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  • How to override JS function from a firefox extension?

    - by BruceBerry
    Hello, I am trying to intercept calls to document.write for all pages. Setting up the interception inside the page by injecting a script like function overrideDocWrite() { alert("Override called"); document.write = function(w) { return function(s) { alert("special dom"); w.call(this, wrapString(s)); }; }(document.write); alert("Override finished"); } is easy and works, but i would like my extension to setup the interception for each document object from inside the extension. I couldn't find a way to do this. I tried to listen for the "load" event and set up the interception there but it also fails. How do I hook calls to doc.write from an extension?

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  • Can you have an extension method on a type instead of on an instance of a type?

    - by SLC
    I can have an extension method like this: DateTime d = new DateTime(); d = d.GetRandomDate(); GetRandomDate is my extension method. However the above doesn't make much sense. What would be better is: DateTime d = DateTime.GetRandomDate(); However, I don't know how to do this. An extension method created as: public static DateTime GetRandomDate(this System.DateTime dt) will only add the GetRandomDate() in the first example above, not the second one. Is there a way to achieve the desired behaviour?

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  • Use Extension method to write cleaner code

    - by Fredrik N
    This blog post will show you step by step to refactoring some code to be more readable (at least what I think). Patrik Löwnedahl gave me some of the ideas when we where talking about making code much cleaner. The following is an simple application that will have a list of movies (Normal and Transfer). The task of the application is to calculate the total sum of each movie and also display the price of each movie. class Program { enum MovieType { Normal, Transfer } static void Main(string[] args) { var movies = GetMovies(); int totalPriceOfNormalMovie = 0; int totalPriceOfTransferMovie = 0; foreach (var movie in movies) { if (movie == MovieType.Normal) { totalPriceOfNormalMovie += 2; Console.WriteLine("$2"); } else if (movie == MovieType.Transfer) { totalPriceOfTransferMovie += 3; Console.WriteLine("$3"); } } } private static IEnumerable<MovieType> GetMovies() { return new List<MovieType>() { MovieType.Normal, MovieType.Transfer, MovieType.Normal }; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } In the code above I’m using an enum, a good way to add types (isn’t it ;)). I also use one foreach loop to calculate the price, the loop has a condition statement to check what kind of movie is added to the list of movies. I want to reuse the foreach only to increase performance and let it do two things (isn’t that smart of me?! ;)). First of all I can admit, I’m not a big fan of enum. Enum often results in ugly condition statements and can be hard to maintain (if a new type is added we need to check all the code in our app to see if we use the enum somewhere else). I don’t often care about pre-optimizations when it comes to write code (of course I have performance in mind). I rather prefer to use two foreach to let them do one things instead of two. So based on what I don’t like and Martin Fowler’s Refactoring catalog, I’m going to refactoring this code to what I will call a more elegant and cleaner code. First of all I’m going to use Split Loop to make sure the foreach will do one thing not two, it will results in two foreach (Don’t care about performance here, if the results will results in bad performance, you can refactoring later, but computers are so fast to day, so iterating through a list is not often so time consuming.) Note: The foreach actually do four things, will come to is later. var movies = GetMovies(); int totalPriceOfNormalMovie = 0; int totalPriceOfTransferMovie = 0; foreach (var movie in movies) { if (movie == MovieType.Normal) { totalPriceOfNormalMovie += 2; Console.WriteLine("$2"); } } foreach (var movie in movies) { if (movie == MovieType.Transfer) { totalPriceOfTransferMovie += 3; Console.WriteLine("$3"); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } To remove the condition statement we can use the Where extension method added to the IEnumerable<T> and is located in the System.Linq namespace: foreach (var movie in movies.Where( m => m == MovieType.Normal)) { totalPriceOfNormalMovie += 2; Console.WriteLine("$2"); } foreach (var movie in movies.Where( m => m == MovieType.Transfer)) { totalPriceOfTransferMovie += 3; Console.WriteLine("$3"); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The above code will still do two things, calculate the total price, and display the price of the movie. I will not take care of it at the moment, instead I will focus on the enum and try to remove them. One way to remove enum is by using the Replace Conditional with Polymorphism. So I will create two classes, one base class called Movie, and one called MovieTransfer. The Movie class will have a property called Price, the Movie will now hold the price:   public class Movie { public virtual int Price { get { return 2; } } } public class MovieTransfer : Movie { public override int Price { get { return 3; } } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The following code has no enum and will use the new Movie classes instead: class Program { static void Main(string[] args) { var movies = GetMovies(); int totalPriceOfNormalMovie = 0; int totalPriceOfTransferMovie = 0; foreach (var movie in movies.Where( m => m is Movie)) { totalPriceOfNormalMovie += movie.Price; Console.WriteLine(movie.Price); } foreach (var movie in movies.Where( m => m is MovieTransfer)) { totalPriceOfTransferMovie += movie.Price; Console.WriteLine(movie.Price); } } private static IEnumerable<Movie> GetMovies() { return new List<Movie>() { new Movie(), new MovieTransfer(), new Movie() }; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   If you take a look at the foreach now, you can see it still actually do two things, calculate the price and display the price. We can do some more refactoring here by using the Sum extension method to calculate the total price of the movies:   static void Main(string[] args) { var movies = GetMovies(); int totalPriceOfNormalMovie = movies.Where(m => m is Movie) .Sum(m => m.Price); int totalPriceOfTransferMovie = movies.Where(m => m is MovieTransfer) .Sum(m => m.Price); foreach (var movie in movies.Where( m => m is Movie)) Console.WriteLine(movie.Price); foreach (var movie in movies.Where( m => m is MovieTransfer)) Console.WriteLine(movie.Price); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now when the Movie object will hold the price, there is no need to use two separate foreach to display the price of the movies in the list, so we can use only one instead: foreach (var movie in movies) Console.WriteLine(movie.Price); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } If we want to increase the Maintainability index we can use the Extract Method to move the Sum of the prices into two separate methods. The name of the method will explain what we are doing: static void Main(string[] args) { var movies = GetMovies(); int totalPriceOfMovie = TotalPriceOfMovie(movies); int totalPriceOfTransferMovie = TotalPriceOfMovieTransfer(movies); foreach (var movie in movies) Console.WriteLine(movie.Price); } private static int TotalPriceOfMovieTransfer(IEnumerable<Movie> movies) { return movies.Where(m => m is MovieTransfer) .Sum(m => m.Price); } private static int TotalPriceOfMovie(IEnumerable<Movie> movies) { return movies.Where(m => m is Movie) .Sum(m => m.Price); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now to the last thing, I love the ForEach method of the List<T>, but the IEnumerable<T> doesn’t have it, so I created my own ForEach extension, here is the code of the ForEach extension method: public static class LoopExtensions { public static void ForEach<T>(this IEnumerable<T> values, Action<T> action) { Contract.Requires(values != null); Contract.Requires(action != null); foreach (var v in values) action(v); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } I will now replace the foreach by using this ForEach method: static void Main(string[] args) { var movies = GetMovies(); int totalPriceOfMovie = TotalPriceOfMovie(movies); int totalPriceOfTransferMovie = TotalPriceOfMovieTransfer(movies); movies.ForEach(m => Console.WriteLine(m.Price)); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The ForEach on the movies will now display the price of the movie, but maybe we want to display the name of the movie etc, so we can use Extract Method by moving the lamdba expression into a method instead, and let the method explains what we are displaying: movies.ForEach(DisplayMovieInfo); private static void DisplayMovieInfo(Movie movie) { Console.WriteLine(movie.Price); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now the refactoring is done! Here is the complete code:   class Program { static void Main(string[] args) { var movies = GetMovies(); int totalPriceOfMovie = TotalPriceOfMovie(movies); int totalPriceOfTransferMovie = TotalPriceOfMovieTransfer(movies); movies.ForEach(DisplayMovieInfo); } private static void DisplayMovieInfo(Movie movie) { Console.WriteLine(movie.Price); } private static int TotalPriceOfMovieTransfer(IEnumerable<Movie> movies) { return movies.Where(m => m is MovieTransfer) .Sum(m => m.Price); } private static int TotalPriceOfMovie(IEnumerable<Movie> movies) { return movies.Where(m => m is Movie) .Sum(m => m.Price); } private static IEnumerable<Movie> GetMovies() { return new List<Movie>() { new Movie(), new MovieTransfer(), new Movie() }; } } public class Movie { public virtual int Price { get { return 2; } } } public class MovieTransfer : Movie { public override int Price { get { return 3; } } } pulbic static class LoopExtensions { public static void ForEach<T>(this IEnumerable<T> values, Action<T> action) { Contract.Requires(values != null); Contract.Requires(action != null); foreach (var v in values) action(v); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } I think the new code is much cleaner than the first one, and I love the ForEach extension on the IEnumerable<T>, I can use it for different kind of things, for example: movies.Where(m => m is Movie) .ForEach(DoSomething); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } By using the Where and ForEach extension method, some if statements can be removed and will make the code much cleaner. But the beauty is in the eye of the beholder. What would you have done different, what do you think will make the first example in the blog post look much cleaner than my results, comments are welcome! If you want to know when I will publish a new blog post, you can follow me on twitter: http://www.twitter.com/fredrikn

