Search Results

Search found 34758 results on 1391 pages for 'linear linked list invert'.

Page 566/1391 | < Previous Page | 562 563 564 565 566 567 568 569 570 571 572 573  | Next Page >

  • C# compiler fails to recognize a class is implementing an interface

    - by Freek
    The following code fails to compile (using VS2010) and I don't see why. The compiler should be able to infer that List is 'compatible' (sorry for lack of a better word) with IEnumerable, but somehow it doesn't. What am I missing here? interface ITest { void Test(); } class TestClass : ITest { public void Test() { } } class Program { static void Test(IEnumerable<ITest> tests) { foreach(var t in tests) { Console.WriteLine(t); } } static void Main(string[] args) { var lst = new List<TestClass>(); Test(lst); // fails, why? Test(lst.Select(t=>t as ITest)); //success Test(lst.ToArray()); // success } }

    Read the article

  • Find and sort by number of ocurrences of tag with Active Admin and act_as_taggable_on

    - by nunopolonia
    I'm using act_as_taggable_on and Active Admin on a Rails project. In that project there are Posts and each Post has Tags. I want to show a list of Tags in Active Admin and the number of ocurrences of each one. The way I found to do this was: index do column :name column :ocurrences do |tag| ocurrences = Post.tag_counts.find(tag.id).count end default_actions end Which will search the Tag List every time for every Post, which performance wise looks really bad. I would also like to be able to sort the tags by ocurrence. Any idea of how I can do it?

    Read the article

  • Whats wrong with my makefile

    - by user577220
    ##################################################################### # This is the filesystem makefile "make_BuddyAlloc". # Author:Michael Gomes # Date:2 jan 2011 ###################################################################### #variable defination CC = gcc CFLAGS = -g -O2 SRC_DIR=src INC_DIR=inc OBJ_DIR=obj #List of source files SOURCE= buddyMain.c \ Copy.c \ #List of object files OBJECTS=$(addprefix $(OBJ_DIR)/,$(SOURCE:.c=.o)) #BuddyAlloc is dependent on "obj/*.o". BuddyAlloc : $(OBJECTS) $(CC) $(CFLAGS) -o BuddyAlloc $< #obj/*.o depends on src/*.c and inc/*.h, we are redirecting the object files to obj folder $(OBJECTS):$(SRC_DIR)/$(SOURCE) $(CC) $(CFLAGS) -I$(INC_DIR) -o $(OBJ_DIR)/$(OBJECTS) -c $< #Cleans all the *.exe files clean: rm -f *.exe I have kept the source files under src folder includes under inc folder and the object files are being saved in obj folder .given above is the makefile i am trying to create for my mini project. I keep getting the error no rule to make target 'Copy.c' needed by 'obj/buddyAlloc.o', but it works fine it i dont include Copy.c, what did i do wrong?

    Read the article

  • How to implement collection with covariance when delegating to another collection for storage?

    - by memelet
    I'm trying to implement a type of SortedMap with extended semantics. I'm trying to delegate to SortedMap as the storage but can't get around the variance constraints: class IntervalMap[A, +B](implicit val ordering: Ordering[A]) //extends ... { var underlying = SortedMap.empty[A, List[B]] } Here is the error I get. I understand why I get the error (I understand variance). What I don't get is how to implement this type of delegation. And yes, the covariance on B is required. error: covariant type B occurs in contravariant position in type scala.collection.immutable.SortedMap[A,List[B]] of parameter of setter underlying_=

    Read the article

  • How to customize the to_json method in rails3?

    - by lashleigh
    I want to convert an array of Place objects to json, I've been doing it like this: var places = <%= @places.to_json.html_safe %>; The only problem is that every place in the @places array has an associated tag list that doesn't get included. I'm using the acts_as_taggable_on gem to handle tags, so to get the tag list for a place I need to say place.tag_list. What do I have to do to get the tag_list included for each place in the javascript array? I think I'll need to write my own to_json method but I don't know how. Thanks

    Read the article

  • Javascript / Jquery Tree Travesal question

    - by Copper
    Suppose I have the following <ul> <li>Item 1</li> <li>Item 2 <ul> <li>Sub Item</li> </ul> </li> <li>Item 3</li> </ul> This list is auto-generated by some other code (so adding exclusive id's/class' is out of the question. Suppose I have some jquery code that states that if I mouseover an li, it gets a background color. However, if I mouseover the "Sub Item" list item, "Item 2" will be highlighted as well. How can I make it so that if the user mouses over "Sub Item" it only puts a background color on that and not on "Item 2" as well?

    Read the article

  • 'Caching' a large table in ASP.NET

    - by TheNewGuy
    I understand that each page refresh, especially in 'AjaxLand', causes my back-end/code-behind class to be called from scratch... This is a problem because my class (which is a member object in System.Web.UI.Page) contains A LOT of data that it sources from a database. So now every page refresh in AjaxLand is causing me to making large backend DB calls, rather than just to reuse a class object from memory. Any fix for this? Is this where session variables come into play? Are session variables the only option I have to retain an object in memory that is linked to a single-user and a single-session instance?

