Search Results

Search found 5015 results on 201 pages for 'compiler construction'.

Page 77/201 | < Previous Page | 73 74 75 76 77 78 79 80 81 82 83 84  | Next Page >

• Star Trek inspired home automation visualisation

  - by Zak McKracken

  I’ve always been a more or less active fan of Star Trek. During the construction phase of my house I started coding a GUI for controlling the house which has an EIB. Just for fun I designed a version inspired by the LCARS design used in Star Trek TNG and showed this to my wife. I showed her several designs before but this was the only one, she really liked. So I decided to go on with this. I started a C# WinForms application. The software runs on a wall mounted Shuttle Barebone-PC. First plan was an industrial panel-pc but the processor was too slow. The now-used Atom is ok. I started with the LCARS-controls found on Codeproject. Since the classic LCARS design divides the screen into two parts this tended to be impracticable, so I used my own design For now the software is able to: Switch lights/wall outlets Show current temperatures for all room controllers Show outside temperature with a 24h trend chart Show the status of the two heat pumps Provide an alarm clock (e.g. for cooking) Play internet radio streams Control absence Mute the door bell Speak status messages via speech synthesis For now, I’m working on an integration of my electric meter. The main heat pump and the electric meter are connected to my LAN. I also tried some speech recognition, but I’ve problems with the microphone. I't’s working when you are right in front of the PC, but not far away, let’s say on the other side of the room. So this is the main view. The table displays raw values which are sent over the EIB – completely useless but looks great For each floor I have a different view. Here you can see the temperatures and check the status of the lights (the buttons are blinking when a light is switched on) This is the view for the heat pump:   Next step would be to integrate a control of my squeezebox server (I use different Squeezeboxes through the house as a multiroom audio solution)

  Read the article

• Questioning the motivation for dependency injection: Why is creating an object graph hard?

  - by oberlies

  Dependency injection frameworks like Google Guice give the following motivation for their usage (source): To construct an object, you first build its dependencies. But to build each dependency, you need its dependencies, and so on. So when you build an object, you really need to build an object graph. Building object graphs by hand is labour intensive (...) and makes testing difficult. But I don't buy this argument: Even without dependency injection, I can write classes which are both easy to instantiate and convenient to test. E.g. the example from the Guice motivation page could be rewritten in the following way: class BillingService { private final CreditCardProcessor processor; private final TransactionLog transactionLog; // constructor for tests, taking all collaborators as parameters BillingService(CreditCardProcessor processor, TransactionLog transactionLog) { this.processor = processor; this.transactionLog = transactionLog; } // constructor for production, calling the (productive) constructors of the collaborators public BillingService() { this(new PaypalCreditCardProcessor(), new DatabaseTransactionLog()); } public Receipt chargeOrder(PizzaOrder order, CreditCard creditCard) { ... } } So dependency injection may really be an advantage in advanced use cases, but I don't need it for easy construction and testability, do I?

  Read the article

• Absence Management White Papers to Assist with your Implementations

  - by Carolyn Cozart

  Absence Management Setup – Additional Resources PeopleSoft is committed to helping our customers sharing our knowledge expertise in our applications. We have prepared a collection of documents (White Papers) containing examples, tips, and techniques to help you when making important decisions during your Absence Management implementation.   These documents can all be found on My Oracle Support. Absence Management Entitlement and Take Setup This document (Document ID 1493866.1) provides an overview of how to set up the main components of Absence Management, such as Absence Entitlement and Take elements, as well as other supporting elements relevant to your Absence Management implementation. Absence Management System Elements This document (Document ID 1493879.1) provides an overview of the system elements related to Absence Management. System elements are building blocks used during the design and construction of your Absence Rules. Knowing how they work and when to use them should help you expedite the implementation of your Absence Policy rules in your company Absence Management Self Service Setup This document (Document ID 1493867.1) provides an overview and guidance on some of the important areas when setting up Absence Self Service. Throughout this document we are providing examples of different configurations supported in Self Service. 

