Search Results

Search found 13180 results on 528 pages for 'non interactive'.

Page 434/528 | < Previous Page | 430 431 432 433 434 435 436 437 438 439 440 441  | Next Page >

  • Getting exception when trying to monkey patch pymongo.connection._Pool

    - by Creotiv
    I use pymongo 1.9 on Ubuntu 10.10 with python 2.6.6 When i trying to monkey patch pymongo.connection._Pool i'm getting error on connection: AutoReconnect: could not find master/primary But when i change _Pool class in pymongo.connection module, it work pretty fine. Even if i copy _Pool implementation from pymongo.connection module and will try to monkey patch by the same code, it still giving same exception. I need to remove threading.local from _Pool class, because i use gevent and i need to implement Pool for all mongo connections(for all threads). I use this code: import pymongo class GPool: """A simple connection pool. Uses thread-local socket per thread. By calling return_socket() a thread can return a socket to the pool. Right now the pool size is capped at 10 sockets - we can expose this as a parameter later, if needed. """ # Non thread-locals __slots__ = ["sockets", "socket_factory", "pool_size","sock"] #sock = None def __init__(self, socket_factory): self.pool_size = 10 if not hasattr(self,"sock"): self.sock = None self.socket_factory = socket_factory if not hasattr(self, "sockets"): self.sockets = [] def socket(self): # we store the pid here to avoid issues with fork / # multiprocessing - see # test.test_connection:TestConnection.test_fork for an example # of what could go wrong otherwise pid = os.getpid() if self.sock is not None and self.sock[0] == pid: return self.sock[1] try: self.sock = (pid, self.sockets.pop()) except IndexError: self.sock = (pid, self.socket_factory()) return self.sock[1] def return_socket(self): if self.sock is not None and self.sock[0] == os.getpid(): # There's a race condition here, but we deliberately # ignore it. It means that if the pool_size is 10 we # might actually keep slightly more than that. if len(self.sockets) < self.pool_size: self.sockets.append(self.sock[1]) else: self.sock[1].close() self.sock = None pymongo.connection._Pool = GPool

    Read the article

  • Auto-resolving a hostname in WCF Metadata Publishing

    - by Mike C
    I am running a self-hosted WCF service. In the service configuration, I am using localhost in my BaseAddresses that I hook my endpoints to. When trying to connect to an endpoint using the WCF test client, I have no problem connecting to the endpoint and getting the metadata using the machine's name. The problem that I run into is that the client that is generated from metadata uses localhost in the endpoint URLs it wants to connect to. I'm assuming that this is because localhost is the endpoint URL published by metadata. As a result, any calls to the methods on the service will fail since localhost on the calling machine isn't running the service. What I would like to figure out is if it is possible for the service metadata to publish the proper URL to a client depending on the client who is calling it. For example, if I was requesting the service metadata from a machine on the same network as the server the endpoint should be net.tcp://MYSERVER:1234/MyEndpoint. If I was requesting it from a machine outside the network, the URL should be net.tcp://MYSERVER.mydomain.com:1234/MyEndpoint. And obviously if the client was on the same machine, THEN the URL could be net.tcp://localhost:1234/MyEndpoint. Is this just a flaw in the default IMetadataExchange contract? Is there some reason the metadata needs to publish the information in a non-contextual way? Is there another way I should be configuring my BaseAddresses in order to get the functionality I want? Thanks, Mike

    Read the article

  • Performance question: Inverting an array of pointers in-place vs array of values

    - by Anders
    The background for asking this question is that I am solving a linearized equation system (Ax=b), where A is a matrix (typically of dimension less than 100x100) and x and b are vectors. I am using a direct method, meaning that I first invert A, then find the solution by x=A^(-1)b. This step is repated in an iterative process until convergence. The way I'm doing it now, using a matrix library (MTL4): For every iteration I copy all coeffiecients of A (values) in to the matrix object, then invert. This the easiest and safest option. Using an array of pointers instead: For my particular case, the coefficients of A happen to be updated between each iteration. These coefficients are stored in different variables (some are arrays, some are not). Would there be a potential for performance gain if I set up A as an array containing pointers to these coefficient variables, then inverting A in-place? The nice thing about the last option is that once I have set up the pointers in A before the first iteration, I would not need to copy any values between successive iterations. The values which are pointed to in A would automatically be updated between iterations. So the performance question boils down to this, as I see it: - The matrix inversion process takes roughly the same amount of time, assuming de-referencing of pointers is non-expensive. - The array of pointers does not need the extra memory for matrix A containing values. - The array of pointers option does not have to copy all NxN values of A between each iteration. - The values that are pointed to the array of pointers option are generally NOT ordered in memory. Hopefully, all values lie relatively close in memory, but *A[0][1] is generally not next to *A[0][0] etc. Any comments to this? Will the last remark affect performance negatively, thus weighing up for the positive performance effects?

