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• Who is code wanderer?

  - by DigiMortal

  In every area of life there are people with some bad habits or misbehaviors that affect the work process. Software development is also not free of this kind of people. Today I will introduce you code wanderer. Who is code wanderer? Code wandering is more like bad habit than serious diagnose. Code wanderers tend to review and “fix” source code in files written by others. When code wanderer has some free moments he starts to open the code files he or she has never seen before and starts making little fixes to these files. Why is code wanderer dangerous? These fixes seem correct and are usually first choice to do when considering nice code. But as changes are made by coder who has no idea about the code he or she “fixes” then “fixing” usually ends up with messing up working code written by others. Often these “fixes” are not found immediately because they doesn’t introduce errors detected by compilers. So these “fixes” find easily way to production environments because there is also very good chance that “fixed” code goes through all tests without any problems. How to stop code wanderer? The first thing is to talk with person and explain him or her why those changes are dangerous. It is also good to establish rules that state clearly why, when and how can somebody change the code written by other people. If this does not work it is possible to isolate this person so he or she can post his or her changes to code repository as patches and somebody reviews those changes before applying them.

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• Dependency injection: what belongs in the constructor?

  - by Adam Backstrom

  I'm evaluating my current PHP practices in an effort to write more testable code. Generally speaking, I'm fishing for opinions on what types of actions belong in the constructor. Should I limit things to dependency injection? If I do have some data to populate, should that happen via a factory rather than as constructor arguments? (Here, I'm thinking about my User class that takes a user ID and populates user data from the database during construction, which obviously needs to change in some way.) I've heard it said that "initialization" methods are bad, but I'm sure that depends on what exactly is being done during initialization. At the risk of getting too specific, I'll also piggyback a more detailed example onto my question. For a previous project, I built a FormField class (which handled field value setting, validation, and output as HTML) and a Model class to contain these fields and do a bit of magic to ease working with fields. FormField had some prebuilt subclasses, e.g. FormText (<input type="text">) and FormSelect (<select>). Model would be subclassed so that a specific implementation (say, a Widget) had its own fields, such as a name and date of manufacture: class Widget extends Model { public function __construct( $data = null ) { $this->name = new FormField('length=20&label=Name:'); $this->manufactured = new FormDate; parent::__construct( $data ); // set above fields using incoming array } } Now, this does violate some rules that I have read, such as "avoid new in the constructor," but to my eyes this does not seem untestable. These are properties of the object, not some black box data generator reading from an external source. Unit tests would progressively build up to any test of Widget-specific functionality, so I could be confident that the underlying FormFields were working correctly during the Widget test. In theory I could provide the Model with a FieldFactory() which could supply custom field objects, but I don't believe I would gain anything from this approach. Is this a poor assumption?

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• When do domain concepts become application constructs?

  - by Noren

  I recently posted a question regarding recovering a DDD architecture that became an anemic domain model into a multitier architecture and this question is a follow-on of sorts. My question is when do domain concepts become application constructs. My application is a local client C# 4/WPF with the following architecture: Presentation Layer Views ViewModels Business Layer ??? Domain Layer Classes that take the POCOs with primitive types and create domain concepts (e.g. image, layer, etc) Sanity checks values (e.g. image width 0) Interfaces for DTOs Interface for a repository that abstracts the filesystem Data Access Layer Classes that parse the proprietary binary files into POCOs with primitive types by explicit knowledge of the file format Implementation of domain DTOs Implementation of domain repository class Local Filesystem Proprietary binary files When does the MyImageType domain class with Int32 width, height, and Int32[] pixels become a System.Windows.Media.ImageDrawing? If I put it in the domain layer, it seems like implemenation details are being leaked (what if I didn't want to use WPF?). If I put it in the presentation layer, it seems like it's doing too much. If I create a business layer, it seems like it would be doing too little since there are few "rules" given the CRUD nature of the application. I think all of my reading has lead to analysis paralysis, so I thought fresh eyes might lend some perspective.

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• Access functions from user control without events?

