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  • Serializing Class Derived from Generic Collection yet Deserializing the Generic Collection

    - by Stacey
    I have a Repository Class with the following method... public T Single<T>(Predicate<T> expression) { using (var list = (Models.Collectable<T>)System.Xml.Serializer.Deserialize(typeof(Models.Collectable<T>), FileName)) { return list.Find(expression); } } Where Collectable is defined.. [Serializable] public class Collectable<T> : List<T>, IDisposable { public Collectable() { } public void Dispose() { } } And an Item that uses it is defined.. [Serializable] [System.Xml.Serialization.XmlRoot("Titles")] public partial class Titles : Collectable<Title> { } The problem is when I call the method, it expects "Collectable" to be the XmlRoot, but the XmlRoot is "Titles" (all of object Title). I have several classes that are collected in .xml files like this, but it seems pointless to rewrite the basic methods for loading each up when the generic accessors do it - but how can I enforce the proper root name for each file without hard coding methods for each one? The [System.Xml.Serialization.XmlRoot] seems to be ignored. When called like this... var titles = Repository.List<Models.Title>(); I get the exception <Titlesxmlns=''> was not expected. The XML is formatted such as. .. <?xml version="1.0" encoding="utf-16"?> <Titles xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Title> <Id>442daf7d-193c-4da8-be0b-417cec9dc1c5</Id> </Title> </Titles> Here is the deserialization code. public static T Deserialize<T>(String xmlString) { System.Xml.Serialization.XmlSerializer XmlFormatSerializer = new System.Xml.Serialization.XmlSerializer(typeof(T)); StreamReader XmlStringReader = new StreamReader(xmlString); //XmlTextReader XmlFormatReader = new XmlTextReader(XmlStringReader); try { return (T)XmlFormatSerializer.Deserialize(XmlStringReader); } catch (Exception e) { throw e; } finally { XmlStringReader.Close(); } }

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  • .NET RegEx for letters and spaces

    - by user70192
    I am trying to create a regular expression in C# that allows only alphanumeric characters and spaces. Currently, I am trying the following: string pattern = @"^\w+$"; Regex regex = new Regex(pattern); if (regex.IsMatch(value) == false) { // Display error } What am I doing wrong?

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  • How one extends JNA interface mappings? (Java)

    - by rukoche
    User32 interface (platform library) is missing some WinAPI functions, so I tried extending it: package myapp import com.sun.jna.platform.win32.W32API public interface User32 extends com.sun.jna.platform.win32.User32 { myapp.User32 INSTANCE boolean IsWindow(W32API.HWND hWnd) } But then calling myapp.User32.INSTANCE.FindWindow(..) results in java.lang.NullPointerException: Cannot invoke method FindWindow() on null object

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  • String generation with regex criteria

    - by menjaraz
    I wonder wether it is feasible to implement an optimal string generator Class meeting the following requirements: Generation criteria using regex Lexicographical order enumeration. Count propetry Indexed access I don't feel comfortable with regular expression: I cannot come up with a starting piece of code but I just think of a naive implementation using a TList as a base class and use a filter (Regex) against "brute force" generated string. Thank you.

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  • Averaging initial values for rolling series

    - by Dave Jarvis
    Question Given a maximum sliding window size of 40 (i.e., the set of numbers in the list cannot exceed 40), what is the calculation to ensure a smooth averaging transition as the set size grows from 1 to 40? Problem Description Creating a trend line for a set of data has skewed initial values. The complete set of values is unknown at runtime: they are provided one at a time. It seems like a reverse-weighted average is required so that the initial values are averaged differently. In the image below the leftmost data for the trend line are incorrectly averaged. Current Solution Created a new type of ArrayList subclass that calculates the appropriate values and ensures its size never goes beyond the bounds of the sliding window: /** * A list of Double values that has a maximum capacity enforced by a sliding * window. Can calculate the average of its values. */ public class AveragingList extends ArrayList<Double> { private float slidingWindowSize = 0.0f; /** * The initial capacity is used for the sliding window size. * @param slidingWindowSize */ public AveragingList( int slidingWindowSize ) { super( slidingWindowSize ); setSlidingWindowSize( ( float )slidingWindowSize ); } public boolean add( Double d ) { boolean result = super.add( d ); // Prevent the list from exceeding the maximum sliding window size. // if( size() > getSlidingWindowSize() ) { remove( 0 ); } return result; } /** * Calculate the average. * * @return The average of the values stored in this list. */ public double average() { double result = 0.0; int size = size(); for( Double d: this ) { result += d.doubleValue(); } return (double)result / (double)size; } /** * Changes the maximum number of numbers stored in this list. * * @param slidingWindowSize New maximum number of values to remember. */ public void setSlidingWindowSize( float slidingWindowSize ) { this.slidingWindowSize = slidingWindowSize; } /** * Returns the number used to determine the maximum values this list can * store before it removes the first entry upon adding another value. * @return The maximum number of numbers stored in this list. */ public float getSlidingWindowSize() { return slidingWindowSize; } } Resulting Image Example Input The data comes into the function one value at a time. For example, data points (Data) and calculated averages (Avg) typically look as follows: Data: 17.0 Avg : 17.0 Data: 17.0 Avg : 17.0 Data: 5.0 Avg : 13.0 Data: 5.0 Avg : 11.0  Related Sites The following pages describe moving averages, but typically when all (or sufficient) data is known: http://www.cs.princeton.edu/introcs/15inout/MovingAverage.java.html http://stackoverflow.com/questions/2161815/r-zoo-series-sliding-window-calculation http://taragana.blogspot.com/ http://www.dreamincode.net/forums/index.php?showtopic=92508 http://blogs.sun.com/nickstephen/entry/dtrace_and_moving_rolling_averages

