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• Au revoir, Python?

  - by GuySmiley

  I'm an ex-C++ programmer who's recently discovered (and fallen head-over-heels with) Python. I've taken some time to become reasonably fluent in Python, but I've encountered some troubling realities that may lead me to drop it as my language of choice, at least for the time being. I'm writing this in the hopes that someone out there can talk me out of it by convincing me that my concerns are easily circumvented within the bounds of the python universe. I picked up python while looking for a single flexible language that will allow me to build end-to-end working systems quickly on a variety of platforms. These include: - web services - mobile apps - cross-platform client apps for PC Development speed is more of a priority at the time-being than execution speed. However, in order to improve performance over time without requiring major re-writes or architectural changes I think it's imperative to be able to interface easily with Java. That way, I can use Java to optimize specific components as the application scales, without throwing away any code. As far as I can tell, my requirement for an enterprise-capable, platform-independent, fast language with a large developer base means it would have to be Java. .NET or C++ would not cut it due to their respective limitations. Also Java is clearly de rigeur for most mobile platforms. Unfortunately, tragically, there doesn't seem to be a good way to meet all these demands. Jython seems to be what I'm looking for in principle, except that it appears to be practically dead, with no one developing, supporting, or using it to any great degree. And also Jython seems too married to the Java libraries, as you can't use many of the CPython standard libraries with it, which has a major impact on the code you end up writing. The only other option that I can see is to use JPype wrapped in marshalling classes, which may work although it seems like a pain and I wonder if it would be worth it in the long run. On the other hand, everything I'm looking for seems to be readily available by using JRuby, which seems to be much better supported. As things stand, I think this is my best option. I'm sad about this because I absolutely love everything about Python, including the syntax. The perl-like constructs in Ruby just feel like such a step backwards to me in terms of readability, but at the end of the day most of the benefits of python are available in Ruby as well. So I ask you - am I missing something here? Much of what I've said is based on what I've read, so is this summary of the current landscape accurate, or is there some magical solution to the Python-Java divide that will snuff these concerns and allow me to comfortably stay in my happy Python place?

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• ArchBeat Link-o-Rama for 2012-06-22

  - by Bob Rhubart

  Guide to integration architecture | Stephanie Mann "The landscape of integration architecture is shifting as service-oriented and cloud-based architecture take the fore," says Stephanie Mann. "To ensure success, enterprise architects and developers are turning to lighter-weight infrastructure to support more complex integration projects." FY13 Oracle PartnerNetwork Kickoff - Tues June 26, 2012 Join us for a one-hour live online event hosted by the Oracle PartnerNetwork team as we kickoff FY13. Other dates/times for EMEA/LAD/JAPAN/APAC. Click the link for details. Why should you choose Oracle WebLogic 12c instead of JBoss EAP 6? | Ricardo Ferreira Okay, you would expect an Oracle guy to make this argument. But Ferreira takes a very deep, very detailed technical dive into the issue. So hear the man out, will ya? Hibernate4 and Coherence | Rene van Wijk According to Oracle ACE Rene van Wijk, "there are two ways to integrate Hibernate and Coherence." In this post he illustrates one of them. Simple Made Easy | Rich Hickey Rich Hickey discusses simplicity, why it is important, how to achieve it in design and how to recognize its absence in the tools, language constructs and libraries in this presentation from QCon London 2012. Starting a cluster | Mark Nelson Fusion Middleware A-Team blogger Mark Nelson looks at Oracle SOA Suite, Oracle BPM, and Oracle Coherence, three products that are " commonly clustered, and which have somewhat different requirements." Why building SaaS well means giving up your servers | GigaOM The biggest benefit to PaaS, reports GigaOM's Derrick Harris, "might be a better product because the company is able to focus on building the app rather than managing servers." Personas - what, why & how | Mascha van Oosterhout "To be able to create a successful, user-friendly website or application," says Mascha van Oosterhout, "every decision you take, whether you are part of the marketing team, the design team or the development team, should be based on what you know about the user." Thought for the Day "Machines take me by surprise with great frequency." — Alan Turing(June 23, 1912 - June 7, 1954) Source: Brainy Quote