  - by BornToCode

  I have an application made with usercontrols and a function on main form that removes the previous user controls and shows the desired usercontrol centered and tweaked: public void DisplayControl(UserControl uControl) I find it much easier to make this function static or access this function by reference from the user control, like this: MainForm mainform_functions = (MainForm)Parent; mainform_functions.DisplayControl(uc_a); You probably think it's a sin to access a function in mainform, from the usercontrol, however, raising an event seems much more complex in such case - I'll give a simple example - let's say I raise an event from usercontrol_A to show usercontrol_B on mainform, so I write this: uc_a.show_uc_b+= (s,e) => { usercontrol_B uc_b = new usercontrol_B(); DisplayControl(uc_b); }; Now what if I want usercontrol_B to also have an event to show usercontrol_C? now it would look like this: uc_a.show_uc_b+= (s,e) => { usercontrol_B uc_b = new usercontrol_B(); DisplayControl(uc_b); uc_b.show_uc_c += (s2,e2) => {usercontrol_C uc_c = new usercontrol_C(); DisplayControl(uc_c);} }; THIS LOOKS AWFUL! The code is much simpler and readable when you actually access the function from the usercontrol itself, therefore I came to the conclusion that in such case it's not so terrible if I break the rules and not use events for such general function, I also think that a readable usercontrol that you need to make small adjustments for another app is preferable than a 100% 'generic' one which makes my code look like a pile of mud. What is your opinion? Am I mistaken?

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• New York Alt.NET Dinner

  - by Liam McLennan

  While I was in the New York area Stephen Bohlen graciously organised an Alt.NET dinner. I left Rockville Centre on the 17:15 train, thinking I had plenty of time to get to Toloache Mexican Bistro on W 50th St. However, when I changed at Penn Station I took the service downtown, instead of uptown. I corrected that mistake and made it to 51st St, but then ended up in completely the wrong place because I did not understand the street numbering system. For future reference I now have the following rules for NYC navigation: Uptown means North, Downtown means South Streets run East-West, Avenues North-South Street number are symmetrical on the 5th Avenue axis. That is, street numbers increase from zero both east and west of 5th Av. Having gotten totally confused I called Steve, who helped me find the restaurant. I still had my luggage, which we stowed in a corner. Over some descent Mexican food we had some great discussions about Alt.NET, the 2010 conference, and other things of interest to Alt.NET folks. Thanks to Steve for organising and to all the guys who turned up.

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• Firefox freezes frequently

  - by user141740

  Good day, The application Firefox freezes very frequently and I have to use 'force quit" to get out and hence I lose all my activities and it is extremely frustrating. Only in one occasion, there was a pop-out message saying that this problem was going to be tracked but in all other occasions there is no tracking and no message I posted this error on Ubuntu community and it was stopped and I was told to post it on launchpad. I did try to do so with no success as after reading pages and pages which i really do not understand who would read them and why so many ridiculous and tedious rules and information, i even could not find the place or the way to post this bug. And I thought of this ASkUBUNTU and so i am posting here in the hope for some useful help and I have to mention I am new to Linux. Just a few minutes ago, I opened the Firefox through the Terminal and it crashed very quickly and there are some error messages and i copy and paste them hoping they can help thank you in advance and look forward to your help and solving this frustrating problem/bug and if you wish you may post it on Launchpad or do with report as you wish as long as the problem is solved. And here the messages appearing in Terminal, after Firefox crashed: ** (firefox:4099): WARNING **: Error calling add_icon method of Contextcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling set_homepage method of Contextcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling clear_indicator method of Indicatorcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling clear_indicator method of Indicatorcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling clear_indicator method of Indicatorcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling set_view_location method of Contextcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling set_view_window method of Contextcontext: Timeout was reached ** (firefox:4099): WARNING **: Error calling set_view_is_active method of Contextcontext: Timeout was reached Killed

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• Code contracts and inheritance