    Read the article

  • PNG Transparency Problems in IE8

    - by user138777
    I'm having problems with a transparent PNG image showing black dithered pixel artifacts around the edge of the non transparent part of the image. It only does this in Internet Explorer and it only does it from a Javascript file it is used in. Here's what I'm talking about... http://70.86.157.71/test/test3.htm (link now dead) ...notice the girl in the bottom right corner. She has artifacts around her in IE8 (I haven't tested it in previous versions of IE, but I'm assuming it probably does the same). It works perfectly in Firefox and Chrome. The image is loaded from a Javascript file to produce the mouseover effect. If you load the image all by itself, it works fine. Here's the image... http://70.86.157.71/test/consultant2.png Does anyone know how to fix this? The image was produced in Photoshop CS3. I've read things about removing the Gama, but that apparently was in previous versions of Photoshop and when I load it in TweakPNG, it doesn't have Gama. Please help!

    Read the article

  • How can I work around WinXP using ports 1025-5000 as ephemeral?

    - by Chris Dolan
    If you create a TCP client socket with port 0 instead of a non-zero port, then the operating system chooses any free ephemeral port for you. Most OSes choose ephemeral ports from the IANA dynamic port range of 49152-65535. However in Windows Server 2003 and earlier (including XP) Microsoft used ports 1025-5000 as the ephemeral range, according to their bind() documentation. I run multiple Java services on the same hardware. On rare occasions, this range collides with well-known ports that I use for other services (e.g. port 4160 for Jini discovery). While rare, this has caused real problems. Is there any easy way to tell Windows or Java to use a different port range for client sockets? Microsoft's docs indicate that I can change the high end of that range via the MaxUserPort TcpIP registry setting, but I see no way to change the low end. Update: I've made some progress on this. It looks like Microsoft has a concept of reserved ports that are exceptions to the ephemeral port range. There's a registry setting that lets you change this permanently and apparently there must be an API to do the same thing because there's a data structure that holds high/low values for reserved port ranges, but I can't find the actual function call anywhere... The registry solution may work, but now I'm fixated on this API.

    Read the article

  • Rhinomocks DynamicMock question

    - by epitka
    My dynamic mock behaves as Parial mock, meaning it executes the actual code when called. Here are the ways I tried it var mockProposal = _mockRepository.DynamicMock<BidProposal>(); SetupResult.For(mockProposal.CreateMarketingPlan(null, null, null)).IgnoreArguments().Repeat.Once().Return( copyPlan); //Expect.Call(mockProposal.CreateMarketingPlan(null, null, null)).IgnoreArguments().Repeat.Once().Return( // copyPlan); // mockProposal.Expect(x => x.CreateMarketingPlan(null, null, null)).IgnoreArguments().Return(copyPlan).Repeat.Once(); Instead of just returning what I expect it runs the code in the method CreateMarketingPlan Here is the error: System.NullReferenceException: Object reference not set to an instance of an object. at Policy.Entities.MarketingPlan.SetMarketingPlanName(MarketingPlanDescription description) in MarketingPlan.cs: line 76 at Policy.Entities.MarketingPlan.set_MarketingPlanDescription(MarketingPlanDescription value) in MarketingPlan.cs: line 91 at Policy.Entities.MarketingPlan.Create(PPOBenefits ppoBenefits, MarketingPlanDescription marketingPlanDescription, MarketingPlanType marketingPlanType) in MarketingPlan.cs: line 23 at Policy.Entities.BidProposal.CreateMarketingPlan(PPOBenefits ppoBenefits, MarketingPlanDescription marketingPlanDescription, MarketingPlanType marketingPlanType) in BidProposal.cs: line 449 at Tests.Policy.Services.MarketingPlanCopyServiceTests.can_copy_MarketingPlan_with_all_options() in MarketingPlanCopyServiceTests.cs: line 32 Update: I figured out what it was. Method was not "virtual" so it could not be mocked because non-virtual methods cannot be proxied.