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• Stagnating in programming

  - by Coder

  Time after time this question came up in my mind, but up until today I wasn't thinking about it much. I have been programming for maybe around 8 years now, and for the last two years it seems I'm not as keen to pick up new technologies anymore. Maybe that's a burnout or something, but I'd say it's experience and what I like, that's stopping me from running after the latest and greatest. I'm C++ developer, by this I mean, I love close to metal programming. I have no problems tracing problems through assembly, using tools like WinDbg or HexView. When I use constructs, I think about how they are realized underneath, how the bits are set and unset under the hood. I love battling with complex threading problems and doing everything hardcore way, even by hand if the regular solutions seem half baked. But I also love the C++0x stuff, and use it a lot. And all C++ code as long as it's not cumbersome compared to C counterparts, sometimes I also fall back to sort of "Super C" if the C++ way is ugly. And then there are all other developers who seem to be way more forward looking, .Net 4.0 MVC, WPF, all those Microsoft X#s, LINQ languages, XML and XSLT, mobile devices and so on. I have done a considerable amount of .NET, SQL, ASPX programming, but the further I go, the less I want to try those technologies. Is that bad? Almost every day I hear people saying that managed code is the only way forward, WPF is the way to go. I hear that C++ is godawful, and you can't code anything in it that's somewhat stable. But I don't buy it. With the experience I have, and the knowledge of how native code is compiled and executes, I can say I find it extremely rare that C++ code is unstable, or leaks, or causes crashes that takes more than 30 seconds to identify and fix. And to tell the truth, I've seen enough problems with other "cool" languages that I'd say C++ is even more stable and production proof than the safe languages, at least for me. The only thing that scares me in C++ is new frameworks, I don't trust them, and I use them extra sparingly. STL - yes, ATL - very sparingly, everything else... Well, not very keen on it. Most huge problems I've ran into, all were related to frameworks, not the language itself. Some overrided operator here, bad hierarchy there, poor class design here, mystical castings there. Other than that, C/C++ (yes, I use them together) still seems a very controlled and stable way to develop applications. Am I stagnating? Should I switch a profession, or force myself in all that marketing hype? Are there more developers who feel the same way?

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• SQL Server PowerShell Provider follows the Version of PowerShell on the Host and other errata

  - by BuckWoody

  There may be some misunderstanding on how the PowerShell Provider for SQL Server works. I’ve written an article or two explaining that you can use PowerShell with SQL Server, without having the SQL Server 2008 (or higher) provider around. After all, PowerShell just uses .NET, and SQL Server “Server Management Objects” or SMO listen to that interface as well. In SQL Server 2008 and higher we created a “MiniShell” for PowerShell that gives you the ability to treat a SQL Server Instance as a drive (called a “Provider” or path or drive) and a few commands (called command-lets). Using these two simple constructs you can move around SQL Server quickly and work with the objects it holds. I read the other day where someone stated that we had “re-compiled” PowerShell, so that you would have version 1.0 from SQL Server and 2.0 on your new server. Not so! Drop to a SQLPS prompt and a PowerShell prompt and type this in each: $PSVersionTable They should return the same value. You can think of a MiniShell as simply a compiled “profile” that gives you those providers and command-lets automatically – that’s all. In fact, you can load the SMO libraries yourself without the SQL Server 2008 Provider anywhere in sight. I do this all the time, since the MiniShell also has other restrictions. Also remember that if you run a PowerShell script as a SQL Agent Job step type (in 2008 and higher) that you’re running under the context of the account that starts Agent – I think most folks know this, but it’s good to keep in mind. There’s a re-written section of Books Online that goes over working with this very nicely – also covers the question “How to I connect to another server using the SQL Server PowerShell Provider” (hint: It’s just CD) and “How do I load all the SMO stuff if I don’t want to use the Provider” and more. Be sure and check out the note at the bottom that explains the firewall exceptions you’ll need to enable to CD to that remote server. Here’s that link: http://msdn.microsoft.com/en-us/library/cc281947.aspx Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Diving into Scala with Cay Horstmann

  - by Janice J. Heiss

  A new interview with Java Champion Cay Horstmann, now up on otn/java, titled  "Diving into Scala: A Conversation with Java Champion Cay Horstmann," explores Horstmann's ideas about Scala as reflected in his much lauded new book,  Scala for the Impatient.  None other than Martin Odersky, the inventor of Scala, called it "a joy to read" and the "best introduction to Scala". Odersky was so enthused by the book that he asked Horstmann if the first section could be made available as a free download on the Typesafe Website, something Horstmann graciously assented to. Horstmann acknowledges that some aspects of Scala are very complex, but he encourages developers to simply stay away from those parts of the language. He points to several ways Java developers can benefit from Scala: "For example," he says, " you can write classes with less boilerplate, file and XML handling is more concise, and you can replace tedious loops over collections with more elegant constructs. Typically, programmers at this level report that they write about half the number of lines of code in Scala that they would in Java, and that's nothing to sneeze at. Another entry point can be if you want to use a Scala-based framework such as Akka or Play; you can use these with Java, but the Scala API is more enjoyable. " Horstmann observes that developers can do fine with Scala without grasping the theory behind it. He argues that most of us learn best through examples and not through trying to comprehend abstract theories. He also believes that Scala is the most attractive choice for developers who want to move beyond Java and C++.  When asked about other choices, he comments: "Clojure is pretty nice, but I found its Lisp syntax a bit off-putting, and it seems very focused on software transactional memory, which isn't all that useful to me. And it's not statically typed. I wanted to like Groovy, but it really bothers me that the semantics seems under-defined and in flux. And it's not statically typed. Yes, there is Groovy++, but that's in even sketchier shape. There are a couple of contenders such as Kotlin and Ceylon, but so far they aren't real. So, if you want to do work with a statically typed language on the JVM that exists today, Scala is simply the pragmatic choice. It's a good thing that it's such a nice choice." Learn more about Scala by going to the interview here.