    Read the article

  • How to add up amount of data from an external file in C# (Stream Reader)

    - by user2985995
    I'm new to this site, and pretty new to programming, at the moment I'm trying to display a count amount for the users names on my donation list, and then I also want to have a sum to work out the total amount of money the donation list contains, If someone could help me with creating a way to add up amount of donors on the donations.txt file that would be great help, I have no idea where to start, but so far this is my coding: string sName; double dAmount; string sTotalNames; double dAmountTotal; double dAmountAverage; using (StreamReader sr = new StreamReader("Donations.txt")) { while (sr.Peek() != -1) { sName = sr.ReadLine(); Console.WriteLine(sName); dAmount = Convert.ToDouble(sr.ReadLine()); Console.WriteLine(dAmount); } Console.WriteLine("Press any key to close"); Console.ReadKey(); }

    Read the article

  • How to remove an item from a structure array in C++?

    - by Antik
    I have the following array structure (linked list): struct str_pair { char ip [50] ; char uri [50] ; str_pair *next ; } ; str_pair *item; I know to create a new item, I need to use item = new str_pair; However, I need to be able to loop through the array and delete a particular item. I have the looping part sorted. But how do I delete an item from an array of structures?

    Read the article

  • What books should be read to become an excelent software architect.

    - by dev-cu
    I know there are good books to start with, but let's make a short list of 3-5 books, i don't think only one book could help you in the way of becoming a good architect. I read some time ago that an architect takes years to have the knowledge and the ability to make good decisions. Suppose someone has the potential, what is the way? Please, answers with books that doesn't repeat over the same theme, making your learning process widely. One short list per answer. Vote up that you think are the best ones. Thanks.

    Read the article

  • C# 3.5 Merge 2 lists of 2 different types

    - by Ehsan
    I have 2 generic Lists List<type1> L1 , List<type2> L2 in C# 3.5 Problem: type1 has an attribute called "key1" and type2 has an attribute called "key2" How to merge L1 and L2 on key1 = key2. Both lists are unsorted but I'm welcome to any ideas on how to sort the lists based on the attribute. I'd like to be able to merge the two lists on a key. I know it's not a dictionary and it would've been nice if it was but there is a very specific reason why they are lists which I will not get in to because that is irrelevant.

    Read the article

  • [CakePHP] Pagination after inserting or updateing record

    - by user198003
    one more question related with cakephp... let's say that i have 20+ records in my table. they are sorted by some criteria, ie. by title. and on a list view, i have a list of 10 records, with available pagination. how can i achieve that when i insert new record, to be redirected to proper page, where i can see record that is just was insterted? how can i get information on which page i have to be redirected? hope my question is enough clear for understanding... tnx in adv!

    Read the article

  • Building a custom iterator.

    - by Isai
    I am making this class which is a custom Map based off a hash map. I have an add method where if you add an object the object will be the key, and its value will be 1 if the object is not currently in the list. However if you add object that is currently in the list its value will be bumped up by 1. So if I added 10 strings which were all the same, the key would be that string and the value will be 10. I understand in practice when I iterate through the map, there is actually only one object to iterate, however, I am trying to create a inner class that will define an iterator that will iterate the same object however many times its value is. I can do this by simply using for loops to construct an appropriate ArrayList and just create an iterator for that, but that is too inefficient. Is there an easy or more efficient way of doing this?

    Read the article

  • A little javascript help needed here (easy).

    - by Camran
    function addOption(selectbox, val, txt){ ...... } addOption(list, "Cars", "Cars"); I need to add this in front of the text of the function: &nbsp;&nbsp;&nbsp; So that there is space coming in before the option text...Never mind what it is for, it is just confusing... I just don't know how to insert it into the js code. If I do it like this: addOption(list, "Cars", "&nbsp;&nbsp;&nbsp;Cars"); Then the &nbsp;&nbsp;&nbsp; comes into the text, so it gets displayed for the users. However I need it to be interpreted as "space"... If you don't understand let me know... How can I do this? Quotes, double quotes etc? Thanks

    Read the article

  • C# Object Array CopyTo links both arrays' values?

    - by Dutchie432
    Okay, I have what I think is a simple question.. or just a case of me being a C# beginner. I have an array of custom objects (clsScriptItem) that I am populating from a database. Once the items are loaded, I want to back them up to "backup" array so I can revert the information back after changing the main array. However, when I use CopyTo to copy the array and then alter the original array, the backup array is also being altered... I though CopyTo merely copied values + structure from one array to another. private void backupItems() { lastSavedItems = new clsScriptItem[items.Length]; items.CopyTo(lastSavedItems, 0); //items[0].nexts[0] is 2 //lastSavedItems[0].nexts[0] is 2 items[0].nexts[0] = "-1"; //items[0].nexts[0] is -1 //lastSavedItems[0].nexts[0] is also -1 } How do I backup this data without having the two arrays be 'linked'??