  - by DigiMortal

  In my last posting about code contracts I introduced you how to force code contracts to classes through interfaces. In this posting I will go step further and I will show you how code contracts work in the case of inherited classes. As a first thing let’s take a look at my interface and code contracts. [ContractClass(typeof(ProductContracts))] public interface IProduct {     int Id { get; set; }     string Name { get; set; }     decimal Weight { get; set; }     decimal Price { get; set; } }   [ContractClassFor(typeof(IProduct))] internal sealed class ProductContracts : IProduct {     private ProductContracts() { }       int IProduct.Id     {         get         {             return default(int);         }         set         {             Contract.Requires(value > 0);         }     }       string IProduct.Name     {         get         {             return default(string);         }         set         {             Contract.Requires(!string.IsNullOrWhiteSpace(value));             Contract.Requires(value.Length <= 25);         }     }       decimal IProduct.Weight     {         get         {             return default(decimal);         }         set         {             Contract.Requires(value > 3);             Contract.Requires(value < 100);         }     }       decimal IProduct.Price     {         get         {             return default(decimal);         }         set         {             Contract.Requires(value > 0);             Contract.Requires(value < 100);         }     } } And here is the product class that inherits IProduct interface. public class Product : IProduct {     public int Id { get; set; }     public string Name { get; set; }     public virtual decimal Weight { get; set; }     public decimal Price { get; set; } } if we run this code and violate the code contract set to Id we will get ContractException. public class Program {     static void Main(string[] args)     {         var product = new Product();         product.Id = -100;     } }   Now let’s make Product to be abstract class and let’s define new class called Food that adds one more contract to Weight property. public class Food : Product {     public override decimal Weight     {         get         {             return base.Weight;         }         set         {             Contract.Requires(value > 1);             Contract.Requires(value < 10);               base.Weight = value;         }     } } Now we should have the following rules at place for Food: weight must be greater than 1, weight must be greater than 3, weight must be less than 100, weight must be less than 10. Interesting part is what happens when we try to violate the lower and upper limits of Food weight. To see what happens let’s try to violate rules #2 and #4. Just comment one of the last lines out in the following method to test another assignment. public class Program {     static void Main(string[] args)     {         var food = new Food();         food.Weight = 12;         food.Weight = 2;     } } And here are the results as pictures to see where exceptions are thrown. Click on images to see them at original size. Violation of lower limit. Violation of upper limit. As you can see for both violations we get ContractException like expected. Code contracts inheritance is powerful and at same time dangerous feature. Although you can always narrow down the conditions that come from more general classes it is possible to define impossible or conflicting contracts at different points in inheritance hierarchy.

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• Software management for 2 programmers

  - by kajo

  me and my very good friend do a small bussiness. We have company and we develop web apps using Scala. We have started 3 months ago and we have a lot of work now. We cannot afford to employ another programmer because we can't pay him now. Until now we try to manage entire developing process very simply. We use excel sheets for simple bug tracking and we work on client requests on the fly. We have no plan for next week or something similar. But now I find it very inefficient and useless. I am trying to find some rules or some methodology for small team or for only two guys. For example Scrum is, imo, unadapted for us. There are a lot of roles (ScrumMaster, Product Owner, Team...) and it seems overkill. Can you something advise me? Have you any experiences with software management in small teams? Is any methodology of current agile development fitten for pair of programmers? Is there any software management for simple bug tracking, maybe wiki or time management for two coders? thanks a lot for sharing.

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• HTML5 data-* (custom data attribute)

  - by Renso

  Goal: Store custom data with the data attribute on any DOM element and retrieve it. Previously under HTML4 we used to use classes to store custom data, something to the affect of <input class="account void limit-5000 over-4999" /> and then have to parse the data out of the class In a book published by Peter-Paul Koch in 2007, ppk on JavaScript, he explains why and how to use custom attributes to make data more accessible to JavaScript, using name-value pairs. Accessing a custom attribute account-limit=5000 is much easier and more intuitive than trying to parse it out of a class, Plus, what if the class name for example "color-5" has a representative class definition in a CSS stylesheet that hides it away or worse some JavaScript plugin that automatically adds 5000 to it, or something crazy like that, just because it is a valid class name. As you can see there are quite a few reasons why using classes is a bad design and why it was important to define custom data attributes in HTML5. Syntax: You define the data attribute by simply prefixing any data item you want to store with any HTML element with "data-". For example to store our customers account data with a hidden input element: <input type="hidden" data-account="void" data-limit=5000 data-over=4999  /> How to access the data: account  -     element.dataset.account limit    -     element.dataset.limit You can also access it by using the more traditional get/setAttribute method or if using jQuery $('#element').attr('data-account','void') Browser support: All except for IE. There is an IE hack around this at http://gist.github.com/362081. Special Note: Be AWARE, do not use upper-case when defining your data elements as it is all converted to lower-case when reading it, so: data-myAccount="A1234" will not be found when you read it with: element.dataset.myAccount Use only lowercase when reading so this will work: element.dataset.myaccount