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• What are the arguments against parsing the Cthulhu way?

  - by smarmy53

  I have been assigned the task of implementing a Domain Specific Language for a tool that may become quite important for the company. The language is simple but not trivial, it already allows nested loops, string concatenation, etc. and it is practically sure that other constructs will be added as the project advances. I know by experience that writing a lexer/parser by hand -unless the grammar is trivial- is a time consuming and error prone process. So I was left with two options: a parser generator à la yacc or a combinator library like Parsec. The former was good as well but I picked the latter for various reasons, and implemented the solution in a functional language. The result is pretty spectacular to my eyes, the code is very concise, elegant and readable/fluent. I concede it may look a bit weird if you never programmed in anything other than java/c#, but then this would be true of anything not written in java/c#. At some point however, I've been literally attacked by a co-worker. After a quick glance at my screen he declared that the code is uncomprehensible and that I should not reinvent parsing but just use a stack and String.Split like everybody does. He made a lot of noise, and I could not convince him, partially because I've been taken by surprise and had no clear explanation, partially because his opinion was immutable (no pun intended). I even offered to explain him the language, but to no avail. I'm positive the discussion is going to re-surface in front of management, so I'm preparing some solid arguments. These are the first few reasons that come to my mind to avoid a String.Split-based solution: you need lot of ifs to handle special cases and things quickly spiral out of control lots of hardcoded array indexes makes maintenance painful extremely difficult to handle things like a function call as a method argument (ex. add( (add a, b), c) very difficult to provide meaningful error messages in case of syntax errors (very likely to happen) I'm all for simplicity, clarity and avoiding unnecessary smart-cryptic stuff, but I also believe it's a mistake to dumb down every part of the codebase so that even a burger flipper can understand it. It's the same argument I hear for not using interfaces, not adopting separation of concerns, copying-pasting code around, etc. A minimum of technical competence and willingness to learn is required to work on a software project after all. (I won't use this argument as it will probably sound offensive, and starting a war is not going to help anybody) What are your favorite arguments against parsing the Cthulhu way?* *of course if you can convince me he's right I'll be perfectly happy as well

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• Why CoffeeScript is tough to maintain

  - by Renso

  I recently started trying out CoffeeScript only to find out that it caused more headaches. The abstraction level of jQuery was perfect, it did not dictate to coders how to design their code, it just works. However, I recently posted a request to the CoffeeScript team to consider introducing curly braces to help with more complex code to control the flow of logic. For example a if-then-else with many nested levels can be near impossible to debug without tracing through it when using CoffeeScript. Also with IDEs like Visual Studio, regular JavaScript intellicense and auto-formatting make it easy to appropriate indent nested levels without any work on the part of the developer and reading it is not that hard, especially with some extensions that show vertical lines in the code editor to help see what is nested within what part of the code.However with CoffeeScript that is not the case. The samples given in the CoffeeScript web site are of course just simple examples to explain the features and one gets excited pretty quick over the powerful shortcuts. I tried to convert a piece of JavaScript over to CoffeeScript and gave up since you need to first of all remove ALL non CoffeeScript coding constructs for it to even compile. However js2coffee can help with that. However to keep track of nested levels became something that was simply not manageable using CoffeeScript.Furthermore, any coding language that controls the flow of logic by indentation is extremely dangerous for obvious reasons. I liked CoffeeScript a lot, but the fact that the logical flow of the code is controlled by how much you indent code, spaces or tabs, is not reliable as there is no way the programmer has an easy way of knowing what parts of the code will get hit when the code spans a page.When I suggested introducing curly braces in CoffeeScript the team, one contributor advised me that my code needs to be re-designed! Needless to say that is absurd. When I included a piece of the code he asked my if it was legacy code. It's like saying to a Java programmer, sorry you cannot use Java because we don't agree with how you write your code.jashkenas from the CoffeeScript blog gave some great suggestions and made the point that introducing curly braces would be very problematic for them as they use them to denote objects. Makes sense, but I would still love to see some way to replace code flow control with spaces and indentation to something more concrete and human readable.

