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  • Any way to stringify a variable id / symbol in Python?

    - by otz
    I'm wondering if it is possible at all in python to stringify variable id/symbol -- that is, a function that behaves as follows: >>> symbol = 'whatever' >>> symbol_name(symbol) 'symbol' Now, it is easy to do it on a function or a class (if it is a direct reference to the object): >>> def fn(): pass >>> fn.func_name 'fn' But I'm looking for a general method that works on all cases, even for indirect object references. I've thought of somehow using id(var), but no luck yet. Is there any way to do it?

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  • C# background worker and timer loop

    - by Mike
    This is my first attempt of a Timer, if someone could help me out where I am going wrong it would be awesome. I'm trying to use a while loop where if the timer hits 30 seconds try to loop it again. private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { System.Windows.Forms.Timer my_timer = new System.Windows.Forms.Timer(); my_timer = null; //int restartticker = 30000; while (true) { my_timer.Start(); if (my_timer.Equals(30000)) { watcherprocess1(); } my_timer = null; } } Object reference not set to an instance of an object. my_timer.Start();

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  • Why isn't the compiler smarter in this const function overloading problem?

    - by Frank
    The following code does not compile: #include <iostream> class Foo { std::string s; public: const std::string& GetString() const { return s; } std::string* GetString() { return &s; } }; int main(int argc, char** argv){ Foo foo; const std::string& s = foo.GetString(); // error return 0; } I get the following error: const1.cc:11: error: invalid initialization of reference of type 'const std::string&' from expression of type 'std::string* It does make some sense because foo is not of type const Foo, but just Foo, so the compiler wants to use the non-const function. But still, why can't it recognize that I want to call the const GetString function, by looking at the (type of) variable I assign it to? I found this kind of surprising.

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  • Spring security with database and multiple roles?

    - by Joe
    I'm trying to make an application using spring 3.0. Now I've decided to try my hand at spring-security and hibernate. I've already seen that it's possible to back it with a databasem and I've seen a reference to defining your own queries? Now the problem I have is that the tutorials I've been finding aren't too clear and that they assume that a user can only have one role. I want to give some users multiple roles. So I was thinking about a database scheme along the lines of: User: user_id username password registrationDate User_Role: user_id role_id Role: role_id rolename Now I was wondering if anyone had some pointers to some usefull tutorials/advice/comments.

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  • Is "programmatically" a word? [closed]

    - by Lo'oris
    I can't find it on any of the online dictionaries I know: dict.org, word reference, urban dictionary, oxford paravia, garzanti. To my ears of a non-native speaker, it sounds horrible. Actually it sounds like a word made-up by another non-native speaker that wanted to say something, didn't know how, and just hacked in a word of his language. The only place I've read it other then user-created-content is the android documentation, so this might or might not be related. Do you happen to know where did it start to be used, why by did it spread so much, what does it really mean?

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  • What is the right way to implement communication between java objects?

    - by imoschak
    I'm working on an academic project which simulates a rather large queuing procedure in java. The core of the simulator rests within one package where there exist 8 classes, each one implementing a single concept. Every class in the project follows SRP. These classes encapsulate the behavior of the simulator and inter-connect every other class in the project. The problem that has arisen is that most of these 8 classes are, as is logical i think, tightly coupled and each one has to have working knowledge of every other class in this package in order to be able to call methods from it when needed. The application needs only one instance of each class so it might be better to create static fields for each class in a new class and use that to make calls -instead of preserving a reference in each class for every other class in the package (which I'm certain that is incorrect)-, but is this considered a correct design solution? or is there a design pattern maybe that better suits my needs?

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  • c++ classes & lua

    - by anon
    I want to have C++ objects that I can read/write in both C++ & Lua. I have looked at: http://www.lua.org/pil/28.html However, I do not like that solution, since my objects have constructors & destructors (and they are important as I use RAII and these take care of reference counts). What I don't like in the PIL solution is that the object is allocated in Lua's heap. What i want instead, is to create hte C++ object on my own, and just have lua have a way to do get/set on them. Does anyone have a good tutorial/link on this? Tanks!

