Search Results

Search found 22104 results on 885 pages for 'programming language'.

Page 642/885 | < Previous Page | 638 639 640 641 642 643 644 645 646 647 648 649  | Next Page >

  • newbie question -- how does one override show for a newtype?

    - by gatoatigrado
    I want to override the default integer constructors in Haskell so they produce strings (mostly for curiosity, but temporarily to make a nice input alternative for LaTeX's \frac{}{} inconvenience). I wanted to be able to use the language itself, instead of a special parser, but I guess that's probably not going to work out... module Main where import Prelude hiding ((+)) newtype A = A Int deriving (Eq, Show, Num) default (A) (+) :: A -> (A -> String) (A a) + (A b) = (show a) ++ " + " ++ (show b) main2 = 3+4 main :: IO () main = putStrLn main2 The problem with the above is that the + function only works for (A, A) instead of (A, String), etc. If one simply leaves out the pattern match "(A a)" and writes "a" instead, then the show() function prepends "A " so "3" becomes "A 3" instead of just "3". I want to override Show for A, but it seems to be quite a headache...

    Read the article

  • Load XML to DataFrame in R

    - by Rohit Kandhal
    I am new to R programming and trying to load a simple XML in RStudio. I tried using XMLToDataFrame but got this error XML content does not seem to be XML: 'temp.xml' XML Schema <root> <row Id="1" UserId="1" Name="Rohit" Date="2009-06-29T10:28:58.013" /> <row Id="2" UserId="3" Name="Rohit" Date="2009-06-29T10:28:58.030" /> </root> Please provide me some direction on which function I should use here.

    Read the article

  • Who is a web developer? What does he do

    - by Sinan
    I am wrting an article on web developers. It seems to me there are some problems on the definition of "what is a web developer". It looks like a web developer title is a bit misunderstood. And people with this title doesnt get the recognition they deserve. While most people at IT have some well defined job defitinitions. A web developer requires multiple skills. Like knowing a programming language, web security, etc. I was wondering what do you think about this issue? What skills does a web developer need? Where does his responsibilities start and end? etc.

    Read the article

  • Help a Python newbie with a Django model inheritance problem

    - by Joshmaker
    I'm working on my first real Django project after years of PHP programming, and I am running into a problem with my models. First, I noticed that I was copying and pasting code between the models, and being a diligent OO programmer I decided to make a parent class that the other models could inherit from: class Common(model.Model): self.name = models.CharField(max_length=255) date_created = models.DateTimeField(auto_now_add=True) date_modified = models.DateTimeField(auto_now=True) def __unicode__(self): return self.name class Meta: abstract=True So far so good. Now all my other models extend "Common" and have names and dates like I want. However, I have a class for "Categories" were the name has to be unique. I assume there should be a relatively simple way for me to access the name attribute from Common and make it unique. However, the different methods I have tried to use have all failed. For example: class Category(Common): def __init__(self, *args, **kwargs): self.name.unique=True Spits up the error "Caught an exception while rendering: 'Category' object has no attribute 'name' Can someone point me in the right direction?

    Read the article

  • Why is thread local storage so slow?

    - by dsimcha
    I'm working on a custom mark-release style memory allocator for the D programming language that works by allocating from thread-local regions. It seems that the thread local storage bottleneck is causing a huge (~50%) slowdown in allocating memory from these regions compared to an otherwise identical single threaded version of the code, even after designing my code to have only one TLS lookup per allocation/deallocation. This is based on allocating/freeing memory a large number of times in a loop, and I'm trying to figure out if it's an artifact of my benchmarking method. My understanding is that thread local storage should basically just involve accessing something through an extra layer of indirection, similar to accessing a variable via a pointer. Is this incorrect? How much overhead does thread-local storage typically have? Note: Although I mention D, I'm also interested in general answers that aren't specific to D, since D's implementation of thread-local storage will likely improve if it is slower than the best implementations.

    Read the article

  • What does this xkcd code do?

    - by cobbal
    On the xkcd site today, the following appeared as a joke in a <script language="scheme"> tag so what does the following code do / represent? (define (eval exp env) (cond ((self-evaluating? exp) exp) ((variable? exp) (lookup-variable-value exp env)) ((quoted? exp) (text-of-quotation exp)) ((assignment? exp) (eval-assignment exp env)) ((definition? exp) (eval-definition exp env)) ((if? exp) (eval-if exp env)) ((lambda? exp) (make-procedure (lambda-parameters exp) (lambda-body exp) env)) ((begin? exp) (eval-sequence (begin-actions exp) env)) ((cond? exp) (eval (cond->if exp) env)) ((application? exp) (apply (eval (operator exp) env) (list-of-values (operands exp) env))) (else (error "Common Lisp or Netscape Navigator 4.0+ Required" exp))))

    Read the article

  • Algorithm for digit summing?