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• Code Coverage for Maven Integrated in NetBeans IDE 7.2

  - by Geertjan

  In NetBeans IDE 7.2, JaCoCo is supported natively, i.e., out of the box, as a code coverage engine for Maven projects, since Cobertura does not work with JDK 7 language constructs. (Although, note that Cobertura is supported as well in NetBeans IDE 7.2.) It isn't part of NetBeans IDE 7.2 Beta, so don't even try there; you need some development build from after that. I downloaded the latest development build today. To enable JaCoCo features in NetBeans IDE, you need do no different to what you'd do when enabling JaCoCo in Maven itself, which is rather wonderful. In both cases, all you need to do is add this to the "plugins" section of your POM: <plugin> <groupId>org.jacoco</groupId> <artifactId>jacoco-maven-plugin</artifactId> <version>0.5.7.201204190339</version> <executions> <execution> <goals> <goal>prepare-agent</goal> </goals> </execution> <execution> <id>report</id> <phase>prepare-package</phase> <goals> <goal>report</goal> </goals> </execution> </executions> </plugin> Now you're done and ready to examine the code coverage of your tests, whether they are JUnit or TestNG. At this point, i.e., for no other reason than that you added the above snippet into your POM, you will have a new Code Coverage menu when you right-click on the project node: If you click Show Report above, the Code Coverage Report window opens. Here, once you've run your tests, you can actually see how many classes have been covered by your tests, which is pretty useful since 100% tests passing doesn't mean much when you've only tested one class, as you can see very graphically below: Then, when you click the bars in the Code Coverage Report window, the class under test is shown, with the methods for which tests exist highlighted in green and those that haven't been covered in red: (Note: Of course, striving for 100% code coverage is a bit nonsensical. For example, writing tests for your getters and setters may not be the most useful way to spend one's time. But being able to measure, and visualize, code coverage is certainly useful regardless of the percentage you're striving to achieve.) Best of all about all this is that everything you see above is available out of the box in NetBeans IDE 7.2. Take a look at what else NetBeans IDE 7.2 brings for the first time to the world of Maven: http://wiki.netbeans.org/NewAndNoteworthyNB72#Maven

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• Some More New ADF Features in JDeveloper 11.1.2

  - by Steven Davelaar

  The official list of new features in JDeveloper 11.1.2 is documented here. While playing with JDeveloper 11.1.2 and scanning the web user interface developer's guide for 11.1.2, I noticed some additional new features in ADF Faces, small but might come in handy:  You can use the af:formatString and af:formatNamed constructs in EL expressions to use substituation variables. For example: <af:outputText value="#{af:formatString('The current user is: {0}',someBean.currentUser)}"/> See section 3.5.2 in web user interface guide for more info. A new ADF Faces Client Behavior tag: af:checkUncommittedDataBehavior. See section 20.3 in web user interface guide for more info. For this tag to work, you also need to set the  uncommittedDataWarning  property on the af:document tag. And this property has quite some issues as you can read here. I did a quick test, the alert is shown for a button that is on the same page, however, if you have a menu in a shell page with dynamic regions, then clicking on another menu item does not raise the alert if you have pending changes in the currently displayed region. For now, the JHeadstart implementation of pending changes still seems the best choice (will blog about that soon). New properties on the af:document tag: smallIconSource creates a so-called favicon that is displayed in front of the URL in the browser address bar. The largeIconSource property specifies the icon used by a mobile device when bookmarking the page to the home page. See section 9.2.5 in web user interface guide for more info. Also notice the failedConnectionText property which I didn't know but was already available in JDeveloper 11.1.1.4. The af:showDetail tag has a new property handleDisclosure which you can set to client for faster rendering. In JDeveloper 11.1.1.x, an expression like #{bindings.JobId.inputValue} would return the internal list index number when JobId was a list binding. To get the actual JobId attribute value, you needed to use #{bindings.JobId.attributeValue}. In JDeveloper 11.1.2 this is no longer needed, the #{bindings.JobId.inputValue} expression will return the attribute value corresponding with the selected index in the choice list. Did you discover other "hidden" new features? Please add them as comment to this blog post so everybody can benefit. 

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• How to wrap console utils in webserver

  - by Alex Brown

  I have a big dataset (100Mbs/day) and a bunch of console a TCL/TK tools to view it - I want to turn it into a web app that I can build, and others can maintain. In long: my group runs simulations yielding 100s of Mbs of data daily, in multiple (mostly but not only) text forms. We have a bunch of scripts and tools, mostly old school 1990's style stuff requiring a 5-button mouse, as well as lots of ad-hoc scripts that engineers build out of frustration every month or so. These produces UIs, graphs, spreadsheets (various sizes), logs, event histories etc. I want to replace (or at least supplement) the xwindows / console style UI with a web-based one, so I need the following properties: pleasant to program can wrap existing command-line tools in separate views (I don't need to scrape GUIs or anything) as I port logic from the existing scripts I can create a modularised and pleasant codebase to replace it I can attach a web-ui to navigate between views - each view is likely to contain keys which might make sense to view in another I am new to building systems that have logic on the back-end and front-end of a web-server. from that point of view, they do this: backend wraps old-school executables, constructs calls into them and them takes the output and wraps it up, niceifies it and delivers it to the web client. For instance the tool might generate a number of indexed images (per invocation) which I might deliver all at once or on-demand. May (probably) need to to heavy stats on some sources. frontend provides navigation connecting multiple views, performs requests from one view for data from another (or self to self), etc. Probably will have some views with a lot of interactivity. Can people please point me towards viable solutions for this? I know it's a bit of an open question so as answers come in I hope to refine the spec until we have a good match. I guess I expect to see answers like "RoR!" "beans!" "Scala!" but please give an indication of why those are a good fit; I know nothing! I got bumped off SO for asking an open-ended question, so sorry if its OT here too (let me know). I take the policy that I use the best/closest matched language for a project but most of my team are extremely low level (ie pipeline stages and CDyn) so I don't have the peer group to know where to start.