  Read the article

• ArchBeat Link-o-Rama for 2012-06-21

  - by Bob Rhubart

  Software Architects Need Not Apply | Dustin Marx "I think there is a place for software architecture," says Dustin Marx, "but a portion of our fellow software architects have harmed the reputation of the discipline." For another angle on this subject, check out Out of the Tower, Into the Trenches from the Nov/Dec edition of Oracle Magazine. Oracle Data Integrator 11g - Faster Files | David Allan David Allan illustrates "a big step for regular file processing on the way to super-charging big data files using Hadoop." 2012 Oracle Fusion Middleware Innovation Awards - Win a FREE Pass to Oracle OpenWorld 2012 in SF Share your use of Oracle Fusion Middleware solutions and how they help your organization drive business innovation. You just might win a free pass to Oracle Openworld 2012 in San Francisco. Deadline for submissions in July 17, 2012. WLST Domain creation using dry-run | Michel Schildmeijer What to do "if you want to browse through your domain to check if settings you want to apply satisfy your requirements." Cloud opens up new vistas for service orientation at Netflix | Joe McKendrick "Many see service oriented architecture as laying the groundwork for cloud. But at one well-known company, cloud has instigated the move to SOA." How to avoid the Portlet Skin mismatch | Martin Deh Detailed how-to from WebCenter A-Team blogger Martin Deh. Internationalize WebCenter Portal - Content Presenter | Stefan Krantz Stefan Krantz explains "how to get Content Presenter and its editorials to comply with the current selected locale for the WebCenter Portal session." Oracle Public Cloud Architecture | Tyler Jewell Tyler Jewell discusses the multi-tenancy model and elasticity solution implemented by Oracle Cloud in this QCon presentation. A Distributed Access Control Architecture for Cloud Computing The authors of this InfoQ article discuss a distributed architecture based on the principles from security management and software engineering. Thought for the Day "Let us change our traditional attitude to the construction of programs. Instead of imagining that our main task is to instruct a computer what to to, let us concentrate rather on explaining to human beings what we want a computer to do." — Donald Knuth Source: Quotes for Software Engineers

  Read the article

• Be There: Tinkerforge/NetBeans Platform Integration Course

  - by Geertjan

  Tinkerforge is an electronic construction kit. It exposes a number of API bindings, including, of course, Java. The nice thing also is that Tinkerforge products are open source, both on the hardware and software levels, so that you can take their bases as a starting point for your own modifications. "The TinkerForge system is a set of pre-built electronics boards that are built in such a way that you can stack the boards (known as bricks), attach accessories (known as bricklets), and have your prototype and and running quickly. Unlike systems, such as the Arduino or Launchpad, the TinkerForge has to be attached to a computer and the computer does all of the work. With an easy set of application programming interfaces (APIs) available in C/C++, C#, Java, PHP, and Ruby, the system is easy to interface and program over USB in a snap." (from this useful article) Henning Krüp, who has arranged several NetBeans Platform Certified Training Courses in the past, in the Nordhorn/Lingen area in Germany, had the inspired idea to focus the next course on integration with Tinkerforge. In other words, the whole course will be focused on creating a standalone Java desktop application that leverages the NetBeans Platform to interact with Tinkerforge! Interested in joining the course or setting up something similar yourself? The course organized by Henning will be held from 19 to 21 September, as explained here, together with contact details.  If you'd like to organize a similar course at a location of your choosing, leave a comment at the end of this blog entry and we'll set something up together!

  Read the article

• Very simple OOP question

  - by Mosty Mostacho

  I was creating and discussing a class diagram with a partner of mine. To simplify things, I've modify the real domain we're working on and made up the following diagram: Basically, a company works on constructions that are quite different one from each other but are still constructions. Note I've added one field for each class but there should be many more. Now, I thought this was the way to go but my partner told me that if in the future new construction classes appear we would have to modify the Company class, which is correct. So the new proposed class diagram would be this: Now I've been wondering: Should the fact that in no place of the application will there be mixed lists of planes and bridges affect the design in any way? When we have to list only planes for a company, how are we supposed to distinguish them from the other elements in the list without checking for their class names? Related to the previous question, is it correct to assume that this type of diagram should be high-level and this is something it shouldn't matter at this stage but rather be thought and decided at implementation time? Any comment will be appreciated.

  Read the article

• 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.

  Read the article

• How to create an extensible rope in Box2D?