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  • HTTPS Everywhere Extension Updates to Version 3.0, Adds Protection for 1,500 More Websites

    - by Asian Angel
    If one of your security goals is to encrypt your communication with websites as much as possible, then you will definitely be pleased with the latest update to the HTTPS Everywhere extension for Firefox and Chrome. This latest release adds encryption protection for an additional 1,500 websites to help make your browsing experience more secure than ever. Images shown above courtesy of EFF. You can learn more about this latest release along with installing the extension for Firefox and/or Chrome directly from the blog post linked below… HTTPS Everywhere 3.0 protects 1,500 more sites [via Softpedia] HTG Explains: What is the Windows Page File and Should You Disable It? How To Get a Better Wireless Signal and Reduce Wireless Network Interference How To Troubleshoot Internet Connection Problems

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  • Moonlight extension not working with new Firefox versions

    - by igi
    The web browser I use is Firefox (currently in version 8 in Oneiric). According the Compatibility Check information the Moonlight extension is not compatible with FF8. Anyway, I enabled this extension using the AddOn Compatibility Reporter. And, actually, I cannot watch Silverlight streams in an acceptable way: the video gets stuck, the HD keeps buffering (I guess), so I have to close the window. Does anybody know if there is a way to fix this or a suitable alternative? I'm looking for something which is fully supported and mantained.

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  • Chrome Countdown Extension [migrated]

    - by Mike Saffold
    I have modified this countdown script to countdown to 4:20pm everyday. I have attempted to create a Google Chrome app that displays the countdown. The javascript is supposed replace a paragraph tag with id of "note" with the time left. It works when I load the page in chrome, but does not work when I load the extension. Example, if I put: <p id="note">asdf</a> I get just the text, "asdf", but when I open the html file I get the countdown. Here is the manifest.json file: { "name": "My First Extension", "version": "1.0", "manifest_version": 2, "description": "The first extension that I made.", "browser_action": { "default_icon": "icon.png", "default_popup": "popup.html" } } Here is the popup.html code: <html> <head> <title>4:20PM Countdown</title> <!-- Our CSS stylesheet file --> <link rel="stylesheet" href="http://fonts.googleapis.com/css?family=Open+Sans+Condensed:300" /> <link rel="stylesheet" href="http://treesmoke.com/cd/assets/css/styles.css" /> <link rel="stylesheet" href="http://treesmoke.com/cd/assets/countdown/jquery.countdown.css" /> </head> <body> <p id="note">asdf</p> <!-- JavaScript includes --> <script type="text/javascript" src="http://code.jquery.com/jquery-1.7.1.min.js"></script> <script type="text/javascript" src="http://treesmoke.com/cd/assets/countdown/jquery.countdown.js"></script> <script type="text/javascript" src="http://treesmoke.com/cd/assets/js/script.js"></script> </body> </html> Here's the popup.html page, showing that the script works. Thanks guys, it isn't that big of a deal if I can't get it to work. I was just bored and decided to learn a little.