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• Was I wrong about JavaScript?

  - by jboyer

  Yes, I was. Recently, I’ve taken a good hard look at JavaScript. I’ve used it before but mostly in the capacity of web design. Using JQuery to make your web page do cool stuff is different than really creating a JavaScript application using all of the language constructs. What I’m finding as I use it more is that I may have been wrong about my assumptions about it. Let me explain.   I enjoyed doing cool stuff with JQuery but the limited experience with JavaScript as a language coupled with the bad things that I heard about it led me to not have any real interest in it. However, JavaScript is ubiquitous on the web and if I want to do any web development, which I do, I need to learn it. So here I am, diving deep into the language with the help of the JavaScript Fundamentals training course at Pluralsight (great training for a low price) and the JavaScript: The Good Parts book by Douglas Crockford.   Now, there are certainly parts of JavaScript that are bad. I think these are well known by any developer that uses it. The parts that I feel are especially egregious are the following: The global object null vs. undefined truthy and falsy limited (nearly nonexistent) scoping ‘==’ and ‘===’ (I just don’t get the reason for coercion)   However, what I am finding hiding under the covers of the bad things is a good language. I am finding that I am legitimately enjoying JavaScript. This I was not expecting. I’m not going to go into a huge dissertation on what I like about it, but some things include: Object literal notation dynamic typing functional style (JavaScript: The Good Parts describes it as LISP in C clothing) JSON (better than XML) There are parts of JavaScript that seem strange to OOP developers like myself. However, just because it is different or seems strange does not mean it is bad. Some differences are quite interesting and useful.   I feel that it is important for developers to challenge their assumptions and also to be able to admit when they are wrong on a topic. Many different situations can arise that lead to this, such as choosing the wrong technology for a problem’s solution, misunderstanding the requirements, etc. I decided to challenge my assumptions about JavaScript instead of moving straight into CoffeeScript or Dart. After exploring it, I find that I am beginning to enjoy it the more I use it. As long as there are those like Crockford to help guide me in the right way to code in JavaScript, I can create elegant and efficient solutions to problems and add another ‘arrow’ to the ‘quiver’, so to speak. I do still intend to learn CoffeeScript to see what the hub-bub is about, but now I no longer have to be afraid of JavaScript as a legitimate programming language.   Has something similar ever happened to you? Tell me about it in the comments below.

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• Which programming language to get into?

  - by user602479

  I'm ending my third term in a few weeks so I have some spare time coming up. I'd like to spend it seriously digging into programming. My problem: I'm not sure which language to begin with. Just to be clear, I don't want to start a language-y-compared-to-language-z discussion. There are a some other issues that play a major role. In my 5th term I'm going to be participating in a major practical course which will include either Java or C programming. It will take a lot of time and energy, as I found out while talking to a few students who passed the final exams (only 15% pass on their first try). Which practical course I will take is randomly decided. My skills so far are the absolute basics of Java and C programming. I know the different data types and how to handle them, objects, pointers, thread programming, etc. All of that is on a very low level, though. My question now is, what language should I start seriously practicing? Java: I did my first GUIs with this language. I'm familiar with Eclipse but I need a project to work on (which I don't have) to really keep me pushing. Besides that, I don't think it would help me if I have to do C in a year. C: As with Java, I can't think of a personal project to keep me working and keep me interested in programming. If I get assigned to Java in a year, this wouldn't give me any advantages either, would it? (No objects, etc.) Objective-C: I recently came up with this idea. I have a Mac; I'm not really familiar with Xcode but I have one or two personal projects I'd like to work on. Further, I would be working with objects (as in Java) and C language constructs which would both be great for this practical course in a year. What do you think I should begin with? Should I just stick to Java and hope for the best, force myself through C or start (nearly) completely from the beginning with Objective C? Maybe you folks could give me some good advice that would stop me from switching from one language to the next?

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• Are closures with side-effects considered "functional style"?