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• Can't update kernel to 2.6.35.27

  - by Uri Herrera

  When I try to update I get this message, I'm guessing I'm missing something here? Filesystem Type Size Used Avail Use% Mounted on /dev/sdb6 ext4 43G 7.7G 33G 20% / none devtmpfs 1.6G 349k 1.6G 1% /dev none tmpfs 1.6G 5.9M 1.6G 1% /dev/shm none tmpfs 1.6G 218k 1.6G 1% /var/run none tmpfs 1.6G 0 1.6G 0% /var/lock /dev/sdb2 fuseblk 258G 198G 60G 77% /media/Backup /dev/sda1 fuseblk 321G 175G 146G 55% /media/Media /dev/sdb1 ext4 96M 84M 6.7M 93% /boot /dev/sdb7 ext4 175G 81G 86G 49% /home Here's the output: Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: linux-image-2.6.35-22-generic 0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded. 5 not fully installed or removed. After this operation, 107MB disk space will be freed. Do you want to continue [Y/n]? y (Reading database ... 282211 files and directories currently installed.) Removing linux-image-2.6.35-22-generic ... Examining /etc/kernel/postrm.d . run-parts: executing /etc/kernel/postrm.d/initramfs-tools 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic run-parts: executing /etc/kernel/postrm.d/zz-update-grub 2.6.35-22-generic /boot/vmlinuz-2.6.35-22-generic /etc/default/grub: 23: Syntax error: newline unexpected run-parts: /etc/kernel/postrm.d/zz-update-grub exited with return code 2 Failed to process /etc/kernel/postrm.d at /var/lib/dpkg/info/linux-image-2.6.35-22- generic.postrm line 328. dpkg: error processing linux-image-2.6.35-22-generic (--remove): subprocess installed post-removal script returned error exit status 1 Errors were encountered while processing: linux-image-2.6.35-22-generic E: Sub-process /usr/bin/dpkg returned an error code (1)

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• Is there a language more general than Lisp?

  - by Jon Purdy

  I've been programming for a long time, and writing in Lisp (well, mostly Scheme) for a little less. My experience in these languages (and other functional languages) has informed my ability to write clean code even with less powerful tools. Lisp-family languages have lovely facilities for implementing every abstraction in common use: S-expressions generalise structure. Macros generalise syntax. Continuations generalise flow control. But I'm dissatisfied. Somehow, I want more. Is there a language that's more general? More powerful? As great as Lisp is, I find it hard to believe no one has come up with anything (dare I say) better. I'm well aware that ordinarily a question like this ought to be closed for its argumentative nature. But there seems to be a broad consensus that Lisp represents the theoretical pinnacle of programming language design. I simply refuse to accept that without some kind of proof. Which I guess amounts to questioning whether the lambda calculus is in fact the ideal abstraction of computation.

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• Is "White-Board-Coding" inappropriate during interviews?

  - by Eoin Campbell

  This is a somewhat subjective quesiton but I'd love to hear feedback/opinions from either interviewers/interviewees on the topic. We split our technical part into 4 parts. Write Code, Read & Analyse Code, Design Session & Code on the white board. For the last part what we ask interviewees to do is write a small code snippet (4-5 lines) on the whiteboard and explain as they go through it. Let me be clear the purpose is not to catch people out. We're not looking for perfect syntax. Hell it can even be pseudo-code. but the point is to give them a very simple problem and see if their brain can communicate the solution to us. By simple problems I mean "Reverse a string", "FizzBuzz" etc... EDIT Just with regards the comment about Pseudo-Code. We always ask for an explicit language first. We;re a .NET C# house. we've only said "pseudo-code" where someone has been blanking/really struggling with the code. My question is "Is it innappropriate / unreasonable to expect a programmer to write a code snippet on a whiteboard during an interview ?"