    - by Joe
    I'm searching for an algorithm for Digit summing. Let me outline the basic principle: Say you have a number: 18268. 1 + 8 + 2 + 6 + 8 = 25 2 + 5 = 7 And 7 is our final number. It's basically adding each number of the whole number until we get down to a single (also known as a 'core') digit. It's often used by numerologists. I'm searching for an algorithm (doesn't have to be language in-specific) for this. I have searched Google for the last hour with terms such as digit sum algorithm and whatnot but got no suitable results. Any help would be great, thanks.

    Read the article

  • jscript "Cannot retrieve referenced URL"

    - by jb
    I have javascript inside a .wsf file and I'm getting the error: C:\bin\LDLSInfo.wsf(53, 34) Windows Script Host: Cannot retrieve referenced URL: S:\tools\JScript\lib\StandardWSH.js At line 53, it says <script language="JScript" src="S:\tools\JScript\lib\StandardWSH.js"/> I know that LDLSInfo.wsf (the main script) and StandardWSH.js (the script to load) both work fine, because I've ran them from a different machine. It works fine on one machine and not on the other, both are Windows 7 x64 computers. So I'm thinking I'm missing some .dll's. Thanks for the help, -jb

    Read the article

  • tetris rotation

    - by Samuel
    Hey, For university we're supposed to write a game (the language is modula2 little chance you know it). Each tetromino is defined through a central piece and 3 relative pieces, Now when it comes to rotation i just rotate the relative blocks (linear algebra). What i am asking myself is how to handle the rotations a user does when the piece has already "landed" because than the user has a little time left to move his pieve quickly into the desired position but in tetris versions all over the web you can "rotate over" other pieces, but i dont seem to get it with my rotation. Over what piece do i need to rotate? are there guidelines? Thanks

    Read the article

  • Flex - Is there a way to change the "Channel Disconnected" error message?

    - by Travesty3
    I have a Flash app with a PHP backend. Whenever there is a PHP error, I get the "Channel Disconnected before an acknowledgement was received" error message. I'm getting ready to push my project to beta and I would prefer if this message said something more like "There was a PHP error, please log a bug" or something instead of a message they don't understand. Anyone know of a way for me to change this error message? BTW I'm pretty much a noob when it comes to Flash programming so please be descriptive. Using Flash Builder 4 Beta 2.

    Read the article

  • Objective C block gives link error

    - by ennuikiller
    I'm trying to use objective-c blocks for some iPhone programming and am getting the following link time error: The relevant code is: - (NSDictionary *) getDistances { CLLocationCoordinate2D parkingSpace; NSMutableDictionary *dict; NSIndexSet *indexForUser; BOOL (^test)(id obj, NSUInteger idx, BOOL *stop); test = ^ (id obj, NSUInteger idx, BOOL *stop) { NSString *user = (NSString *)[(NSDictionary *)obj valueForKey:@"userid"]; if ([user isEqualToString:self->sharedUser.userName]) { return YES; } return NO; }; [self->sharedUser.availableParking indexesOfObjectsPassingTest:test]; } Any help would be very much appreciated!!

    Read the article

  • CSS file pathing problem

    - by Alan Harris-Reid
    Hi there, When designing a HTML template in my favorite editor (TextPad at the moment) I can view my code in a browser by pressing F11 or the appropriate toolbar button. I have my common css rules in a separate file so my HTML contains the code: <link rel="stylesheet" href="commoncss.css" type="text/css"> This works when the .css file is in the same folder as the .html file, or if I fully path the .css file in the href property, eg. ///c:/mycssfolder/commoncss.css However, in a 'live' situation I want the .css file to reside in a common folder which is accessible from a number of .html files (eg. href='css/commoncss.css', where the css folder is configured at web-server level). How can I achieve this design vs. live dilemma without copying css file to all .html folders (and all the maintenance headaches that comes with it)? I am using Python 3.1 with Jinja2, but I guess this problem is applicable across any language and template-engine. Any help would be appreciated. Alan

    Read the article

  • What web browser engine, version, and capabilities are used to display web pages inside Visual Studio 2010?

    - by Phrogz
    My company is developing a plugin/add-on for Visual Studio 2010. When the user asks to display the help for our product, we plan on opening an HTML page (or suite of pages) within Visual Studio. I'm helping to design and implement the help system. What web engine/version is used within Visual Studio 2010? According to Wikipedia it is not Trident(!). Am I allowed to load remote JavaScript content (via a <script> element)? Am I allowed to use XHR to load remote content? Will my page be trusted and have access to the FileSystemObject? I would appreciate any resources you can give me on programming specifically to the 'web' capabilities of VisualStudio2010-as-a-browser.

    Read the article

  • Can everything be done programmatically in WCF or are configuration files for certain features?