  - by Giorgio

  Many modern programming languages support some concept of closure, i.e. of a piece of code (a block or a function) that Can be treated as a value, and therefore stored in a variable, passed around to different parts of the code, be defined in one part of a program and invoked in a totally different part of the same program. Can capture variables from the context in which it is defined, and access them when it is later invoked (possibly in a totally different context). Here is an example of a closure written in Scala: def filterList(xs: List[Int], lowerBound: Int): List[Int] = xs.filter(x => x >= lowerBound) The function literal x => x >= lowerBound contains the free variable lowerBound, which is closed (bound) by the argument of the function filterList that has the same name. The closure is passed to the library method filter, which can invoke it repeatedly as a normal function. I have been reading a lot of questions and answers on this site and, as far as I understand, the term closure is often automatically associated with functional programming and functional programming style. The definition of function programming on wikipedia reads: In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast to the imperative programming style, which emphasizes changes in state. and further on [...] in functional code, the output value of a function depends only on the arguments that are input to the function [...]. Eliminating side effects can make it much easier to understand and predict the behavior of a program, which is one of the key motivations for the development of functional programming. On the other hand, many closure constructs provided by programming languages allow a closure to capture non-local variables and change them when the closure is invoked, thus producing a side effect on the environment in which they were defined. In this case, closures implement the first idea of functional programming (functions are first-class entities that can be moved around like other values) but neglect the second idea (avoiding side-effects). Is this use of closures with side effects considered functional style or are closures considered a more general construct that can be used both for a functional and a non-functional programming style? Is there any literature on this topic? IMPORTANT NOTE I am not questioning the usefulness of side-effects or of having closures with side effects. Also, I am not interested in a discussion about the advantages / disadvantages of closures with or without side effects. I am only interested to know if using such closures is still considered functional style by the proponent of functional programming or if, on the contrary, their use is discouraged when using a functional style.

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• Oracle Linux Partner Pavilion Spotlight - Part II

  - by Ted Davis

  As we draw closer to the first day of Oracle OpenWorld, starting in less than a week, we continue to showcase some of our premier partners exhibiting in the Oracle Linux Partner Pavilion ( Booth #1033). We have Independent Hardware Vendors, Independent Software Vendors and Systems Integrators that show the breadth of support in the Oracle Linux and Oracle VM ecosystem. In today's post we highlight three additional Oracle Linux / Oracle VM Partners from the pavilion. Micro Focus delivers mainframe solutions software and software delivery tools with its Borland products. These tools are grouped under the following solutions: Analysis and testing tools for JDeveloper Micro Focus Enterprise Analyzer is key to the success of application overhaul and modernization strategies by ensuring that they are based on a solid knowledge foundation. It reveals the reality of enterprise application portfolios and the detailed constructs of business applications. COBOL for Oracle Database, Oracle Linux, and Tuxedo Micro Focus Visual COBOL delivers the next generation of COBOL development and deployment. Itbrings the productivity of the Eclipse IDE to COBOL, and provides the ability to deploy key business critical COBOL applications to Oracle Linux both natively and under a JVM. Migration and Modernization tooling for mainframes Enterprise application knowledge, development, test and workload re-hosting tools significantly improves the efficiency of business application delivery, enabling CIOs and IT leaders to modernize application portfolios and target platforms such as Oracle Linux. When it comes to Oracle Linux database environments, supporting high transaction rates with minimal response times is no longer just a goal. It’s a strategic imperative. The “data deluge” is impacting the ability of databases and other strategic applications to access data and provide real-time analytics and reporting. As such, customer demand for accelerated application performance is increasing. Visit LSI at the Oracle Linux Pavilion, #733, to find out how LSI Nytro Application Acceleration products are designed from the ground up for database acceleration. Our intelligent solid-state storage solutions help to eliminate I/O bottlenecks, increase throughput and enable Oracle customers achieve the highest levels of DB performance. Accelerate Your Exadata Success With Teleran. Teleran’s software solutions for Oracle Exadata and Oracle Database reduce the cost, time and effort of migrating and consolidating applications on Exadata. In addition Teleran delivers visibility and control solutions for BI/data warehouse performance and user management that ensure service levels and cost efficiency.Teleran will demonstrate these solutions at the Oracle Open World Linux Pavilion: Consolidation Accelerator - Reduces the cost, time and risk ofof migrating and consolidation applications on Exadata. Application Readiness – Identifies legacy application performance enhancements needed to take advantage of Exadata performance features Workload Accelerator – Identifies and clusters workloads for faster performance on Exadata Application Visibility and Control - Improves performance, user productivity, and alignment to business objectives while reducing support and resource costs. Thanks for reading today's Partner Spotlight. Three more partners will be highlighted tomorrow. If you missed our first Partner Spotlight check it out here.

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• Is there a factory pattern to prevent multiple instances for same object (instance that is Equal) good design?