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  • How do I set values for a class without using any setter methods?

    - by fari
    Please can anyone help me public class KalaGameState implements Cloneable { // your code goes here public KalaGameState(int startingStones) throws InvalidStartingStonesException { // your code goes here } public int getTurn() { // your code goes here } public int getKala(int playerNum) throws IllegalPlayerNumException { // your code goes here } public int getNumStones(int sidePitNum) throws IllegalSidePitNumException { // your code goes here } public int getNumStones(int playerNum, int sidePitNum) throws IllegalPlayerNumException, IllegalSidePitNumException { // your code goes here } public int getScore(int playerNum) throws IllegalPlayerNumException { // your code goes here } private int getSidePitArrayIndex(int sidePitNum) throws IllegalSidePitNumException { // your code goes here } public boolean gameOver() { // your code goes here } public void makeMove(int sidePitNum) throws IllegalSidePitNumException, IllegalMoveException { // your code goes here } }

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  • What are 'len', 'dir', 'vars' named?

    - by johannix
    I was wondering what language to use when talking about a function that takes in a specific object, acts on it and returns something else. Clearly they're functions, but I was wondering if there's a more specific term. A couple examples of Python built-in functions that fit this spec are: 'len', 'dir', 'vars' I thought it was 'predicate', but apparently that's specific to functions that return a boolean value.

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  • Case-Insensitive String Comparison not working in C#?

    - by SB2055
    Based on the answer to this question: C# Case insensitive string compare I'm trying to do a case-insensitive comparison without using Compare or ToLower: var user = db.Users.FirstOrDefault(s => String.Equals(s.Username, username, StringComparison.OrdinalIgnoreCase)); However I get an error: Incorrect number of arguments supplied for call to method 'Boolean Equals(System.String, System.String, System.StringComparison)' What am I doing wrong?

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  • Simple string pattern matching

    - by Joonas Trussmann
    What's the easiest way of doing simple pattern matching a la .something.com something.com/ something.com/somefolder/*.jpg in the iPhone SDK? At this point it looks like I'm going to have to use a regular expression library of some sort, which is really overkill when all I need is simple wildcard matching. None of the standard NSString methods seem to be available on the iPhone.

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  • Why doesn't the conditional operator correctly allow the use of "null" for assignment to nullable ty

    - by Daniel Coffman
    This will not compile, stating "Type of conditional expression cannot be determined because there is no implicit conversion between 'System.DateTime' and ''" task.ActualEndDate = TextBoxActualEndDate.Text != "" ? DateTime.Parse(TextBoxActualEndDate.Text) : null; This works just fine if (TextBoxActualEndDate.Text != "") task.ActualEndDate = DateTime.Parse(TextBoxActualEndDate.Text); else task.ActualEndDate = null;

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  • Is this way of storing typed objects in memory good?