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• Linear Search in Python? [closed]

  - by POTUS

  def find_interval(mesh,x): '''This function finds the interval containing x according to the following rules, mesh is an ordered list with n numbers return 0 if x < mesh[0] return n if mesh[n-1] < x return k if mesh[k-1] <= x < mesh[k] return n-1 if mesh[n-2] <= x <= mesh[n-1] This function does a Linear search. 08/29/2012 ''' for n in range(len(mesh)): for k in range(len(mesh)): if x == mesh[n]: print "Found x at index:" return n elif x<mesh[n]: return 0 elif mesh[n-1]<x: return n elif mesh[n-2]<=x<=mesh[n-1]: return n-1 elif mesh[k-1]<=x<mesh[k]: return k mesh = [0, 0.1, 0.25, 0.5, 0.6, 0.75, 0.9, 1] print mesh print find_interval(mesh, -1) print find_interval(mesh, 0) print find_interval(mesh, 0.1) print find_interval(mesh, 0.8) print find_interval(mesh, 0.9) print find_interval(mesh, 1) print find_interval(mesh, 1.01) Output: [0, 0.100000000000000, 0.250000000000000, 0.500000000000000, 0.600000000000000, 0.750000000000000, 0.900000000000000, 1] 0 Found x at index: 0 2 6 -1 -1 0 I don't think the output is correct. Can anyone help me fix it? Thanks.

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• does ubuntu 11.10 is support ns2.29

  - by nasser

  I need your help, I'm a beginner on NS2 , and I'm trying to install ns2.29 on ubuntu 11.10 32bits but i can't. This message appear and installation stopped : Build tcl8.4.11 ============================================================ loading cache ./config.cache checking whether to use symlinks for manpages... no checking whether to compress the manpages... no checking whether to add a package name suffix for the manpages... no checking for gcc... gcc checking whether the C compiler (gcc ) works... yes checking whether the C compiler (gcc ) is a cross-compiler... no checking whether we are using GNU C... yes checking whether gcc accepts -g... yes checking for building with threads... no (default) checking if the compiler understands -pipe... yes checking how to run the C preprocessor... gcc -pipe -E checking for sin... no checking for main in -lieee... yes checking for main in -linet... no checking for net/errno.h... no checking for connect... yes checking for gethostbyname... yes checking how to build libraries... static checking for ranlib... ranlib checking if 64bit support is requested... no checking if 64bit Sparc VIS support is requested... no checking system version (for dynamic loading)... ./configure: 1: Syntax error: Unterminated quoted string tcl8.3.2 configuration failed! Exiting ... Tcl is not part of the ns project. Please see www.Scriptics.com to see if they have a fix for your platform. Anyone can help me?

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• What follows after lexical analysis?

  - by madflame991

  I'm working on a toy compiler (for some simple language like PL/0) and I have my lexer up and running. At this point I should start working on building the parse tree, but before I start I was wondering: How much information can one gather from just the string of tokens? Here's what I gathered so far: One can already do syntax highlighting having only the list of tokens. Numbers and operators get coloured accordingly and keywords also. Autoformatting (indenting) should also be possible. How? Specify for each token type how many white spaces or new line characters should follow it. Also when you print tokens modify an alignment variable (when the code printer reads "{" increment the alignment variable by 1, and decrement by 1 for "}". Whenever it starts printing on a new line the code printer will align according to this alignment variable) In languages without nested subroutines one can get a complete list of subroutines and their signature. How? Just read what follows after the "procedure" or "function" keyword until you hit the first ")" (this should work fine in a Pascal language with no nested subroutines) In languages like Pascal you can even determine local variables and their types, as they are declared in a special place (ok, you can't handle initialization as well, but you can parse sequences like: "var a, b, c: integer") Detection of recursive functions may also be possible, or even a graph representation of which subroutine calls who. If one can identify the body of a function then one can also search if there are any mentions of other function's names. Gathering statistics about the code, like number of lines, instructions, subroutines EDIT: I clarified why I think some processes are possible. As I read comments and responses I realise that the answer depends very much on the language that I'm parsing.

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• How can I call a URL as a cron job in Webmin?