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  • Silverlight 4 Tools for Visual Studio 2010, l'extension fournit des templates et des librairies pour

    Mise à jour du 18/05/10 Silverlight 4 Tools for Visual Studio 2010 L'extension fournit des templates et des librairies pour Visual Studio et WPF Silverlight 4, la nouvelle mouture de l'alternative de Microsoft au Flash d'Adobe, avait été dévoilé le mois dernier (lire ci-avant). C'est aujourd'hui au tour de l'extension pour Visual Studio de faire son apparition. « Silverlight 4 Tools for Visual Studio 2010 » permet par exemple d'exploiter les fonctionnalités de création d'applications « out of the browser ». Il propose également des templates et de nouvelles librairies pour faciliter l'accès aux données. L'équipe...

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  • Let apache run perlscripts that don't have an extension

    - by tiMbeRdroP
    I'd like to use perlscripts without their extension. f.e. "index" instead of "index.pl". Changing the DefaultType-directive from text/plain to application/x-perl didn't do the trick. Instead of running the script the server offered to download its source. I'm not exactly sure if changing this directive is the right approach. Telling apache to read the shebang-line when there is no extension sounds much better to me. I hope someone with more experience on this topic can help me out.

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  • Use Extension Methods to find first and last day of the month

    - by Tim Hibbard
    A lot of reports work on data from last month.  It is a nice touch to have these dates pre-populated for your users.  Using extension methods, the code can look cleaner too. Extension Methods: public static class DateHelper { public static DateTime FirstOfTheMonth(this DateTime dt) { return new DateTime(dt.Year, dt.Month, 1); }   public static DateTime LastOfTheMonth(this DateTime dt) { return dt.FirstOfTheMonth().AddMonths(1).AddDays(-1); } } Consuming Code: void Prepopulate() { startDateBox.CurrentlySelectedDate = DateTime.Now.AddMonths(-1).FirstOfTheMonth(); endDateBox.CurrentlySelectedDate = DateTime.Now.AddMonths(-1).LastOfTheMonth(); }

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  • NextPlease Firefox extension doesn't work in 3.6+. Any updates or similar extension?

    - by Tony_Henrich
    I use a Firefox extension called NextPlease which allows me to use the keyboard to go to the next or previous page on web pages which have Previous/Next paging links. Like the Google search results. I downloaded a version from http://cisengineer.com/firefox/ for my Windows XP. On a Windows 7 FF 3.6 machine, Firefox can't import the extension because it's not compatible with FF 3.6 even though it worked in FF 3.6 in Windows XP. Is there an update to this extension or is there a similar extension? I downgraded to FF 3.5.7 to have the extension working.

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  • Why is writing a compiler in a functional language easier?

    - by wvd
    Hello all, I've been thinking of this question very long, but really couldn't find the answer on Google as well a similar question on Stackoverflow. If there is a duplicate, I'm sorry for that. A lot of people seem to say that writing compilers and other language tools in functional languages such as OCaml and Haskell is much more efficient and easier then writing them in imperative languages. Is this true? And if so -- why is it so efficient and easy to write them in functional languages instead of in an imperative language, like C? Also -- isn't a language tool in a functional language slower then in some low-level language like C? Thanks in advance, William v. Doorn

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  • Why is writing a compiler in a functional language so efficient and easier?

    - by wvd
    Hello all, I've been thinking of this question very long, but really couldn't find the answer on Google as well a similar question on Stackoverflow. If there is a duplicate, I'm sorry for that. A lot of people seem to say that writing compilers and other language tools in functional languages such as OCaml and Haskell is much more efficient and easier then writing them in imperative languages. Is this true? And if so -- why is so efficient and easy to write them in functional languages instead of in an imperative language, like C? Also -- isn't a language tool in a functional language slower then in some low-level language like C? Thanks in advance, William v. Doorn

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  • is it better to use a "natural" language to write code?

    - by M.H
    I recently saw a programming language called supernova and they said in the web page : The Supernova Programming language is a modern scripting language and the First one presents the concept of programming with direct Fiction Description using Clear subset of pure Human Language. and you can write code like: i want window and the window title is Hello World. i want button and button caption is Close. and button name is btn1. btn1 mouse click. instructions are you close window end of instructions my question is not about the language itself but it is that are we need such languages and did they make writing code easier or not?

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  • is it better to use a "natural" language to write codes ?

    - by M.H
    I recently saw a programming language called supernova and they said in the web page : The Supernova Programming language is a modern scripting language and the First one presents the concept of programming with direct Fiction Description using Clear subset of pure Human Language. and you can write codes like : i want window and the window title is Hello World. i want button and button caption is Close. and button name is btn1. btn1 mouse click. instructions are you close window end of instructions my question is not about the language itself but it is that are we need such languages and did they make writing codes more easier or not ?