    - by Pindatjuh
    This is an "is this okay, or can it be done better" question. Topic: Storing typed objects in memory. Background information: I'm building a compiler for the x86-32 platform for my language. My goal includes typed objects. Idea: Every primitive is a semi-class (it can be used as if it was a normal class, but it's stored more compact). Every class is represented by primitives and some meta-data (containing class-properties, inheritance stuff, etc.). The meta-data is complex: it doesn't use fields but instead context-switches. For primitives, the meta-data is very small, compared to a "real" class, which is alot bigger. This enables another idea that "primitives are objects", in my language, which I found nessecairy. Example: If I have an array of 32 booleans, then the pure content of this array is exactly 4 byte (32 bits of booleans). The meta-data will contain flags that the type is an array of booleans, which contains 32 entries. The meta-data is very compacted, on bit-level: using a sort of "packing" mechanism, which is read by a FSM at runtime, when doing inspection of the type (like when passing the object to methods for checking, etc.) For instance (read from left to right, top to bottom, remember vertical possition when going to the right, and check nearest column header for meaning of switch): Primitive? Array? Type-Meta 1 Byte? || Size (1 byte) 1 1 [...] 1 [...] done 0 2 Bytes? || Size (2 bytes) 1 [...] done || Size (4 bytes) 0 [...] done Integer? 1 Byte? 2 Bytes? 0 1 0 1 done 1 done 0 done Boolean? Byte? 0 1 0 done 1 done More-Primitives 0 .... Class-Stuff (Huge) 0 ... (After reaching done the data is inserted. || = byte alignement. [...] is variable sized. ... is not described here, for simplicity. And let's call them cost-based-data-structures.) For an array of 32 booleans containing all true values, the memory for this type would be (read top-down): 1 Primitive 1 Array 1 ArrayType: Primitive 0 Not-Array 0 Not-Integer 1 Boolean 0 Not-Byte (thus bit) 1 Integer Size: 1 Byte 00100000 Array size 11111111 11111111 11111111 11111111 Data Thus, 8 bytes represent 32 booleans in an array: 11100101 00100000 11111111 11111111 11111111 11111111 Is this okay, or can it be done better?

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  • Seam - list all components

    - by Walter White
    Hi all, I would like to get a list of all the components so that I can further process them. Is this possible, if so, how can I do that? I don't believe I can observe all postCreate events since it is simply an exact match and not a regular expression. @Observer("org.jboss.seam.postCreate.") You can only observe those events and not * as it is put into a map where the key is a string. Any ideas? Walter

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  • vb.net system beep sound on XP

    - by Toby
    Is it possible to have a vb.net program sound the PC's internal speaker? you know the one that produces C's \a BELL I have tried beep(), but this only produces the error sound on the sound card. I have also tried <Runtime.InteropServices.DllImport("KERNEL32.DLL", EntryPoint:="Beep", SetLastError:=True, _ CharSet:=Runtime.InteropServices.CharSet.Unicode, ExactSpelling:=True, _ CallingConvention:=Runtime.InteropServices.CallingConvention.StdCall)> _ Public Shared Function _ aBeep(ByVal dwFreq As Integer, ByVal dwDuration As Integer) _ As Boolean End Function With no joy apparently its only good on vista and above Any suggestions? thanks

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  • Turtle Graphics as a Haskell Monad

    - by iliis
    I'm trying to implement turtle graphis in Haskell. The goal is to be able to write a function like this: draw_something = do fordward 100 right 90 forward 100 ... and then have it produce a list of points (maybe with additional properties): > draw_something (0,0) 0 -- start at (0,0) facing east (0 degrees) [(0,0), (0,100), (-100,100), ...] I have all this working in a 'normal' way, but I fail to implement it as a Haskell Monad and use the do-notation. The basic code: data State a = State (a, a) a -- (x,y), angle deriving (Show, Eq) initstate :: State Float initstate = State (0.0,0.0) 0.0 -- constrain angles to 0 to 2*pi fmod :: Float -> Float fmod a | a >= 2*pi = fmod (a-2*pi) | a < 0 = fmod (a+2*pi) | otherwise = a forward :: Float -> State Float -> [State Float] forward d (State (x,y) angle) = [State (x + d * (sin angle), y + d * (cos angle)) angle] right :: Float -> State Float -> [State Float] right d (State pos angle) = [State pos (fmod (angle+d))] bind :: [State a] -> (State a -> [State a]) -> [State a] bind xs f = xs ++ (f (head $ reverse xs)) ret :: State a -> [State a] ret x = [x] With this I can now write > [initstate] `bind` (forward 100) `bind` (right (pi/2)) `bind` (forward 100) [State (0.0,0.0) 0.0,State (0.0,100.0) 0.0,State (0.0,100.0) 1.5707964,State (100.0,99.99999) 1.5707964] And get the expected result. However I fail to implement this as an instance of Monad. instance Monad [State] where ... results in `State' is not applied to enough type arguments Expected kind `*', but `State' has kind `* -> *' In the instance declaration for `Monad [State]' And if I wrap the list in a new object data StateList a = StateList [State a] instance Monad StateList where return x = StateList [x] I get Couldn't match type `a' with `State a' `a' is a rigid type variable bound by the type signature for return :: a -> StateList a at logo.hs:38:9 In the expression: x In the first argument of `StateList', namely `[x]' In the expression: StateList [x] I tried various other versions but I never got it to run as I'd like to. What am I doing wrong? What do I understand incorrectly?

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  • Java2D Distance Collision Detection

    - by Trizicus
    My current setup is only useful once collision has been made; obviously there has to be something better than this? public boolean CollisionCheck(Rectangle rect1, Rectangle rect2) { if(rect1.intersects(rect2)) { return true; } return false; } How can I do preemptive collision detection?

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  • How can I test when a feature was added to Perl?

