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  • What is the fastest way to do division in C for 8bit MCUs?

    - by Jordan S
    I am working on the firmware for a device that uses an 8bit mcu (8051 architecture). I am using SDCC (Small Device C Compiler). I have a function that I use to set the speed of a stepper motor that my circuit is driving. The speed is set by loading a desired value into the reload register for a timer. I have a variable, MotorSpeed that is in the range of 0 to 1200 which represents pulses per second to the motor. My function to convert MotorSpeed to the correct 16bit reload value is shown below. I know that float point operations are pretty slow and I am wondering if there is a faster way of doing this... void SetSpeed() { float t = MotorSpeed; unsigned int j = 0; t = 1/t ; t = t / 0.000001; j = MaxInt - t; TMR3RL = j; // Set reload register for desired freq return; }

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  • Refreshing a JPA result list which is bound with a jTable

    - by exhuma
    First off, I hage to write this on my mobile. But I'll try to format it properly. In Netbeans I created a jTable and bound it's values to a JPA result set. This works great. The qery contains a param which i set in the pre-create box of the "query result" component. So just before netbeans creates the query result i write this: myQuery.setParameter("year", "1997"); This works fine. Now, I have an event handler which is supposed to change the param and display the new values in the table. So I do this: myQuery.setParameter("year", "2005"); myResultList.clear(); myResultList.addAll(myQuery.getResultList()); jTable1.updateUI(); This works, but it feels wrong to me. Note: the result set is bound to the table. So I was hoping there was something like this: myQuery.setParameter("year", "2005"); myResultList.refresh(); Is there something like this?

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  • Is it safe to silently catch ClassCastException when searching for a specific value?

    - by finnw
    Suppose I am implementing a sorted collection (simple example - a Set based on a sorted array.) Consider this (incomplete) implementation: import java.util.*; public class SortedArraySet<E> extends AbstractSet<E> { @SuppressWarnings("unchecked") public SortedArraySet(Collection<E> source, Comparator<E> comparator) { this.comparator = (Comparator<Object>) comparator; this.array = source.toArray(); Collections.sort(Arrays.asList(array), this.comparator); } @Override public boolean contains(Object key) { return Collections.binarySearch(Arrays.asList(array), key, comparator) >= 0; } private final Object[] array; private final Comparator<Object> comparator; } Now let's create a set of integers Set<Integer> s = new SortedArraySet<Integer>(Arrays.asList(1, 2, 3), null); And test whether it contains some specific values: System.out.println(s.contains(2)); System.out.println(s.contains(42)); System.out.println(s.contains("42")); The third line above will throw a ClassCastException. Not what I want. I would prefer it to return false (as HashSet does.) I can get this behaviour by catching the exception and returning false: @Override public boolean contains(Object key) { try { return Collections.binarySearch(Arrays.asList(array), key, comparator) >= 0; } catch (ClassCastException e) { return false; } } Assuming the source collection is correctly typed, what could go wrong if I do this?

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  • Open an Emacs buffer when a command tries to open an editor in shell-mode

    - by Chris Conway
    I like to use Emacs' shell mode, but it has a few deficiencies. One of those is that it's not smart enough to open a new buffer when a shell command tries to invoke an editor. For example with the environment variable VISUAL set to vim I get the following from svn propedit: $ svn propedit svn:externals . "svn-prop.tmp" 2L, 149C[1;1H ~ [4;1H~ [5;1H~ [6;1H~ [7;1H~ ... (It may be hard to tell from the representation, but it's a horrible, ugly mess.) With VISUAL set to "emacs -nw", I get $ svn propedit svn:externals . emacs: Terminal type "dumb" is not powerful enough to run Emacs. It lacks the ability to position the cursor. If that is not the actual type of terminal you have, use the Bourne shell command `TERM=... export TERM' (C-shell: `setenv TERM ...') to specify the correct type. It may be necessary to do `unset TERMINFO' (C-shell: `unsetenv TERMINFO') as well.svn: system('emacs -nw svn-prop.tmp') returned 256 (It works with VISUAL set to just emacs, but only from inside an Emacs X window, not inside a terminal session.) Is there a way to get shell mode to do the right thing here and open up a new buffer on behalf of the command line process?

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  • In Fluent NHibernate, how would I map the following domain models?