  - by EmmyS

  (Possibly this belongs on stackoverflow, although it's not really a programming issue since the code works when run directly. If it needs to be moved, though, no problem.) I have a PHP file (which consumers a National Weather Service web service via SOAP, if it matters) that I need to run on a scheduled basis. I'm trying to set up a cron job in Webmin. If I use an absolute path to the file in the Command field, when I run it I get some strange errors: /var/www/html/mysite.com/test/ndfdXMLclient.php: line 1: ?php: No such file or directory /var/www/html/mysite.com/test/ndfdXMLclient.php: line 2: //: is a directory /var/www/html/mysite.com/test/ndfdXMLclient.php: line 3: //DOCUMENTATION: No such file or directory /var/www/html/mysite.com/test/ndfdXMLclient.php: line 4: //: is a directory /var/www/html/mysite.com/test/ndfdXMLclient.php: line 5: syntax error near unexpected token `"running client code",' /var/www/html/mysite.com/test/ndfdXMLclient.php: line 5: `error_log("running client code", 1, "[email protected]");' The actual code in my file for those 5 lines looks like this: <?php // *************************************************************************** //DOCUMENTATION FROM WEATHER.GOV ALL STORED IN xmlClientComments.txt // *************************************************************************** error_log("running client code", 1, "[email protected]"); The code runs perfectly fine when I run it directly in my browser, so why doesn't webmin recognize it as code? (The same thing happens if I enter the actual URL in the command field - http://mysite.com/test/ndfdXMLclient.php.) I've never worked with webmin before; most of our hosts' cron control panels allow cron jobs to run PHP files like this with no issue. Is there some trick to getting webmin to read php as actual php?

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• Why is Ubuntu offline (except torrents) while Windows is online?

  - by Fahim al Islam

  I am using a static wired connection. Everything was perfect. But suddenly from few hours back I can't access any website. Dropbox, Ubuntu One also can't connect. Ping request is also unsuccessful, but I can download through torrent. I am not trying torrent download and browsing at the same time. So, I think it's not an issue about torrent using all the bandwidth. One important point is that this connection works perfectly on Windows on this same PC (My PC is dual-boot). I have tried the way what izx has suggested (using "sudo sh -c 'echo nameserver 8.8.8.8 /etc/resolv.conf'"), but I'm facing the same problem again. Now I can't even ping 8.8.8.8 and google.com. Though I can ping 74.125.228.2 (which is Google IP address) I can't understand what's happening and why this is happening. I'm new in this website many rules and regulations is unknown to me. So, please don't be bothered for my mistakes. Looking forward for help from anyone. Thanks to all.

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• Benefits of classic OOP over Go-like language

  - by tylerl

  I've been thinking a lot about language design and what elements would be necessary for an "ideal" programming language, and studying Google's Go has led me to question a lot of otherwise common knowledge. Specifically, Go seems to have all of the interesting benefits from object oriented programming without actually having any of the structure of an object oriented language. There are no classes, only structures; there is no class/structure inheritance -- only structure embedding. There aren't any hierarchies, no parent classes, no explicit interface implementations. Instead, type casting rules are based on a loose system similar to duck-typing, such that if a struct implements the necessary elements of a "Reader" or a "Request" or an "Encoding", then you can cast it and use it as one. Does such a system obsolete the concept of OOP? Or is there something about OOP as implemented in C++ and Java and C# that is inherently more capable, more maintainable, somehow more powerful that you have to give up when moving to a language like Go? What benefit do you have to give up to gain the simplicity that this new paradigm represents?

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• Understanding math used to determine if vector is clockwise / counterclockwise from your vector

  - by MTLPhil

  I'm reading Programming Game AI by Example by Mat Buckland. In the Math & Physics primer chapter there's a listing of the declaration of a class used to represent 2D vectors. This class contains a method called Sign. It's implementation is as follows //------------------------ Sign ------------------------------------------ // // returns positive if v2 is clockwise of this vector, // minus if anticlockwise (Y axis pointing down, X axis to right) //------------------------------------------------------------------------ enum {clockwise = 1, anticlockwise = -1}; inline int Vector2D::Sign(const Vector2D& v2)const { if (y*v2.x > x*v2.y) { return anticlockwise; } else { return clockwise; } } Can someone explain the vector rules that make this hold true? What do the values of y*v2.x and x*v2.y that are being compared actually represent? I'd like to have a solid understanding of why this works rather than just accepting that it does without figuring it out. I feel like it's something really obvious that I'm just not catching on to. Thanks for your help.