    Read the article

  • Find the clicked li number

    - by fire
    I have a standard list... <ul> <li><a href="#">blah 1</a></li> <li><a href="#">blah 2</a></li> <li><a href="#">blah 3</a></li> <li><a href="#">blah 4</a></li> </ul> And my jQuery: $('ul li a').live('click', function() { var parent = $(this).parent('li'); }); What I want to find out is the parent li's position in the list of the clicked link e.g. clicking on blah 3 would give me 2, blah 4 would give 3 etc. Any ideas?

    Read the article

  • Netbeans Intellisense for Rails

    - by irishfury
    Has anybody figured out a way to make the Netbeans intellisense for ruby and rails better? It either has too many options in the list (which I understand is a problem since it is a dynamic language). Or it has no options in the list, as if it is not dynamic enough to find everything. Are there any hacks to make it better, or is this just something that needs to be improved within the Netbeans source code? I'm currently using 6.8. Please spare me the posts about how I don't really need to use intellisense, and I should use vim or emacs. I'm sure the vim programmers are 10 times more productive than me with all their cool shortcuts, but I have no desire to learn these tools.

    Read the article

  • Does the order of the columns in a SELECT statement make a difference?

    - by Frank Computer
    This question was inspired by a previous question posted on SO, "Does the order of the WHERE clause make a differnece?". Would it improve a SELECT statement's performance if the the columns used in the WHERE section are placed at the begining of the SELECT statement? example: SELECT customer.id, transaction.id, transaction.efective_date, transaction.a, [...] FROM customer, transaction WHERE customer.id = transaction.id; I do know that limiting the list of columns to only the needed ones in a SELECT statement improves performance as opposed to using SELECT * because the current list is smaller.

    Read the article

  • null pointer exception in textview of setcontent

    - by kitokid
    I am getting the java.lang.NullPointerException on createTabContent for the following code. There are two tabspecs. When I called and set the tab , changed the tabs for the first time it is ok. But when i called again while I am on the second tab, its hit the null pointer exception for line : NoStudentText.setVisibility(View.VISIBLE); I will show No Student Text if there is no data for the student list. It shows the text for the first time call. But If I do second time call to that tab, got the error. tspecStudent.setContent(new TabContentFactory() { public View createTabContent(String arg0) { if(listStudent != null && listStudent .size() > 0) { //show the student list } else { TextView noStudentText = (TextView)findViewById(R.id.NoStudentText); noStudentText.setVisibility(View.VISIBLE); return noStudentText; } } });

    Read the article

  • Is pthread_spin_trylock safe inside of sigsegv handler of multithreaded application?

    - by TWMouton
    I am trying to implement a handler that on SIGSEGV will collect some information such as process-id, thread-id and a backtrace and write this information to a file/pipe/socket. The problem lies in that there is the (probably pretty high) possibility that if one thread experienced a SIGSEGV that the others will shortly follow. If two threads happen to make it to the bit of code where they're writing their report out at the same time then they'll interleave their writing (to the same file). I know that I should only be using async-signal-safe functions as detailed in signal(7) I also have seen at least two cases here and video linked in top answer here where others have used pthread_spin_trylock to get around this problem. Is this a safe way to prevent the above problem?

    Read the article

  • QComboBox returns None Type . How to get Current Data ?

    - by vettipayyan
    I've implemented 2 QComboBoxes with one having items manually inserted every time and another one having items inserted with a list (I'm using Python ) But when i attempt to get the current value of Combobox , it returns None . I proceeded as specified in this question : I referred this i have provided wat i've coded ."command" and "option" are QComboBoxes ( Pardon me for bad style) Is there any mistake in Indexes ? self.command.insertItem(1,'Convert') self.command.insertItem(2,'Compose') self.command.insertItem(3,'Animate') self.option.insertItems(268,list) and retrieval : self.selected_com=self.command.itemData(self.command.currentIndex()) self.selected_opt=self.option.itemData(self.option.currentIndex())

    Read the article

  • Java Package, Project , NoSuchMethod error

    - by hamam
    I have 2 projects linked and these 2 projects each have a package under them. XProject - XPackage - XClass - X1Method(); X2Method(); YProject - YPackage - YClass - Y1Method(); I'm trying to call X1 and X2 methods from Y1 Method. I can call X1 Method but when I call X2 method I get a runtime error (java.lang.NoSuchMethodError:) All methods are public and there is nothing wrong with method names. It is just nonsense to have one of them working while other is giving runtime errors. Any help would be appreciated. Thanks.

    Read the article

  • Drupal 6: moving localhost to server | clear cached data

    - by artmania
    Hi friends, I worked on localhost to build my drupal site. then, I moved to server. Steps: Clear cache tables (Site Configuration Performance Clear Cached Data button) on localhost Export db and then import on live server Move files/folders to live server Edit settings.php to reflect live server config everything is working great until I make Clear Cached Data on Server. than my custom theme, custom front page, etc... all mess up :( What can be the problem? I appreciate helps so much!! Thanks! !!SORTED!! I used a subtheme for Zen, named mgf . then I had taken a back-up as mgf- somehow after I make Clear Cached Data, Drupal links to this mgf- which is old and doesnt have latest stylings. I just removed this folder from themes, and it linked to the right-latest mgf.

    Read the article

< Previous Page | 562 563 564 565 566 567 568 569 570 571 572 573  | Next Page >