    - by Brandon
    I have a user class that looks something like this public class User { public virtual int Id { get; set; } public virtual long ValueA { get; set; } public virtual int? ValueB { get; set; } } ValueA is automatically assigned by the system. It is used in a lookup that would map to UserClass. However, if a value for ValueB exists, then it would do the lookup for UserClass in a different way. Right now the way I handle it is to get the User and then perform a separate lookup each time. return user.ValueB.HasValue ? Find(user.ValueB.Value) : Find(user.ValueA); Is there any way to make Fluent NHibernate do this for me so I can have UserClass as a property on the User class instead of having to do the lookup separately? I was thinking of the ComponentMap but I'm not sure how to make it account for the two possible lookup values.

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  • How do I create a graph from this datastructure?

    - by Shawn Mclean
    I took this data structure from this A* tutorial: public interface IHasNeighbours<N> { IEnumerable<N> Neighbours { get; } } public class Path<TNode> : IEnumerable<TNode> { public TNode LastStep { get; private set; } public Path<TNode> PreviousSteps { get; private set; } public double TotalCost { get; private set; } private Path(TNode lastStep, Path<TNode> previousSteps, double totalCost) { LastStep = lastStep; PreviousSteps = previousSteps; TotalCost = totalCost; } public Path(TNode start) : this(start, null, 0) { } public Path<TNode> AddStep(TNode step, double stepCost) { return new Path<TNode>(step, this, TotalCost + stepCost); } public IEnumerator<TNode> GetEnumerator() { for (Path<TNode> p = this; p != null; p = p.PreviousSteps) yield return p.LastStep; } IEnumerator IEnumerable.GetEnumerator() { return this.GetEnumerator(); } } I have no idea how to create a simple graph with. How do I add something like the following undirected graph using C#: Basically I'd like to know how to connect nodes. I have my own datastructures that I can already determine the neighbors and the distance. I'd now like to convert that into this posted datastructure so I can run it through the AStar algorithm. I was seeking something more like: Path<EdgeNode> startGraphNode = new Path<EdgeNode>(tempStartNode); startGraphNode.AddNeighbor(someOtherNode, distance);

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  • how to make accessor for Dictionary in a way that returned Dictionary cannot be changed C# / 2.0

    - by matti
    I thought of solution below because the collection is very very small. But what if it was big? private Dictionary<string, OfTable> _folderData = new Dictionary<string, OfTable>(); public Dictionary<string, OfTable> FolderData { get { return new Dictionary<string,OfTable>(_folderData); } } With List you can make: public class MyClass { private List<int> _items = new List<int>(); public IList<int> Items { get { return _items.AsReadOnly(); } } } That would be nice! Thanks in advance, Cheers & BR - Matti NOW WHEN I THINK THE OBJECTS IN COLLECTION ARE IN HEAP. SO MY SOLUTION DOES NOT PREVENT THE CALLER TO MODIFY THEM!!! CAUSE BOTH Dictionary s CONTAIN REFERENCES TO SAME OBJECT. DOES THIS APPLY TO List EXAMPLE ABOVE? class OfTable { private string _wTableName; private int _table; private List<int> _classes; private string _label; public OfTable() { _classes = new List<int>(); } public int Table { get { return _table; } set { _table = value; } } public List<int> Classes { get { return _classes; } set { _classes = value; } } public string Label { get { return _label; } set { _label = value; } } } so how to make this immutable??

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  • Lost in dates and timezones

    - by Sebastien
    I'm working on an application that stores conferences with their start and end date. Up until now, I was developing in Belgium and my server is in France, so everything is in the same timezone, no problem. But today, I'm in San Francisco, my server is in France and I noticed I have a bug. I'm setting dates from a Flex client (ActionScript automatically adapts date display according to client local timezone, which is GMT-8 for me today. My server runs on Hibernate and MySQL in France (GMT+1). So when I look at my database using phpMyAdmin, I see a date set to "2010-06-07 00:00:01" but in my Flex client it displays "2010-06-06 15:00:01". Ultimately, what I want is that the dates are displayed in the local timezone of the event, which is the date I set it to. So when I'm in Belgium and I set the start date of an event to be "2010-06-07 00:00:01" I want to retrieve it that way. But I'm lost as to what layer adapts what. Is timezone stored in DATETIME MySQL columns (I can't see it in MySQL)? Does Hibernate to anything to it when it transfers it to java.lang.Date that has Timezone information? And ultimately, what is the best way to solve this mess?