    Read the article

  • Winsock tcp/ip Socket listening but connection refused, race condition?

    - by Wayne
    Hello folks. This involves two automated unit tests which each start up a tcp/ip server that creates a non-blocking socket then bind()s and listen()s in a loop on select() for a client that connects and downloads some data. The catch is that they work perfectly when run separately but when run as a test suite, the second test client will fail to connect with WSACONNREFUSED... UNLESS there is a Thread.Sleep() of several seconds between them??!!! Interestingly, there is retry loop every 1 second for connecting after any failure. So the second test loops for a while until timeout after 10 minutes. During that time, netstat -na shows the correct port number is in the LISTEN state for the server socket. So if it is in the listen state? Why won't it accept the connection? In the code, there are log messages that show the select NEVER even gets a socket ready to read (which means ready to accept a connection when it applies to a listening socket). Obviously the problem must be related to some race condition between finishing one test which means close() and shutdown() on each end of the socket, and the start up of the next. This wouldn't be so bad if the retry logic allowed it to connect eventually after a couple of seconds. However it seems to get "gummed up" and won't even retry. However, for some strange reason the listening socket SAYS it's in the LISTEN state even through keeps refusing connections. So that means it's the Windoze O/S which is actually catching the SYN packet and returning a RST packet (which means "Connection Refused"). The only other time I ever saw this error was when the code had a problem that caused hundreds of sockets to get stuck in TIME_WAIT state. But that's not the case here. netstat shows only about a dozen sockets with only 1 or 2 in TIME_WAIT at any given moment. Please help.

    Read the article

  • Linked Measure Groups and Local Dimensions

    - by ekoner
    Mulling over something I've been reading up on. According to Chris Webb, A linked measure group can only be used with dimensions from the same database as the source measure group. So I took this to mean as long as two cubes share a database, a linked measure group can be used with a dimension. So I created a new cube and added a local measure group, a local dimension and a linked measure group. However, I can't create a relationship between the linked measure group and the local dimension even though they are within the same database. I get the message below: Regular relationships in the current database between non-linked (local) dimensions and linked measure groups cannot be edited. These relationship can only be created through the wizard. This dialog can be used to delete these relationships. I see that I can go to the original cube and add the dimension there, but does the message below mean I have an alternative? I just know it's going to be something simple and trivial! Thanks for reading.

    Read the article

  • haml - if-else with different identations

    - by egarcia
    Hi everyone, I'm trying to render a calendar with rails and haml. The dates used come from a variable called @dates. It is a Date range that contains the first and last days to be presented on the calendar. The first day is always sunday and the last one is always monday. I'm planning to render a typical calendar, with one column per weekday (sunday is going to be the first day of the week) using an html table. So, I need to put a %tr followed by a %td on sundays, but the rest of the days I just need a %td. I'm having trouble modelling that on haml. This seems to require different levels of identation, and that's something it doesn't like. Here's my failed attempt: %table %tr %th= t('date.day_names')[0] # Sunday %th= t('date.day_names')[1] %th= t('date.day_names')[2] %th= t('date.day_names')[3] %th= t('date.day_names')[4] %th= t('date.day_names')[5] %th= t('date.day_names')[6] # Monday [email protected] do |date| - if(date.wday == 0) # if date is sunday %tr %td=date.to_s - else %td=date.to_s This doesn't work the way I want. The %tds for the non-sunday days appear outside of the %tr: <tr> <td>2010-04-24</td> </tr> <td>2010-04-25</td> <td>2010-04-26</td> <td>2010-04-27</td> <td>2010-04-28</td> <td>2010-04-29</td> <td>2010-04-30</td> I tried adding two more spaces to the else but then haml complained about improper identation. What's the best way to do this? Note: I'm not interested on rendering the calendar using unordered lists. Please don't suggest that.