  - by Thomas

  Let's say I'm trying to create a ninja lowering himself down a rope, or pulling himself back up, all whilst he might be swinging from side to side or hit by objects. Basically like http://ninja.frozenfractal.com/ but with Box2D instead of hacky JavaScript. Ideally I would like to use a rope joint in Box2D that allows me to change the length after construction. The standard Box2D RopeJoint doesn't offer that functionality. I've considered a PulleyJoint, connecting the other end of the "pulley" to an invisible kinematic body that I can control to change the length, but PulleyJoint is more like a rod than a rope: it constrains maximum length, but unlike RopeJoint it constrains the minimum as well. Re-creating a RopeJoint every frame using a new length is rather inefficient, and I'm not even sure it would work properly in the simulation. I could create a "chain" of bodies connected by RotationJoints but that is also less efficient, and less robust. I also wouldn't be able to change the length arbitrarily, but only by adding and removing a whole number of links, and it's not obvious how I would connect the remainder without violating existing joints. This sounds like something that should be straightforward to do. Am I overlooking something?

  Read the article

• My approach towards SEO implementation needs improvements. [closed]

  - by Eritrea

  I have always copy/paste this below code as a template for meta tags on project, but I think they are not effective as they could possible be. So, I need to know if there is anyway I can improve it. suppose I have a site called coop.com for a company called Coopm and we do import and export as a business in France. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html;charset=utf-8" /> <meta name="rpbots" content="index, follow" /> <meta name="description" content="ccop is a major import and export company" /> <meta name="keywords" content="coop, coop.com coop company, import export, import export france, " /> <meta name='REVISIT-AFTER' content='30 DAYS'> <title>coop is an import and export company located in France</title> </head> The reason I am asking, is because I want to know if there are better ways of constructing your SEO tags, and construction.

  Read the article

• Algorithm to infer tag hierarchy

  - by Tom

  I'm looking for an algorithm to infer a hierarchy from a set of tagged items. E.g. if the following items have the tags: 1 a 2 a,b 3 a,c 4 a,c,e 5 a,b 6 a,c 7 d 8 d,f Then I can construct an undirected graph (or graphs) by tallying the node weights and edge weights: node weights edge weights a 6 a-b 2 b 2 a-c 3 c 3 c-e 1 d 2 a-e 1 <-- this edge is parallel to a-c and c-e and not wanted e 1 d-f 1 f 1 The first problem is how to drop any redundant edges to get to the simplified graph? Note that it's only appropriate to remove that redundant a-e edge in this case because something is tagged as a-c-e, if that wasn't the case and the tag was a-e, that edge would have to remain. I suspect that means the removal of edges can only happen during the construction of the graph, not after everything has been tallied up. What I'd then like to do is identify the direction of the edges to create a directed graph (or graphs) and pick out root nodes to hopefully create a tree (or trees): trees a d // \\ | b c f \ e It seems like it could be a string algorithm - longest common subsequences/prefixes - or a tree/graph algorithm, but I am a little stuck since I don't know the correct terminology to search for it.

  Read the article

• Asynchrony in C# 5 (Part I)