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  • Problem importing Oracle .dmp file

    - by BitFiddler
    So I have looked at all the suggested ways of importing .dmp files and non of them seem to answer this question: where does the data go once you import it? Context: I created a user like so: SQL> create user IMPORTER identified by "12345"; SQL> grant connect, unlimited tablespace, resource to IMPORTER; I then ran the 'imp' command as follows: C:\>imp system/password FROMUSER=OVIEDOE TOUSER=IMPORTER file=c:\database1.dmp Now there were 9 .dmp files, after each one it asked me for the next one and then I received the message "Import terminated successfully with warnings." The warning was: Warning: the objects were exported by OVIEDOE, not by you import done in WE8MSWIN1252 character set and AL16UTF16 NCHAR character set export client uses WE8ISO8859P1 character set (possible charset conversion) IMP-00046: using FILESIZE value from export file of 2147483648 Now it says it was terminated successfully so my assumption (I am new to oracle so this may be wrong) is that the data was loaded. However, when I use SQL developer to connect to the database and look under the 'tables' node under the IMPORTER user, there is nothing there. What is going on? Did the data load? If so, where can I find it?

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  • Deserialize json with json.net c#

    - by 76mel
    Hi, am new to Json so a little green. I have a Rest Based Service that returns a json string; {"treeNode":[{"id":"U-2905","pid":"R","userId":"2905"}, {"id":"U-2905","pid":"R","userId":"2905"}]} I have been playing with the Json.net and trying to Deserialize the string into Objects etc. I wrote an extention method to help. public static T DeserializeFromJSON<T>(this Stream jsonStream, Type objectType) { T result; using (StreamReader reader = new StreamReader(jsonStream)) { JsonSerializer serializer = new JsonSerializer(); try { result = (T)serializer.Deserialize(reader, objectType); } catch (Exception e) { throw; } } return result; } I was expecting an array of treeNode[] objects. But its seems that I can only deserialize correctly if treeNode[] property of another object. public class treeNode { public string id { get; set; } public string pid { get; set; } public string userId { get; set; } } I there a way to to just get an straight array from the deserialization ? Cheers

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  • WPF: ComboBox SelectedIndex = -1 ??

    - by msfanboy
    Hello, I am using a MVVM Wizard with several pages. When I set a value in the combobox and go to the next page and switch back I want to reset the value I set before. But all whats happening is that the combobox is empty at top and the index is -1 ? What do I wrong? <ComboBox ItemsSource="{Binding Path=LessonNumbers}" SelectedIndex="{Binding SelectedLessonNumber}" /> private ReadOnlyCollection<int> _lessonNumbers; public ReadOnlyCollection<int> LessonNumbers { get { if (_lessonNumbers == null) this.CreateLessonNumbers(); return _lessonNumbers; } } private void CreateLessonNumbers() { var list = new List<int>(); for (int i = 1; i < 24; i++) { list.Add(i); } _lessonNumbers = new ReadOnlyCollection<int>(list); } private int _selectedLessonNumber; public int SelectedLessonNumber { get { return _selectedLessonNumber; } set { if (_selectedLessonNumber == value) return; _selectedLessonNumber = value; this.OnPropertyChanged("SelectedLessonNumber"); } }

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  • Testing form submission with Cucumber

    - by picardo
    I wrote a simple Cuke feature for a form on a demo site. The feature looks like this. Given I am on the home page When I set the "Start Date" to "2010-10-25" And I set the "End Date" to "2011-1-3" And I press the "Go" button Then I should see "Cake Shop" The idea is that after I press the Go button, a new page will load, showing a list of results, and one of the results should be "Cake Shop." But I have not managed to get this to work. Is there something that I am missing? Edit: here is the step definitions. Given /^I am on the "([^"]*)" page$/ do |page| visit root_path end When /^I set the "([^"]*)" to "([^"]*)"$/ do |field, date| fill_in field, :with=>date end When /^I press the "([^"]*)" button$/ do |arg1| click_button('Go') end The final step is defined in web_steps.rb I believe....and it's always there that it's failing. Then I should see "Cake Shop" # features/step_definitions/web_steps.rb:107 expected #has_content?("Cake Shop") to return true, got false (RSpec::Expectations::ExpectationNotMetError) ./features/step_definitions/web_steps.rb:110:in block (2 levels) in <top (required)>' ./features/step_definitions/web_steps.rb:14:in with_scope' ./features/step_definitions/web_steps.rb:108:in /^(?:|I )should see "([^"]*)"(?: within "([^"]*)")?$/' features/specify_timerange.feature:12:in Then I should see "Cake Shop"'

