departure date. I wrote this query: SELECT wposts.* FROM wp_posts wposts LEFT JOIN wp_postmeta wpostmeta ON wposts.ID = wpostmeta.post_id LEFT JOIN wp_term_relationships ON (wposts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) WHERE wp_term_taxonomy.taxonomy = 'category' AND wp_term_taxonomy.term_id IN(3,4) AND ( wpostmeta.meta_key = 'event_start_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) > '2010-07-31' ) ) AND ( wpostmeta.meta_key = 'event_end_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) < '2010-05-01' ) ) ) ORDER BY wpostmeta.meta_value ASC And, of course it returns no records. The problem I believe is in the dual reference to wpostmeta.meta_key, but how to get around that?

Read the article

In perl, how can I call a method whose name I have in a string?

- by Ryan Thompson

I'm trying to write some abstract code for searching through a list of similar objects for the first one whose attributes match specific values. In order to do this, I need to call a bunch of accessor methods and check all their values one by one. I'd like to use an abstraction like this: sub verify_attribute { my ($object, $attribute_method, $wanted_value) = @_; if ( call_method($object, $attribute_method) ~~ $wanted_value ) { return 1; } else { return; } } Then I can loop through a hash whose keys are accessor method names and whose values are the values I'm looking for for those attributes. For example, if that hash is called %wanted, I might use code like this to find the object I want: my $found_object; FINDOBJ: foreach my $obj (@list_of_objects) { foreach my $accessor (keys %wanted) { next FINDOBJ unless verify_attribute($obj, $accessor, $wanted{$accessor}); } # All attrs verified $found_object = $obj; last FINDOBJ; } Of course, the only problem is that call_method does not exsit. Or does it? How can I call a method if I have a string containing its name? Or is there a better solution to this whole problem?

Read the article

How to add an array value to the middle of an associative array?

- by Citizen

Lets say I have this array: $array = array('a'=>1,'z'=>2,'d'=>4); Later in the script, I want to add the value 'c'=>3 before 'z'. How can I do this? EDIT: Yes, the order is important. When I run a foreach() through the array, I do NOT want this newly added value added to the end of the array. I am getting this array from a mysql_fetch_assoc() EDIT 2: The keys I used above are placeholders. Using ksort() will not achieve what I want. EDIT 3: http://www.php.net/manual/en/function.array-splice.php#88896 accomplishes what I'm looking for but I'm looking for something simpler. EDIT 4: Thanks for the downvotes. I gave feedback to your answers and you couldn't help, so you downvoted and requested to close the question because you didn't know the answer. Thanks. EDIT 5: Take a sample db table with about 30 columns. I get this data using mysql_fetch_assoc(). In this new array, after column 'pizza' and 'drink', I want to add a new column 'full_dinner' that combines the values of 'pizza' and 'drink' so that when I run a foreach() on the said array, 'full_dinner' comes directly after 'drink'

Read the article

Can I use Eclipse JDT to create new 'working copies' of source files in memory only?

- by RYates

I'm using Eclipse JDT to build a Java refactoring platform, for exploring different refactorings in memory before choosing one and saving it. I can create collections of working copies of the source files, edit them in memory, and commit the changes to disk using the JDT framework. However, I also want to generate new 'working copy' source files in memory as part of refactorings, and only create the corresponding real source file if I commit the working copy. I have seen various hints that this is possible, e.g. http://www.jarvana.com/jarvana/view/org/eclipse/jdt/doc/isv/3.3.0-v20070613/isv-3.3.0-v20070613.jar!/guide/jdt%5Fapi%5Fmanip.htm says "Note that the compilation unit does not need to exist in the Java model in order for a working copy to be created". So far I have only been able to create a new real file, i.e. ICompilationUnit newICompilationUnit = myPackage.createCompilationUnit(newName, "package piffle; public class Baz{private int i=0;}", false, null); This is not what I want. Does anyone know how to create a new 'working copy' source file, that does not appear in my file system until I commit it? Or any other mechanism to achieve the same thing?