    - by Eric Strom
    Are there any services similar to codepad that will allow you to test Perl constructs on old versions of perl? Ideally, a system where you could enter an expression and it will tell you the oldest version of perl that it will work with. Of course it's possible to use CPANTS for this, but that seems like an abuse of the service (if only for making the BackPan bigger). And it could take several days/weeks to get decent test coverage on old versions.

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  • Java: minimum number of operations for conjunctive inequalities?

    - by HH
    I try to simplify conditionals in for (int t=0,size=fo.getPrintViewsPerFile().size();t<size&&t<countPerFile;t++){, more precisely: t<s&&t<c You need to compare two times, then calc the boolean value from them. Is there any simpler way to do it? If no, how can you prove it? I can simplify it to some extent, proof tree.

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  • Multiple foreign keys to same table using Elixir

    - by Suvir
    Hello, I am new to ORMs in general. I have a table (lets call it Entity) with columns -- ID expression type ( can be 'long_word', 'short_word' or 'sentence' ) Often, the first two types occur in a 'sentence', so, I want to maintain another table which maps 'Sentences' to 'long_word' or 'short_word' using the 'ID' field. All i need is another table with 2 'Integer fields' referring to 'ID' as a foreign key. But, how do i do this in Elixir? Thanks a lot...

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  • validate hostname in Python

    - by kostmo
    Following up to Regular expression to match hostname or IP Address? and using Restrictions on valid host names as a reference, what is the most readable, concise way to match/validate a hostname/fqdn (fully qualified domain name) in Python? I've answered with my attempt below, improvements welcome.

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  • Putting update logic in your migrations

    - by Daniel Abrahamsson
    A couple of times I've been in the situation where I've wanted to refactor the design of some model and have ended up putting update logic in migrations. However, as far as I've understood, this is not good practice (especially since you are encouraged to use your schema file for deployment, and not your migrations). How do you deal with these kind of problems? To clearify what I mean, say I have a User model. Since I thought there would only be two kinds of users, namely a "normal" user and an administrator, I chose to use a simple boolean field telling whether the user was an adminstrator or not. However, after I while I figured I needed some third kind of user, perhaps a moderator or something similar. In this case I add a UserType model (and the corresponding migration), and a second migration for removing the "admin" flag from the user table. And here comes the problem. In the "add_user_type_to_users" migration I have to map the admin flag value to a user type. Additionally, in order to do this, the user types have to exist, meaning I can not use the seeds file, but rather create the user types in the migration (also considered bad practice). Here comes some fictional code representing the situation: class CreateUserTypes < ActiveRecord::Migration def self.up create_table :user_types do |t| t.string :name, :nil => false, :unique => true end #Create basic types (can not put in seed, because of future migration dependency) UserType.create!(:name => "BASIC") UserType.create!(:name => "MODERATOR") UserType.create!(:name => "ADMINISTRATOR") end def self.down drop_table :user_types end end class AddTypeIdToUsers < ActiveRecord::Migration def self.up add_column :users, :type_id, :integer #Determine type via the admin flag basic = UserType.find_by_name("BASIC") admin = UserType.find_by_name("ADMINISTRATOR") User.all.each {|u| u.update_attribute(:type_id, (u.admin?) ? admin.id : basic.id)} #Remove the admin flag remove_column :users, :admin #Add foreign key execute "alter table users add constraint fk_user_type_id foreign key (type_id) references user_types (id)" end def self.down #Re-add the admin flag add_column :users, :admin, :boolean, :default => false #Reset the admin flag (this is the problematic update code) admin = UserType.find_by_name("ADMINISTRATOR") execute "update users set admin=true where type_id=#{admin.id}" #Remove foreign key constraint execute "alter table users drop foreign key fk_user_type_id" #Drop the type_id column remove_column :users, :type_id end end As you can see there are two problematic parts. First the row creation part in the first model, which is necessary if I would like to run all migrations in a row, then the "update" part in the second migration that maps the "admin" column to the "type_id" column. Any advice?

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  • Regex negative look-behind in hgignore file

    - by jco
    I'm looking for a way to modify my .hgignore file to ignore all "Properties/AssemblyInfo.cs" files except those in either the "Test/" or the "Tests/" subfolders. I tried using the negative look-behind expression (?<!Test)/Properties/AssemblyInfo\.cs$, but I didn't find a way to "un-ignore" in both folders "Test/" and "Tests/".

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  • In XMLHttpRequest, where is error flag variable?

    - by Tiangolo
    In the XMLHttpRequest Spec it says that: The DONE state has an associated error flag that indicates some type of network error or abortion. It can be either true or false and has an initial value of false. Also says something similar about a "send() flag" in an "OPENED" state. It's said in the specification but not in the IDL and when I create a new XMLHttpRequest I can't find those "flags". Where are those boolean variables?

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