Search Results

Search found 3265 results on 131 pages for 'ph zero'.

Page 124/131 | < Previous Page | 120 121 122 123 124 125 126 127 128 129 130 131  | Next Page >

• Are there any suggestions for these new assembly mnemonics?

  - by Noctis Skytower

  Greetings! Last semester in college, my teacher in the Computer Languages class taught us the esoteric language named Whitespace. In the interest of learning the language better with a very busy schedule (midterms), I wrote an interpreter and assembler in Python. An assembly language was designed to facilitate writing programs easily, and a sample program was written with the given assembly mnemonics. Now that it is summer, a new project has begun with the objective being to rewrite the interpreter and assembler for Whitespace 0.3, with further developments coming afterwards. Since there is so much extra time than before to work on its design, you are presented here with an outline that provides a revised set of mnemonics for the assembly language. This post is marked as a wiki for their discussion. Have you ever had any experience with assembly languages in the past? Were there some instructions that you thought should have been renamed to something different? Did you find yourself thinking outside the box and with a different paradigm than in which the mnemonics were named? If you can answer yes to any of those questions, you are most welcome here. Subjective answers are appreciated! Stack Manipulation (IMP: [Space]) Stack manipulation is one of the more common operations, hence the shortness of the IMP [Space]. There are four stack instructions. hold N Push the number onto the stack copy Duplicate the top item on the stack copy N Copy the nth item on the stack (given by the argument) onto the top of the stack swap Swap the top two items on the stack drop Discard the top item on the stack drop N Slide n items off the stack, keeping the top item Arithmetic (IMP: [Tab][Space]) Arithmetic commands operate on the top two items on the stack, and replace them with the result of the operation. The first item pushed is considered to be left of the operator. add Addition sub Subtraction mul Multiplication div Integer Division mod Modulo Heap Access (IMP: [Tab][Tab]) Heap access commands look at the stack to find the address of items to be stored or retrieved. To store an item, push the address then the value and run the store command. To retrieve an item, push the address and run the retrieve command, which will place the value stored in the location at the top of the stack. save Store load Retrieve Flow Control (IMP: [LF]) Flow control operations are also common. Subroutines are marked by labels, as well as the targets of conditional and unconditional jumps, by which loops can be implemented. Programs must be ended by means of [LF][LF][LF] so that the interpreter can exit cleanly. L: Mark a location in the program call L Call a subroutine goto L Jump unconditionally to a label if=0 L Jump to a label if the top of the stack is zero if<0 L Jump to a label if the top of the stack is negative return End a subroutine and transfer control back to the caller halt End the program I/O (IMP: [Tab][LF]) Finally, we need to be able to interact with the user. There are IO instructions for reading and writing numbers and individual characters. With these, string manipulation routines can be written. The read instructions take the heap address in which to store the result from the top of the stack. print chr Output the character at the top of the stack print int Output the number at the top of the stack input chr Read a character and place it in the location given by the top of the stack input int Read a number and place it in the location given by the top of the stack Question: How would you redesign, rewrite, or rename the previous mnemonics and for what reasons?

  Read the article

• How to deploy a visual studio custom tool?

  - by Aen Sidhe

  Hello. I have a my own custom tool for Visual Studio 2008 SP1. It consists of 5 assemblies: 3 assemblies with code that used heavily in my other projects, 1 assembly-wrapper above VS2008 SDK and assembly with the tool. If I'd debug my tool from visual studio, using "Run external program" option with command line "C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe" and arguments "/ranu /rootsuffix Exp" all work perfectly. After that I trying to deploy it to my working VS copy, not to experimental hive doing: gacutil /i Asm1.dll for all my assemblies and doing RegAsm Asm1.dll only for assembly with custom tool. Neither of utils prints any error, all work as planned, even registry keys appeared. But my tool don't work even after PC restart. What did I do wrong? Wrapper looks like that: [ComVisible(true)] public abstract class CustomToolBase : IVsSingleFileGenerator, IObjectWithSite { #region IVsSingleFileGenerator Members int IVsSingleFileGenerator.DefaultExtension(out string pbstrDefaultExtension) { pbstrDefaultExtension = ".cs"; return 0; } int IVsSingleFileGenerator.Generate(string wszInputFilePath, string bstrInputFileContents, string wszDefaultNamespace, IntPtr[] rgbOutputFileContents, out uint pcbOutput, IVsGeneratorProgress pGenerateProgress) { GenerationEventArgs gea = new GenerationEventArgs( bstrInputFileContents, wszInputFilePath, wszDefaultNamespace, new ServiceProvider(Site as Microsoft.VisualStudio.OLE.Interop.IServiceProvider) .GetService(typeof(ProjectItem)) as ProjectItem, new GenerationProgressFacade(pGenerateProgress) ); if (OnGenerateCode != null) { OnGenerateCode(this, gea); } byte[] bytes = gea.GetOutputCodeBytes(); int outputLength = bytes.Length; rgbOutputFileContents[0] = Marshal.AllocCoTaskMem(outputLength); Marshal.Copy(bytes, 0, rgbOutputFileContents[0], outputLength); pcbOutput = (uint)outputLength; return VSConstants.S_OK; } #endregion #region IObjectWithSite Members void IObjectWithSite.GetSite(ref Guid riid, out IntPtr ppvSite) { IntPtr pUnk = Marshal.GetIUnknownForObject(Site); IntPtr intPointer = IntPtr.Zero; Marshal.QueryInterface(pUnk, ref riid, out intPointer); ppvSite = intPointer; } void IObjectWithSite.SetSite(object pUnkSite) { Site = pUnkSite; } #endregion #region Public Members public object Site { get; private set; } public event EventHandler<GenerationEventArgs> OnGenerateCode; [ComRegisterFunction] public static void Register(Type type) { using (var parent = Registry.LocalMachine.OpenSubKey(@"Software\Microsoft\VisualStudio\9.0", true)) foreach (CustomToolRegistrationAttribute ourData in type.GetCustomAttributes(typeof(CustomToolRegistrationAttribute), false)) ourData.Register(x => parent.CreateSubKey(x), (x, name, value) => x.SetValue(name, value)); } [ComUnregisterFunction] public static void Unregister(Type type) { using (var parent = Registry.LocalMachine.OpenSubKey(@"Software\Microsoft\VisualStudio\9.0", true)) foreach (CustomToolRegistrationAttribute ourData in type.GetCustomAttributes(typeof(CustomToolRegistrationAttribute), false)) ourData.Unregister(x => parent.DeleteSubKey(x, false)); } #endregion } My tool code: [ComVisible(true)] [Guid("55A6C192-D29F-4e22-84DA-DBAF314ED5C3")] [CustomToolRegistration(ToolName, typeof(TransportGeneratorTool))] [ProvideObject(typeof(TransportGeneratorTool))] public class TransportGeneratorTool : CustomToolBase { private const string ToolName = "TransportGeneratorTool"; public TransportGeneratorTool() { OnGenerateCode += GenerateCode; } private static void GenerateCode(object s, GenerationEventArgs e) { try { var serializer = new XmlSerializer(typeof (Parser.System)); using (var reader = new StringReader(e.InputText)) using (var writer = new StringWriter(e.OutputCode)) { Generator.System = (Parser.System) serializer.Deserialize(reader); Generator.System.Namespace = e.Namespace; Generator.GenerateSource(writer); } } catch (Exception ex) { e.Progress.GenerateError(ex.ToString()); } } } Resulting registry keys: Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Generators] [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Generators\{FAE04EC1-301F-11D3-BF4B-00C04F79EFBC}] [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Generators\{FAE04EC1-301F-11D3-BF4B-00C04F79EFBC}\TransportGeneratorTool] @="TransportGeneratorTool" "CLSID"="{55a6c192-d29f-4e22-84da-dbaf314ed5c3}" "GeneratesDesignTimeSource"=dword:00000001 "GeneratesSharedDesignTimeSource"=dword:00000001

  Read the article

• black screen while retrieving result from webservices in android

  - by Aswan

  Hi Folks i am using following webservices for retrieving data from server server side:.net client side:ksoap2 whenever activity start, onCreate i am using spinner for displying data returned by the webservices when this activity start it showing black screen after lunching the activity .i found black screen is coming when activity connecting to webservices How to resolve this MyCode public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); try { //Display the online and busy people display in spinner //people are display in relative people only(Mygroup) /* get the online and busy people who are in user group from DB*/ users_names_ids=new ParseXMLString().convertusernames(new DataParsingComm().ILGetOnlinePeoples("<spGetOnlinePeoples><UserID>"+GetCurrentUserID.id+"</UserID></spGetOnlinePeoples>")); /* create an array with the size of number of peoples whose status is online or busy */ String[] array =new String[users_names_ids.size()]; int setselction=0;// initialize the selection to 0. /* if array length is greater than zero, that means getting at least one person whose status is online or busy */ if(array.length>0){ /* Returns an enumeration on the keys of this Hashtable instance. And assigns into Enumeration instance variable */ Enumeration e= users_names_ids.keys(); /* Iterate list Enumeration until it does't has any more elements */ for(int i=0;e.hasMoreElements();i++) try{ /* get all persons names into the array list */ array[i]=e.nextElement().toString(); /* Get the ChatUserName value from the ChatInPeopleDetails preferences. And If it is in this list set selection to the index 'i' */ if(getSharedPreferences("ChatInPeopleDetails", 0).getString("ChatUserName", "").equals(array[i])) setselction=i; /* * Get the String value of Relname, that previously added with putExtra() as extended data to the parent intent * If that value is not null and exists in the array list then * set the selection to the index 'i'. * */ else if(getIntent().getStringExtra("Relname")!=null && getIntent().getStringExtra("Relname").equals(array[i])) setselction=i; }catch(Exception ex){ ex.printStackTrace(); } finally { System.gc(); System.runFinalization(); } } /* create a new array adapter with the ChatForm context and array objects */ ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(ChatForm.this,android.R.layout.simple_spinner_item, array); /* Set the layout resource to create the drop down views. */ adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); /* The Adapter is used to provide the data which backs this Spinner SpinnerUsersToChat. */ ((Spinner)findViewById(R.id.SpinnerUsersToChat)).setAdapter(adapter2); /* Get the ChatUserName value from the ChatInPeopleDetails preferences. If this value is not null*/ if(getSharedPreferences("ChatInPeopleDetails", 0).getString("ChatUserName", "") !=null) { /* Set the currently selected item of spinner based on selection variable value */ ((Spinner)findViewById(R.id.SpinnerUsersToChat)).setSelection(setselction); } /* Register a callback to be invoked when an item in this AdapterView has been selected.*/ ((Spinner)findViewById(R.id.SpinnerUsersToChat)).setOnItemSelectedListener(new OnItemSelectedListener() { public void onItemSelected(AdapterView<?> parent,View v,int position,long id) { /* call getMsg() to get messages and display them*/ getMsg(); /* Causes the Runnable to be added to the message queue. The runnable will be run on the user interface thread.*/ ((ScrollView)findViewById(R.id.ScrollView06)).post(new Runnable() { public void run() { /* This fullScroll() method will scroll the view to the bottom .*/ ((ScrollView)findViewById(R.id.ScrollView06)).fullScroll(View.FOCUS_DOWN); } }); } /* on nothing selected to do somthing . this an overridden method */ public void onNothingSelected(AdapterView<?> arg0) { } }); } catch (Exception e1) { e1.printStackTrace(); } }