    - by CuriousCoder
    I have a strong preference for working in code, leverage IntelliSense and opening up all of the power of the C# language to work with WCF but I want to make sure that I'm not moving in a direction that ultimately will limit the WCF feature set I can access. My experience is so limited with WCF that I don't understand the benefits of using the configuration files, especially if you can do everything in code (?). Note: I'm using .NET 3.5. Can you do 'everything' with WCF programmatically or are configuration files required for the full WCF feature set?

    Read the article

  • How can I sandbox Python in pure Python?

    - by Blixt
    I'm developing a web game in pure Python, and want some simple scripting available to allow for more dynamic game content. Game content can be added live by privileged users. It would be nice if the scripting language could be Python. However, it can't run with access to the environment the game runs on since a malicious user could wreak havoc which would be bad. Is it possible to run sandboxed Python in pure Python? If not, are there any open source script interpreters written in pure Python that I could use? The requirements are support for variables, basic conditionals and function calls (not definitions).

    Read the article

  • Handling User Authentication in C#.NET?

    - by Daniel
    I am new to .NET, and don't have much experience in programming. What is the standard way of handling user authentication in .NET in the following situation? 1.In Process A, User inputs ID/Password 2.Process A sends the ID/Password to Process B over a nonsecure public channel. 3.Process B authenticates the user with the recieved ID/Password what are some of the standard cryptographic algorithms I can use in above model? The users(customers that bought my company's software) will be running the software(Process A) locally in their computer(connected to internet). I need to authenticate the users so that only registered users can run the program. Thank You!

    Read the article

  • Function parameter types in Python

    - by Leif Andersen
    Unless I'm mistaken, creating a function in python works like this def my_func(param1, param2): /*stuff*/ However, you don't actually give the types of those parameters. Also, if I remember, python is a strongly typed language, as such, it seams like python shouldn't let you pass in a parameter of a different type then the function creator expected. However, how does python know that the user of the function is passing in the proper types? Or will the program just die if it's the wrong type, assuming the function actually uses the parameter? Or do you have to specify the type/I'm missing something? Thank you.

    Read the article

  • Young people using Emacs?

    - by bigmonachus
    I am a college student that has fallen in love with Emacs. I have used IDEs in the past, and although features like Intellisense made the switch to Emacs very hard, I now think that Emacs is much more powerful, and features like Intellisense can be pretty closely matched by various modes depending on language (and I am not referring to M-/). I am happily writing Elisp code for everything that I need that isn't provided by modes or by Emacs itself and I love the way that it adapts and molds to my needs. However, I do think that its main disadvantage is the fact that it has a pretty steep learning curve and that most new programmers will not even begin to learn it out of many common misconceptions. So, I want to know the opinions of young people (or any person who didn't start using Emacs before there were IDEs) that are Emacs users. Just to get some reassurance that Emacs is not dead within our Eclipse-loving generation =). (Opinions of users of any other highly extensible editor like Jedit are also welcome)

    Read the article

  • Education After High School

    - by Travis O.
    I know this isn't specifically a programming question, but please bear with me. I'm currently a high-school junior. I have no idea what to look for in a college: what degree, what school, etc. I've searched all around the internet but can't really find anything that relevant. I know I need a degree, but I don't know which or what to specialize in. My grades are good and I am in the top 15 percent of my class. I scored about a 1800 on the SAT and have not yet taken the ACT. I'd like to go to a 4 year school that doesn't cost too much. What do I need to be looking for and what is important to colleges accepting CS students and the business after college?

    Read the article

  • Warning: Ignoring library 'com.motorola.android.iextdispservice', missing property value

    - by user1342684
    Hi I am trying to get my eclipse environment setup so I can start playing with programming for android... The Android SDK Manager is installing the following packages (everything else says installed except these two): Android 2.3.3 (API 10) Dual Screen APIs - Not Installed Android 2.2 (API 8) Dual Screen APIs - Not Installed Error Messages: [2012-04-19 13:06:41 - SDK Manager] Warning: Ignoring library 'com.motorola.android.iextdispservice', missing property value [2012-04-19 13:15:27 - SDK Manager] Operation timed out [2012-04-19 13:18:16 - SDK Manager] Operation timed out Any tips? So close to getting the environment ready! I want to start playing around!