  - by javarg

  I’ve been playing around with the new Async CTP preview available for download from Microsoft. It’s amazing how language trends are influencing the evolution of Microsoft’s developing platform. Much effort is being done at language level today than previous versions of .NET. In these post series I’ll review some major features contained in this release: Asynchronous functions TPL Dataflow Task based asynchronous Pattern Part I: Asynchronous Functions This is a mean of expressing asynchronous operations. This kind of functions must return void or Task/Task<> (functions returning void let us implement Fire & Forget asynchronous operations). The two new keywords introduced are async and await. async: marks a function as asynchronous, indicating that some part of its execution may take place some time later (after the method call has returned). Thus, all async functions must include some kind of asynchronous operations. This keyword on its own does not make a function asynchronous thought, its nature depends on its implementation. await: allows us to define operations inside a function that will be awaited for continuation (more on this later). Async function sample: Async/Await Sample async void ShowDateTimeAsync() {     while (true)     {         var client = new ServiceReference1.Service1Client();         var dt = await client.GetDateTimeTaskAsync();         Console.WriteLine("Current DateTime is: {0}", dt);         await TaskEx.Delay(1000);     } } The previous sample is a typical usage scenario for these new features. Suppose we query some external Web Service to get data (in this case the current DateTime) and we do so at regular intervals in order to refresh user’s UI. Note the async and await functions working together. The ShowDateTimeAsync method indicate its asynchronous nature to the caller using the keyword async (that it may complete after returning control to its caller). The await keyword indicates the flow control of the method will continue executing asynchronously after client.GetDateTimeTaskAsync returns. The latter is the most important thing to understand about the behavior of this method and how this actually works. The flow control of the method will be reconstructed after any asynchronous operation completes (specified with the keyword await). This reconstruction of flow control is the real magic behind the scene and it is done by C#/VB compilers. Note how we didn’t use any of the regular existing async patterns and we’ve defined the method very much like a synchronous one. Now, compare the following code snippet  in contrast to the previuous async/await: Traditional UI Async void ComplicatedShowDateTime() {     var client = new ServiceReference1.Service1Client();     client.GetDateTimeCompleted += (s, e) =>     {         Console.WriteLine("Current DateTime is: {0}", e.Result);         client.GetDateTimeAsync();     };     client.GetDateTimeAsync(); } The previous implementation is somehow similar to the first shown, but more complicated. Note how the while loop is implemented as a chained callback to the same method (client.GetDateTimeAsync) inside the event handler (please, do not do this in your own application, this is just an example).  How it works? Using an state workflow (or jump table actually), the compiler expands our code and create the necessary steps to execute it, resuming pending operations after any asynchronous one. The intention of the new Async/Await pattern is to let us think and code as we normally do when designing and algorithm. It also allows us to preserve the logical flow control of the program (without using any tricky coding patterns to accomplish this). The compiler will then create the necessary workflow to execute operations as the happen in time.

  Read the article

• What are the most commonly used and basic Apache htaccess redirects?

  - by bybe

  This question is here so we can offer users who are looking for information on how to make one or more common or basic redirects in Apache using the htaccess file. All future questions pertaining to finding information that is that is covered by the question should be closed as a duplication of this question. As per this Meta question. Whats the point in this question? The idea while not perfect is catch the most commonly asked questions regarding redirects using the htaccess on the Apache platform either on some type of lamp or a live server. The type of answers should be generally those that you could imagine are used by 100,000’s of sites world-wide and are constantly asked here at Pro Webmasters repeatedly over and over in various forms. A few examples of the type of answers we are looking for: How can I redirect non-www to www? How can I redirect a sub domain to the main domain? How can I redirect a sub folder from domain to a root or a subdomain? How can I redirect an old URL to a new URL? A few examples of the types of answers that we are not looking for: Answers that do not involve a redirect. Any answers relating to NGinx, IIS or any other non-Apache platform. Answers that involve custom and complex string or query removals. Resources for Advanced to Complex Mod_Rewrite Rules: Everything you ever wanted to know about mod rewrite rules but were afraid to ask Please note: that this question is still in construction and may need some refining either by myself or a real moderator of Pro Webmasters, if you have any concerns or questions please use the meta page I made a few days back here.

  Read the article

• Advantage of Software Development [on hold]

  - by user93319

  The worth of a brand that a corporation carries is way too high than its physical presence. If you are venturing into an online business, you need to take special care about the corporate image of your business. Nowadays, it is very important for every organization to have its own website. To enhance the online presence of a company it is important to have a good website design as well as the blueprint of the design. A quality site can enhance organizational growth and it can lend a hand an in achieving company’s goals promptly. When websites have gained so much meaning, it is advisable for an organization to seek professional support for the construction of its own exclusive portals. Expert help may again is essential when one needs for a complete renovation on the Web. Any group is necessary to do a bit of introspection before it make a decision to look for the services of a professional web software development company. It is good to be completely clear-headed regarding one’s requirements. To start with, a business should be familiar with who its potential clientele are. Once this main factor has been give consideration, an association can go ahead and get its website designed accordingly. On approaching a corporation that offers software development services India to its customers, a client can make sure that their site is ready with all the most up-to-date features. Professional Assistance Matters Professional service supplier is identified to furnish a site with easy to use features that prompt visitors to come back again and again. Yet one more benefit of receiving aid from professionals is that they can let you know of the type of content that you should place on display over your site. For example, a business that wants to draw the interest of experts belong to the corporate world must make sure that the language used on its website is crisp and official.