  Read the article

• .NET Programmatically invoke screenclick doesn't work?

  - by ropstah

  I'm trying to programmatically invoke an onclick event however the click is not received/handled. Am I missing something, or is security preventing the click to be executed? I have a forms application which is invisible. Basically I would like to say: DoDoubleClick(wait, x, y) This should raise two click (mousedown+mouseup) events on screen with the specified wait interval. However the click isn't received in a Flash application in Firefox (which is running at that moment). Here's my code: Form: Public Class Form1 Private WithEvents gmh As GlobalMouseHook Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load gmh = New GlobalMouseHook() Me.Visible = false gmh.DoDoubleClick(50, 800, 600) End Sub Private Sub Form1_FormClosed(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles MyBase.FormClosed gmh.Dispose() End Sub Private Sub gmh_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles gmh.MouseDown End Sub Private Sub gmh_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles gmh.MouseMove End Sub Private Sub gmh_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles gmh.MouseUp End Sub End Class GlobalMouseHook class: Friend Class GlobalMouseHook Implements IDisposable Private hhk As IntPtr = IntPtr.Zero Private disposedValue As Boolean = False Public Event MouseDown As MouseEventHandler Public Event MouseUp As MouseEventHandler Public Event MouseMove As MouseEventHandler Public Sub New() Hook() End Sub Private Sub Hook() Dim hInstance As IntPtr = LoadLibrary("User32") hhk = SetWindowsHookEx(WH_MOUSE_LL, AddressOf Me.HookProc, hInstance, 0) End Sub Private Sub Unhook() UnhookWindowsHookEx(hhk) End Sub Public Sub DoDoubleClick(ByVal wait As Integer, ByVal x As Integer, ByVal y As Integer) RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Left, 1, x, y, 0)) RaiseEvent MouseUp(Me, Nothing) System.Threading.Thread.Sleep(wait) RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Left, 1, x, y, 0)) RaiseEvent MouseUp(Me, Nothing) End Sub Private Function HookProc(ByVal nCode As Integer, ByVal wParam As UInteger, ByRef lParam As MSLLHOOKSTRUCT) As Integer If nCode >= 0 Then Select Case wParam Case WM_LBUTTONDOWN RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Left, 0, lParam.pt.x, lParam.pt.y, 0)) Case WM_RBUTTONDOWN RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Right, 0, lParam.pt.x, lParam.pt.y, 0)) Case WM_MBUTTONDOWN RaiseEvent MouseDown(Me, New MouseEventArgs(MouseButtons.Middle, 0, lParam.pt.x, lParam.pt.y, 0)) Case WM_LBUTTONUP, WM_RBUTTONUP, WM_MBUTTONUP RaiseEvent MouseUp(Nothing, Nothing) Case WM_MOUSEMOVE RaiseEvent MouseMove(Nothing, Nothing) Case WM_MOUSEWHEEL, WM_MOUSEHWHEEL Case Else Console.WriteLine(wParam) End Select End If Return CallNextHookEx(hhk, nCode, wParam, lParam) End Function Private Structure API_POINT Public x As Integer Public y As Integer End Structure Private Structure MSLLHOOKSTRUCT Public pt As API_POINT Public mouseData As UInteger Public flags As UInteger Public time As UInteger Public dwExtraInfo As IntPtr End Structure Private Const WM_MOUSEWHEEL As UInteger = &H20A Private Const WM_MOUSEHWHEEL As UInteger = &H20E Private Const WM_MOUSEMOVE As UInteger = &H200 Private Const WM_LBUTTONDOWN As UInteger = &H201 Private Const WM_LBUTTONUP As UInteger = &H202 Private Const WM_MBUTTONDOWN As UInteger = &H207 Private Const WM_MBUTTONUP As UInteger = &H208 Private Const WM_RBUTTONDOWN As UInteger = &H204 Private Const WM_RBUTTONUP As UInteger = &H205 Private Const WH_MOUSE_LL As Integer = 14 Private Delegate Function LowLevelMouseHookProc(ByVal nCode As Integer, ByVal wParam As UInteger, ByRef lParam As MSLLHOOKSTRUCT) As Integer Private Declare Auto Function LoadLibrary Lib "kernel32" (ByVal lpFileName As String) As IntPtr Private Declare Auto Function SetWindowsHookEx Lib "user32.dll" (ByVal idHook As Integer, ByVal lpfn As LowLevelMouseHookProc, ByVal hInstance As IntPtr, ByVal dwThreadId As UInteger) As IntPtr Private Declare Function CallNextHookEx Lib "user32" (ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As UInteger, ByRef lParam As MSLLHOOKSTRUCT) As Integer Private Declare Function UnhookWindowsHookEx Lib "user32" (ByVal hhk As IntPtr) As Boolean ' IDisposable Protected Overridable Sub Dispose(ByVal disposing As Boolean) If Not Me.disposedValue Then If disposing Then ' TODO: free other state (managed objects). End If Unhook() End If Me.disposedValue = True End Sub ' This code added by Visual Basic to correctly implement the disposablepattern. Public Sub Dispose() Implements IDisposable.Dispose ' Do not change this code. Put cleanup code in Dispose(ByValdisposing As Boolean) above. Dispose(True) GC.SuppressFinalize(Me) End Sub End Class

  Read the article

• Business rule validation of hierarchical list of objects ASP.NET MVC

  - by SergeanT

  I have a list of objects that are organized in a tree using a Depth property: public class Quota { [Range(0, int.MaxValue, ErrorMessage = "Please enter an amount above zero.")] public int Amount { get; set; } public int Depth { get; set; } [Required] [RegularExpression("^[a-zA-Z]+$")] public string Origin { get; set; } // ... another properties with validation attributes } For data example (amount - origin) 100 originA 200 originB 50 originC 150 originD the model data looks like: IList<Quota> model = new List<Quota>(); model.Add(new Quota{ Amount = 100, Depth = 0, Origin = "originA"); model.Add(new Quota{ Amount = 200, Depth = 0, Origin = "originB"); model.Add(new Quota{ Amount = 50, Depth = 1, Origin = "originC"); model.Add(new Quota{ Amount = 150, Depth = 1, Orinig = "originD"); Editing of the list Then I use Editing a variable length list, ASP.NET MVC 2-style to raise editing of the list. Controller actions QuotaController.cs: public class QuotaController : Controller { // // GET: /Quota/EditList public ActionResult EditList() { IList<Quota> model = // ... assigments as in example above; return View(viewModel); } // // POST: /Quota/EditList [HttpPost] public ActionResult EditList(IList<Quota> quotas) { if (ModelState.IsValid) { // ... save logic return RedirectToAction("Details"); } return View(quotas); // Redisplay the form with errors } // ... other controller actions } View EditList.aspx: <%@ Page Title="" Language="C#" ... Inherits="System.Web.Mvc.ViewPage<IList<Quota>>" %> ... <h2>Edit Quotas</h2> <%=Html.ValidationSummary("Fix errors:") %> <% using (Html.BeginForm()) { foreach (var quota in Model) { Html.RenderPartial("QuotaEditorRow", quota); } %> <% } %> ... Partial View QuotaEditorRow.ascx: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Quota>" %> <div class="quotas" style="margin-left: <%=Model.Depth*45 %>px"> <% using (Html.BeginCollectionItem("Quotas")) { %> <%=Html.HiddenFor(m=>m.Id) %> <%=Html.HiddenFor(m=>m.Depth) %> <%=Html.TextBoxFor(m=>m.Amount, new {@class = "number", size = 5})%> <%=Html.ValidationMessageFor(m=>m.Amount) %> Origin: <%=Html.TextBoxFor(m=>m.Origin)%> <%=Html.ValidationMessageFor(m=>m.Origin) %> ... <% } %> </div> Business rule validation How do I implement validation of business rule: Amount of quota and sum of amounts of nested quotas should equal (e.a. 200 = 50 + 150 in example)? I want to appropriate inputs Html.TextBoxFor(m=>m.Amount) be highlighted red if the rule is broken for it. In example if user enters not 200, but 201 - it should be red on submit. Using sever validation only. Thanks a lot for any advise.