    Read the article

  • include_once error : failed to open stream in Boonex Dolphin v7.0.9

    - by Guillaume Pierre
    first let me say I'm a beginner in PHP, specifically PHP Object-oriented programming. I'm working on a V7.0.9 dolphin version.http://www.boonex.com/dolphin While I'm trying to include a class.php from a 3rd-part developer I work with <?php include_once ('modules/developer/configure/classes/class.php'); I get this error : Warning: include_once(modules/developer/configure/classes/ClassExample.php): failed to open stream: No such file or directory in /var/www/vhosts/mysite.com/httpdocs/dolphin/inc/classes/BxDolPageView.php(612) : eval()'d code on line 2 Warning: include_once(): Failed opening 'modules/developer/configure/classes/ClassExample.php' for inclusion (include_path='.:') in /var/www/vhosts/mysite.com/httpdocs/dolphin/inc/classes/BxDolPageView.php(612) : eval()'d code on line 2 Fatal error: Class 'ClassExample' not found in /var/www/vhosts/mysite.com/httpdocs/dolphin/inc/classes/BxDolPageView.php(612) : eval()'d code on line 6 I'm trying to figure out where is the problem... does it comes from Boonex? or is it linked to my server configuration? I really don't know where to begin to resolve... Thx in advance for your kind help if you get knowledge on it

    Read the article

  • Which Dependency Injection Tool Should I Use? (2)

    - by Mendy
    The original post is: Which Dependency Injection Tool Should I Use? While the original post is good, in this days I see a lot of people using StructureMap as their Dependency Injection tool, and in the original post no one even took it seriously. In addition, this quote: If I had to choose today: I would probably go with StructureMap. It has the best support for C# 3.0 language features, and the most flexibility in initialization. Which Dependency Injection Tool Should I Use? Out of this ones: Unity Framework - Microsoft StructureMap - Jeremy Miller Castle Windsor NInject Spring Framework Autofac Managed Extensibility Framework

    Read the article

  • Incorrectly formatted html inconsistencies between DOM and what's displayed in firefox plugin

    - by deadalnix
    I'm currently developing a firefox plugin. This plugin has to handle very crappy website that is really incorrectly formatted. I cannot modify these websites, so I have to handle them. I reduced the bug I'm facing to a short sample of html (if this appellation is appropriate for an horror like this) : <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <title>Some title.</title> <!-- Oh fuck yes ! --> <div style="visability:hidden;"> <a href="//example.com"> </a> </div> <!-- If meta are reduced, then the bug disapears ! --> <meta name="description" content="Homepage of Company.com, Company's corporate Web site" /> <meta name="keywords" content="Company, Company & Co., Inc., blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla" /> <meta http-equiv="Content-Language" content="en-US" /> <meta http-equiv="content-type" content="text/html; charset=utf-8"/> </head> <body class="homePage"> <div class="globalWrapper"><a href="/page.html">My gorgeous link !</a></div> </body> </html> When opening the webpage, « My gorgeous link ! » if displayed and clickable. However, when I'm exploring the DOM with Javascript into my plugin, everything behaves (DOM exploration and innerHTML property) like the code was this one : <html> <head> <title>Some title.</title> <!-- Oh fuck yes ! --> </head><body><div style="visability:hidden;"> <a href="//example.com"> </a> </div> <!-- If meta are reduced, then the bug disapears ! --> <meta name="description" content="Homepage of Company.com, Company's corporate Web site"> <meta name="keywords" content="Company, Company &amp; Co., Inc., blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla, blablabla"> <meta http-equiv="Content-Language" content="en-US"> </body> </html> So, when exploring the DOM within the plugin, the document is somehow fixed by firefox. But this fixed DOM is inconsistent with what is in the webpage. Thus, my plugin doesn't behave as expected. I'm really puzzled with that issue. The problem exists in both firefox 3.6 and firefox 4 (didn't tested firefox 5 yet). For example, reducing the meta, will fix the issue. Where does this discrepancy come from ? How can I handle it ? EDIT: With the answer I get, I think I should be a little more precise. I do know what firefow is doing when modifying the webpage in the second code snippet. The problem is the following one : « In the fixed DOM that I get into my plugin, the gorgeous link doesn't appear anywhere, but this link is actually visible on the webpage, and works. So the DOM I'm manipulating, and the DOM in the webpage are different - they are fixed in a different manner. » . So where does the difference come in the fixing behaviour, and how can I handle that, or, in other terms, how can I be aware, in my plugin, of the existance of the gorgeous link ?

    Read the article

  • OpenCL: does it play well with OpenMP, can I connect other languages to it, etc.

    - by Cem Karan
    The 1.0 spec for OpenCL just came out a few days ago (Spec is here) and I've just started to read through it. I want to know if it plays well with other high performance multiprocessing APIs like OpenMP (spec) and I want to know what I should learn. So, here are my basic questions: If I am already using OpenMP, will that break OpenCL or vice-versa? Is OpenCL more powerful than OpenMP? Or are they intended to be complementary? Is there a standard way of connecting an OpenCL program to a standard C99 program (or any other language)? What is it? Does anyone know if anyone is writing an OpenCL book? I'm reading the spec, but I've found books to be more helpful.

    Read the article

< Previous Page | 638 639 640 641 642 643 644 645 646 647 648 649  | Next Page >