  Read the article

• How Security Products Are Made; An Interview with BitDefender

  - by Jason Fitzpatrick

  Most of us use anti-virus and malware scanners, without giving the processes behind their construction and deployment much of a thought. Get an inside look at security product development with this BitDefender interview. Over at 7Tutorials they took a trip to the home offices of BitDefender for an interview with Catalin Co?oi–seen here–BitDefender’s Chief Security Researcher. While it’s notably BitDefender-centric, it’s also an interesting look at the methodology employed by a company specializing in virus/malware protection. Here’s an excerpt from the discussion about data gathering techniques: Honeypots are systems we distributed across our network, that act as victims. Their role is to look like vulnerable targets, which have valuable data on them. We monitor these honeypots continuously and collect all kinds of malware and information about black hat activities. Another thing we do, is broadcast fake e-mail addresses that are automatically collected by spammers from the Internet. Then, they use these addresses to distribute spam, malware or phishing e-mails. We collect all the messages we receive on these addresses, analyze them and extract the required data to update our products and keep our users secure and spam free. Hit up the link below for the full interview. How To Properly Scan a Photograph (And Get An Even Better Image) The HTG Guide to Hiding Your Data in a TrueCrypt Hidden Volume Make Your Own Windows 8 Start Button with Zero Memory Usage

  Read the article

• PHP/MySQL Database application development tool

  - by RCH

  I am an amateur PHP coder, and have built a couple of dozen projects from scratch (including fairly simple e-commerce systems with user authentication, PayPal integration etc - all coded by hand from a clean page. Have also done a price comparison engine that takes data from multiple sites etc.). But I am no expert with OO and other such advanced techniques - I just have a fairly decent grasp of the basics of data processing, logic, functions and trying to optimize code as much as possible. I just want to make this clear so you have some idea of where I'm coming from. I have a couple of fairly large new projects on my plate for corporate clients - both require bespoke database-driven applications with complex relationships, many tables and lots of different front-end functions to manipulate that data for the internal staff in these companies. I figured building these systems from scratch would probably be a huge waste of time. Instead, there must be tools out there that will allow me to construct MySQL databases and build the pages with things like pagination, action buttons, table construction etc. Some kind of database abstraction layer, or system generator, if you will. What tool do you recommend for such a purpose for someone at my level? Open source would be great, but I don't mind paying for something decent as well. Thanks for any advice.

  Read the article

• Scaling along an arbitrary axis (Dealing with non-uniform scale)

  - by Jon

  I'm trying to build my own little engine to get more familiar with the concepts of 3D programming. I have a transform class that on each frame it creates a Scaling Matrix (S), a Rotation Matrix from a Quaternion (R) and concatenates them together (S*R). Once i have SR, I insert the translation values into the bottom of the three columns. So i end up with a transformation matrix that looks like: [SR SR SR 0] [SR SR SR 0] [SR SR SR 0] [tx ty tz 1] This works perfectly in all cases except when rotating an object that has a non-uniform scale. For example a unit cube with ScaleX = 4, ScaleY = 2, ScaleZ = 1 will give me a rectangular box that is 4 times as wide as the depth and twice as high as the depth. If i then translate this around, the box stays the same and looks normal. The problem happens whenever I try to rotate this scaled box. The shape itself becomes distorted and it appears as though the Scale factors are affecting the object on the World X,Y,Z axis rather than the local X,Y,Z axis of the object. I've done some pretty extensive research through a variety of textbooks (Eberly, Moller/Hoffman, Phar etc) and there isn't a ton there to go off of. Online, most of the answers say to avoid non-uniform scaling which I understand the desire to avoid it, but I'd still like to figure out how to support it. The only thing I can think off is that when constructing a Scale Matrix: [sx 0 0 0] [0 sy 0 0] [0 0 sz 0] [0 0 0 1] This is scaling along the World Axis instead of the object's local Direction, Up and Right vectors or it's local Z, Y, X axis. Does anyone have any tips or ideas on how to handle construction a transformation matrix that allows for non-uniform scaling and rotation? Thanks!