    Read the article

  • drupal form textfield #default_value not working

    - by alvin.ng
    I am working on a custom module with multi-page form on drupal 6. I found that #default_value is not working when my '#type' = 'textfield'. However, when '#type'='textarea', it displays correctly with the '#default_value' specified. Basically, I wrote a FormFactory to return different form definition ($form) based on the post parameter received. Initially, it returns the display of directories list, user then selects from radio buttos until a specific directory contains a xml file, it will become edit form. The edit form will have text fields display the data (#default_value) inside the xml file, however the type 'textarea' works here rather than 'textfield'. How can I make my '#default_value' work in this case? Below is the non-working field definition: $form['pageset']['newsTitle'] = array( '#type' => 'textfield', '#title' => 'News Title', '#default_value' => "{$element->newsTitle}", '#rows' => 1, '#required' => TRUE, ); Then I changed it to textarea as shown below to make it work: $form['pageset']['newsTitle'] = array( '#type' => 'textarea', '#title' => 'News Title', '#default_value' => "{$element->newsTitle}", '#rows' => 1, '#required' => TRUE, );

    Read the article

  • Help on understanding multiple columns on an index?

    - by Xaisoft
    Assume I have a table called "table" and I have 3 columns, a, b, and c. What does it mean to have a non-clustered index on columns a,b? Is a nonclustered index on columns a,b the same as a nonclustered index on columns b,a? (Note the order). Also, Is a nonclustered index on column a the same as a nonclustered index on a,c? I was looking at the website sqlserver performance and they had these dmv scripts where it would tell you if you had overlapping indexes and I believe it was saying that having an index on a is the same as a,b, so it is redundant. Is this true about indexes? One last question is why is the clustered index put on the primary key. Most of the time the primary key is not queried against, so shouldn't the clustered index be on the most queried column. I am probably missing something here like having it on the primary key speeds up joins? Great explanations. Should I turn this into a wiki and change the title index explanation?

    Read the article

  • serialport error

    - by I__
    i have the following code: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Threading; namespace WindowsFormsApplication1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } public class ThreadWork { public static void DoWork() { serialPort1.Open(); serialPort1.Write("AT+CMGF=1\r\n"); //Thread.Sleep(500); serialPort1.Write("AT+CNMI=2,2\r\n"); //Thread.Sleep(500); serialPort1.Write("AT+CSCA=\"+4790002100\"\r\n"); //Thread.Sleep(500); serialPort1.DataReceived += serialPort1_DataReceived_1; } } private void Form1_Load(object sender, EventArgs e) { ThreadStart myThreadDelegate = new ThreadStart(ThreadWork.DoWork); Thread myThread = new Thread(myThreadDelegate); myThread.Start(); } private void serialPort1_DataReceived_1(object sender, System.IO.Ports.SerialDataReceivedEventArgs e) { string response = serialPort1.ReadLine(); this.BeginInvoke(new MethodInvoker(() => textBox1.AppendText(response + "\r\n"))); } } } and for all the serialport1 lines i am getting this error: Error 1 An object reference is required for the non-static field, method, or property 'WindowsFormsApplication1.Form1.serialPort1' C:\Users\alexluvsdanielle\AppData\Local\Temporary Projects\WindowsFormsApplication1\Form1.cs 23 17 WindowsFormsApplication1 what am i doing wrong?

    Read the article

  • Image drawing library for Haskell?

    - by absz
    I'm working on a Haskell program for playing spatial games: I have a graph of a bunch of "individuals" playing the Prisoner's Dilemma, but only with their immediate neighbors, and copying the strategies of the people who do best. I've reached a point where I need to draw an image of the world, and this is where I've hit problems. Two of the possible geometries are easy: if people have four or eight neighbors each, then I represent each one as a filled square (with color corresponding to strategy) and tile the plane with these. However, I also have a situation where people have six neighbors (hexagons) or three neighbors (triangles). My question, then, is: what's a good Haskell library for creating images and drawing shapes on them? I'd prefer that it create PNGs, but I'm not incredibly picky. I was originally using Graphics.GD, but it only exports bindings to functions for drawing points, lines, arcs, ellipses, and non-rotated rectangles, which is not sufficient for my purposes (unless I want to draw hexagons pixel by pixel*). I looked into using foreign import, but it's proving a bit of a hassle (partly because the polygon-drawing function requires an array of gdPoint structs), and given that my requirements may grow, it would be nice to use an in-Haskell solution and not have to muck about with the FFI (though if push comes to shove, I'm willing to do that). Any suggestions? * That is also an option, actually; any tips on how to do that would also be appreciated, though I think a library would be easier.