  Read the article

• WCF using windows service

  - by Lijo

  Hi, I am creating a WCF service which is to be hosted in Windows Service. I created a console application as follows I went to management console (services.msc) and started the service. But I got the following error "The LijosWindowsService service on Local Computer started and then stopped. Some services stop automatically if they have no work to do, for example, the Performance Logs and Alerts service" I went to the event viewer and got the following "Service cannot be started. System.InvalidOperationException: Service 'Lijo.Samples.WeatherService' has zero application (non-infrastructure) endpoints. This might be because no configuration file was found for your application, or because no service element matching the service name could be found in the configuration file, or because no endpoints were defined in the service element." Could you please let me know what is the missing link here? File name [LijosService.cs] using System.ComponentModel; using System.ServiceModel; using System.ServiceProcess; using System.Configuration; using System.Configuration.Install; namespace Lijo.Samples { [ServiceContract(Namespace = "http://Lijo.Samples")] public interface IWeather { [OperationContract] double Add(double n1, double n2); } public class WeatherService : IWeather { public double Add(double n1, double n2) { double result = n1 + n2; return result; } } public class MyWindowsService : ServiceBase { public ServiceHost serviceHost = null; public MyWindowsService() { // Windows Service name ServiceName = "LijosWindowsService"; } public static void Main() { ServiceBase.Run(new MyWindowsService()); } protected override void OnStart(string[] args) { if (serviceHost != null) { serviceHost.Close(); } serviceHost = new ServiceHost(typeof(WeatherService)); serviceHost.Open(); } protected override void OnStop() { if (serviceHost != null) { serviceHost.Close(); serviceHost = null; } } } // ProjectInstaller [RunInstaller(true)] public class ProjectInstaller : Installer { private ServiceProcessInstaller myProcess; private ServiceInstaller myService; public ProjectInstaller() { myProcess = new ServiceProcessInstaller(); myProcess.Account = ServiceAccount.LocalSystem; myService = new ServiceInstaller(); myService.ServiceName = "LijosWindowsService"; Installers.Add(myProcess); Installers.Add(myService); } } } App.config <?xml version="1.0" encoding="utf-8" ?> <configuration> <system.serviceModel> <services> <service name="Lijo.Samples.WeatherService" behaviorConfiguration="WeatherServiceBehavior"> <host> <baseAddresses> <add baseAddress="http://localhost:8000/ServiceModelSamples/LijosService"/> </baseAddresses> </host> <endpoint address="" binding="wsHttpBinding" contract="Lijo.Samples.IWeather" /> <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" /> </service> </services> <behaviors> <serviceBehaviors> <behavior name="WeatherServiceBehavior"> <serviceMetadata httpGetEnabled="true"/> <serviceDebug includeExceptionDetailInFaults="False"/> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> </configuration> Thanks Lijo

  Read the article

• Why do I get a segmentation fault while redirecting sys.stdout to Tkinter.Text widget in Python?

  - by Brent Nash

  I'm in the process of building a GUI-based application with Python/Tkinter that builds on top of the existing Python bdb module. In this application, I want to silence all stdout/stderr from the console and redirect it to my GUI. To accomplish this purpose, I've written a specialized Tkinter.Text object (code at the end of the post). The basic idea is that when something is written to sys.stdout, it shows up as a line in the "Text" with the color black. If something is written to sys.stderr, it shows up as a line in the "Text" with the color red. As soon as something is written, the Text always scrolls down to view the most recent line. I'm using Python 2.6.1 at the moment. On Mac OS X 10.5, this seems to work great. I have had zero problems with it. On RedHat Enterprise Linux 5, however, I pretty reliably get a segmentation fault during the run of a script. The segmentation fault doesn't always occur in the same place, but it pretty much always occurs. If I comment out the sys.stdout= and sys.stderr= lines from my code, the segmentation faults seem to go away. I'm sure there are other ways around this that I will probably have to resort to, but can anyone see anything I'm doing blatantly wrong here that could be causing these segmentation faults? It's driving me nuts. Thanks! PS - I realize redirecting sys.stderr to the GUI might not be a great idea, but I still get segmentation faults even when I only redirect sys.stdout and not sys.stderr. I also realize that I'm allowing the Text to grow indefinitely at the moment. class ConsoleText(tk.Text): '''A Tkinter Text widget that provides a scrolling display of console stderr and stdout.''' class IORedirector(object): '''A general class for redirecting I/O to this Text widget.''' def __init__(self,text_area): self.text_area = text_area class StdoutRedirector(IORedirector): '''A class for redirecting stdout to this Text widget.''' def write(self,str): self.text_area.write(str,False) class StderrRedirector(IORedirector): '''A class for redirecting stderr to this Text widget.''' def write(self,str): self.text_area.write(str,True) def __init__(self, master=None, cnf={}, **kw): '''See the __init__ for Tkinter.Text for most of this stuff.''' tk.Text.__init__(self, master, cnf, **kw) self.started = False self.write_lock = threading.Lock() self.tag_configure('STDOUT',background='white',foreground='black') self.tag_configure('STDERR',background='white',foreground='red') self.config(state=tk.DISABLED) def start(self): if self.started: return self.started = True self.original_stdout = sys.stdout self.original_stderr = sys.stderr stdout_redirector = ConsoleText.StdoutRedirector(self) stderr_redirector = ConsoleText.StderrRedirector(self) sys.stdout = stdout_redirector sys.stderr = stderr_redirector def stop(self): if not self.started: return self.started = False sys.stdout = self.original_stdout sys.stderr = self.original_stderr def write(self,val,is_stderr=False): #Fun Fact: The way Tkinter Text objects work is that if they're disabled, #you can't write into them AT ALL (via the GUI or programatically). Since we want them #disabled for the user, we have to set them to NORMAL (a.k.a. ENABLED), write to them, #then set their state back to DISABLED. self.write_lock.acquire() self.config(state=tk.NORMAL) self.insert('end',val,'STDERR' if is_stderr else 'STDOUT') self.see('end') self.config(state=tk.DISABLED) self.write_lock.release()

  Read the article

• Increasing speed of python code

  - by Curious2learn

  Hi, I have some python code that has many classes. I used cProfile to find that the total time to run the program is 68 seconds. I found that the following function in a class called Buyers takes about 60 seconds of those 68 seconds. I have to run the program about 100 times, so any increase in speed will help. Can you suggest ways to increase the speed by modifying the code? If you need more information that will help, please let me know. def qtyDemanded(self, timePd, priceVector): '''Returns quantity demanded in period timePd. In addition, also updates the list of customers and non-customers. Inputs: timePd and priceVector Output: count of people for whom priceVector[-1] < utility ''' ## Initialize count of customers to zero ## Set self.customers and self.nonCustomers to empty lists price = priceVector[-1] count = 0 self.customers = [] self.nonCustomers = [] for person in self.people: if person.utility >= price: person.customer = 1 self.customers.append(person) else: person.customer = 0 self.nonCustomers.append(person) return len(self.customers) self.people is a list of person objects. Each person has customer and utility as its attributes. EDIT - responsed added ------------------------------------- Thanks so much for the suggestions. Here is the response to some questions and suggestions people have kindly made. I have not tried them all, but will try others and write back later. (1) @amber - the function is accessed 80,000 times. (2) @gnibbler and others - self.people is a list of Person objects in memory. Not connected to a database. (3) @Hugh Bothwell cumtime taken by the original function - 60.8 s (accessed 80000 times) cumtime taken by the new function with local function aliases as suggested - 56.4 s (accessed 80000 times) (4) @rotoglup and @Martin Thomas I have not tried your solutions yet. I need to check the rest of the code to see the places where I use self.customers before I can make the change of not appending the customers to self.customers list. But I will try this and write back. (5) @TryPyPy - thanks for your kind offer to check the code. Let me first read a little on the suggestions you have made to see if those will be feasible to use. EDIT 2 Some suggested that since I am flagging the customers and noncustomers in the self.people, I should try without creating separate lists of self.customers and self.noncustomers using append. Instead, I should loop over the self.people to find the number of customers. I tried the following code and timed both functions below f_w_append and f_wo_append. I did find that the latter takes less time, but it is still 96% of the time taken by the former. That is, it is a very small increase in the speed. @TryPyPy - The following piece of code is complete enough to check the bottleneck function, in case your offer is still there to check it with other compilers. Thanks again to everyone who replied. import numpy class person(object): def __init__(self, util): self.utility = util self.customer = 0 class population(object): def __init__(self, numpeople): self.people = [] self.cus = [] self.noncus = [] numpy.random.seed(1) utils = numpy.random.uniform(0, 300, numpeople) for u in utils: per = person(u) self.people.append(per) popn = population(300) def f_w_append(): '''Function with append''' P = 75 cus = [] noncus = [] for per in popn.people: if per.utility >= P: per.customer = 1 cus.append(per) else: per.customer = 0 noncus.append(per) return len(cus) def f_wo_append(): '''Function without append''' P = 75 for per in popn.people: if per.utility >= P: per.customer = 1 else: per.customer = 0 numcustomers = 0 for per in popn.people: if per.customer == 1: numcustomers += 1 return numcustomers

  Read the article

• Why might a System.String object not cache its hash code?