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• OOW content for Pattern Matching....

  - by KLaker

  If you missed my sessions at OpenWorld then don't worry - all the content we used for pattern matching (presentation and hands-on lab) is now available for download. My presentation "SQL: The Best Development Language for Big Data?" is available for download from the OOW Content Catalog, see here: https://oracleus.activeevents.com/2013/connect/sessionDetail.ww?SESSION_ID=9101 For the hands-on lab ("Pattern Matching at the Speed of Thought with Oracle Database 12c") we used the Oracle-By-Example content. The OOW hands-on lab uses Oracle Database 12c Release 1 (12.1) and uses the MATCH_RECOGNIZE clause to perform some basic pattern matching examples in SQL. This lab is broken down into four main steps: Logically partition and order the data that is used in the MATCH_RECOGNIZE clause with its PARTITION BY and ORDER BY clauses. Define patterns of rows to seek using the PATTERN clause of the MATCH_RECOGNIZE clause. These patterns use regular expressions syntax, a powerful and expressive feature, applied to the pattern variables you define. Specify the logical conditions required to map a row to a row pattern variable in the DEFINE clause. Define measures, which are expressions usable in the MEASURES clause of the SQL query. You can download the setup files to build the ticker schema and the student notes from the Oracle Learning Library. The direct link to the example on using pattern matching is here: http://apex.oracle.com/pls/apex/f?p=44785:24:0::NO:24:P24_CONTENT_ID,P24_PREV_PAGE:6781,2.

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• Grouping a comma separated value on common data [closed]

  - by Ankit

  I have a table with col1 id int, col2 as varchar (comma separated values) and column 3 for assigning group to them. Table looks like col1 col2 group .............................. 1 2,3,4 2 5,6 3 1,2,5 4 7,8 5 11,3 6 22,8 This is only the sample of real data, now I have to assign a group no to them in such a way that output looks like col1 col2 group .............................. 1 2,3,4 1 2 5,6 1 3 1,2,5 1 4 7,8 2 5 11,3 1 6 22,8 2 The logic for assigning group no is that every similar comma separated value of string in col2 have to be same group no as every where in col2 where '2' is there it has to be same group no but the complication is that 2,3,4 are together so they all three int value if found in any where in col2 will be assigned same group. The major part is 2,3,4 and 1,2,5 both in col2 have 2 so all int 1,2,3,4,5 have to assign same group no. Tried store procedure with match against on col2 but not getting desired result Most imp (I can't use normalization, because I can't afford to make new table from my original table which have millions of records), even normalization is not helpful in my context. This question is also on stackoverflow with bounty on this link Achieved so far:- I have set the group column auto increment and then wrote this procedure:- BEGIN declare cil1_new,col2_new,group_new int; declare done tinyint default 0; declare group_new varchar(100); declare cur1 cursor for select col1,col2,`group` from company ; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1; open cur1; REPEAT fetch cur1 into col1_new,col2_new,group_new; update company set group=group_new where match(col2) against(concat("'",col2_new,"'")); until done end repeat; close cur1; select * from company; END This procedure is working, no syntax mistake but the problem is that I am not achieving the desired result exactly.

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• What do I need to know to design a language and write a interpreter for it?

  - by alFReD NSH

  I know this question has been asked and even there are thousands of books and articles about it. But the problem is that there are too many, and I don't know are they good enough, I have to design a language and write a interpreter for it. The base language is javascript (using nodejs) but it's ok if the compiler was written in another language that I can use from node. I had done a research about compiler compilers in JS, there is jison (Bison implementaion in JS), waxeye, peg.js. I decided to give jison a try, due to the popularity and its being used by coffee script, so it should be able to cover my language too. The grammar definition syntax is similar to bison. But when I tried read the bison manual it seemed very hard to understand for me. And I think it's because I don't know a lot of things about what I'm doing. Like I don't what is formal language theory. I am experienced in Javascript (I'm more talented in JS than most average programmers). And also know basic C and C++ (not much experience but can write a working code for basic things). I haven't had any formal education, so I may not be familiar with some software engineering and computer science principles. Though everyday I try to grasp a lot of articles and improve. So I'm asking if you know any good book or article that can help me. Please also write why the resource you're suggesting is good. --update-- The language I'm trying to create, is not really complicated. All it has is expressions (with or without units), comparisons and logical operators. There are no functions, loops, ... The goal is to create a language that non-programmers can easily learn. And to write customized validations and calculations.