    Read the article

  • Jquery set tr with empty td lower than with text in td

    - by PavelBY
    I have html, and jquery for sorting my table (also there is non-standart sorting (with multi-tbody)). My code could be found here: http://jsfiddle.net/GuRxj/ As you can see there, td with prices (on russian ????) are sorted ascending (but tech-as not!? why? (it a question too))... But as you see, i need to send this tr's with prices to top of this tbody (now there are in the bottom), while empty-price-tr send to bottom... How to do this? part of js: $('.prcol').click(function(e) { var $sort = this; var $table = $('#articles-table'); var $rows = $('tbody.analogs_art > tr',$table); $rows.sort(function(a, b){ var keyA = $('td:eq(3)',a).text(); var keyB = $('td:eq(3)',b).text(); if (keyA.length > 0 && keyB.length > 0) { if($($sort).hasClass('asc')){ console.log("bbb"); return (keyA > keyB) ? 1 : 0; } else { console.log(keyA+"-"+keyB); return (keyA > keyB) ? 1 : 0; } } }); $.each($rows, function(index, row){ //console.log(row); $table.append(row); //$("table.123").append(row); }); e.preventDefault(); });

    Read the article

  • Hierarchical object model with property inheritance and event bubbling?

    - by Winston Fassett
    I'm writing a document-based client application and I need a DOM or WPF-like, but non-visual model that: Is a tree composed of elements Can accept an unlimited number of custom properties that get/set any CLR type, including collections. Can inherit their values from their parent Can inherit their default values from an ancestor Can be derived/calculated from other properties, ancestors, or descendants Support event bubbling / tunneling There will be a core set of properties but other plugins may add their own or even create custom documents Supports full inspection by the owning document in order to persist the tree and attributes in an XML format. I realize that's a tall order but I was really hoping there would be something out there to help me get started. Unfortunately WPF DependencyObjects are too closed, proprietary, and coupled to WPF to be of any use as a document model. My needs also have a strong resemblance to the HTML DOM but I haven't been able to find any clean DOM implementations that could be decoupled from HTML or ported to .NET. My current platform is .NET/C# but if anyone knows of anything that might be useful for inspiration or embedding, regardless of the platform, I'd love to know.

    Read the article

  • Can Core Data be used for objects with variable schemas?

    - by glenc
    I'm implementing a new iPhone app and am relatively new to Cocoa development overall. I am at the stage of choosing how the persistence layer of this app will work, and it looks like I'm basically choosing between Core Data and sqlite3. The persisted models in this app are intended to have a schema that is loaded at runtime (from some kind of defn file, probably XML). By which I mean, this app is intended to have objects that are user-definable to some extent, e.g. the Customer type (which has certain built-in fields like "name" and "email") can be modified to have extra fields based on the user's specific needs (e.g. a user might want to add a "favourite fruit" field to their Customer type). Having said that, will Core Data work for an app with a non-baked-in data model like this? I've just started playing around with the Core Data object designer thing in XCode and it seems like this thing wants to work with objects that have fixed fields that are compiled in. I'm definitely trying to take the path of least resistance here, and I can see the benefits of using an Apple-supplied data framework, but don't want to start down that path if it's going to lock me into a data model that's defined at compile time.