  - by Dan Tao

  A glance at the source code for string.GetHashCode using Reflector reveals the following (for mscorlib.dll version 4.0): public override unsafe int GetHashCode() { fixed (char* str = ((char*) this)) { char* chPtr = str; int num = 0x15051505; int num2 = num; int* numPtr = (int*) chPtr; for (int i = this.Length; i > 0; i -= 4) { num = (((num << 5) + num) + (num >> 0x1b)) ^ numPtr[0]; if (i <= 2) { break; } num2 = (((num2 << 5) + num2) + (num2 >> 0x1b)) ^ numPtr[1]; numPtr += 2; } return (num + (num2 * 0x5d588b65)); } } Now, I realize that the implementation of GetHashCode is not specified and is implementation-dependent, so the question "is GetHashCode implemented in the form of X or Y?" is not really answerable. I'm just curious about a few things: If Reflector has disassembled the DLL correctly and this is the implementation of GetHashCode (in my environment), am I correct in interpreting this code to indicate that a string object, based on this particular implementation, would not cache its hash code? Assuming the answer is yes, why would this be? It seems to me that the memory cost would be minimal (one more 32-bit integer, a drop in the pond compared to the size of the string itself) whereas the savings would be significant, especially in cases where, e.g., strings are used as keys in a hashtable-based collection like a Dictionary<string, [...]>. And since the string class is immutable, it isn't like the value returned by GetHashCode will ever even change. What could I be missing? UPDATE: In response to Andras Zoltan's closing remark: There's also the point made in Tim's answer(+1 there). If he's right, and I think he is, then there's no guarantee that a string is actually immutable after construction, therefore to cache the result would be wrong. Whoa, whoa there! This is an interesting point to make (and yes it's very true), but I really doubt that this was taken into consideration in the implementation of GetHashCode. The statement "therefore to cache the result would be wrong" implies to me that the framework's attitude regarding strings is "Well, they're supposed to be immutable, but really if developers want to get sneaky they're mutable so we'll treat them as such." This is definitely not how the framework views strings. It fully relies on their immutability in so many ways (interning of string literals, assignment of all zero-length strings to string.Empty, etc.) that, basically, if you mutate a string, you're writing code whose behavior is entirely undefined and unpredictable. I guess my point is that for the author(s) of this implementation to worry, "What if this string instance is modified between calls, even though the class as it is publicly exposed is immutable?" would be like for someone planning a casual outdoor BBQ to think to him-/herself, "What if someone brings an atomic bomb to the party?" Look, if someone brings an atom bomb, party's over.

  Read the article

• RackSpace Cloud Strips $_SESSION if URL Has Certain File Extensions

  - by macinjosh

  The Situation I am creating a video training site for a client on the RackSpace Cloud using the traditional LAMP stack (RackSpace's cloud has both Windows and LAMP stacks). The videos and other media files I'm serving on this site need to be protected as my client charges money for access to them. There is no DRM or funny business like that, essentially we store the files outside of the web root and use PHP to authenticate user's before they are able to access the files by using mod_rewrite to run the request through PHP. So let's say the user requests a file at this URL: http://www.example.com/uploads/preview_image/29.jpg I am using mod_rewrite to rewrite that url to: http://www.example.com/files.php?path=%2Fuploads%2Fpreview_image%2F29.jpg Here is a simplified version of the files.php script: <?php // Setups the environment and sets $logged_in // This part requires $_SESSION require_once('../../includes/user_config.php'); if (!$logged_in) { // Redirect non-authenticated users header('Location: login.php'); } // This user is authenticated, continue $content_type = "image/jpeg"; // getAbsolutePathForRequestedResource() takes // a Query Parameter called path and uses DB // lookups and some string manipulation to get // an absolute path. This part doesn't have // any bearing on the problem at hand $file_path = getAbsolutePathForRequestedResource($_GET['path']); // At this point $file_path looks something like // this: "/path/to/a/place/outside/the/webroot" if (file_exists($file_path) && !is_dir($file_path)) { header("Content-Type: $content_type"); header('Content-Length: ' . filesize($file_path)); echo file_get_contents($file_path); } else { header('HTTP/1.0 404 Not Found'); header('Status: 404 Not Found'); echo '404 Not Found'; } exit(); ?> The Problem Let me start by saying this works perfectly for me. On local test machines it works like a charm. However once deployed to the cloud it stops working. After some debugging it turns out that if a request to the cloud has certain file extensions like .JPG, .PNG, or .SWF (i.e. extensions of typically static media files.) the request is routed to a cache system called Varnish. The end result of this routing is that by the time this whole process makes it to my PHP script the session is not present. If I change the extension in the URL to .PHP or if I even add a query parameter Varnish is bypassed and the PHP script can get the session. No problem right? I'll just add a meaningless query parameter to my requests! Here is the rub: The media files I am serving through this system are being requested through compiled SWF files that I have zero control over. They are generated by third-party software and I have no hope of adding or changing the URLs that they request. Are there any other options I have on this? Update: I should note that I have verified this behavior with RackSpace support and they have said there is nothing they can do about it.

  Read the article

• Problem calling method inside same method in php?

  - by Fero

  Hi all, Will any one please tell me how to run this class. I am getting the FATAL ERROR: Fatal error: Call to undefined function readnumber() in E:\Program Files\xampp\htdocs\numberToWords\numberToWords.php on line 20 while giving input as 120 <?php class Test { function readnumber($num, $depth) { $num = (int)$num; $retval =""; if ($num < 0) // if it's any other negative, just flip it and call again return "negative " + readnumber(-$num, 0); if ($num > 99) // 100 and above { if ($num > 999) // 1000 and higher $retval .= readnumber($num/1000, $depth+3); $num %= 1000; // now we just need the last three digits if ($num > 99) // as long as the first digit is not zero $retval .= readnumber($num/100, 2)." hundred\n"; $retval .=readnumber($num%100, 1); // our last two digits } else // from 0 to 99 { $mod = floor($num / 10); if ($mod == 0) // ones place { if ($num == 1) $retval.="one"; else if ($num == 2) $retval.="two"; else if ($num == 3) $retval.="three"; else if ($num == 4) $retval.="four"; else if ($num == 5) $retval.="five"; else if ($num == 6) $retval.="six"; else if ($num == 7) $retval.="seven"; else if ($num == 8) $retval.="eight"; else if ($num == 9) $retval.="nine"; } else if ($mod == 1) // if there's a one in the ten's place { if ($num == 10) $retval.="ten"; else if ($num == 11) $retval.="eleven"; else if ($num == 12) $retval.="twelve"; else if ($num == 13) $retval.="thirteen"; else if ($num == 14) $retval.="fourteen"; else if ($num == 15) $retval.="fifteen"; else if ($num == 16) $retval.="sixteen"; else if ($num == 17) $retval.="seventeen"; else if ($num == 18) $retval.="eighteen"; else if ($num == 19) $retval.="nineteen"; } else // if there's a different number in the ten's place { if ($mod == 2) $retval.="twenty "; else if ($mod == 3) $retval.="thirty "; else if ($mod == 4) $retval.="forty "; else if ($mod == 5) $retval.="fifty "; else if ($mod == 6) $retval.="sixty "; else if ($mod == 7) $retval.="seventy "; else if ($mod == 8) $retval.="eighty "; else if ($mod == 9) $retval.="ninety "; if (($num % 10) != 0) { $retval = rtrim($retval); //get rid of space at end $retval .= "-"; } $retval.=readnumber($num % 10, 0); } } if ($num != 0) { if ($depth == 3) $retval.=" thousand\n"; else if ($depth == 6) $retval.=" million\n"; if ($depth == 9) $retval.=" billion\n"; } return $retval; } } $objTest = new Test(); $objTest->readnumber(120,0); ?>

  Read the article

• Why i cannot get the frame of a UIView in order to move it? The view is defined.

  - by Jann

  I am creating a nav-based app with a view that floats at the bottom of the screen (Alpha .7 most of the time). I create it like this... // stuff to create the tabbar/nav bar. // THIS ALL WORKS... // then add it to subview. [window addSubview:tabBarController.view]; // need this last line to display the window (and tab bar controller) [window makeKeyAndVisible]; // Okay, here is the code i am using to create a grey-ish strip exactly `zlocationAccuracyHeight` pixels high at `zlocationAccuracyVerticalStartPoint` starting point vertically. CGRect locationManagerAccuracyUIViewFrame = CGRectMake(0,zlocationAccuracyVerticalStartPoint,[[UIScreen mainScreen] bounds].size.width,zlocationAccuracyHeight); self.locationManagerAccuracyUIView = [[UIView alloc] initWithFrame:locationManagerAccuracyUIViewFrame]; self.locationManagerAccuracyUIView.autoresizingMask = (UIViewAutoresizingFlexibleWidth); self.locationManagerAccuracyUIView.backgroundColor = [UIColor darkGrayColor]; [self.locationManagerAccuracyUIView setAlpha:0]; CGRect locationManagerAccuracyLabelFrame = CGRectMake(0, 0,[[UIScreen mainScreen] bounds].size.width,zlocationAccuracyHeight); locationManagerAccuracyLabel = [[UILabel alloc] initWithFrame:locationManagerAccuracyLabelFrame]; if ([myGizmoClass useLocationServices] == 0) { locationManagerAccuracyLabel.text = @"GPS Accuracy: Using Manual Location"; } else { locationManagerAccuracyLabel.text = @"GPS Accuracy: One Moment Please..."; } locationManagerAccuracyLabel.font = [UIFont boldSystemFontOfSize:12]; locationManagerAccuracyLabel.textAlignment = UITextAlignmentCenter; locationManagerAccuracyLabel.textColor = [UIColor whiteColor]; locationManagerAccuracyLabel.backgroundColor = [UIColor clearColor]; [locationManagerAccuracyLabel setAlpha:0]; [self.locationManagerAccuracyUIView addSubview: locationManagerAccuracyLabel]; [window addSubview: self.locationManagerAccuracyUIView]; this all works (i am not sure about the order i create the uiview in ... meaning i am creating the frame, the view, creating the "accuracy text" and adding that to the view, then adding the uiview as a subview of the window . It works and seems correct in my logic. So, here is the tough part. I have a timer that i am testing with. I am trying to float the uiview up by 30 pix. here is that code: [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.3]; CGRect rect = [ self.locationManagerAccuracyUIView frame]; NSLog(@"ORIGIN: %d x %d (%@)\n",rect.origin.x,rect.origin.y,rect); rect.origin.y -= 30; [UIView commitAnimations]; The problem? rect is nill, rect.origin.x and rect.origin.y are both zero. Can anyone tell me why? Here is how i set up self.locationManagerAccuracyUIView in my files: Delegate.h UIView *locationManagerAccuracyUIView; UILabel *locationManagerAccuracyLabel; ... @property (nonatomic, retain) IBOutlet UIView *locationManagerAccuracyUIView; @property (nonatomic, retain) IBOutlet UILabel *locationManagerAccuracyLabel; Delegate.m ... @synthesize locationManagerAccuracyUIView; @synthesize locationManagerAccuracyLabel; ... BTW: Other places in another timer i DO set the alpha to fade in and out and THAT works! So locationManagerAccuracyUIView is valid and defined as a view... For instance: [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [locationManagerAccuracyLabel setAlpha:1]; [UIView commitAnimations]; [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.5]; [self.locationManagerAccuracyUIView setAlpha:.7]; [UIView commitAnimations]; ...and it DOES work. Can anyone help me? As an aside: I know, when typing this I used self.locationManagerAccuracyUIView and locationManagerAccuracyUIView interchangeably to see if for some reason that was the issue. It is not. :) Thx

  Read the article

• Do you have suggestions for these assembly mnemonics?