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  • jQuery Globalization Plugin from Microsoft

    - by ScottGu
    Last month I blogged about how Microsoft is starting to make code contributions to jQuery, and about some of the first code contributions we were working on: jQuery Templates and Data Linking support. Today, we released a prototype of a new jQuery Globalization Plugin that enables you to add globalization support to your JavaScript applications. This plugin includes globalization information for over 350 cultures ranging from Scottish Gaelic, Frisian, Hungarian, Japanese, to Canadian English.  We will be releasing this plugin to the community as open-source. You can download our prototype for the jQuery Globalization plugin from our Github repository: http://github.com/nje/jquery-glob You can also download a set of samples that demonstrate some simple use-cases with it here. Understanding Globalization The jQuery Globalization plugin enables you to easily parse and format numbers, currencies, and dates for different cultures in JavaScript. For example, you can use the Globalization plugin to display the proper currency symbol for a culture: You also can use the Globalization plugin to format dates so that the day and month appear in the right order and the day and month names are correctly translated: Notice above how the Arabic year is displayed as 1431. This is because the year has been converted to use the Arabic calendar. Some cultural differences, such as different currency or different month names, are obvious. Other cultural differences are surprising and subtle. For example, in some cultures, the grouping of numbers is done unevenly. In the "te-IN" culture (Telugu in India), groups have 3 digits and then 2 digits. The number 1000000 (one million) is written as "10,00,000". Some cultures do not group numbers at all. All of these subtle cultural differences are handled by the jQuery Globalization plugin automatically. Getting dates right can be especially tricky. Different cultures have different calendars such as the Gregorian and UmAlQura calendars. A single culture can even have multiple calendars. For example, the Japanese culture uses both the Gregorian calendar and a Japanese calendar that has eras named after Japanese emperors. The Globalization Plugin includes methods for converting dates between all of these different calendars. Using Language Tags The jQuery Globalization plugin uses the language tags defined in the RFC 4646 and RFC 5646 standards to identity cultures (see http://tools.ietf.org/html/rfc5646). A language tag is composed out of one or more subtags separated by hyphens. For example: Language Tag Language Name (in English) en-AU English (Australia) en-BZ English (Belize) en-CA English (Canada) Id Indonesian zh-CHS Chinese (Simplified) Legacy Zu isiZulu Notice that a single language, such as English, can have several language tags. Speakers of English in Canada format numbers, currencies, and dates using different conventions than speakers of English in Australia or the United States. You can find the language tag for a particular culture by using the Language Subtag Lookup tool located here:  http://rishida.net/utils/subtags/ The jQuery Globalization plugin download includes a folder named globinfo that contains the information for each of the 350 cultures. Actually, this folder contains more than 700 files because the folder includes both minified and un-minified versions of each file. For example, the globinfo folder includes JavaScript files named jQuery.glob.en-AU.js for English Australia, jQuery.glob.id.js for Indonesia, and jQuery.glob.zh-CHS for Chinese (Simplified) Legacy. Example: Setting a Particular Culture Imagine that you have been asked to create a German website and want to format all of the dates, currencies, and numbers using German formatting conventions correctly in JavaScript on the client. The HTML for the page might look like this: Notice the span tags above. They mark the areas of the page that we want to format with the Globalization plugin. We want to format the product price, the date the product is available, and the units of the product in stock. To use the jQuery Globalization plugin, we’ll add three JavaScript files to the page: the jQuery library, the jQuery Globalization plugin, and the culture information for a particular language: In this case, I’ve statically added the jQuery.glob.de-DE.js JavaScript file that contains the culture information for German. The language tag “de-DE” is used for German as spoken in Germany. Now that I have all of the necessary scripts, I can use the Globalization plugin to format the product price, date available, and units in stock values using the following client-side JavaScript: The jQuery Globalization plugin extends the jQuery library with new methods - including new methods named preferCulture() and format(). The preferCulture() method enables you to set the default culture used by the jQuery Globalization plugin methods. Notice that the preferCulture() method accepts a language tag. The method will find the closest culture that matches the language tag. The $.format() method is used to actually format the currencies, dates, and numbers. The second parameter passed to the $.format() method is a format specifier. For example, passing “c” causes the value to be formatted as a currency. The ReadMe file at github details the meaning of all of the various format specifiers: http://github.com/nje/jquery-glob When we open the page in a browser, everything is formatted correctly according to German language conventions. A euro symbol is used for the currency symbol. The date is formatted using German day and month names. Finally, a period instead of a comma is used a number separator: You can see a running example of the above approach with the 3_GermanSite.htm file in this samples download. Example: Enabling a User to Dynamically Select a Culture In the previous example we explicitly said that we wanted to globalize in German (by referencing the jQuery.glob.de-DE.js file). Let’s now look at the first of a few examples that demonstrate how to dynamically set the globalization culture to use. Imagine that you want to display a dropdown list of all of the 350 cultures in a page. When someone selects a culture from the dropdown list, you want all of the dates in the page to be formatted using the selected culture. Here’s the HTML for the page: Notice that all of the dates are contained in a <span> tag with a data-date attribute (data-* attributes are a new feature of HTML 5 that conveniently also still work with older browsers). We’ll format the date represented by the data-date attribute when a user selects a culture from the dropdown list. In order to display dates for any possible culture, we’ll include the jQuery.glob.all.js file like this: The jQuery Globalization plugin includes a JavaScript file named jQuery.glob.all.js. This file contains globalization information for all of the more than 350 cultures supported by the Globalization plugin.  At 367KB minified, this file is not small. Because of the size of this file, unless you really need to use all of these cultures at the same time, we recommend that you add the individual JavaScript files for particular cultures that you intend to support instead of the combined jQuery.glob.all.js to a page. In the next sample I’ll show how to dynamically load just the language files you need. Next, we’ll populate the dropdown list with all of the available cultures. We can use the $.cultures property to get all of the loaded cultures: Finally, we’ll write jQuery code that grabs every span element with a data-date attribute and format the date: The jQuery Globalization plugin’s parseDate() method is used to convert a string representation of a date into a JavaScript date. The plugin’s format() method is used to format the date. The “D” format specifier causes the date to be formatted using the long date format. And now the content will be globalized correctly regardless of which of the 350 languages a user visiting the page selects.  You can see a running example of the above approach with the 4_SelectCulture.htm file in this samples download. Example: Loading Globalization Files Dynamically As mentioned in the previous section, you should avoid adding the jQuery.glob.all.js file to a page whenever possible because the file is so large. A better alternative is to load the globalization information that you need dynamically. For example, imagine that you have created a dropdown list that displays a list of languages: The following jQuery code executes whenever a user selects a new language from the dropdown list. The code checks whether the globalization file associated with the selected language has already been loaded. If the globalization file has not been loaded then the globalization file is loaded dynamically by taking advantage of the jQuery $.getScript() method. The globalizePage() method is called after the requested globalization file has been loaded, and contains the client-side code to perform the globalization. The advantage of this approach is that it enables you to avoid loading the entire jQuery.glob.all.js file. Instead you only need to load the files that you need and you don’t need to load the files more than once. The 5_Dynamic.htm file in this samples download demonstrates how to implement this approach. Example: Setting the User Preferred Language Automatically Many websites detect a user’s preferred language from their browser settings and automatically use it when globalizing content. A user can set a preferred language for their browser. Then, whenever the user requests a page, this language preference is included in the request in the Accept-Language header. When using Microsoft Internet Explorer, you can set your preferred language by following these steps: Select the menu option Tools, Internet Options. Select the General tab. Click the Languages button in the Appearance section. Click the Add button to add a new language to the list of languages. Move your preferred language to the top of the list. Notice that you can list multiple languages in the Language Preference dialog. All of these languages are sent in the order that you listed them in the Accept-Language header: Accept-Language: fr-FR,id-ID;q=0.7,en-US;q=0.3 Strangely, you cannot retrieve the value of the Accept-Language header from client JavaScript. Microsoft Internet Explorer and Mozilla Firefox support a bevy of language related properties exposed by the window.navigator object, such as windows.navigator.browserLanguage and window.navigator.language, but these properties represent either the language set for the operating system or the language edition of the browser. These properties don’t enable you to retrieve the language that the user set as his or her preferred language. The only reliable way to get a user’s preferred language (the value of the Accept-Language header) is to write server code. For example, the following ASP.NET page takes advantage of the server Request.UserLanguages property to assign the user’s preferred language to a client JavaScript variable named acceptLanguage (which then allows you to access the value using client-side JavaScript): In order for this code to work, the culture information associated with the value of acceptLanguage must be included in the page. For example, if someone’s preferred culture is fr-FR (French in France) then you need to include either the jQuery.glob.fr-FR.js or the jQuery.glob.all.js JavaScript file in the page or the culture information won’t be available.  The “6_AcceptLanguages.aspx” sample in this samples download demonstrates how to implement this approach. If the culture information for the user’s preferred language is not included in the page then the $.preferCulture() method will fall back to using the neutral culture (for example, using jQuery.glob.fr.js instead of jQuery.glob.fr-FR.js). If the neutral culture information is not available then the $.preferCulture() method falls back to the default culture (English). Example: Using the Globalization Plugin with the jQuery UI DatePicker One of the goals of the Globalization plugin is to make it easier to build jQuery widgets that can be used with different cultures. We wanted to make sure that the jQuery Globalization plugin could work with existing jQuery UI plugins such as the DatePicker plugin. To that end, we created a patched version of the DatePicker plugin that can take advantage of the Globalization plugin when rendering a calendar. For example, the following figure illustrates what happens when you add the jQuery Globalization and the patched jQuery UI DatePicker plugin to a page and select Indonesian as the preferred culture: Notice that the headers for the days of the week are displayed using Indonesian day name abbreviations. Furthermore, the month names are displayed in Indonesian. You can download the patched version of the jQuery UI DatePicker from our github website. Or you can use the version included in this samples download and used by the 7_DatePicker.htm sample file. Summary I’m excited about our continuing participation in the jQuery community. This Globalization plugin is the third jQuery plugin that we’ve released. We’ve really appreciated all of the great feedback and design suggestions on the jQuery templating and data-linking prototypes that we released earlier this year.  We also want to thank the jQuery and jQuery UI teams for working with us to create these plugins. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. You can follow me at: twitter.com/scottgu