  Read the article

• What alternative is better to diagram this scenario?

  - by Mosty Mostacho

  I was creating and discussing a class diagram with a partner of mine. To simplify things, I've modify the real domain we're working on and made up the following diagram: Basically, a company works on constructions that are quite different one from each other but are still constructions. Note I've added one field for each class but there should be many more. Now, I thought this was the way to go but my partner told me that if in the future new construction classes appear we would have to modify the Company class, which is correct. So the new proposed class diagram would be this: Now I've been wondering: Should the fact that in no place of the application will there be mixed lists of planes and bridges affect the design in any way? When we have to list only planes for a company, how are we supposed to distinguish them from the other elements in the list without checking for their class names? Related to the previous question, is it correct to assume that this type of diagram should be high-level and this is something it shouldn't matter at this stage but rather be thought and decided at implementation time? Any comment will be appreciated.

  Read the article

• Can higher-order functions in FP be interpreted as some kind of dependency injection?

  - by Giorgio

  According to this article, in object-oriented programming / design dependency injection involves a dependent consumer, a declaration of a component's dependencies, defined as interface contracts, an injector that creates instances of classes that implement a given dependency interface on request. Let us now consider a higher-order function in a functional programming language, e.g. the Haskell function filter :: (a -> Bool) -> [a] -> [a] from Data.List. This function transforms a list into another list and, in order to perform its job, it uses (consumes) an external predicate function that must be provided by its caller, e.g. the expression filter (\x -> (mod x 2) == 0) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] selects all even numbers from the input list. But isn't this construction very similar to the pattern illustrated above, where the filter function is the dependent consumer, the signature (a -> Bool) of the function argument is the interface contract, the expression that uses the higher-order is the injector that, in this particular case, injects the implementation (\x -> (mod x 2) == 0) of the contract. More in general, can one relate higher-order functions and their usage pattern in functional programming to the dependency injection pattern in object-oriented languages? Or in the inverse direction, can dependency injection be compared to using some kind of higher-order function?

  Read the article

• Quickly ubuntu-application + indicator template don't work

  - by aliasbody

  I've started to work with quickly and python (because I wanted to have some GTk3 integration and create and appindicator), and so I create the projecto like this : quickly create ubuntu-application ualarm cd ualarm quickly run And the application launched. But then I tried to add the appindicator like this : quickly add indicator And since then the application doesn't start anymore and this error appear : aliasbody@BodyUbuntu-PC:~/Projectos/ualarm$ quickly run (ualarm:8515): Gtk-WARNING **: Theme parsing error: gnome-panel.css:28:11: Not using units is deprecated. Assuming 'px'. /usr/lib/python2.7/dist-packages/gi/overrides/Gtk.py:391: Warning: g_object_set_property: construct property "type" for object `Window' can't be set after construction Gtk.Window.__init__(self, type=type, **kwds) Traceback (most recent call last): File "bin/ualarm", line 33, in <module> ualarm.main() File "/home/aliasbody/Projectos/ualarm/ualarm/__init__.py", line 33, in main window = UalarmWindow.UalarmWindow() File "/home/aliasbody/Projectos/ualarm/ualarm_lib/Window.py", line 35, in __new__ new_object.finish_initializing(builder) File "/home/aliasbody/Projectos/ualarm/ualarm/UalarmWindow.py", line 24, in finish_initializing super(UalarmWindow, self).finish_initializing(builder) File "/home/aliasbody/Projectos/ualarm/ualarm_lib/Window.py", line 75, in finish_initializing self.indicator = indicator.new_application_indicator(self) File "/home/aliasbody/Projectos/ualarm/ualarm/indicator.py", line 52, in new_application_indicator ind = Indicator(window) File "/home/aliasbody/Projectos/ualarm/ualarm/indicator.py", line 20, in __init__ self.indicator = AppIndicator3.Indicator('ualarm', '', AppIndicator3.IndicatorCategory.APPLICATION_STATUS) TypeError: GObject.__init__() takes exactly 0 arguments (3 given) How can I solve this problem ?