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  • What's the best way to return something like a collection of `std::auto_ptr`s in C++03?

    - by Billy ONeal
    std::auto_ptr is not allowed to be stored in an STL container, such as std::vector. However, occasionally there are cases where I need to return a collection of polymorphic objects, and therefore I can't return a vector of objects (due to the slicing problem). I can use std::tr1::shared_ptr and stick those in the vector, but then I have to pay a high price of maintaining separate reference counts, and object that owns the actual memory (the container) no longer logically "owns" the objects because they can be copied out of it without regard to ownership. C++0x offers a perfect solution to this problem in the form of std::vector<std::unique_ptr<t>>, but I don't have access to C++0x. Some other notes: I don't have access to C++0x, but I do have TR1 available. I would like to avoid use of Boost (though it is available if there is no other option) I am aware of boost::ptr_container containers (i.e. boost::ptr_vector), but I would like to avoid this because it breaks the debugger (innards are stored in void *s which means it's difficult to view the object actually stored inside the container in the debugger)

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  • How long people take to learn a new programming language?

    - by Cawas
    In general aspects, this might be a good reference for everyone. Having an idea of how long people take in average for properly learning how to code can give a very good idea on how dense or long is the path. Someone who never programmed should take weeks or months, even years maybe while someone who's already experienced in the area and know at least 2 different languages might take days, hours or even minutes to start coding. But other than being able to write code that runs, there are ways to write the same program, and it's much harder to get deep knowledge on that than actually being able to program. And sometimes languages differ a lot from one to another on that aspect as well. For instance, we should never have to worry with code-injection in JavaScript like we do in C. So, is there any place we can see some good numbers for how long it takes to learn a language, maybe divided into level of knowledge categories, languages and paradigms, etc?

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  • Handling orientation changes yourself

    - by synic
    From the documentation regarding the android:configChanges='orientation' attribute of the activity tag in the manifest: Note: Using this attribute should be avoided and used only as a last-resort. Please read Handling Runtime Changes for more information about how to properly handle a restart due to a configuration change. Why does it say this? In the case of threads and networking requests via a service API library, a request could be made with a reference to the original Activity, and then an orientation change could occur, leaving the thread pointing to the old Activity. While this can be fixed, it's tedious and ugly compared to just handling the configuration changes yourself. Why should it be avoided?

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  • What is the time complexity of LinkedList.getLast() in Java?

    - by i.
    I have a private LinkedList in a Java class & will frequently need to retrieve the last element in the list. The lists need to scale, so I'm trying to decide whether I need to keep a reference to the last element when I make changes (to achieve O(1)) or if the LinkedList class does that already with the getLast() call. What is the big-O cost of LinkedList.getLast() and is it documented? (i.e. can I rely on this answer or should I make no assumptions & cache it even if it's O(1)?)

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  • JQuery selectors select from an html object other than from document root?

    - by orangebrainer
    jQuery selectors select from the document. How do I select from somewhere else other than root? Say I want to select some children from an html object. For this function dothis(obj) { $j("#tabs").removeClass(); $j("#tabs>ul").removeClass(); $j("#tabs>ul>li>a").each(function() { var tabNum = $j(this).attr("href").replace("#", ""); var tabContent = $j("div[id=" + tabNum + "]"); tabContent.removeClass(); $(tabContent).before("<br><h1>" +$j(this).text() + "</h1>\n" ); }); $j("#tabs>ul").each(function() { $j(this).empty();//remove Ul links on top }); } I want to reference the selectors from an html Object (obj) i passed into as argument, instead of selecting from document. Sorry I'm pretty new to jQuery.