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  • Problem creating XML using c#

    - by Pankaj
    I am searching a batter solution for creating xml through xml serialization. What i need, i have a given format like this <product Id="1"> <name>2 1/2 X 6 PVC NIPPLE TOE SCH 80</name> <notes> <note>!--note 1---</note> <note>!--note 2--</note> ...... </notes> </product> what i am doing here, i created a 2 classes like this public class product { [XmlElement("name")] public string Name { get; set; } [XmlArray("notes")] public List<notes> ListNotes { get; set; } } public class notes { [XmlIgnore] public string Note { get; set; } } when i am serializing this then i am getting xml in this formate <product Id="1"> <name>2 1/2 X 6 PVC NIPPLE TOE SCH 80</name> <notes> <notes> <note>!--note 1---</note> <note>!--note 2--</note> </notes> </notes> </product> i don't want extra <notes>. Any batter solution to solve this problem? Thanks

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  • Problem with UITextView

    - by user367039
    I have a strange problem with trying to pass a string from one viewcontroller to another view controller if the string originates from a UITextview instead of UITextfield. Both UITextview.text and UITextfield.text are of type NSString. The following code takes either Textfield.text or Textview.text depending on the fieldType and puts it into a string called aString. NSString *aString = [[NSString alloc] init]; if (fieldType == 3) { aString = textView.text; } else { aString = textField.text; } When I examine aString on either cases, I can see that it has successfully assigned the text into aString. I then pass the string to the other view controller using this code. [delegate updateSite:aString :editedFieldKey :fieldType]; [self.navigationController popViewControllerAnimated:YES]; This works fine if aString originated from textfield.text but nothing happens except the view controller is popped if aString was from textview.text This is the code that takes aString and does stuff with it, however it doesn't even execute the first line of code "NSLog(@"Returned object: %@, field type:%@", aString,editedFieldKey);" if aString was from textview.text Any help will be appreciated. -(void)updateSite:(NSString *)aString :(NSString *)editedFieldKey :(int)fieldType { NSLog(@"Returned object: %@, field type:%@", aString,editedFieldKey); switch (fieldType) { case 0: //string [aDiveSite setValue:aString forKey:editedFieldKey] ; NSLog(@"String set %@",[aDiveSite valueForKey:editedFieldKey] ); break; case 1: //int [aDiveSite setValue:[NSNumber numberWithInt:aString.intValue] forKey:editedFieldKey]; NSLog(@"Integer set"); break; case 2: //float NSLog(@"Saving floating value"); [aDiveSite setValue:[NSNumber numberWithFloat:aString.floatValue] forKey:editedFieldKey]; NSLog(@"Float set"); break; case 3: //Text view [aDiveSite setValue:aString forKey:editedFieldKey]; NSLog(@"Textview text saved"); default: break; } [self.tableView reloadData]; }

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  • Need help implementing this algorithm with map Hadoop MapReduce

    - by Julia
    Hi all! i have algorithm that will go through a large data set read some text files and search for specific terms in those lines. I have it implemented in Java, but I didnt want to post code so that it doesnt look i am searching for someone to implement it for me, but it is true i really need a lot of help!!! This was not planned for my project, but data set turned out to be huge, so teacher told me I have to do it like this. EDIT(i did not clarified i previos version)The data set I have is on a Hadoop cluster, and I should make its MapReduce implementation I was reading about MapReduce and thaught that i first do the standard implementation and then it will be more/less easier to do it with mapreduce. But didnt happen, since algorithm is quite stupid and nothing special, and map reduce...i cant wrap my mind around it. So here is shortly pseudo code of my algorithm LIST termList (there is method that creates this list from lucene index) FOLDER topFolder INPUT topFolder IF it is folder and not empty list files (there are 30 sub folders inside) FOR EACH sub folder GET file "CheckedFile.txt" analyze(CheckedFile) ENDFOR END IF Method ANALYZE(CheckedFile) read CheckedFile WHILE CheckedFile has next line GET line FOR(loops through termList) GET third word from line IF third word = term from list append whole line to string buffer ENDIF ENDFOR END WHILE OUTPUT string buffer to file Also, as you can see, each time when "analyze" is called, new file has to be created, i understood that map reduce is difficult to write to many outputs??? I understand mapreduce intuition, and my example seems perfectly suited for mapreduce, but when it comes to do this, obviously I do not know enough and i am STUCK! Please please help.