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  • How can a Virtual PC with Win XP install the East Asian Language? (or does any browser come with Chi

    - by Jian Lin
    How can a Virtual PC with Win XP on it install the East Asian Language? (or does any browser come with Chinese fonts?) After setting up a virtual PC with Win XP, if Chinese font is needed, then the usual way is to go to the Control Panel, select "Regional and Language" and go to the second tab and check the box "Install Files for East Asian Languages". After clicking OK, it asks for the file cplexe.exe on the XP SP3 CD 3... and is said to be about 230MB... In such case, how can the language pack or fonts be installed? (Update: I found that it is true for Window 7's Virtual PC with XP on it, as well as the XP SP3 with IE 8 that can be downloaded in the link below.) (I downloaded the virtual hard drive file .vhd from http://www.microsoft.com/downloads/details.aspx?FamilyId=21EABB90-958F-4B64-B5F1-73D0A413C8EF&displaylang=en so there is no "CD 3"... there) Or does any browser come with all the unicode fonts without needing the OS to support it?

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  • Goto for the Java Programming Language

    - by darcy
    Work on JDK 8 is well-underway, but we thought this late-breaking JEP for another language change for the platform couldn't wait another day before being published. Title: Goto for the Java Programming Language Author: Joseph D. Darcy Organization: Oracle. Created: 2012/04/01 Type: Feature State: Funded Exposure: Open Component: core/lang Scope: SE JSR: 901 MR Discussion: compiler dash dev at openjdk dot java dot net Start: 2012/Q2 Effort: XS Duration: S Template: 1.0 Reviewed-by: Duke Endorsed-by: Edsger Dijkstra Funded-by: Blue Sun Corporation Summary Provide the benefits of the time-testing goto control structure to Java programs. The Java language has a history of adding new control structures over time, the assert statement in 1.4, the enhanced for-loop in 1.5,and try-with-resources in 7. Having support for goto is long-overdue and simple to implement since the JVM already has goto instructions. Success Metrics The goto statement will allow inefficient and verbose recursive algorithms and explicit loops to be replaced with more compact code. The effort will be a success if at least twenty five percent of the JDK's explicit loops are replaced with goto's. Coordination with IDE vendors is expected to help facilitate this goal. Motivation The goto construct offers numerous benefits to the Java platform, from increased expressiveness, to more compact code, to providing new programming paradigms to appeal to a broader demographic. In JDK 8, there is a renewed focus on using the Java platform on embedded devices with more modest resources than desktop or server environments. In such contexts, static and dynamic memory footprint is a concern. One significant component of footprint is the code attribute of class files and certain classes of important algorithms can be expressed more compactly using goto than using other constructs, saving footprint. For example, to implement state machines recursively, some parties have asked for the JVM to support tail calls, that is, to perform a complex transformation with security implications to turn a method call into a goto. Such complicated machinery should not be assumed for an embedded context. A better solution is just to expose to the programmer the desired functionality, goto. The web has familiarized users with a model of traversing links among different HTML pages in a free-form fashion with some state being maintained on the side, such as login credentials, to effect behavior. This is exactly the programming model of goto and code. While in the past this has been derided as leading to "spaghetti code," spaghetti is a tasty and nutritious meal for programmers, unlike quiche. The invokedynamic instruction added by JSR 292 exposes the JVM's linkage operation to programmers. This is a low-level operation that can be leveraged by sophisticated programmers. Likewise, goto is a also a low-level operation that should not be hidden from programmers who can use more efficient idioms. Some may object that goto was consciously excluded from the original design of Java as one of the removed feature from C and C++. However, the designers of the Java programming languages have revisited these removals before. The enum construct was also left out only to be added in JDK 5 and multiple inheritance was left out, only to be added back by the virtual extension method methods of Project Lambda. As a living language, the needs of the growing Java community today should be used to judge what features are needed in the platform tomorrow; the language should not be forever bound by the decisions of the past. Description From its initial version, the JVM has had two instructions for unconditional transfer of control within a method, goto (0xa7) and goto_w (0xc8). The goto_w instruction is used for larger jumps. All versions of the Java language have supported labeled statements; however, only the break and continue statements were able to specify a particular label as a target with the onerous restriction that the label must be lexically enclosing. The grammar addition for the goto statement is: GotoStatement: goto Identifier ; The new goto statement similar to break except that the target label can be anywhere inside the method and the identifier is mandatory. The compiler simply translates the goto statement into one of the JVM goto instructions targeting the right offset in the method. Therefore, adding the goto statement to the platform is only a small effort since existing compiler and JVM functionality is reused. Other language changes to support goto include obvious updates to definite assignment analysis, reachability analysis, and exception analysis. Possible future extensions include a computed goto as found in gcc, which would replace the identifier in the goto statement with an expression having the type of a label. Testing Since goto will be implemented using largely existing facilities, only light levels of testing are needed. Impact Compatibility: Since goto is already a keyword, there are no source compatibility implications. Performance/scalability: Performance will improve with more compact code. JVMs already need to handle irreducible flow graphs since goto is a VM instruction.

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  • Alert show when extension of FileUpLoads are not allowed

    - by Vy Clarks
    I have a asp FileUpload control in my aspx page. And the code behind to check file's extension and then insert them into database: private string Write(HttpPostedFile file, string table) { string fileNameMain = Path.GetFileName(file.FileName); // check for the valid file extension string fileExtension = Path.GetExtension(fileNameMain).ToLower(); if (fileExtension.Equals(".pdf") || fileExtension.Equals(".doc")) { ...insert fileupload into database } else { LabelError.Text = "Extension of files are not allowed."; return null; } } With the code above, it checks the extension and then show the message "Extension of files are not allowed." in a LabelError if the fileupload is not allowed. Now, I'm required to do the "check-extension" in the other way: at the moment the client click and choose FileUpload, an alert show "Extension of files are not allowed.". I need a way to make an alert show at the momment the FileUpload choosed in browser. Help!!!!

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  • Gnome Tweak Tool problems

    - by Nguy?n Duy Khánh
    I am now using Ubuntu 12.10 and I tried to install Gnome Shel Extension and Gnome Tweak Tool. However, here is my problem : You can see that my tweak tool does not receive user themes.. When I checked the Ubuntu Software Center, I see that GNOME Shell Extension Preferences and GNOME Shel User Themes has already installed. So, what is my problem, and how can I fix it ? Please help me. Thanks.

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  • A ToDynamic() Extension Method For Fluent Reflection