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  • IE7 preventDefault() not working on skip links

    - by josh
    I currently have skip links that jump to the div ids and was using e.preventDefault() to stop the url from changing when jumping to the element but in IE7 and IE8 it doesn't work at all using e.preventDefault() and if I take it out the url changes to the div the anchor tag contains reference to. Is their any fix or way around this? Here is the code $('body').delegate('a.skiplink-accessible-text', 'click', function (e) { //e.preventDefault(); if (!$.browser.msie) { e.preventDefault(); } var jumpTo = $(this).attr('href'); $('body').find(jumpTo).attr('tabindex', - 1).focus(); }); EDIT: heres a little jsbin example for testing purposes http://jsbin.com/welcome/20846/edit

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  • Pass C++ object to Lua function

    - by peterdemin
    Hello there. I have a C++ project, where 1 method of a 1 class changes very often. So I want to take that code from C++ to Lua. Note, I'm novice to Lua. The whole task: Bind some class methods to Lua state machine; Pass reference to class object to a function, written in Lua; Operate with passed C++ object in Lua function. I've found how to make first step with Lunar, and can't cope with second and third. I can't use SWIG and boost.

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  • Android App Support Options

    - by Pughjl
    I've got a free app I'm planning on submitting to the marketplace. Looking over the submission form I see they expect a web site or email for support. Users?! I've got to worry about users if I submit an app? I suppose I would like to get some abuse from users, but I don't want to go broke doing it. So what are my options? I have a web site--I suppose I could install forum software on it--that sounds like a lot of work though. Some apps reference a blogspot page--or I could use my Word Press site. They seems a bit disorganized for getting user feedback though.

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  • Changing the context of a self-executing function

    - by TaylorMac
    This code is copied directly from: http://www.bennadel.com/blog/2264-Changing-The-Execution-Context-Of-Your-Self-Executing-Function-Blocks-In-JavaScript.htm // Set the singleton value to the return value of the self- // executing function block. var singleton = (function(){ // Declare a private variable. var message = "Stop playing with your context!"; this.getMessage = function(){ return( message ); }; // Return this object reference. return( this ); }).call( {} ); // alert the singleton message. alert( "Message:", singleton.getMessage()); ?My thought is that I can use this to better contain the variables and functions in my programs. However, when I try to run the code in a JSfiddle: http://jsfiddle.net/xSKHh/ It does not return the message. What am I missing?

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  • C++ - How to call a member function for an inherited object.

    - by Francisco P.
    Hello! I have a few classes (heat, gas, contact, pressure) inheriting from a main one (sensor). I have a need to store them in a vector<Sensor *> (part of the specification). At some point in time, I need to call a function that indiscriminately stores those Sensor *. (also part of the specification, not open for discussion) Something like this: for(size_t i = 0; i < Sensors.size(); ++i) Sensors[i]->storeSensor(os) //os is an ofstream kind of object, passed onwards by reference Where and how shall storeSensor be defined? Is there any simple way to do this or will I need to disregard the specification? Mind you, I'm a beginner! Thanks for your time!

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  • is it possible to create a multi-project template that references n number of existing projects and

    - by jcollum
    The situation: I need to create about 40+ solutions that all reference 3 projects and have one project that is unique to each one. I'd like to create a multi-project template that does this, but from what I've read it looks like it's very difficult or impossible (related SO question, but doesn't answer). I want my solution to look like this (names changed of course): These three are used by all solutions created under this "family": MyCompany.Extensions MyCompany.MyProject.Tests.Shared MyCompany.MyProject.Scripts This one is the one that makes the solution unique, 123, 124, 125 etc: MyCompany.MyProject.Tests.Unit123 Is it possible to set up a multi-project template that will generate this structure? References: MSDN Create Multi Project Templates

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  • how to use constants in SQL CREATE TABLE?

    - by kchiu
    Hi, I have 3 SQL tables, defined as follows: CREATE TABLE organs( abbreviation VARCHAR(16), -- ... other stuff ); CREATE TABLE blocks( abbreviation VARCHAR(16), -- ... other stuff ); CREATE TABLE slides( title VARCHAR(16), -- ... other stuff ); The 3 fields above all use VARCHAR(16) because they're related and have the same length restriction. Is there a (preferably portable) way to put '16' into a constant / variable and reference that instead in CREATE TABLE? eg. something like this would be nice: CREATE TABLE slides( title VARCHAR(MAX_TITLE_LENGTH), -- ... other stuff ); I'm using PostgreSQL 8.4. thanks a lot, and Happy New Year! cheers.