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  • Retaining parameters in ASP.NET MVC

    - by MapDot
    Many MVC frameworks (e.g. PHP's Zend Framework) have a way of providing basic state management through URLs. The basic principle is this: Any parameters that were not explicitly modified or un-set get copied into every URL For instance, consider a listing with pagination. You'll have the order, direction and page number passed as URL parameters. You may also have a couple of filters. Changing the value of a filter should not alter the sort order. ASP.net MVC seems to remember your controller and action by default: <%: Html.RouteLink("Next", "MyRoute", new {id = next.ItemId}) %> This will not re-set your action or controller. However, it does seem to forget all other parameters. The same is true of ActionLink. Parameters that get set earlier on in your URL seem to get retained as well. Is there a way to make it retain more than that? For instance, this does not seem to affect any of the links being generated: RouteValues.RouteData.Values["showDeleted"] = true;

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  • Generic cast type to primitive.

    - by Nix
    Is there a way to do the below? Imagine a generic result wrapper class. Where you have a type and an associated error list. When there is no result to return to the user we will use boolean to indicate success failure. I want to create a constructor that takes in an error list, and if the list is null or count 0, AND the type is a bool/Boolean i want to set it to true.... Seemingly simple, but amazingly not possible. public class Result<T>{ private T valueObject { get;set;} private List<Error> errors{ get;set;} public Result(T valueObj, List<Error> errorList){ this.valueObject = valueObj; this.errors = errorList; } public Result(List<Error> errors) { this.valueObject = default(ReturnType); if (valueObject is Boolean) { //Wont work compile //(valueObject as Boolean) = ((errors == null) || errors.Count == 0); //Compiles but detaches reference //bool temp = ((bool)(valueObject as object)) ; //temp = ((errors == null) || errors.Count == 0); } this.errors = errors; } } } Am I missing something simple? And in general I would prefer to do it without reflection.

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  • Add an event to HTML elements with a specific class.

    - by Juan C. Rois
    Hello everybody, I'm working on a modal window, and I want to make the function as reusable as possible. Said that, I want to set a few anchor tags with a class equals to "modal", and when a particular anchor tag is clicked, get its Id and pass it to a function that will execute another function based on the Id that was passed. This is what I have so far: // this gets an array with all the elements that have a class equals to "modal" var anchorTrigger = document.getElementsByClassName('modal'); Then I tried to set the addEventListener for each item in the array by doing this: var anchorTotal = anchorTrigger.length; for(var i = 0; i < anchorTotal ; i++){ anchorTrigger.addEventListener('click', fireModal, false); } and then run the last function "fireModal" that will open the modal, like so: function fireModal(){ //some more code here ... } My problem is that in the "for" loop, I get an error saying that anchorTrigger.addEvent ... is not a function. I can tell that the error might be related to the fact that I'm trying to set up the "addEventListener" to an array as oppose to individual elements, but I don't know what I'm supposed to do. Any help would be greatly appreciated.

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  • Maven 3 plugin - How to programatically exclude a dependency and all its transitive dependencies?

    - by electrotype
    I'm developing a Maven 3 plugin and I want to exclude some dependencies, and their transitive dependencies, when a configuration is set to true in the plugin. I don't want to use <exclusions> in the POM itself, even in a profile. I want to exclude those dependencies programatically. In fact, what I want is to prevent the dependency jars to be included in the final war (I'm building a war), when a plugin configuration is set to true. I tried : @Mojo(requiresDependencyResolution=ResolutionScope.COMPILE, name="compileHook",defaultPhase=LifecyclePhase.COMPILE) public class compileHook extends AbstractMojo { @Override public void execute() throws MojoExecutionException, MojoFailureException { // ... Set<Artifact> artifacts = this.project.getArtifacts(); for(Artifact artifact : artifacts) { if("org.package.to.remove".equalsIgnoreCase(artifact.getGroupId())) { artifact.setScope("provided"); } } // ... } } Since this occures at the compile phase, it will indeed remove the artifacts with a group id "org.package.to.remove" from having their jars included in the war when packaged. But this doesn't remove the transitive artifacts those dependencies add! What is the best way to programatically remove some dependencies, and their transitive dependencies, from being included in a final .jar/.war?