  Read the article

• Serve my website from different server during downtime

  - by nfedyashev.mp

  I have a VPS server running in the cloud. Fully automated server image upgrade/downgrade(by RAM/HDD plans). The problem is that server upgrade/downgrade takes time and involves total unavailability during this period(up to 30 minutes). Goal: during this downtime server my website(http://mydomain.here) from different server with some message like "Under construction". How can I do this? -- mydomain.here is hosted on godaddy and uses its DNS(If I call it right). It's pointing with A-record to my VPS's IP address now. Change in these DNS settings will take more than 30minutes, so it's not an option. How can I find mode "dynamic" DNS? What should I learn?

  Read the article

• Advice on choosing a book to read

  - by Kioshiki

  I would like to ask for some recommendations on useful books to read. Initially I had intended on posting quite a long description of my current issue and asking for advice. But I realised that I didn’t have a clear idea of what I wanted to ask. One thing that is clear to me is that my knowledge in various areas needs improving and reading is one method of doing that. Though choosing the right book to read seems like a task in itself when there are so many books out there. I am a programmer but I also deal with analysis, design & testing. So I am not sure what type of book to read. One option might be to work through two books at the same time. I had thought maybe one about design or practices and another of a more technical focus. Recently I came across one book that I thought might be useful to read: http://xunitpatterns.com/index.html It seems like an interesting book, but the comments I read on amazon.co.uk show that the book is probably longer than it needs to be. Has anyone read it and can comment on this? Another book that I already own and would probably be a good one to finish reading is this: http://www.amazon.co.uk/Code-Complete-Practical-Handbook-Construction/dp/0735619670/ref=sr_1_1?ie=UTF8&qid=1309438553&sr=8-1 Has anyone else read this who can comment on its usefulness? Beyond these two I currently have no clear idea of what to read. I have thought about reading a book related to OO design or the GOF design patterns. But I wonder if I am worrying too much about the process and practices and not focusing on the actual work. I would be very grateful for any suggestions or comments. Many Thanks, Kioshiki

  Read the article

• The long road to bug-free software

  - by Tony Davis

  The past decade has seen a burgeoning interest in functional programming languages such as Haskell or, in the Microsoft world, F#. Though still on the periphery of mainstream programming, functional programming concepts are gradually seeping into the imperative C# language (for example, Lambda expressions have their root in functional programming). One of the more interesting concepts from functional programming languages is the use of formal methods, the lofty ideal behind which is bug-free software. The idea is that we write a specification that describes exactly how our function (say) should behave. We then prove that our function conforms to it, and in doing so have proved beyond any doubt that it is free from bugs. All programmers already use one form of specification, specifically their programming language's type system. If a value has a specific type then, in a type-safe language, the compiler guarantees that value cannot be an instance of a different type. Many extensions to existing type systems, such as generics in Java and .NET, extend the range of programs that can be type-checked. Unfortunately, type systems can only prevent some bugs. To take a classic problem of retrieving an index value from an array, since the type system doesn't specify the length of the array, the compiler has no way of knowing that a request for the "value of index 4" from an array of only two elements is "unsafe". We restore safety via exception handling, but the ideal type system will prevent us from doing anything that is unsafe in the first place and this is where we start to borrow ideas from a language such as Haskell, with its concept of "dependent types". If the type of an array includes its length, we can ensure that any index accesses into the array are valid. The problem is that we now need to carry around the length of arrays and the values of indices throughout our code so that it can be type-checked. In general, writing the specification to prove a positive property, even for a problem very amenable to specification, such as a simple sorting algorithm, turns out to be very hard and the specification will be different for every program. Extend this to writing a specification for, say, Microsoft Word and we can see that the specification would end up being no simpler, and therefore no less buggy, than the implementation. Fortunately, it is easier to write a specification that proves that a program doesn't have certain, specific and undesirable properties, such as infinite loops or accesses to the wrong bit of memory. If we can write the specifications to prove that a program is immune to such problems, we could reuse them in many places. The problem is the lack of specification "provers" that can do this without a lot of manual intervention (i.e. hints from the programmer). All this might feel a very long way off, but computing power and our understanding of the theory of "provers" advances quickly, and Microsoft is doing some of it already. Via their Terminator research project they have started to prove that their device drivers will always terminate, and in so doing have suddenly eliminated a vast range of possible bugs. This is a huge step forward from saying, "we've tested it lots and it seems fine". What do you think? What might be good targets for specification and verification? SQL could be one: the cost of a bug in SQL Server is quite high given how many important systems rely on it, so there's a good incentive to eliminate bugs, even at high initial cost. [Many thanks to Mike Williamson for guidance and useful conversations during the writing of this piece] Cheers, Tony.