  - by Noctis Skytower

  Greetings! Last semester in college, my teacher in the Computer Languages class taught us the esoteric language named Whitespace. In the interest of learning the language better with a very busy schedule (midterms), I wrote an interpreter and assembler in Python. An assembly language was designed to facilitate writing programs easily, and a sample program was written with the given assembly mnemonics. Now that it is summer, a new project has begun with the objective being to rewrite the interpreter and assembler for Whitespace 0.3, with further developments coming afterwards. Since there is so much extra time than before to work on its design, you are presented here with an outline that provides a revised set of mnemonics for the assembly language. This post is marked as a wiki for their discussion. Have you ever had any experience with assembly languages in the past? Were there some instructions that you thought should have been renamed to something different? Did you find yourself thinking outside the box and with a different paradigm than in which the mnemonics were named? If you can answer yes to any of those questions, you are most welcome here. Subjective answers are appreciated! Stack Manipulation (IMP: [Space]) Stack manipulation is one of the more common operations, hence the shortness of the IMP [Space]. There are four stack instructions. hold N Push the number onto the stack copy Duplicate the top item on the stack copy N Copy the nth item on the stack (given by the argument) onto the top of the stack swap Swap the top two items on the stack drop Discard the top item on the stack drop N Slide n items off the stack, keeping the top item Arithmetic (IMP: [Tab][Space]) Arithmetic commands operate on the top two items on the stack, and replace them with the result of the operation. The first item pushed is considered to be left of the operator. add Addition sub Subtraction mul Multiplication div Integer Division mod Modulo Heap Access (IMP: [Tab][Tab]) Heap access commands look at the stack to find the address of items to be stored or retrieved. To store an item, push the address then the value and run the store command. To retrieve an item, push the address and run the retrieve command, which will place the value stored in the location at the top of the stack. save Store load Retrieve Flow Control (IMP: [LF]) Flow control operations are also common. Subroutines are marked by labels, as well as the targets of conditional and unconditional jumps, by which loops can be implemented. Programs must be ended by means of [LF][LF][LF] so that the interpreter can exit cleanly. L: Mark a location in the program call L Call a subroutine goto L Jump unconditionally to a label if=0 L Jump to a label if the top of the stack is zero if<0 L Jump to a label if the top of the stack is negative return End a subroutine and transfer control back to the caller halt End the program I/O (IMP: [Tab][LF]) Finally, we need to be able to interact with the user. There are IO instructions for reading and writing numbers and individual characters. With these, string manipulation routines can be written. The read instructions take the heap address in which to store the result from the top of the stack. print chr Output the character at the top of the stack print int Output the number at the top of the stack input chr Read a character and place it in the location given by the top of the stack input int Read a number and place it in the location given by the top of the stack Question: How would you redesign, rewrite, or rename the previous mnemonics and for what reasons?

  Read the article

• RSA encryption/ Decryption in a client server application

  - by user308806

  Hi guys, probably missing something very straight forward on this, but please forgive me, I'm very naive! Have a client server application where the client identifies its self with an RSA encrypted username & password. Unfortunately I'm getting a "bad padding exception: data must start with zero" when i try to decrypt with the public key on the client side. I'm fairly sure the key is correct as I have tested encrypting with public key then decrypting with private key on the client side with no problems at all. Just seems when I transfer it over the connection it messses it up somehow?! Using PrintWriter & BufferedReader on the sockets if thats of importance. EncodeBASE64 & DecodeBASE64 encode byte[] to 64base and vice versa respectively. Any ideas guys?? Client side: Socket connectionToServer = new Socket("127.0.0.1", 7050); InputStream in = connectionToServer.getInputStream(); DataInputStream dis = new DataInputStream(in); int length = dis.readInt(); byte[] data = new byte[length]; // dis.readFully(data); dis.read(data); System.out.println("The received Data*****************************************"); System.out.println("The length of bits "+ length); System.out.println(data); System.out.println("***********************************************************"); Decryption d = new Decryption(); byte [] ttt = d.decrypt(data); System.out.print(data); String ss = new String(ttt); System.out.println("***********************"); System.out.println(ss); System.out.println("************************"); Server Side: in = connectionFromClient.getInputStream(); OutputStream out = connectionFromClient.getOutputStream(); DataOutputStream dataOut = new DataOutputStream(out); LicenseList licenses = new LicenseList(); String ValidIDs = licenses.getAllIDs(); System.out.println(ValidIDs); Encryption enc = new Encryption(); byte[] encrypted = enc.encrypt(ValidIDs); byte[] dd = enc.encrypt(ValidIDs); String tobesent = new String(dd); //byte[] rsult = enc.decrypt(dd); //String tt = String(rsult); System.out.println("The sent data**********************************************"); System.out.println(dd); String temp = new String(dd); System.out.println(temp); System.out.println("*************************************************************"); //BufferedWriter bf = new BufferedWriter(OutputStreamWriter(out)); //dataOut.write(ValidIDs.getBytes().length); dataOut.writeInt(ValidIDs.getBytes().length); dataOut.flush(); dataOut.write(encrypted); dataOut.flush(); System.out.println("********Testing**************"); System.out.println("Here are the ids:::"); System.out.println(licenses.getAllIDs()); System.out.println("**********************"); //bw.write("it is working well\n");

  Read the article

• Jquery autocomplete UI - No results on multiple fields

  - by pjammer

  Andrew's answer to my comment has sparked this question. According to his awesome answer in the link above, the code at the bottom of the question will only work for ONE widget. But it's killer nice code and makes sense... I guess I want the best of both worlds. Nice JS, (if that is possible) and to have the zero results show() just the element that we're using at the time. This code snippet is the main crux of my problem, as I see it: source: function (request, response) { jQuery.ajax({ url: "/autocomplete.json", data: { term: request.term }, success: function (data) { if (data.length == 0) { jQuery('span.guest_investor_email').show(); jQuery('span.investor_field_delete_button').show(); } response(data); } }); Currently: I have a button on my page that says "Add more Information" and each time you click it, a new instance of the autocomplete text field appears, complete with some hidden fields and a display:none; on guest_investor_email. If I use the autocomplete text field, say 3 times, and i have 3 autocomplete instances on the page and the third one finds 0 results: The code will show() all 3 instances of the guest_investor_email text field, instead of just this one that is blank. QUESTION: How do i get something like jQuery(this).siblings(('span.guest_investor_email').show(); to work? this is an Object and not an array of elements to select. If it isn't with this I don't mind, as long as I know how to get at it. Thanks. Full Code: jQuery(".auto_search_complete").live("click", function() { jQuery(this).autocomplete({ minLength: 3, source: function (request, response) { jQuery.ajax({ url: "/autocomplete.json", data: { term: request.term }, success: function (data) { if (data.length == 0) { jQuery('span.guest_investor_email').show(); jQuery('span.investor_field_delete_button').show(); } response(data); } }); }, focus: function(event, ui) { jQuery(this).val(ui.item.user ? ui.item.user.name : ui.item.pitch.name); return false; }, select: function(event, ui) { jQuery(this).val(ui.item.user ? ui.item.user.name : ui.item.pitch.name); jQuery(this).siblings('div.hidden_fields').children('.poly_id').val(ui.item.user ? ui.item.user.id : ui.item.pitch.id); jQuery(this).siblings('div.hidden_fields').children('.poly_type').val(ui.item.user ? "User" : "Pitch"); jQuery(this).siblings('span.guest_investor_email').hide(); jQuery(this).siblings('span.investor_field_delete_button').show(); jQuery(this).attr('readonly','readonly'); jQuery(this).attr('id', "investor-selected"); return false; } }).each(function() { jQuery(this).data( "autocomplete" )._renderItem = function( ul, item ) { return jQuery( "" ) .data( "item.autocomplete", item ) .append("" + (item.user ? item.user.name : item.pitch.name) + "" + (item.user ? item.user.investor_type : item.pitch.investor_type) + " - " + (item.user ? item.user.city : item.pitch.city) + "" ) .appendTo( ul ); }; }); });