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  • JavaScript prototype(ing) question

    - by OneNerd
    Trying to grasp Prototyping in Javascript. Trying to create my own namespace to extend the String object in JavaScript. Here is what I have so far (a snippet): var ns { alert: function() { alert (this); } } String.prototype.$ns = ns; As you can see, I am trying to place what will be a series of functions into the ns namespace. So I can execute a command like this: "hello world".$ns.alert(); But the problem is, the this doesn't seem to reference the text being sent (in this case, "hello world"). What I get is an alert box with the following: [object Object] Not having a full grasp of the object-oriented nature of JavaScript, I am at a loss, but I am guessing I am missing something simple. Does anyone know how to achieve this? Thanks -

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  • How can I loop through all the open instances of a particular form?

    - by raz3r
    I need to update a ListBox of a Form2 created dinamically. Let's say that in the event where I have to update this ListBox (in Form1 of course) I don't have a reference of this Form2 so I can't call the UpdateList method (and no, I can't make it static). I don't even know if there is a Form2 opened, it could be or not. What do you suggest? Is there a way to loop through all the open istances of Form2? Code Sample: //Form1 public void event() { //UPDATE FORM2 LISTBOX } //SOMEWHERE IN FORM1 Form2 runTime = new Form2(); //Form2 public void UpdateList() { //UPDATE LISTBOX }

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  • Unit testing of static library that involves NSDocumentDirectory and other iOS App specific calls.

    - by Shiun
    Hi, I'm attempting to run unit tests for a static library that attempts to create/write/read a file in the document directory. Since this is a static library and not an application for the iOS, attempts to reference the NSDocumentDirectory is returning me directory for the form "/Users//Library/Application Support/iPhone Simulator/Documents" This directory does not exist. When attempting to access a directory from an actual application, the NSDocumentDirectory returns something of the form: "/Users//Library/Application Support/iPhone Simulator/4.2/FEDBEF5F-1326-4383-A087-CDA1B865E61A/Documents" (Please note the simulator version as well as application ID as part of the path) How can I overcome this shortcoming in the unit test framework for static libraries that implement tests that require iOS app specific calls? Thanks in advance.

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  • Python 2.7 creating a multidimensional list

    - by poop
    I don't know why I am having so much trouble creating a 3 dimensional list. I need the program to create an empty n by n list. So for n = 4: x = [[[],[],[],[]],[[],[],[],[]],[[],[],[],[]],[[],[],[],[]]] I've tried using: y = [n*[n*[]]] y = [[[]]* n for i in range(n)] Which both appear to be creating copies of a reference. I've also tried naieve application of the list builder with little success: y = [[[]* n for i in range(n)]* n for i in range(n)] y = [[[]* n for i in range(1)]* n for i in range(n)] I've also tried building up the array iteratively using loops, with no success. In my rapid flurry of attempts to not post something stupidly easy to SO, I came upon a solution: y = [] for i in range(0,n): y.append([[]*n for i in range(n)]) Is there an easier/ more intuitive way of doing this?

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  • SQL Server 2005 Reporting Services: How to count rows that are not null? Any hints for calculating t

    - by user329266
    Is there a way to count only records that are not null; similar to "COUNTA" in Excel? I would think this would be very simple process, but nothing I have tried has worked. If necessary, I can try to work this into my SQL query, but the query is already incredibly complicated. Also, I've found very little documentation for how to calculate report totals, and how to total from groups. Would anyone have any recommendations on what to use as a reference?

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  • Question about r-value in C++0x

    - by Goofy
    Rvalues IMHO are great improvement in C++, but at the beginning the're seems quite. Please look at code below: #include <string> std::string && foo (void) { std::string message ("Hello!"); return std::move (message); } void bar (const std::string &message2) { if (message == "Bye Bye!") return; } int main () { bar (foo ()); } Reference message2 is last owner of original message object returned by foo(), right?

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