Read the article

How to Inserting message into View that depends on session value. ASP.NET MVC. Best practice

- by Andrew Florko

User have to populate multistep questionnaire web-forms and step messages depend on the option chosen by user at the very beginning. Messages are stored in web.config file. I use asp.net mvc project, strong typed views and keep business logic separated from controller in static class. I don't want to make business logic dependency on web.config. Well, I have to insert message into view that depends on session value. There are at least 2 options how to implement this: View model has property that is populated in controller/businessLogic and rendered in view like <%: Model.HelpMessage1 %>. I have to pass web.config values from controller to businessLogic that makes business logic methods signature too complex. I don't want to make configuration source abstract (in order to let business logic read configuration values from its methods directly) also. Create static helper class that is called from view like <%: ViewHelper.HelpMessage1(Model.Option1) %>. But in this case logic what to show seems to be separated into two classes: business logic & viewHelper. What will you suggest? Thank you in advance!

Read the article

Android - Adding external library to project

- by mmontalbo

Hi, I am having a lot of trouble adding the WEKA library to a project I am working on. I have followed several tutorials that explain how to do this including the Android Developers guide: http://developer.android.com/guide/appendix/faq/commontasks.html#addexternallibrary and several of the postings on SO. I have created a folder in my project with the weka.jar file, created a new library (adding the weka.jar file to the library) and included this library in my build path. I have also added the library under the "Order and Export" tab in the project properties. I have also tried importing the jar file so that the actual contents of the jar are extracted into a directory in my project. The end result of all of this is that my project is able to build correctly and without error, but when it comes time to run my code on the emulator I get the following exception: 04-10 22:52:21.051: ERROR/dalvikvm(582): Could not find class 'weka.classifiers.trees.J48', referenced from method edu.usc.student.composure.classifier.GaitClassifierImpl. with J48 being the class I reference in my code. Does anyone have any additional suggestions that I may have overlooked? Thanks!

Read the article

How does the receiver of a cipher text know the IV used for encryption?

- by PatrickL

If a random IV is used in encrypting plain text, how does the receiver of the cipher text know what the IV is in order to decrypt it? This is a follow-up question to a response to the previous stackoverflow question on IVs here. The IV allows for plaintext to be encrypted such that the encrypted text is harder to decrypt for an attacker. Each bit of IV you use will double the possibilities of encrypted text from a given plain text. The point is that the attacker doesn't know what the IV is and therefore must compute every possible IV for a given plain text to find the matching cipher text. In this way, the IV acts like a password salt. Most commonly, an IV is used with a chaining cipher (either a stream or block cipher). ... So, if you have a random IV used to encrypt the plain text, how do you decrypt it? Simple. Pass the IV (in plain text) along with your encrypted text. Wait. You just said the IV is randomly generated. Then why pass it as plain text along with the encrypted text?

Read the article

Integrated Windows authentication in IIS causing ADO.NET failure

- by TrueWill

We have a .NET 3.5 Web Service running under IIS. It must use identity impersonate="true" and Integrated Windows authentication in order to authenticate to third-party software. In addition, it connects to a SQL Server database using ADO.NET and SQL Server Authentication (specifying a fixed User ID and Password in the connection string). Everything worked fine until the database was moved to another SQL Server. Then the Web Service would throw the following exception: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) This error only occurs if identity impersonate is true in the Web.config. Again, the connection string hasn't changed and it specifies the user. I have tested the connection string and it works, both under the impersonated account and under the service account (and from both the remote machine and the server). What needs to be changed to get this to work with impersonation?

Read the article

Rotating png images using css in IE

- by Ernest Shulikovski

Here is a mockup for something called "Diversity Disc": http://diversity.iest.pl/ It is just three disks that you can rotate and read "results". I am using there just four png images, and rotate using jQuery f.i: $.fn.rleft = function() { return this.animate({ rotate: '-=45deg' }); }; It works not so bad in most new browser. But in all versions of IE things go terribly wrong. There is problem with rotation, and with png: after rotation, there is happening something very ugly with alpha transparency of those images. So my question is, is this possible to make it work in IE 8 and 7 (and, more or less IE 6?). If no I will be forced to order it in Flash. But I would like first to try to do it using just css and javascript (svg?). So what I am doing wrong? Do you have any tips, for using different technology, or js library? Thank you in advance for any answers.

Read the article

Variable length argument list - How to understand we retrieved the last argument?

- by hkBattousai

I have a Polynomial class which holds coefficients of a given polynomial. One of its overloaded constructors is supposed to receive these coefficients via variable argument list. template <class T> Polynomial<T>::Polynomial(T FirstCoefficient, ...) { va_list ArgumentPointer; va_start(ArgumentPointer, FirstCoefficient); T NextCoefficient = FirstCoefficient; std::vector<T> Coefficients; while (true) { Coefficients.push_back(NextCoefficient); NextCoefficient = va_arg(ArgumentPointer, T); if (/* did we retrieve all the arguments */) // How do I implement this? { break; } } m_Coefficients = Coefficients; } I know that we usually pass an extra parameter which tells the recipient method the total number of parameters, or we pass a sentimental ending parameter. But in order to keep thing short and clean, I don't prefer passing an extra parameter. Is there any way of doing this without modifying the method signature in the example?