  Read the article

• Overloading '-' for array subtraction

  - by Chris Wilson

  I am attempting to subtract two int arrays, stored as class members, using an overloaded - operator, but I'm getting some peculiar output when I run tests. The overload definition is Number& Number :: operator-(const Number& NumberObject) { for (int count = 0; count < NumberSize; count ++) { Value[count] -= NumberObject.Value[count]; } return *this; } Whenever I run tests on this, NumberObject.Value[count] always seems to be returning a zero value. Can anyone see where I'm going wrong with this? The line in main() where this subtraction is being carried out is cout << "The difference is: " << ArrayOfNumbers[0] - ArrayOfNumbers[1] << endl; ArrayOfNumbers contains two Number objects. The class declaration is #include <iostream> using namespace std; class Number { private: int Value[50]; int NumberSize; public: Number(); // Default constructor Number(const Number&); // Copy constructor Number(int, int); // Non-default constructor void SetMemberValues(int, int); // Manually set member values int GetNumberSize() const; // Return NumberSize member int GetValue() const; // Return Value[] member Number& operator-=(const Number&); }; inline Number operator-(Number Lhs, const Number& Rhs); ostream& operator<<(ostream&, const Number&); The full class definition is as follows: #include <iostream> #include "../headers/number.h" using namespace std; // Default constructor Number :: Number() {} // Copy constructor Number :: Number(const Number& NumberObject) { int Temp[NumberSize]; NumberSize = NumberObject.GetNumberSize(); for (int count = 0; count < NumberObject.GetNumberSize(); count ++) { Temp[count] = Value[count] - NumberObject.GetValue(); } } // Manually set member values void Number :: SetMemberValues(int NewNumberValue, int NewNumberSize) { NumberSize = NewNumberSize; for (int count = NewNumberSize - 1; count >= 0; count --) { Value[count] = NewNumberValue % 10; NewNumberValue = NewNumberValue / 10; } } // Non-default constructor Number :: Number(int NumberValue, int NewNumberSize) { NumberSize = NewNumberSize; for (int count = NewNumberSize - 1; count >= 0; count --) { Value[count] = NumberValue % 10; NumberValue = NumberValue / 10; } } // Return the NumberSize member int Number :: GetNumberSize() const { return NumberSize; } // Return the Value[] member int Number :: GetValue() const { int ResultSoFar; for (int count2 = 0; count2 < NumberSize; count2 ++) { ResultSoFar = ResultSoFar * 10 + Value[count2]; } return ResultSoFar; } Number& operator-=(const Number& Rhs) { for (int count = 0; count < NumberSize; count ++) { Value[count] -= Rhs.Value[count]; } return *this; } inline Number operator-(Number Lhs, const Number& Rhs) { Lhs -= Rhs; return Lhs; } // Overloaded output operator ostream& operator<<(ostream& OutputStream, const Number& NumberObject) { OutputStream << NumberObject.GetValue(); return OutputStream; }

  Read the article

• Odd C++ template behaviour with static member vars

  - by jon hanson

  This piece of code is supposed to calculate an approximation to e (i.e. the mathematical constant ~ 2.71828183) at compile-time, using the following approach; e1 = 2 / 1 e2 = (2 * 2 + 1) / (2 * 1) = 5 / 2 = 2.5 e3 = (3 * 5 + 1) / (3 * 2) = 16 / 6 ~ 2.67 e4 = (4 * 16 + 1) / (4 * 6) = 65 / 24 ~ 2.708 ... e(i) = (e(i-1).numer * i + 1) / (e(i-1).denom * i) The computation is returned via the result static member however, after 2 iterations it yields zero instead of the expected value. I've added a static member function f() to compute the same value and that doesn't exhibit the same problem. #include <iostream> #include <iomanip> // Recursive case. template<int ITERS, int NUMERATOR = 2, int DENOMINATOR = 1, int I = 2> struct CalcE { static const double result; static double f () {return CalcE<ITERS, NUMERATOR * I + 1, DENOMINATOR * I, I + 1>::f ();} }; template<int ITERS, int NUMERATOR, int DENOMINATOR, int I> const double CalcE<ITERS, NUMERATOR, DENOMINATOR, I>::result = CalcE<ITERS, NUMERATOR * I + 1, DENOMINATOR * I, I + 1>::result; // Base case. template<int ITERS, int NUMERATOR, int DENOMINATOR> struct CalcE<ITERS, NUMERATOR, DENOMINATOR, ITERS> { static const double result; static double f () {return result;} }; template<int ITERS, int NUMERATOR, int DENOMINATOR> const double CalcE<ITERS, NUMERATOR, DENOMINATOR, ITERS>::result = static_cast<double>(NUMERATOR) / DENOMINATOR; // Test it. int main (int argc, char* argv[]) { std::cout << std::setprecision (8); std::cout << "e2 ~ " << CalcE<2>::result << std::endl; std::cout << "e3 ~ " << CalcE<3>::result << std::endl; std::cout << "e4 ~ " << CalcE<4>::result << std::endl; std::cout << "e5 ~ " << CalcE<5>::result << std::endl; std::cout << std::endl; std::cout << "e2 ~ " << CalcE<2>::f () << std::endl; std::cout << "e3 ~ " << CalcE<3>::f () << std::endl; std::cout << "e4 ~ " << CalcE<4>::f () << std::endl; std::cout << "e5 ~ " << CalcE<5>::f () << std::endl; return 0; } I've tested this with VS 2008 and VS 2010, and get the same results in each case: e2 ~ 2 e3 ~ 2.5 e4 ~ 0 e5 ~ 0 e2 ~ 2 e3 ~ 2.5 e4 ~ 2.6666667 e5 ~ 2.7083333 Why does result not yield the expected values whereas f() does? According to Rotsor's comment below, this does work with GCC, so I guess the question is, am i relying on some type of undefined behaviour with regards to static initialisation order, or is this a bug with Visual Studio?

  Read the article

• Help in building an 16 bit os

  - by Barshan Das

  I am trying to build an old 16 bit dos like os. My bootloader code: ; This is not my code. May be of Fritzos. I forgot the source. ORG 7c00h jmp Start drive db 0 msg db " Loader Initialization",0 msg2 db "ACos Loaded",0 print: lodsb cmp al, 0 je end mov ah, 0Eh int 10h jmp print end: ret Start: mov [ drive ], dl ; Get the floppy OS booted from ; Update the segment registers xor ax, ax ; XOR ax mov ds, ax ; Mov AX into DS mov si,msg call print ; Load Kernel. ResetFloppy: mov ax, 0x00 ; Select Floppy Reset BIOS Function mov dl, [ drive ] ; Select the floppy ADos booted from int 13h ; Reset the floppy drive jc ResetFloppy ; If there was a error, try again. ReadFloppy: mov bx, 0x9000 ; Load kernel at 9000h. mov ah, 0x02 ; Load disk data to ES:BX mov al, 17 ; Load two floppy head full's worth of data. mov ch, 0 ; First Cylinder mov cl, 2 ; Start at the 2nd Sector to load the Kernel mov dh, 0 ; Use first floppy head mov dl, [ drive ] ; Load from the drive kernel booted from. int 13h ; Read the floppy disk. jc ReadFloppy ; Error, try again. ; Clear text mode screen mov ax, 3 int 10h ;print starting message mov si,msg2 call print mov ax, 0x0 mov ss, ax mov sp, 0xFFFF jmp 9000h ; This part makes sure the bootsector is 512 bytes. times 510-($-$$) db 0 ;bootable sector signature dw 0xAA55 My example kernel code: asm(".code16\n"); void putchar(char); int main() { putchar('A'); return 0; } void putchar(char val) { asm("movb %0, %%al\n" "movb $0x0E, %%ah\n" "int $0x10\n" : :"r"(val) ) ; } This is how I compile it : nasm -f bin -o ./bin/boot.bin ./source/boot.asm gcc -nostdinc -fno-builtin -I./include -c -o ./bin/kernel.o ./source/kernel.c ld -Ttext=0x9000 -o ./bin/kernel.bin ./bin/kernel.o -e 0x0 dd if=/dev/zero of=./bin/empty.bin bs=1440K count=1 cat ./bin/boot.bin ./bin/kernel.bin ./bin/empty.bin|head -c 1440K > ./bin/os rm ./bin/empty.bin and I run it in virtual machine. When I make the putchar function ( in kernel code ) for constant value ....i.e like this: void putchar() { char val = 'A'; asm("movb %0, %%al\n" "movb $0x0E, %%ah\n" "int $0x10\n" : :"r"(val) ) ; } then it works fine. But when I pass argument to it ( That is in the previous code ) , then it prints a space for any character. What should I do?

  Read the article

• Decomposing a rotation matrix

  - by DeadMG

  I have a rotation matrix. How can I get the rotation around a specified axis contained within this matrix? Edit: It's a 3D matrix (4x4), and I want to know how far around a predetermined (not contained) axis the matrix rotates. I can already decompose the matrix but D3DX will only give the entire matrix as one rotation around one axis, whereas I need to split the matrix up into angle of rotation around an already-known axis, and the rest. Sample code and brief problem description: D3DXMATRIX CameraRotationMatrix; D3DXVECTOR3 CameraPosition; //D3DXVECTOR3 CameraRotation; inline D3DXMATRIX GetRotationMatrix() { return CameraRotationMatrix; } inline void TranslateCamera(float x, float y, float z) { D3DXVECTOR3 rvec, vec(x, y, z); #pragma warning(disable : 4238) D3DXVec3TransformNormal(&rvec, &vec, &GetRotationMatrix()); #pragma warning(default : 4238) CameraPosition += rvec; RecomputeVPMatrix(); } inline void RotateCamera(float x, float y, float z) { D3DXVECTOR3 RotationRequested(x, y, z); D3DXVECTOR3 XAxis, YAxis, ZAxis; D3DXMATRIX rotationx, rotationy, rotationz; XAxis = D3DXVECTOR3(1, 0, 0); YAxis = D3DXVECTOR3(0, 1, 0); ZAxis = D3DXVECTOR3(0, 0, 1); #pragma warning(disable : 4238) D3DXVec3TransformNormal(&XAxis, &XAxis, &GetRotationMatrix()); D3DXVec3TransformNormal(&YAxis, &YAxis, &GetRotationMatrix()); D3DXVec3TransformNormal(&ZAxis, &ZAxis, &GetRotationMatrix()); #pragma warning(default : 4238) D3DXMatrixIdentity(&rotationx); D3DXMatrixIdentity(&rotationy); D3DXMatrixIdentity(&rotationz); D3DXMatrixRotationAxis(&rotationx, &XAxis, RotationRequested.x); D3DXMatrixRotationAxis(&rotationy, &YAxis, RotationRequested.y); D3DXMatrixRotationAxis(&rotationz, &ZAxis, RotationRequested.z); CameraRotationMatrix *= rotationz; CameraRotationMatrix *= rotationy; CameraRotationMatrix *= rotationx; RecomputeVPMatrix(); } inline void RecomputeVPMatrix() { D3DXMATRIX ProjectionMatrix; D3DXMatrixPerspectiveFovLH( &ProjectionMatrix, FoV, (float)D3DDeviceParameters.BackBufferWidth / (float)D3DDeviceParameters.BackBufferHeight, FarPlane, NearPlane ); D3DXVECTOR3 CamLookAt; D3DXVECTOR3 CamUpVec; #pragma warning(disable : 4238) D3DXVec3TransformNormal(&CamLookAt, &D3DXVECTOR3(1, 0, 0), &GetRotationMatrix()); D3DXVec3TransformNormal(&CamUpVec, &D3DXVECTOR3(0, 1, 0), &GetRotationMatrix()); #pragma warning(default : 4238) D3DXMATRIX ViewMatrix; #pragma warning(disable : 4238) D3DXMatrixLookAtLH(&ViewMatrix, &CameraPosition, &(CamLookAt + CameraPosition), &CamUpVec); #pragma warning(default : 4238) ViewProjectionMatrix = ViewMatrix * ProjectionMatrix; D3DVIEWPORT9 vp = { 0, 0, D3DDeviceParameters.BackBufferWidth, D3DDeviceParameters.BackBufferHeight, 0, 1 }; D3DDev->SetViewport(&vp); } Effectively, after a certain time, when RotateCamera is called, it begins to rotate in the relative X axis- even though constant zero is passed in for that request when responding to mouse input, so I know that when moving the mouse, the camera should not roll at all. I tried spamming 0,0,0 requests and saw no change (one per frame at 1500 frames per second), so I'm fairly sure that I'm not seeing FP error or matrix accumulation error. I tried writing a RotateCameraYZ function and stripping all X-axis from the function. I've spent several days trying to discover why this is the case, and eventually decided on just hacking around it. Just for reference, I've seen some diagrams on Wikipedia, and I actually have a relatively strange axis layout, which is Y axis up, but X axis forwards and Z axis right, so Y axis yaw, Z axis pitch, X axis roll.