    - by Dixin
    Recently I needed to demonstrate some code with reflection, but I felt it inconvenient and tedious. To simplify the reflection coding, I created a ToDynamic() extension method. The source code can be downloaded from here. Problem One example for complex reflection is in LINQ to SQL. The DataContext class has a property Privider, and this Provider has an Execute() method, which executes the query expression and returns the result. Assume this Execute() needs to be invoked to query SQL Server database, then the following code will be expected: using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // Executes the query. Here reflection is required, // because Provider, Execute(), and ReturnValue are not public members. IEnumerable<Product> results = database.Provider.Execute(query.Expression).ReturnValue; // Processes the results. foreach (Product product in results) { Console.WriteLine("{0}, {1}", product.ProductID, product.ProductName); } } Of course, this code cannot compile. And, no one wants to write code like this. Again, this is just an example of complex reflection. using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // database.Provider PropertyInfo providerProperty = database.GetType().GetProperty( "Provider", BindingFlags.NonPublic | BindingFlags.GetProperty | BindingFlags.Instance); object provider = providerProperty.GetValue(database, null); // database.Provider.Execute(query.Expression) // Here GetMethod() cannot be directly used, // because Execute() is a explicitly implemented interface method. Assembly assembly = Assembly.Load("System.Data.Linq"); Type providerType = assembly.GetTypes().SingleOrDefault( type => type.FullName == "System.Data.Linq.Provider.IProvider"); InterfaceMapping mapping = provider.GetType().GetInterfaceMap(providerType); MethodInfo executeMethod = mapping.InterfaceMethods.Single(method => method.Name == "Execute"); IExecuteResult executeResult = executeMethod.Invoke(provider, new object[] { query.Expression }) as IExecuteResult; // database.Provider.Execute(query.Expression).ReturnValue IEnumerable<Product> results = executeResult.ReturnValue as IEnumerable<Product>; // Processes the results. foreach (Product product in results) { Console.WriteLine("{0}, {1}", product.ProductID, product.ProductName); } } This may be not straight forward enough. So here a solution will implement fluent reflection with a ToDynamic() extension method: IEnumerable<Product> results = database.ToDynamic() // Starts fluent reflection. .Provider.Execute(query.Expression).ReturnValue; C# 4.0 dynamic In this kind of scenarios, it is easy to have dynamic in mind, which enables developer to write whatever code after a dot: using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // database.Provider dynamic dynamicDatabase = database; dynamic results = dynamicDatabase.Provider.Execute(query).ReturnValue; } This throws a RuntimeBinderException at runtime: 'System.Data.Linq.DataContext.Provider' is inaccessible due to its protection level. Here dynamic is able find the specified member. So the next thing is just writing some custom code to access the found member. .NET 4.0 DynamicObject, and DynamicWrapper<T> Where to put the custom code for dynamic? The answer is DynamicObject’s derived class. I first heard of DynamicObject from Anders Hejlsberg's video in PDC2008. It is very powerful, providing useful virtual methods to be overridden, like: TryGetMember() TrySetMember() TryInvokeMember() etc.  (In 2008 they are called GetMember, SetMember, etc., with different signature.) For example, if dynamicDatabase is a DynamicObject, then the following code: dynamicDatabase.Provider will invoke dynamicDatabase.TryGetMember() to do the actual work, where custom code can be put into. Now create a type to inherit DynamicObject: public class DynamicWrapper<T> : DynamicObject { private readonly bool _isValueType; private readonly Type _type; private T _value; // Not readonly, for value type scenarios. public DynamicWrapper(ref T value) // Uses ref in case of value type. { if (value == null) { throw new ArgumentNullException("value"); } this._value = value; this._type = value.GetType(); this._isValueType = this._type.IsValueType; } public override bool TryGetMember(GetMemberBinder binder, out object result) { // Searches in current type's public and non-public properties. PropertyInfo property = this._type.GetTypeProperty(binder.Name); if (property != null) { result = property.GetValue(this._value, null).ToDynamic(); return true; } // Searches in explicitly implemented properties for interface. MethodInfo method = this._type.GetInterfaceMethod(string.Concat("get_", binder.Name), null); if (method != null) { result = method.Invoke(this._value, null).ToDynamic(); return true; } // Searches in current type's public and non-public fields. FieldInfo field = this._type.GetTypeField(binder.Name); if (field != null) { result = field.GetValue(this._value).ToDynamic(); return true; } // Searches in base type's public and non-public properties. property = this._type.GetBaseProperty(binder.Name); if (property != null) { result = property.GetValue(this._value, null).ToDynamic(); return true; } // Searches in base type's public and non-public fields. field = this._type.GetBaseField(binder.Name); if (field != null) { result = field.GetValue(this._value).ToDynamic(); return true; } // The specified member is not found. result = null; return false; } // Other overridden methods are not listed. } In the above code, GetTypeProperty(), GetInterfaceMethod(), GetTypeField(), GetBaseProperty(), and GetBaseField() are extension methods for Type class. For example: internal static class TypeExtensions { internal static FieldInfo GetBaseField(this Type type, string name) { Type @base = type.BaseType; if (@base == null) { return null; } return @base.GetTypeField(name) ?? @base.GetBaseField(name); } internal static PropertyInfo GetBaseProperty(this Type type, string name) { Type @base = type.BaseType; if (@base == null) { return null; } return @base.GetTypeProperty(name) ?? @base.GetBaseProperty(name); } internal static MethodInfo GetInterfaceMethod(this Type type, string name, params object[] args) { return type.GetInterfaces().Select(type.GetInterfaceMap).SelectMany(mapping => mapping.TargetMethods) .FirstOrDefault( method => method.Name.Split('.').Last().Equals(name, StringComparison.Ordinal) && method.GetParameters().Count() == args.Length && method.GetParameters().Select( (parameter, index) => parameter.ParameterType.IsAssignableFrom(args[index].GetType())).Aggregate( true, (a, b) => a && b)); } internal static FieldInfo GetTypeField(this Type type, string name) { return type.GetFields( BindingFlags.GetField | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).FirstOrDefault( field => field.Name.Equals(name, StringComparison.Ordinal)); } internal static PropertyInfo GetTypeProperty(this Type type, string name) { return type.GetProperties( BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).FirstOrDefault( property => property.Name.Equals(name, StringComparison.Ordinal)); } // Other extension methods are not listed. } So now, when invoked, TryGetMember() searches the specified member and invoke it. The code can be written like this: dynamic dynamicDatabase = new DynamicWrapper<NorthwindDataContext>(ref database); dynamic dynamicReturnValue = dynamicDatabase.Provider.Execute(query.Expression).ReturnValue; This greatly simplified reflection. ToDynamic() and fluent reflection To make it even more straight forward, A ToDynamic() method is provided: public static class DynamicWrapperExtensions { public static dynamic ToDynamic<T>(this T value) { return new DynamicWrapper<T>(ref value); } } and a ToStatic() method is provided to unwrap the value: public class DynamicWrapper<T> : DynamicObject { public T ToStatic() { return this._value; } } In the above TryGetMember() method, please notice it does not output the member’s value, but output a wrapped member value (that is, memberValue.ToDynamic()). This is very important to make the reflection fluent. Now the code becomes: IEnumerable<Product> results = database.ToDynamic() // Here starts fluent reflection. .Provider.Execute(query.Expression).ReturnValue .ToStatic(); // Unwraps to get the static value. With the help of TryConvert(): public class DynamicWrapper<T> : DynamicObject { public override bool TryConvert(ConvertBinder binder, out object result) { result = this._value; return true; } } ToStatic() can be omitted: IEnumerable<Product> results = database.ToDynamic() .Provider.Execute(query.Expression).ReturnValue; // Automatically converts to expected static value. Take a look at the reflection code at the beginning of this post again. Now it is much much simplified! Special scenarios In 90% of the scenarios ToDynamic() is enough. But there are some special scenarios. Access static members Using extension method ToDynamic() for accessing static members does not make sense. Instead, DynamicWrapper<T> has a parameterless constructor to handle these scenarios: public class DynamicWrapper<T> : DynamicObject { public DynamicWrapper() // For static. { this._type = typeof(T); this._isValueType = this._type.IsValueType; } } The reflection code should be like this: dynamic wrapper = new DynamicWrapper<StaticClass>(); int value = wrapper._value; int result = wrapper.PrivateMethod(); So accessing static member is also simple, and fluent of course. Change instances of value types Value type is much more complex. The main problem is, value type is copied when passing to a method as a parameter. This is why ref keyword is used for the constructor. That is, if a value type instance is passed to DynamicWrapper<T>, the instance itself will be stored in this._value of DynamicWrapper<T>. Without the ref keyword, when this._value is changed, the value type instance itself does not change. Consider FieldInfo.SetValue(). In the value type scenarios, invoking FieldInfo.SetValue(this._value, value) does not change this._value, because it changes the copy of this._value. I searched the Web and found a solution for setting the value of field: internal static class FieldInfoExtensions { internal static void SetValue<T>(this FieldInfo field, ref T obj, object value) { if (typeof(T).IsValueType) { field.SetValueDirect(__makeref(obj), value); // For value type. } else { field.SetValue(obj, value); // For reference type. } } } Here __makeref is a undocumented keyword of C#. But method invocation has problem. This is the source code of TryInvokeMember(): public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result) { if (binder == null) { throw new ArgumentNullException("binder"); } MethodInfo method = this._type.GetTypeMethod(binder.Name, args) ?? this._type.GetInterfaceMethod(binder.Name, args) ?? this._type.GetBaseMethod(binder.Name, args); if (method != null) { // Oops! // If the returnValue is a struct, it is copied to heap. object resultValue = method.Invoke(this._value, args); // And result is a wrapper of that copied struct. result = new DynamicWrapper<object>(ref resultValue); return true; } result = null; return false; } If the returned value is of value type, it will definitely copied, because MethodInfo.Invoke() does return object. If changing the value of the result, the copied struct is changed instead of the original struct. And so is the property and index accessing. They are both actually method invocation. For less confusion, setting property and index are not allowed on struct. Conclusions The DynamicWrapper<T> provides a simplified solution for reflection programming. It works for normal classes (reference types), accessing both instance and static members. In most of the scenarios, just remember to invoke ToDynamic() method, and access whatever you want: StaticType result = someValue.ToDynamic()._field.Method().Property[index]; In some special scenarios which requires changing the value of a struct (value type), this DynamicWrapper<T> does not work perfectly. Only changing struct’s field value is supported. The source code can be downloaded from here, including a few unit test code.