Read the article

Double null-terminated string

- by wengseng

I need to format a string to be double null-terminated string in order to use SHFileOperation. Interesting part is i found one of the following working, but not both: // Example 1 CString szDir(_T("D:\\Test")); szDir = szDir + _T('\0') + _T('\0'); // Example 2 CString szDir(_T("D:\\Test")); szDir = szDir + _T("\0\0"); //Delete folder SHFILEOPSTRUCT fileop; fileop.hwnd = NULL; // no status display fileop.wFunc = FO_DELETE; // delete operation fileop.pFrom = szDir; // source file name as double null terminated string fileop.pTo = NULL; // no destination needed fileop.fFlags = FOF_NOCONFIRMATION|FOF_SILENT; // do not prompt the user fileop.fAnyOperationsAborted = FALSE; fileop.lpszProgressTitle = NULL; fileop.hNameMappings = NULL; int ret = SHFileOperation(&fileop); Does anyone has idea on this? Is there other way to append double-terminated string?

Read the article

Sorting arrays in java

- by user360706

Write a static method in Java : public static void sortByFour (int[] arr) That receives as a paramater an array full of non-negative numbers (zero or positive) and sorts the array in the following way : In the beginning of the array all the numbers that devide by four without a remainder will appear. After them all the numbers in the array that devide by 4 with a remainder of 1 will appear. After them all the numbers in the array that devide by 4 with a remainder of 2 will appear. In the end of the array all the rest numbers (those who divide by 4 with the remainder 3) will appear. (The order of the numbers in each group doesn't matter) The method must be the most efficient it can. This is what I wrote but unfortunately it doesn't work well... :( public static void swap( int[] arr, int left, int right ) { int temp = arr[left]; arr[left] = arr[right]; arr[right] = temp; } public static void sortByFour( int[] arr ) { int left = 0; int right = ( arr.length - 1 ); int mid = ( arr.length / 2 ); while ( left < right ) { if ( ( arr[left] % 4 ) > ( arr[right] % 4 ) ) { swap( arr, left, right ); right--; } if ( ( arr[left] % 4 ) == ( arr[right] % 4 ) ) left++; else left++; } } Can someone please help me by fixing my code so that it will work well or rewriting it?

Read the article

Cocoa NSTextField Drag & Drop Requires Subclass... Really?

- by ipmcc

Until today, I've never had occasion to use anything other than an NSWindow itself as an NSDraggingDestination. When using a window as a one-size-fits-all drag destination, the NSWindow will pass those messages on to its delegate, allowing you to handle drops without subclassing NSWindow. The docs say: Although NSDraggingDestination is declared as an informal protocol, the NSWindow and NSView subclasses you create to adopt the protocol need only implement those methods that are pertinent. (The NSWindow and NSView classes provide private implementations for all of the methods.) Either a window object or its delegate may implement these methods; however, the delegate’s implementation takes precedence if there are implementations in both places. Today, I had a window with two NSTextFields on it, and I wanted them to have different drop behaviors, and I did not want to allow drops anywhere else in the window. The way I interpret the docs, it seems that I either have to subclass NSTextField, or make some giant spaghetti-conditional drop handlers on the window's delegate that hit-checks the draggingLocation against each view in order to select the different drop-area behaviors for each field. The centralized NSWindow-delegate-based drop handler approach seems like it would be onerous in any case where you had more than a small handful of drop destination views. Likewise, the subclassing approach seems onerous regardless of the case, because now the drop handling code lives in a view class, so once you accept the drop you've got to come up with some way to marshal the dropped data back to the model. The bindings docs warn you off of trying to drive bindings by setting the UI value programmatically. So now you're stuck working your way back around that too. So my question is: "Really!? Are those the only readily available options? Or am I missing something straightforward here?" Thanks.

Read the article

in Rails, with check_box_tag, how do I keep the checkboxes checked after submitting query?