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  • nhibernate mapping: delete collection, insert new collection with old IDs

    - by npeBeg
    my issue lokks similar to this one: (link) but i have one-to-many association: <set name="Fields" cascade="all-delete-orphan" lazy="false" inverse="true"> <key column="[TEMPLATE_ID]"></key> <one-to-many class="MyNamespace.Field, MyLibrary"/> </set> (i also tried to use ) this mapping is for Template object. this one and the Field object has their ID generators set to identity. so when i call session.Update for the Template object it works fine, well, almost: if the Field object has an Id number, UPDATE sql request is called, if the Id is 0, the INSERT is performed. But if i delete a Field object from the collection it has no effect for the Database. I found that if i also call session.Delete for this Field object, everything will be ok, but due to client-server architecture i don't know what to delete. so i decided to delete all the collection elements from the DB and call session.Update with a new collection. and i've got an issue: nhibernate performs the UPDATE operation for the Field objects that has non-zero Id, but they are removed from DB! maybe i should use some other Id generator or smth.. what is the best way to make nhibernate perform "delete all"/"insert all" routine for the collection?

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  • Why is TRest in Tuple<T1... TRest> not constrained?

    - by Anthony Pegram
    In a Tuple, if you have more than 7 items, you can provide an 8th item that is another tuple and define up to 7 items, and then another tuple as the 8th and on and on down the line. However, there is no constraint on the 8th item at compile time. For example, this is legal code for the compiler: var tuple = new Tuple<int, int, int, int, int, int, int, double> (1, 1, 1, 1, 1, 1, 1, 1d); Even though the intellisense documentation says that TRest must be a Tuple. You do not get any error when writing or building the code, it does not manifest until runtime in the form of an ArgumentException. You can roughly implement a Tuple in a few minutes, complete with a Tuple-constrained 8th item. I just wonder why it was left off the current implementation? Is it possibly a forward-compatibility issue where they could add more elements with a hypothetical C# 5? Short version of rough implementation interface IMyTuple { } class MyTuple<T1> : IMyTuple { public T1 Item1 { get; private set; } public MyTuple(T1 item1) { Item1 = item1; } } class MyTuple<T1, T2> : MyTuple<T1> { public T2 Item2 { get; private set; } public MyTuple(T1 item1, T2 item2) : base(item1) { Item2 = item2; } } class MyTuple<T1, T2, TRest> : MyTuple<T1, T2> where TRest : IMyTuple { public TRest Rest { get; private set; } public MyTuple(T1 item1, T2 item2, TRest rest) : base(item1, item2) { Rest = rest; } } ... var mytuple = new MyTuple<int, int, MyTuple<int>>(1, 1, new MyTuple<int>(1)); // legal var mytuple2 = new MyTuple<int, int, int>(1, 2, 3); // illegal

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  • implementing a read/write field for an interface that only defines read

    - by PaulH
    I have a C# 2.0 application where a base interface allows read-only access to a value in a concrete class. But, within the concrete class, I'd like to have read/write access to that value. So, I have an implementation like this: public abstract class Base { public abstract DateTime StartTime { get; } } public class Foo : Base { DateTime start_time_; public override DateTime StartTime { get { return start_time_; } internal set { start_time_ = value; } } } But, this gives me the error: Foo.cs(200,22): error CS0546: 'Foo.StartTime.set': cannot override because 'Base.StartTime' does not have an overridable set accessor I don't want the base class to have write access. But, I do want the concrete class to provide read/write access. Is there a way to make this work? Thanks, PaulH Unfortunately, Base can't be changed to an interface as it contains non-abstract functionality also. Something I should have thought to put in the original problem description. public abstract class Base { public abstract DateTime StartTime { get; } public void Buzz() { // do something interesting... } } My solution is to do this: public class Foo : Base { DateTime start_time_; public override DateTime StartTime { get { return start_time_; } } internal void SetStartTime { start_time_ = value; } } It's not as nice as I'd like, but it works.