    Read the article

  • equality on the sender of an event

    - by Berryl
    I have an interface for a UI widget, two of which are attributes of a presenter. public IMatrixWidget NonProjectActivityMatrix { set { // validate the incoming value and set the field _nonProjectActivityMatrix = value; .... // configure & load non-project activities } public IMatrixWidget ProjectActivityMatrix { set { // validate the incoming value and set the field _projectActivityMatrix = value; .... // configure & load project activities } The widget has an event that both presenter objects subscribe to, and so there is an event handler in the presenter like so: public void OnActivityEntry(object sender, EntryChangedEventArgs e) { // calculate newTotal here .... if (ReferenceEquals(sender, _nonProjectActivityMatrix)) { _nonProjectActivityMatrix.UpdateTotalHours(feedback.ActivityTotal); } else if (ReferenceEquals(sender, _projectActivityMatrix)) { _projectActivityMatrix.UpdateTotalHours(feedback.ActivityTotal); } else { // ERROR - we should never be here } } The problem is that the ReferenceEquals on the sender fails, even though it is the implemented widget that is the sender - the same implemented widget that was set to the presenter attribute! Can anyone spot what the problem / fix is? Cheers, Berryl I didn't know you could edit nicely. Cool. Here is the event raising code: void OnGridViewNumericUpDownEditingControl_ValueChanged(object sender, EventArgs e) { // omitted to save sapce if (EntryChanged == null) return; var args = new EntryChangedEventArgs(activityID, dayID, Convert.ToDouble(amount)); EntryChanged(this, args); } Here is the debugger dump of the presenter attribute, sans namespace info: ?_nonProjectActivityMatrix {WinPresentation.Widgets.MatrixWidgetDgv} [WinPresentation.Widgets.MatrixWidgetDgv]: {WinPresentation.Widgets.MatrixWidgetDgv} Here is the debugger dump of the sender: ?sender {WinPresentation.Widgets.MatrixWidgetDgv} base {Core.GUI.Widgets.Lookup.MatrixWidgetBase<Core.GUI.Widgets.Lookup.DynamicDisplayDto>}: {WinPresentation.Widgets.MatrixWidgetDgv} _configuration: {Domain.Presentation.Timesheet.Matrix.WeeklyMatrixConfiguration} _wrappedWidget: {Win.Widgets.DataGridViewDynamicLookupWidget} AllowUserToAddRows: true ColumnCount: 11 Count: 4 EntryChanged: {Method = {Void OnActivityEntry(System.Object, Smack.ConstructionAdmin.Domain.Presentation.Timesheet.Matrix.EntryChangedEventArgs)}} SelectedCell: {DataGridViewNumericUpDownCell { ColumnIndex=3, RowIndex=3 }} SelectedCellValue: "0.00" SelectedColumn: {DataGridViewNumericUpDownColumn { Name=MONDAY, Index=3 }} SelectedItem: {'AdministrativeActivity: 130-04', , AdministrativeTime, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00, 0.00} Berryl

    Read the article

  • trackroll does not works as i want or expect to do,blackberry

    - by SWATI
    i am working on blackberry curve 8300 i have added some components in the main screen,now i want to move the focus vertically when the trackball moves up or down and move the focus horizontally when track-Wheel moves left or right. ================================================================================== --Title area that contains a focusable field(BACK)-- --Non focusable Label field that indicates the name of the user-- --A horizontal field manager1 that contains 4 buttons-- --A horizontal field manager2 that contains 4 buttons-- --A horizontal field manager2 that contains 4 buttons-- ================================================================================== now suppose currently focus is on BACK button and i scroll the track-wheel downwards then, focus should come on 1st button of manager1 Again when i scroll downwards,then focus should come on the 1st button of manager2 and not the 2nd button of manager1(as its happening on device) my code is ::: protected boolean trackwheelRoll(int amount, int status, int time) { focusIndex = this.getFieldWithFocusIndex(); System.out.println("focus index ::::::::::::::::"+focusIndex); Field f; if(focusIndex!=0) { if(amount==-1) { //move up if(focusIndex>=0) { focusIndex = focusIndex-1; f = getField(focusIndex); f.setFocus(); } } if(amount==1) { //moving down if(focusIndex<=3) { f = getField(++focusIndex); f.setFocus(); } } } return super.trackwheelRoll(amount, status, time); } even after this control moves abruptly on simulator but on device no change took place