- by Sebastien Paquet

Ok, I know this is for the Saas course and people have been asking questions related to that as well but i've spent a lot of time trying and reading and I'm stuck. First of all, When you have a model called Movie, is it better to use Ratings as a model and associate them or just keep Ratings in an array floating in space(!). Second, here's what I have now in my controller: def index @movies = Movie.where(params[:ratings].present? ? {:rating => (params[:ratings].keys)} : {}).order(params[:sort]) @sort = params[:sort] @ratings = Ratings.all end Now, I decided to create a Ratings model since I thought It would be better. Here's my view: = form_tag movies_path, :method => :get do Include: - @ratings.each do |rating| = rating.rating = check_box_tag "ratings[#{rating.rating}]" = submit_tag "Refresh" I tried everything that is related to using a conditional ternary inside the checkbox tag ending with " .include?(rating) ? true : "" I tried everything that's supposed to work but it doesn't. I don't want the exact answer, I just need guidance.Thanks in advance!

Read the article

Querying calender events even if they do not have any for the day

- by StealthRT

Hey everyone, i am trying to figure out a way of query my mysql server so that even if a company does not have anything posted for the day the user clicks on their logo, it still adds them to the list. That sounds a little confusing so let me try to explain it another way. Say i have 3 company's in my database: Comp1 Comp2 Comp3 And Comp1 & Comp3 have something for today on the calender but Comp2 does not. I still need it to populate and place that company on the page but have something along the lines of "nothing on the calender for today". The other 2 companys (Comp1 & Comp3) would show the calender posting for that day. This is the code i have right now: SELECT clientinfo.id, clientinfo.theCompName, clientinfo.theURL, clientinfo.picURL, clientinfo.idNumber, clientoffers.idNumber, clientoffers.theDateStart, clientoffers.theDateEnd FROM clientinfo, clientoffers WHERE clientinfo.accountStats = 'OPEN' AND clientinfo.idNumber = clientinfo.idNumber AND '2010-05-08' BETWEEN clientoffers.theDateStart AND clientoffers.theDateEnd GROUP BY clientinfo.idNumber ORDER BY clientinfo.theCompName ASC That executes just fine but for Comp2, it just places the calender info from Comp1 into it when it really doesn't have anything. The output looks like this: Comp1 | 2010-05-08 | this is the calender event 1 | etc etc Comp2 | 2010-05-08 | this is the calender event 1 | etc etc comp3 | 2010-05-09 | this is the calender event 2 | etc etc Any help would be great :o) David

Read the article

Currently using View, Should I use a hard table instead?

- by 1001010101

Read the article

what is the best way to optimize my json on an asp.net-mvc site

- by ooo

i am currently using jqgrid on an asp.net mvc site and we have a pretty slow network (internal application) and it seems to be taking the grid a long time to load (the issue is both network as well as parsing, rendering) I am trying to determine how to minimized what i send over to the client to make it as fast as possible. Here is a simplified view of my controller action to load data into the grid: [AcceptVerbs(HttpVerbs.Get)] public ActionResult GridData1(GridData args) { var paginatedData = applications.GridPaginate(args.page ?? 1, args.rows ?? 10, i => new { i.Id, Name = "<div class='showDescription' id= '" + i.id+ "'>" + i.Name + "</div>", MyValue = GetImageUrl(_map, i.value, "star"), ExternalId = string.Format("<a href=\"{0}\" target=\"_blank\">{1}</a>", Url.Action("Link", "Order", new { id = i.id }), i.Id), i.Target, i.Owner, EndDate = i.EndDate, Updated = "<div class='showView' aitId= '" + i.AitId + "'>" + GetImage(i.EndDateColumn, "star") + "</div>", }) return Json(paginatedData); } So i am building up a json data (i have about 200 records of the above) and sending it back to the GUI to put in the jqgrid. The one thing i can thihk of is Repeated data. In some of the json fields i am appending HTML on top of the raw "data". This is the same HTML on every record. It seems like it would be more efficient if i could just send the data and "append" the HTML around it on the client side. Is this possible? Then i would just be sending the actual data over the wire and have the client side add on the rest of the HTML tags (the divs, etc) be put together. Also, if there are any other suggestions on how i can minimize the size of my messages, that would be great. I guess at some point these solution will increase the client side load but it may be worth it to cut down on network traffic.