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  • Why is there no service-oriented language?

    - by Wolfgang
    Edit: To avoid further confusion: I am not talking about web services and such. I am talking about structuring applications internally, it's not about how computers communicate. It's about programming languages, compilers and how the imperative programming paradigm is extended. Original: In the imperative programming field, we saw two paradigms in the past 20 years (or more): object-oriented (OO), and service-oriented (SO) aka. component-based (CB). Both paradigms extend the imperative programming paradigm by introducing their own notion of modules. OO calls them objects (and classes) and lets them encapsulates both data (fields) and procedures (methods) together. SO, in contrast, separates data (records, beans, ...) from code (components, services). However, only OO has programming languages which natively support its paradigm: Smalltalk, C++, Java and all other JVM-compatibles, C# and all other .NET-compatibles, Python etc. SO has no such native language. It only comes into existence on top of procedural languages or OO languages: COM/DCOM (binary, C, C++), CORBA, EJB, Spring, Guice (all Java), ... These SO frameworks clearly suffer from the missing native language support of their concepts. They start using OO classes to represent services and records. This leads to designs where there is a clear distinction between classes that have methods only (services) and those that have fields only (records). Inheritance between services or records is then simulated by inheritance of classes. Technically, its not kept so strictly but in general programmers are adviced to make classes to play only one of the two roles. They use additional, external languages to represent the missing parts: IDL's, XML configurations, Annotations in Java code, or even embedded DSL like in Guice. This is especially needed, but not limited to, since the composition of services is not part of the service code itself. In OO, objects create other objects so there is no need for such facilities but for SO there is because services don't instantiate or configure other services. They establish an inner-platform effect on top of OO (early EJB, CORBA) where the programmer has to write all the code that is needed to "drive" SO. Classes represent only a part of the nature of a service and lots of classes have to be written to form a service together. All that boiler plate is necessary because there is no SO compiler which would do it for the programmer. This is just like some people did it in C for OO when there was no C++. You just pass the record which holds the data of the object as a first parameter to the procedure which is the method. In a OO language this parameter is implicit and the compiler produces all the code that we need for virtual functions etc. For SO, this is clearly missing. Especially the newer frameworks extensively use AOP or introspection to add the missing parts to a OO language. This doesn't bring the necessary language expressiveness but avoids the boiler platform code described in the previous point. Some frameworks use code generation to produce the boiler plate code. Configuration files in XML or annotations in OO code is the source of information for this. Not all of the phenomena that I mentioned above can be attributed to SO but I hope it clearly shows that there is a need for a SO language. Since this paradigm is so popular: why isn't there one? Or maybe there are some academic ones but at least the industry doesn't use one.

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