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• The Science Behind Technological Moral Panics

  - by Jason Fitzpatrick

  Why do some new technologies cause ripples and reactionary backlash in society but others slip into our daily lives almost entirely uncontested? It turns out there’s a rather specific combination of things the new technology must do to upset the public. At Wired they highlight the work of Genevieve Bell and her studies of how society reacts to new technology: Genevieve Bell believes she’s cracked this puzzle. Bell, director of interaction and experience research at Intel, has long studied how everyday people incorporate new tech into their lives. In a 2011 interview with The Wall Street Journal‘s Tech Europe blog, she outlined an interesting argument: To provoke moral panic, a technology must satisfy three rules. First, it has to change our relationship to time. Then it has to change our relationship to space. And, crucially, it has to change our relationship to one another. Individually, each of these transformations can be unsettling, but if you hit all three? Panic! Why We Freak Out About Some Technologies but Not Others [Wired] How To Play DVDs on Windows 8 6 Start Menu Replacements for Windows 8 What Is the Purpose of the “Do Not Cover This Hole” Hole on Hard Drives?

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• Intelligent Conflict Detection and Resolution

  - by Doug Reid

  0 false 18 pt 18 pt 0 0 false false false /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Conflict Detection and Resolution in Oracle GoldenGate11gR2 has gone through a significant overhaul. The improvements that have been made to this area are substantial and will make it easier for customers to implement complex, heterogeneous GoldenGate configurations. GoldenGate has provided methods for conflict detection and resolution for a number of past releases, but at Oracle we have the opportunity to take advantage of some of the great ideas in this area. Oracle has had feature rich conflict detection and resolution framework in other products, which has been implemented in Oracle GoldenGate 11gR2. These improvements are geared toward helping customers more easily implement advanced configurations that require conflict detection and resolution by providing a robust framework for conflict detection for all DML statements and resolution via pre-built methods, all with less code and simpler syntax than in prior releases. Conflict Detection and Resolution in Oracle GoldenGate 11gR2 is available for our supported heterogeneous platforms, which includes Oracle Database, MySQL, Sybase ASE, SQL Server, and DB2 Linux, Unix, Windows, z/OS, plus DB2 on i Series, which is newly supported in this release. Additional information on the Conflict Detection and Resolution capabilities can be found in our documentation. 

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• StyleCop 4.7.34.0 has been released

  - by TATWORTH

  StyleCop 4.7.34.0 was released, today, 6/July at http://stylecop.codeplex.com/releases/view/79972Compatible with the Visual Studio 2012 RC (11.0.50522).Install order should be : VS2008VS2010VS2012 RCR#6.1.1 (for VS2010)R#7.0 (tested with daily build 7.0.83.281) (down load from http://confluence.jetbrains.net/display/ReSharper/ReSharper+7+EAP)StyleCop This version is now compatible with R# 5.1 (5.1.3000.12), R# 6.0 (6.0.2202.688), R# 6.1 (6.1.37.86), R# 6.1.1 (6.1.1000.82) and R# 7.0 (7.0.83.281).Here are the bug details for fixed in 4.7 and closed in 4.7 issues (over 100 issues fixed since 4.6)Here are the bug details for all issues since 4.3.3.0 that have been fixed and closed (over 450 fixes).Updated Release Notes are available hereOnline Rules documentation is available hereFixes for this release are:Update ReSharper 7.0 references to 7.0.83.281Fix for 7343. Inheritdoc was raising false positives for some partial classes. Added regression test data.Fix for 7351. Remove the correct blank lines for SA1512 on code cleanup.Fix for 7346. Insert documentation fully on cleanup and on bulb items.Ensure that the SuppressMessage bulbItem can calculate the correct element to insert at.Fix for 7352. Module level suppressmessages were not working.Spelling mistake.Add missing typenames to resource file.Spelling fixes.Remove obsolete files.

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