Read the article

Organising UI code in .NET forms

- by sb3700

Hi I'm someone who has taught myself programming, and haven't had any formal training in .NET programming. A while back, I started C# in order to develop a GUI program to control sensors, and the project has blossomed. I was just wondering how best to organise the code, particularly UI code, in my forms. My forms currently are a mess, or at least seem a mess to me. I have a constructor which initialises all the parameters and creates events. I have a giant State property, which updates the Enabled state of all my form control as users progress through the application (ie: disconnected, connected, setup, scanning) controlled by a States enum. I have 3-10 private variables accessed through properties, some of which have side-effects in changing the values of form elements. I have a lot of "UpdateXXX" functions to handle UI elements that depend on other UI elements - ie: if a sensor is changed, then change the baud rate drop down list. They are separated into regions I have a lot of events calling these Update functions I have a background worker which does all the scanning and analysis. My problem is this seems like a mess, particularly the State property, and is getting unmaintainable. Also, my application logic code and UI code are in the same file and to some degree, intermingled which seems wrong and means I need to do a lot of scrolling to find what I need. How do you structure your .net forms? Thanks

Read the article

C++ destructor problem with boost::scoped_ptr

- by bb-generation

I have a question about the following code: #include <iostream> #include <boost/scoped_ptr.hpp> class Interface { }; class A : public Interface { public: A() { std::cout << "A()" << std::endl; } virtual ~A() { std::cout << "~A()" << std::endl; } }; Interface* get_a() { A* a = new A; return a; } int main() { { std::cout << "1" << std::endl; boost::scoped_ptr<Interface> x(get_a()); std::cout << "2" << std::endl; } std::cout << "3" << std::endl; } It creates the following output: 1 A() 2 3 As you can see, it doesn't call the destructor of A. The only way I see to get the destructor of A being called, is to add a destructor for the Interface class like this: virtual ~Interface() { } But I really want to avoid any Implementation in my Interface class and virtual ~Interface() = 0; doesn't work (produces some linker errors complaining about a non existing implementation of ~Interface(). So my question is: What do I have to change in order to make the destructor being called, but (if possible) leave the Interface as an Interface (only abstract methods).

Read the article

Why doesn't this PHP execute?

- by cam

I copied the code from this site exactly: http://davidwalsh.name/web-service-php-mysql-xml-json as follows, /* require the user as the parameter */ if(isset($_GET['user']) && intval($_GET['user'])) { /* soak in the passed variable or set our own */ $number_of_posts = isset($_GET['num']) ? intval($_GET['num']) : 10; //10 is the default $format = strtolower($_GET['format']) == 'json' ? 'json' : 'xml'; //xml is the default $user_id = intval($_GET['user']); //no default /* connect to the db */ $link = mysql_connect('localhost','username','password') or die('Cannot connect to the DB'); mysql_select_db('db_name',$link) or die('Cannot select the DB'); /* grab the posts from the db */ $query = "SELECT post_title, guid FROM wp_posts WHERE post_author = $user_id AND post_status = 'publish' ORDER BY ID DESC LIMIT $number_of_posts"; $result = mysql_query($query,$link) or die('Errant query: '.$query); /* create one master array of the records */ $posts = array(); if(mysql_num_rows($result)) { while($post = mysql_fetch_assoc($result)) { $posts[] = array('post'=>$post); } } /* output in necessary format */ if($format == 'json') { header('Content-type: application/json'); echo json_encode(array('posts'=>$posts)); } else { header('Content-type: text/xml'); echo '<posts>'; foreach($posts as $index => $post) { if(is_array($post)) { foreach($post as $key => $value) { echo '<',$key,'>'; if(is_array($value)) { foreach($value as $tag => $val) { echo '<',$tag,'>',htmlentities($val),'</',$tag,'>'; } } echo '</',$key,'>'; } } } echo '</posts>'; } /* disconnect from the db */ @mysql_close($link); } And the php doesn't execute, it just displays as plain text. What's the dealio? The host supports PHP, I use it to run a Wordpress blog and other things.