  Read the article

• Resumable upload from Java client to Grails web application?

  - by dersteps

  After almost 2 workdays of Googling and trying several different possibilities I found throughout the web, I'm asking this question here, hoping that I might finally get an answer. First of all, here's what I want to do: I'm developing a client and a server application with the purpose of exchanging a lot of large files between multiple clients on a single server. The client is developed in pure Java (JDK 1.6), while the web application is done in Grails (2.0.0). As the purpose of the client is to allow users to exchange a lot of large files (usually about 2GB each), I have to implement it in a way, so that the uploads are resumable, i.e. the users are able to stop and resume uploads at any time. Here's what I did so far: I actually managed to do what I wanted to do and stream large files to the server while still being able to pause and resume uploads using raw sockets. I would send a regular request to the server (using Apache's HttpClient library) to get the server to send me a port that was free for me to use, then open a ServerSocket on the server and connect to that particular socket from the client. Here's the problem with that: Actually, there are at least two problems with that: I open those ports myself, so I have to manage open and used ports myself. This is quite error-prone. I actually circumvent Grails' ability to manage a huge amount of (concurrent) connections. Finally, here's what I'm supposed to do now and the problem: As the problems I mentioned above are unacceptable, I am now supposed to use Java's URLConnection/HttpURLConnection classes, while still sticking to Grails. Connecting to the server and sending simple requests is no problem at all, everything worked fine. The problems started when I tried to use the streams (the connection's OutputStream in the client and the request's InputStream in the server). Opening the client's OutputStream and writing data to it is as easy as it gets. But reading from the request's InputStream seems impossible to me, as that stream is always empty, as it seems. Example Code Here's an example of the server side (Groovy controller): def test() { InputStream inStream = request.inputStream if(inStream != null) { int read = 0; byte[] buffer = new byte[4096]; long total = 0; println "Start reading" while((read = inStream.read(buffer)) != -1) { println "Read " + read + " bytes from input stream buffer" //<-- this is NEVER called } println "Reading finished" println "Read a total of " + total + " bytes" // <-- 'total' will always be 0 (zero) } else { println "Input Stream is null" // <-- This is NEVER called } } This is what I did on the client side (Java class): public void connect() { final URL url = new URL("myserveraddress"); final byte[] message = "someMessage".getBytes(); // Any byte[] - will be a file one day HttpURLConnection connection = url.openConnection(); connection.setRequestMethod("GET"); // other methods - same result // Write message DataOutputStream out = new DataOutputStream(connection.getOutputStream()); out.writeBytes(message); out.flush(); out.close(); // Actually connect connection.connect(); // is this placed correctly? // Get response BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream())); String line = null; while((line = in.readLine()) != null) { System.out.println(line); // Prints the whole server response as expected } in.close(); } As I mentioned, the problem is that request.inputStream always yields an empty InputStream, so I am never able to read anything from it (of course). But as that is exactly what I'm trying to do (so I can stream the file to be uploaded to the server, read from the InputStream and save it to a file), this is rather disappointing. I tried different HTTP methods, different data payloads, and also rearranged the code over and over again, but did not seem to be able to solve the problem. What I hope to find I hope to find a solution to my problem, of course. Anything is highly appreciated: hints, code snippets, library suggestions and so on. Maybe I'm even having it all wrong and need to go in a totally different direction. So, how can I implement resumable file uploads for rather large (binary) files from a Java client to a Grails web application without manually opening ports on the server side?

  Read the article

• Termite colony simulator using java

  - by ashii

  hi everyone, i hve to design a simulator that will maintain an environment, which consists of a collection of patches arranged in a rectangular grid of arbitrary size. Each patch contains zero or more wood chips. A patch may be occupied by one or more termites or predators, which are mobile entities that live within the world and behave according to simple rules. A TERMITE can pick up a wood chip from the patch that it is currently on, or drop a wood chip that it is carrying. Termites travel around the grid by moving randomly from their current patch to a neighbouring patch, in one of four possible directions. New termites may hatch from eggs, and this is simulated by the appearance of a new termite at a random patch within the environment. A PREDATOR moves in a similar way to termites, and if a predator moves onto a patch that is occupied by a termite, then the predator eats the termite. At initialization, the termites, predators, and wood chips are distributed randomly in the environment. Simulation then proceeds in a loop, and the new state of the environment is obtained at each iteration. i have designed the arena using jpanel but im not able to randomnly place wood,termite and predator in that arena. can any one help me out?? my code for the arena is as following: 01 import java.awt.*; 02 import javax.swing.*; 03 04 public class Arena extends JPanel 05 { 06 private static final int Rows = 8; 07 private static final int Cols = 8; 08 public void paint(Graphics g) 09 { 10 Dimension d = this.getSize(); 11 // don't draw both sets of squares, when you can draw one 12 // fill in the entire thing with one color 13 g.setColor(Color.WHITE); 14 // make the background 15 g.fillRect(0,0,d.width,d.height); 16 // draw only black 17 g.setColor(Color.BLACK); 18 // pick a square size based on the smallest dimension 19 int sqsize = ((d.width<d.height) ? d.width/Cols : d.height/Rows); 20 // loop for rows 21 for (int row=0; row<Rows; row++) 22 { 23 int y = row*sqsize; // y stays same for entire row, set here 24 int x = (row%2)*sqsize; // x starts at 0 or one square in 25 for (int i=0; i<Cols/2; i++) 26 { 27 // you will only be drawing half the squares per row 28 // draw square 29 g.fillRect(x,y,sqsize,sqsize); 30 // move two square sizes over 31 x += sqsize*2; 32 } 33 } 34 35 } 36 37 38 39 public void update(Graphics g) { paint(g); } 40 41 42 43 public static void main (String[] args) 44 { 45 46 JFrame frame = new JFrame("Arena"); 47 frame.setSize(600,400); 48 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 49 frame.setContentPane(new Arena()); 50 frame.setVisible(true); 51 } 52 53 }

  Read the article

• Agile: User Stories for Machine Learning Project?

  - by benjismith

  I've just finished up with a prototype implementation of a supervised learning algorithm, automatically assigning categorical tags to all the items in our company database (roughly 5 million items). The results look good, and I've been given the go-ahead to plan the production implementation project. I've done this kind of work before, so I know how the functional components of the software. I need a collection of web crawlers to fetch data. I need to extract features from the crawled documents. Those documents need to be segregated into a "training set" and a "classification set", and feature-vectors need to be extracted from each document. Those feature vectors are self-organized into clusters, and the clusters are passed through a series of rebalancing operations. Etc etc etc etc. So I put together a plan, with about 30 unique development/deployment tasks, each with time estimates. The first stage of development -- ignoring some advanced features that we'd like to have in the long-term, but aren't high enough priority to make it into the development schedule yet -- is slated for about two months worth of work. (Keep in mind that I already have a working prototype, so the final implementation is significantly simpler than if the project was starting from scratch.) My manager said the plan looked good to him, but he asked if I could reorganize the tasks into user stories, for a few reasons: (1) our project management software is totally organized around user stories; (2) all of our scheduling is based on fitting entire user stories into sprints, rather than individually scheduling tasks; (3) other teams -- like the web developers -- have made great use of agile methodologies, and they've benefited from modelling all the software features as user stories. So I created a user story at the top level of the project: As a user of the system, I want to search for items by category, so that I can easily find the most relevant items within a huge, complex database. Or maybe a better top-level story for this feature would be: As a content editor, I want to automatically create categorical designations for the items in our database, so that customers can easily find high-value data within our huge, complex database. But that's not the real problem. The tricky part, for me, is figuring out how to create subordinate user stories for the rest of the machine learning architecture. Case in point... I know that the algorithm requires two major architectural subdivisions: (A) training, and (B) classification. And I know that the training portion of the architecture requires construction of a cluster-space. All the Agile Development literature I've read seems to indicate that a user story should be the "smallest possible implementation that provides any business value". And that makes a lot of sense when designing a piece of end-user software. Start small, and then incrementally add value when users demand additional functionality. But a cluster-space, in and of itself, provides zero business value. Nor does a crawler, or a feature-extractor. There's no business value (not for the end-user, or for any of the roles internal to the company) in a partial system. A trained cluster-space is only possible with the crawler and feature extractor, and only relevant if we also develop an accompanying classifier. I suppose it would be possible to create user stories where the subordinate components of the system act as the users in the stories: As a supervised-learning cluster-space construction routine, I want to consume data from a feature extractor, so that I can exist. But that seems really weird. What benefit does it provide me as the developer (or our users, or any other stakeholders, for that matter) to model my user stories like that? Although the main story can be easily divided along architectural-component boundaries (crawler, trainer, classifier, etc), I can't think of any useful decomposition from a user's perspective. What do you guys think? How do you plan Agile user stories for sophisticated, indivisible, non-user-facing components?