  Read the article

• Live Webcast: Discover Primavera Unifier - December 5th

  - by Melissa Centurio Lopes

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* 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-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Join our live webcast to see what Primavera Unifier can do for you and your organization. We are very excited to introduce you to the newest addition to the Primavera product family, Primavera Unifier (formerly known as Skire Unifier). Attend this webcast and learn why this new cloud-based solution is the most comprehensive Enterprise Project Portfolio Management (EPPM) offering to manage the complete project lifecycle, from capital planning and construction to operations and maintenance. Save your seat: Register today for this online event and learn how the addition of Primavera Unifier can help your organization manage their projects and facilities with more predictability and financial control, improving profitability and operational efficiency

  Read the article

• Is there a common programming term for the problems of adding features to an already-featureful program?

  - by Jeremy Friesner

  I'm looking for a commonly used programming term to describe a software-engineering phenomenon, which (for lack of a better way to describe it) I'll illustrate first with a couple of examples-by-analogy: Scenario 1: We want to build/extend a subway system on the outskirts of a small town in Wyoming. There are the usual subway-problems to solve, of course (hiring the right construction company, choosing the best route, buying the subway cars), but other than that it's pretty straightforward to implement the system because there aren't a huge number of constraints to satisfy. Scenario 2: Same as above, except now we need to build/extend the subway system in downtown Los Angeles. Here we face all of the problems we did in case (1), but also additional problems -- most of the applicable space is already in use, and has a vocal constituency which will protest loudly if we inconvenience them by repurposing, redesigning, or otherwise modifying the infrastructure that they rely on. Because of this, extensions to the system happen either very slowly and expensively, or they don't happen at all. I sometimes see a similar pattern with software development -- adding a new feature to a small/simple program is straightforward, but as the program grows, adding further new features becomes more and more difficult, if only because it is difficult to integrate the new feature without adversely affecting any of the large number of existing use-cases or user-constituencies. (even with a robust, adaptable program design, you run into the problem of the user interface becoming so elaborate that the program becomes difficult to learn or use) Is there a term for this phenomenon?

  Read the article

• Resource Acquisition is Initialization in C#

  - by codeWithoutFear

  Resource Acquisition Is Initialization (RAII) is a pattern I grew to love when working in C++.  It is perfectly suited for resource management such as matching all those pesky new's and delete's.  One of my goals was to limit the explicit deallocation statements I had to write.  Often these statements became victims of run-time control flow changes (i.e. exceptions, unhappy path) or development-time code refactoring. The beauty of RAII is realized by tying your resource creation (acquisition) to the construction (initialization) of a class instance.  Then bind the resource deallocation to the destruction of that instance.  That is well and good in a language with strong destructor semantics like C++, but languages like C# that run on garbage-collecting runtimes don't provide the same instance lifetime guarantees. Here is a class and sample that combines a few features of C# to provide an RAII-like solution: using System; namespace RAII { public class DisposableDelegate : IDisposable { private Action dispose; public DisposableDelegate(Action dispose) { if (dispose == null) { throw new ArgumentNullException("dispose"); } this.dispose = dispose; } public void Dispose() { if (this.dispose != null) { Action d = this.dispose; this.dispose = null; d(); } } } class Program { static void Main(string[] args) { Console.Out.WriteLine("Some resource allocated here."); using (new DisposableDelegate(() => Console.Out.WriteLine("Resource deallocated here."))) { Console.Out.WriteLine("Resource used here."); throw new InvalidOperationException("Test for resource leaks."); } } } } The output of this program is: Some resource allocated here. Resource used here. Unhandled Exception: System.InvalidOperationException: Test for resource leaks. at RAII.Program.Main(String[] args) in c:\Dev\RAII\RAII\Program.cs:line 40 Resource deallocated here. Code without fear! --Don

  Read the article

< Previous Page | 73 74 75 76 77 78 79 80 81 82 83 84  | Next Page >