  - by dsollen

  I have a number of objects storing state. There are essentially two types of fields. The ones that uniquely define what the object is (what node, what edge etc), and the others that store state describing how these things are connected (this node is connected to these edges, this edge is part of these paths) etc. My model is updating the state variables using package methods, so all these objects act as immutable to anyone not in Model scope. All Objects extend one base type. I've toyed with the idea of a Factory approach which accepts a Builder object and constructs the applicable object. However, if an instance of the object already exists (ie would return true if I created the object defined by the builder and passed it to the equal method for the existing instance) the factory returns the current object instead of creating a new instance. Because the Equal method would only compare what uniquely defines the type of object (this is node A to node B) but won't check the dynamic state stuff (node A is currently connected to nodes C and E) this would be a way of ensuring anyone that wants my Node A automatically knows its state connections. More importantly it would prevent aliasing nightmares of someone trying to pass an instance of node A with different state then the node A in my model has. I've never heard of this pattern before, and it's a bit odd. I would have to do some overriding of serialization methods to make it work (ensure that when I read in a serilized object I add it to my facotry list of known instances, and/or return an existing factory in its place), as well as using a weakHashMap as if it was a weakHashSet to know whether an instance exists without worrying about a quasi-memory leak occuring. I don't know if this is too confusing or prone to its own obscure bugs. One thing I know is that plugins interface with lowest level hardware. The plugins have to be able to return state that is different than my memory; to tell my memory when its own state is inconsistent. I believe this is possible despite their fetching objects that exist in my memory; we allow building of objects without checking their consistency with the model until the addToModel is called anyways; and the existing plugins design was written before all this extra state existed and worked fine without ever being aware of it. Should I just be using some other design to avoid this crazyness? (I have another question to that affect that I'm posting).

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• How Does EoR Design Work with Multi-tiered Data Center Topology

  - by S.C.

  I just did a ton of reading about the different multi-tier network topology options as outlined by Cisco, and now that I'm looking at the physical options (End of Row (EoR) vs Top of Rack(ToR)), I find myself confused about how these fit into the logical constructs. With ToR it also maps 1:1: at the top of each rack there is a switch(es) that essentially act as the access layer. They connect via fiber to other switches, maybe chassis-based, that act as the aggregation layer, that then connect to the core layer. With EoR it seems that the servers are connecting directly to the aggregation layer, skipping the access layer all together, by plugging directly into what are typically chassis switches. In EoR then is the standard 3-tier model now a 2-tier model: the servers go to the chassis switch which goes straight to the core switch? The reason it matters to me is that my understanding was that the 3-tier model was more desirable due to less complexity. The agg switch pair acts as default gateway and does routing; if you use up all of your ports in your agg layer pair it's much more complicated to add additional switches, than simply adding more switches at the access layer. Are there other downsides to this layout? Does this 3-tier architecture still apply in some way in EoR? Thanks.

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• Euro character messed up during FTP transfer

  - by djechelon

  My customer is using a very outdated ecommerce management system on my hosting service. For that product, no support is being provided anymore by the vendor. Brief explanation: the shop website, that claims to run under LAMP stack, is built by an old Visual Basic Windows application running on MS Access. The user constructs the shop, defines the HTML template, adds products and categories, etc. Then the VB exe builds the PHP pages (one for each template page) and the SQL script to run on MySQL. It also uploads everything via FTP and runs the installation/upgrade script on its own. The problem Browsing the website, many products' descriptions are cut before the euro sign. For example, what was supposed to be "Product price €1000" becomes "Product price" The analysis MySQL contains a cutted description until the € sign, so it's not PHP fault The Access databases contain full description with € sign, so it's not fault of the webmaster writing bad description or eDisplay cutting them The SQL that will run once the site gets uploaded, stored on my local machine before upload, contains the € sign The same script, after being FTPed by eDisplay and opened with nano from SSH, shows the € sign messed up like this: ^À vsftpd log reports (obfuscated for privacy) Sat Dec 15 11:16:57 2012 22 xxx.xxx.128.13 1112727 /srv/www/domains/xxxxxx.it/htdocs/db.sql b _ i r xxxxxxx ftp 0 * c which seems to be a binary transfer (and also a huge security vulnerability because you can download the whole database from unauthenticated HTTP) The eDisplay internal FTP client provides no option for ascii/binary transfer modes [Add] Trying to manually upload the SQL file via SFTP shows messing up euro [Add2] Trying to manually upload using Xftp client with explicit ASCII mode doesn't fix too It looks like the file gets uploaded as binary. Perhaps on the customer's previous host it all worked fine because that was a Windows host. The server It's an Azure virtual machine running openSUSE 12.2 with both vsftpd and openSSH The question Without asking the customer to manually upload files using FileZilla or replacing € with &euro;, because he refuses, what can I do on server side to prevent vsftpd to screw up euro sign?