  Read the article

• Create and Share a File (Also a mysterious error)

  - by Kirk

  My goal is to create a XML file and then send it through the share Intent. I'm able to create a XML file using this code FileOutputStream outputStream = context.openFileOutput(fileName, Context.MODE_WORLD_READABLE); PrintStream printStream = new PrintStream(outputStream); String xml = this.writeXml(); // get XML here printStream.println(xml); printStream.close(); I'm stuck trying to retrieve a Uri to the output file in order to share it. I first tried to access the file by converting the file to a Uri File outFile = context.getFileStreamPath(fileName); return Uri.fromFile(outFile); This returns file:///data/data/com.my.package/files/myfile.xml but I cannot appear to attach this to an email, upload, etc. If I manually check the file length, it's proper and shows there is a reasonable file size. Next I created a content provider and tried to reference the file and it isn't a valid handle to the file. The ContentProvider doesn't ever seem to be called a any point. Uri uri = Uri.parse("content://" + CachedFileProvider.AUTHORITY + "/" + fileName); return uri; This returns content://com.my.package.provider/myfile.xml but I check the file and it's zero length. How do I access files properly? Do I need to create the file with the content provider? If so, how? Update Here is the code I'm using to share. If I select Gmail, it does show as an attachment but when I send it gives an error Couldn't show attachment and the email that arrives has no attachment. public void onClick(View view) { Log.d(TAG, "onClick " + view.getId()); switch (view.getId()) { case R.id.share_cancel: setResult(RESULT_CANCELED, getIntent()); finish(); break; case R.id.share_share: MyXml xml = new MyXml(); Uri uri; try { uri = xml.writeXmlToFile(getApplicationContext(), "myfile.xml"); //uri is "file:///data/data/com.my.package/files/myfile.xml" Log.d(TAG, "Share URI: " + uri.toString() + " path: " + uri.getPath()); File f = new File(uri.getPath()); Log.d(TAG, "File length: " + f.length()); // shows a valid file size Intent shareIntent = new Intent(); shareIntent.setAction(Intent.ACTION_SEND); shareIntent.putExtra(Intent.EXTRA_STREAM, uri); shareIntent.setType("text/plain"); startActivity(Intent.createChooser(shareIntent, "Share")); } catch (FileNotFoundException e) { e.printStackTrace(); } break; } } I noticed that there is an Exception thrown here from inside createChooser(...), but I can't figure out why it's thrown. E/ActivityThread(572): Activity com.android.internal.app.ChooserActivity has leaked IntentReceiver com.android.internal.app.ResolverActivity$1@4148d658 that was originally registered here. Are you missing a call to unregisterReceiver()? I've researched this error and can't find anything obvious. Both of these links suggest that I need to unregister a receiver. Chooser Activity Leak - Android Why does Intent.createChooser() need a BroadcastReceiver and how to implement? I have a receiver setup, but it's for an AlarmManager that is set elsewhere and doesn't require the app to register / unregister. Code for openFile(...) In case it's needed, here is the content provider I've created. public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException { String fileLocation = getContext().getCacheDir() + "/" + uri.getLastPathSegment(); ParcelFileDescriptor pfd = ParcelFileDescriptor.open(new File(fileLocation), ParcelFileDescriptor.MODE_READ_ONLY); return pfd; }

  Read the article

• Javascript style objects in Objective-C

  - by awolf

  Background: I use a ton of NSDictionary objects in my iPhone and iPad code. I'm sick of the verbose way of getting/setting keys to these state dictionaries. So a little bit of an experiment: I just created a class I call Remap. Remap will take any arbitrary set[VariableName]:(NSObject *) obj selector and forward that message to a function that will insert obj into an internal NSMutableDictionary under the key [vairableName]. Remap will also take any (zero argument) arbitrary [variableName] selector and return the NSObject mapped in the NSMutableDictionary under the key [variableName]. e.g. Remap * remap = [[Remap alloc] init]; NSNumber * testNumber = [NSNumber numberWithInt:46]; [remap setTestNumber:testNumber]; testNumber = [remap testNumber]; [remap setTestString:@"test string"]; NSString * testString = [remap testString]; NSMutableDictionary * testDict = [NSMutableDictionary dictionaryWithObject:testNumber forKey:@"testNumber"]; [remap setTestDict:testDict]; testDict = [remap testDict]; where none of the properties testNumber, testString, or testDict are actually defined in Remap. The crazy thing? It works... My only question is how can I disable the "may not respond to " warnings for JUST accesses to Remap? P.S. : I'll probably end up scrapping this and going with macros since message forwarding is quite inefficient... but aside from that does anyone see other problems with Remap? Here's Remap's .m for those who are curious: #import "Remap.h" @interface Remap () @property (nonatomic, retain) NSMutableDictionary * _data; @end @implementation Remap @synthesize _data; - (void) dealloc { relnil(_data); [super dealloc]; } - (id) init { self = [super init]; if (self != nil) { NSMutableDictionary * dict = [[NSMutableDictionary alloc] init]; [self set_data:dict]; relnil(dict); } return self; } - (void)forwardInvocation:(NSInvocation *)anInvocation { NSString * selectorName = [NSString stringWithUTF8String: sel_getName([anInvocation selector])]; NSRange range = [selectorName rangeOfString:@"set"]; NSInteger numArguments = [[anInvocation methodSignature] numberOfArguments]; if (range.location == 0 && numArguments == 4) { //setter [anInvocation setSelector:@selector(setData:withKey:)]; [anInvocation setArgument:&selectorName atIndex:3]; [anInvocation invokeWithTarget:self]; } else if (numArguments == 3) { [anInvocation setSelector:@selector(getDataWithKey:)]; [anInvocation setArgument:&selectorName atIndex:2]; [anInvocation invokeWithTarget:self]; } } - (NSMethodSignature *) methodSignatureForSelector:(SEL) aSelector { NSString * selectorName = [NSString stringWithUTF8String: sel_getName(aSelector)]; NSMethodSignature * sig = [super methodSignatureForSelector:aSelector]; if (sig == nil) { NSRange range = [selectorName rangeOfString:@"set"]; if (range.location == 0) { sig = [self methodSignatureForSelector:@selector(setData:withKey:)]; } else { sig = [self methodSignatureForSelector:@selector(getDataWithKey:)]; } } return sig; } - (NSObject *) getDataWithKey: (NSString *) key { NSObject * returnValue = [[self _data] objectForKey:key]; return returnValue; } - (void) setData: (NSObject *) data withKey:(NSString *)key { if (key && [key length] >= 5 && data) { NSRange range; range.length = 1; range.location = 3; NSString * firstChar = [key substringWithRange:range]; firstChar = [firstChar lowercaseString]; range.length = [key length] - 5; // the 4 we have processed plus the training : range.location = 4; NSString * adjustedKey = [NSString stringWithFormat:@"%@%@", firstChar, [key substringWithRange:range]]; [[self _data] setObject:data forKey:adjustedKey]; } else { //assert? } } @end

  Read the article

• How do I recursively define a Hash in Ruby from supplied arguments?

  - by Sarah Beckham

  This snippet of code populates an @options hash. values is an Array which contains zero or more heterogeneous items. If you invoke populate with arguments that are Hash entries, it uses the value you specify for each entry to assume a default value. def populate(*args) args.each do |a| values = nil if (a.kind_of? Hash) # Converts {:k => "v"} to `a = :k, values = "v"` a, values = a.to_a.first end @options[:"#{a}"] ||= values ||= {} end end What I'd like to do is change populate such that it recursively populates @options. There is a special case: if the values it's about to populate a key with are an Array consisting entirely of (1) Symbols or (2) Hashes whose keys are Symbols (or some combination of the two), then they should be treated as subkeys rather than the values associated with that key, and the same logic used to evaluate the original populate arguments should be recursively re-applied. That was a little hard to put into words, so I've written some test cases. Here are some test cases and the expected value of @options afterwards: populate :a => @options is {:a => {}} populate :a => 42 => @options is {:a => 42} populate :a, :b, :c => @options is {:a => {}, :b => {}, :c => {}} populate :a, :b => "apples", :c => @options is {:a => {}, :b => "apples", :c => {}} populate :a => :b => @options is {:a => :b} # Because [:b] is an Array consisting entirely of Symbols or # Hashes whose keys are Symbols, we assume that :b is a subkey # of @options[:a], rather than the value for @options[:a]. populate :a => [:b] => @options is {:a => {:b => {}}} populate :a => [:b, :c => :d] => @options is {:a => {:b => {}, :c => :d}} populate :a => [:a, :b, :c] => @options is {:a => {:a => {}, :b => {}, :c => {}}} populate :a => [:a, :b, "c"] => @options is {:a => [:a, :b, "c"]} populate :a => [:one], :b => [:two, :three => "four"] => @options is {:a => :one, :b => {:two => {}, :three => "four"}} populate :a => [:one], :b => [:two => {:four => :five}, :three => "four"] => @options is {:a => :one, :b => { :two => { :four => :five } }, :three => "four" } } It is acceptable if the signature of populate needs to change to accommodate some kind of recursive version. There is no limit to the amount of nesting that could theoretically happen. Any thoughts on how I might pull this off?

  Read the article

< Previous Page | 120 121 122 123 124 125 126 127 128 129 130 131  | Next Page >