    Read the article

  • Lazy Sequences that "Look Ahead" for Project Euler Problem 14

    - by ivar
    I'm trying to solve Project Euler Problem 14 in a lazy way. Unfortunately, I may be trying to do the impossible: create a lazy sequence that is both lazy, yet also somehow 'looks ahead' for values it hasn't computed yet. The non-lazy version I wrote to test correctness was: (defn chain-length [num] (loop [len 1 n num] (cond (= n 1) len (odd? n) (recur (inc len) (+ 1 (* 3 n))) true (recur (inc len) (/ n 2))))) Which works, but is really slow. Of course I could memoize that: (def memoized-chain (memoize (fn [n] (cond (= n 1) 1 (odd? n) (+ 1 (memoized-chain (+ 1 (* 3 n)))) true (+ 1 (memoized-chain (/ n 2))))))) However, what I really wanted to do was scratch my itch for understanding the limits of lazy sequences, and write a function like this: (def lazy-chain (letfn [(chain [n] (lazy-seq (cons (if (odd? n) (+ 1 (nth lazy-chain (dec (+ 1 (* 3 n))))) (+ 1 (nth lazy-chain (dec (/ n 2))))) (chain (+ n 1)))))] (chain 1))) Pulling elements from this will cause a stack overflow for n2, which is understandable if you think about why it needs to look 'into the future' at n=3 to know the value of the tenth element in the lazy list because (+ 1 (* 3 n)) = 10. Since lazy lists have much less overhead than memoization, I would like to know if this kind of thing is possible somehow via even more delayed evaluation or queuing?

    Read the article

  • How to provide js-ctypes in a spidermonkey embedding?

    - by Triston J. Taylor
    Summary I have looked over the code the SpiderMonkey 'shell' application uses to create the ctypes JavaScript object, but I'm a less-than novice C programmer. Due to the varying levels of insanity emitted by modern build systems, I can't seem to track down the code or command that actually links a program with the desired functionality. method.madness This js-ctypes implementation by The Mozilla Devs is an awesome addition. Since its conception, scripting has been primarily used to exert control over more rigorous and robust applications. The advent of js-ctypes to the SpiderMonkey project, enables JavaScript to stand up and be counted as a full fledged object oriented rapid application development language flying high above 'the bar' set by various venerable application development languages such as Microsoft's VB6. Shall we begin? I built SpiderMonkey with this config: ./configure --enable-ctypes --with-system-nspr followed by successful execution of: make && make install The js shell works fine and a global ctypes javascript object was verified operational in that shell. Working with code taken from the first source listing at How to embed the JavaScript Engine -MDN, I made an attempt to instantiate the JavaScript ctypes object by inserting the following code at line 66: /* Populate the global object with the ctypes object. */ if (!JS_InitCTypesClass(cx, global)) return NULL; /* I compiled with: g++ $(./js-config --cflags --libs) hello.cpp -o hello It compiles with a few warnings: hello.cpp: In function ‘int main(int, const char**)’: hello.cpp:69:16: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null] hello.cpp:80:20: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings] hello.cpp:89:17: warning: NULL used in arithmetic [-Wpointer-arith] But when you run the application: ./hello: symbol lookup error: ./hello: undefined symbol: JS_InitCTypesClass Moreover JS_InitCTypesClass is declared extern in 'dist/include/jsapi.h', but the function resides in 'ctypes/CTypes.cpp' which includes its own header 'CTypes.h' and is compiled at some point by some command during 'make' to yeild './CTypes.o'. As I stated earlier, I am less than a novice with the C code, and I really have no idea what to do here. Please give or give direction to a generic example of making the js-ctypes object functional in an embedding.

    Read the article

  • Recognizing terminals in a CFG production previously not defined as tokens.

    - by kmels
    I'm making a generator of LL(1) parsers, my input is a CoCo/R language specification. I've already got a Scanner generator for that input. Suppose I've got the following specification: COMPILER 1. CHARACTERS digit="0123456789". TOKENS number = digit{digit}. decnumber = digit{digit}"."digit{digit}. PRODUCTIONS Expression = Term{"+"Term|"-"Term}. Term = Factor{"*"Factor|"/"Factor}. Factor = ["-"](Number|"("Expression")"). Number = (number|decnumber). END 1. So, if the parser generated by this grammar receives a word "1+1", it'd be accepted i.e. a parse tree would be found. My question is, the character "+" was never defined in a token, but it appears in the non-terminal "Expression". How should my generated Scanner recognize it? It would not recognize it as a token. Is this a valid input then? Should I add this terminal in TOKENS and then consider an error routine for a Scanner for it to skip it? How does usual language specifications handle this?