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  • EF/LINQ: Where() against a property of a subtype

    - by ladenedge
    I have a set of POCOs, all of which implement the following simple interface: interface IIdObject { int Id { get; set; } } A subset of these POCOs implement this additional interface: interface IDeletableObject : IIdObject { bool IsDeleted { get; set; } } I have a repository hierarchy that looks something like this: IRepository<T <: BasicRepository<T <: ValidatingRepository<T (where T is IIdObject) I'm trying to add a FilteringRepository to the hierarchy such that all of the POCOs that implement IDeletableObject have a Where(p => p.IsDeleted == false) filter applied before any other queries take place. My goal is to avoid duplicating the hierarchy solely for IDeletableObjects. My first attempt looked like this: public override IQueryable<T> Query() { return base.Query().Where(t => ((IDeletableObject)t).IsDeleted == false); } This works well with LINQ to Objects, but when I switch to an EF backend I get: "LINQ to Entities only supports casting Entity Data Model primitive types." I went on to try some fancier parameterized solutions, but they ultimately failed because I couldn't make T covariant in the following case for some reason I don't quite understand: interface IQueryFilter<out T> // error { Expression<Func<T, bool>> GetFilter(); } I'd be happy to go into more detail on my more complicated solutions if it would help, but I think I'll stop here for now in hope that someone might have an idea for me to try. Thanks very much in advance!

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  • Length-1 arrays can be converted to python scalars error? python

    - by Randy
    from numpy import * from pylab import * from math import * def LogisticMap(a,x): return 4.*a*x*(1.-x) def CosineMap(a,x): return a*cos(x/(2.*pi)) def TentMap(a,x): if x>= 0 or x<0.5: return 2.*a*x if x>=0.5 or x<=1.: return 2.*a*(1.-x) a = 0.98 N = 40 xaxis = arange(0.0,N,1.0) Func = CosineMap subplot(211) title(str(Func.func_name) + ' at a=%g and its second iterate' %a) ylabel('X(n+1)') # set y-axis label plot(xaxis,Func(a,xaxis), 'g', antialiased=True) subplot(212) ylabel('X(n+1)') # set y-axis label xlabel('X(n)') # set x-axis label plot(xaxis,Func(a,Func(a,xaxis)), 'bo', antialiased=True) My program is supposed to take any of the three defined functions and plot it. They all take in a value x from the array xaxis from 0 to N and then return the value. I want it to plot a graph of xaxis vs f(xaxis) with f being any of the three above functions. The logisticmap function works fine, but for CosineMap i get the error "only length-1 arrays can be converted to python scalars" and for TentMap i get error "The truth value of an array with more than one element is ambiguous, use a.any() or a.all()". My tent map function is suppose to return 2*a*x if 0<=x<0.5 and it's suppose to return 2*a*(1-x) if 0.5<=0<=1.

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  • Removing dotted border without setting NoFocus in Windows PyQt

    - by Cryptite
    There are a few questions on SO about this, all of which seem to say that the only way to remove the dotted border is to set the focusPolicy on widget/item in question to NoFocus. While this works as a temporary fix, this prevents further interaction with said widget/item in the realm of other necessary focusEvents. Said border in question: Here's an example of why this doesn't work. I have a Non-Modal widget popup, think a lightbox for an image. I want to detect a mousePressEvent outside of the widget and close the widget as a result. To do this, I should catch the focusOutEvent. However, if a vast majority of widgets in my program are set as NoFocus (to remove the border issue), then I cannot catch the focusOutEvent because, you guessed it, they have no focus policy. Here's another example: I have a QTreeWidget that is subclassed so I can catch keyPressEvents for various reasons. The QTreeWidget is also set as NoFocus to prevent the border. Because of this, however, the widget never has focus and therefore no keyPressEvents can be caught. A workaround for this (kludgy, imo) is to use the widget's grabKeyboard class, which is dangerous if I forget to releaseKeyboard later. This is not optimal. So then the question is, is there a way to remove this weird (mostly just ugly) dotted border without turning off focus for everything in my app? Thanks in advance!

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