Read the article

Need an advice for unit testing using mock object

- by Andree

Hi there, I just recently read about "Mocking objects" for unit testing and currently I'm having a difficulties implementing this approach in my application. Please let me explain my problem. I have a User model class, which is dependent on 2 data sources (database and facebook web service). The controller class simply use this User model as an interface to access data and it doesn't care about where the data came from. Currently I never done any unit test to this User model because it is dependent on an external web service. But just a while ago, I read about object mocking and now I know that it is a common approach to unit test a class that depends on external resources (like in my case). Now I want to create a unit test for the User model, but then I encountered a design issue: In order for the User model to use a mocked Facebook SDK, I have to inject this mocked Facebook SDK to the User object (probably using a setter). Therefore I can't construct the Facebook SDK inside the User object. I have to construct it outside the User object, and inject the SDK into the User object. The real client of my User model is the application's controller. Therefore I have to construct the Facebook SDK inside the controller and inject it to the user object. Well, this is a problem because I want my controller to be as clean as possible. I want my controller to be ignorant about the application's data source. I'm not good at explaining something systematically, so you'll probably sleeping before reading this last paragraph. But anyway, I want to ask if anyone here ever encountered the same problem as mine? How do you solve this problem? Regards, Andree

Read the article

Prolog singleton variables in Python

- by Rubens

I'm working on a little set of scripts in python, and I came to this: line = "a b c d e f g" a, b, c, d, e, f, g = line.split() I'm quite aware of the fact that these are decisions taken during implementation, but shouldn't (or does) python offer something like: _, _, var_needed, _, _, another_var_needed, _ = line.split() as well as Prolog does offer, in order to exclude the famous singleton variables. I'm not sure, but wouldn't it avoid unnecessary allocation? Or creating references to the result of the split call does not count up as overhead? EDIT: Sorry, my point here is: in Prolog, as far as I'm concerned, in an expression like: test(L, N) :- test(L, 0, N). test([], N, N). test([_|T], M, N) :- V is M + 1, test(T, V, N). The variable represented by _ is not accessible, for what I suppose the reference to the value that does exist in the list [_|T] is not even created. But, in Python, if I use _, I can use the last value assigned to _, and also, I do suppose the assignment occurs for each of the variables _ -- which may be considered an overhead. My question here is if shouldn't there be (or if there is) a syntax to avoid such unnecessary attributions.

Read the article

Managing StringBuilder Resources

- by Jim Fell

My C# (.NET 2.0) application has a StringBuilder variable with a capacity of 2.5MB. Obviously, I do not want to copy such a large buffer to a larger buffer space every time it fills. By that point, there is so much data in the buffer anyways, removing the older data is a viable option. Can anyone see any obvious problems with how I'm doing this (i.e. am I introducing more performance problems than I'm solving), or does it look okay? tText_c = new StringBuilder(2500000, 2500000); private void AppendToText(string text) { if (tText_c.Length * 100 / tText_c.Capacity > 95) { tText_c.Remove(0, tText_c.Length / 2); } tText_c.Append(text); } EDIT: Additional information: In this application new data is received very rapidly (on the order of milliseconds) through a serial connection. I don't want to populate the multiline textbox with this new information so frequently because that kills the performance of the application, so I'm saving it to a StringBuilder. Every so often, the application copies the contents of the StringBuilder to the textbox and wipes out the StringBuilder contents.

Read the article

What's the best way to "shuffle" a table of database records?

- by Darth

Say that I have a table with a bunch of records, which I want to randomly present to users. I also want users to be able to paginate back and forth, so I have to perserve some sort of order, at least for a while. The application is basically only AJAX and it uses cache for already visited pages, so even if I always served random results, when the user tries to go back, he will get the previous page, because it will load from the local cache. The problem is, that if I return only random results, there might be some duplicates. Each page contains 6 results, so to prevent this, I'd have to do something like WHERE id NOT IN (1,2,3,4 ...) where I'd put all the previously loaded IDs. Huge downside of that solution is that it won't be possible to cache anything on the server side, as every user will request different data. Alternate solution might be to create another column for ordering the records, and shuffle it every insert time unit here. The problem here is, I'd need to set random number out of a sequence to every record in the table, which would take as many queries as there are records. I'm using Rails and MySQL if that's of any relevance.

Search Results

Search found 17924 results on 717 pages for 'z order'.

Page 599/717 | < Previous Page | 595 596 597 598 599 600 601 602 603 604 605 606 | Next Page >

- by Thomas Bennett

- by andrevr

- by Ryan Thompson

- by Citizen

- by RYates

- by Andrew Florko

- by mmontalbo

- by PatrickL

- by TrueWill

- by Ernest Shulikovski

- by hkBattousai

- by wengseng

- by user360706

- by ipmcc

- by Sebastien Paquet

- by StealthRT

- by 1001010101

- by ooo

- by sb3700

- by bb-generation

- by cam

- by Andree

- by Rubens

- by Jim Fell

- by Darth

< Previous Page | 595 596 597 598 599 600 601 602 603 604 605 606 | Next Page >