    Read the article

  • Running commands over ssh with Java

    - by Ichorus
    Scenerio: I'd like to run commands on remote machines from a Java program over ssh (I am using OpenSSH on my development machine). I'd also like to make the ssh connection by passing the password rather than setting up keys as I would with 'expect'. Problem: When trying to do the 'expect' like password login the Process that is created with ProcessBuilder cannot seem to see the password prompt. When running regular non-ssh commands (e.g 'ls') I can get the streams and interact with them just fine. I am combining standard error and standard out into one stream with redirectErrorStream(true); so I am not missing it in standard error...When I run ssh with the '-v' option, I see all of the logging in the stream but I do not see the prompt. This is my first time trying to use ProcessBuilder for something like this. I know it would be easier to use Python, Perl or good ol' expect but my boss wants to utilize what we are trying to get back (remote log files and running scripts) within an existing Java program so I am kind of stuck. Thanks in advance for the help!

    Read the article

  • Can I use POSIX signals in my Perl program to create event-driven programming?

    - by Shiftbit
    Is there any POSIX signals that I could utilize in my Perl program to create event-driven programming? Currently, I have multi-process program that is able to cross communicate but my parent thread is only able to listen to listen at one child at a time. foreach (@proc) { sysread(${$_}{'read'}, my $line, 100); #problem here chomp($line); print "Parent hears: $line\n"; } The problem is that the parent sits in a continual wait state until it receives it a signal from the first child before it can continue on. I am relying on 'pipe' for my intercommunication. My current solution is very similar to: http://stackoverflow.com/questions/2558098/how-can-i-use-pipe-to-facilitate-interprocess-communication-in-perl If possible I would like to rely on a $SIG{...} event or any non-CPAN solution. Update: As Jonathan Leffler mentioned, kill can be used to send a signal: kill USR1 = $$; # send myself a SIGUSR1 My solution will be to send a USR1 signal to my child process. This event tells the parent to listen to the particular child. child: kill USR1 => $parentPID if($customEvent); syswrite($parentPipe, $msg, $buffer); #select $parentPipe; print $parentPipe $msg; parent: $SIG{USR1} = { #get child pid? sysread($array[$pid]{'childPipe'}, $msg, $buffer); }; But how do I get my the source/child pid that signaled the parent? Have the child Identify itself in its message. What happens if two children signal USR1 at the same time?

    Read the article

  • Standard Android Button with a different color

    - by Mike
    I'd like to change the color of a standard Android button slightly in order to better match a client's branding. For example, see the "Find a Table" button for the OpenTable application: The best way I've found to do this so far is to change the Button's drawable to the following drawable located in res/drawable/red_button.xml: <?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:drawable="@drawable/red_button_pressed" /> <item android:state_focused="true" android:drawable="@drawable/red_button_focus" /> <item android:drawable="@drawable/red_button_rest" /> </selector> But doing that requires that I actually create three different drawables for each button I want to customize (one for the button at rest, one when focused, and one when pressed). That seems more complicated and non-DRY than I need. All I really want to do is apply some sort of color transform to the button. Is there an easier way to go about changing a button's color than I'm doing?

    Read the article

  • How to create a fully lazy singleton for generics

    - by Brendan Vogt
    I have the following code implementation of my generic singleton provider: public sealed class Singleton<T> where T : class, new() { Singleton() { } public static T Instance { get { return SingletonCreator.instance; } } class SingletonCreator { static SingletonCreator() { } internal static readonly T instance = new T(); } } This sample was taken from 2 articles and I merged the code to get me what I wanted: http://www.yoda.arachsys.com/csharp/singleton.html and http://www.codeproject.com/Articles/11111/Generic-Singleton-Provider. This is how I tried to use the code above: public class MyClass { public static IMyInterface Initialize() { if (Singleton<IMyInterface>.Instance == null // Error 1 { Singleton<IMyInterface>.Instance = CreateEngineInstance(); // Error 2 Singleton<IMyInterface>.Instance.Initialize(); } return Singleton<IMyInterface>.Instance; } } And the interface: public interface IMyInterface { } The error at Error 1 is: 'MyProject.IMyInterace' must be a non-abstract type with a public parameterless constructor in order to use it as parameter 'T' in the generic type or method 'MyProject.Singleton<T>' The error at Error 2 is: Property or indexer 'MyProject.Singleton<MyProject.IMyInterface>.Instance' cannot be assigned to -- it is read only How can I fix this so that it is in line with the 2 articles mentioned above? Any other ideas or suggestions are appreciated.

    Read the article

< Previous Page | 430 431 432 433 434 435 436 437 438 439 440 441  | Next Page >