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• The Evolution Of C#

  - by Paulo Morgado

  The first release of C# (C# 1.0) was all about building a new language for managed code that appealed, mostly, to C++ and Java programmers. The second release (C# 2.0) was mostly about adding what wasn’t time to built into the 1.0 release. The main feature for this release was Generics. The third release (C# 3.0) was all about reducing the impedance mismatch between general purpose programming languages and databases. To achieve this goal, several functional programming features were added to the language and LINQ was born. Going forward, new trends are showing up in the industry and modern programming languages need to be more: Declarative With imperative languages, although having the eye on the what, programs need to focus on the how. This leads to over specification of the solution to the problem in hand, making next to impossible to the execution engine to be smart about the execution of the program and optimize it to run it more efficiently (given the hardware available, for example). Declarative languages, on the other hand, focus only on the what and leave the how to the execution engine. LINQ made C# more declarative by using higher level constructs like orderby and group by that give the execution engine a much better chance of optimizing the execution (by parallelizing it, for example). Concurrent Concurrency is hard and needs to be thought about and it’s very hard to shoehorn it into a programming language. Parallel.For (from the parallel extensions) looks like a parallel for because enough expressiveness has been built into C# 3.0 to allow this without having to commit to specific language syntax. Dynamic There was been lots of debate on which ones are the better programming languages: static or dynamic. The fact is that both have good qualities and users of both types of languages want to have it all. All these trends require a paradigm switch. C# is, in many ways, already a multi-paradigm language. It’s still very object oriented (class oriented as some might say) but it can be argued that C# 3.0 has become a functional programming language because it has all the cornerstones of what a functional programming language needs. Moving forward, will have even more. Besides the influence of these trends, there was a decision of co-evolution of the C# and Visual Basic programming languages. Since its inception, there was been some effort to position C# and Visual Basic against each other and to try to explain what should be done with each language or what kind of programmers use one or the other. Each language should be chosen based on the past experience and familiarity of the developer/team/project/company and not by particular features. In the past, every time a feature was added to one language, the users of the other wanted that feature too. Going forward, when a feature is added to one language, the other will work hard to add the same feature. This doesn’t mean that XML literals will be added to C# (because almost the same can be achieved with LINQ To XML), but Visual Basic will have auto-implemented properties. Most of these features require or are built on top of features of the .NET Framework and, the focus for C# 4.0 was on dynamic programming. Not just dynamic types but being able to talk with anything that isn’t a .NET class. Also introduced in C# 4.0 is co-variance and contra-variance for generic interfaces and delegates. Stay tuned for more on the new C# 4.0 features.

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• Code is not the best way to draw

  - by Bertrand Le Roy

  It should be quite obvious: drawing requires constant visual feedback. Why is it then that we still draw with code in so many situations? Of course it’s because the low-level APIs always come first, and design tools are built after and on top of those. Existing design tools also don’t typically include complex UI elements such as buttons. When we launched our Touch Display module for Netduino Go!, we naturally built APIs that made it easy to draw on the screen from code, but very soon, we felt the limitations and tedium of drawing in code. In particular, any modification requires a modification of the code, followed by compilation and deployment. When trying to set-up buttons at pixel precision, the process is not optimal. On the other hand, code is irreplaceable as a way to automate repetitive tasks. While tools like Illustrator have ways to repeat graphical elements, they do so in a way that is a little alien and counter-intuitive to my developer mind. From these reflections, I knew that I wanted a design tool that would be structurally code-centric but that would still enable immediate feedback and mouse adjustments. While thinking about the best way to achieve this goal, I saw this fantastic video by Bret Victor: The key to the magic in all these demos is permanent execution of the code being edited. Whenever a parameter is being modified, everything is re-executed immediately so that the impact of the modification is instantaneously visible. If you do this all the time, the code and the result of its execution fuse in the mind of the user into dual representations of a single object. All mental barriers disappear. It’s like magic. The tool I built, Nutshell, is just another implementation of this principle. It manipulates a list of graphical operations on the screen. Each operation has a nice editor, and translates into a bit of code. Any modification to the parameters of the operation will modify the bit of generated code and trigger a re-execution of the whole program. This happens so fast that it feels like the drawing reacts instantaneously to all changes. The order of the operations is also the order in which the code gets executed. So if you want to bring objects to the front, move them down in the list, and up if you want to move them to the back: But where it gets really fun is when you start applying code constructs such as loops to the design tool. The elements that you put inside of a loop can use the loop counter in expressions, enabling crazy scenarios while retaining the real-time edition features. When you’re done building, you can just deploy the code to the device and see it run in its native environment: This works thanks to two code generators. The first code generator is building JavaScript that is executed in the browser to build the canvas view in the web page hosting the tool. The second code generator is building the C# code that will run on the Netduino Go! microcontroller and that will drive the display module. The possibilities are fascinating, even if you don’t care about driving small touch screens from microcontrollers: it is now possible, within a reasonable budget, to build specialized design tools for very vertical applications. Direct feedback is a powerful ally in many domains. Code generation driven by visual designers has become more approachable than ever thanks to extraordinary JavaScript libraries and to the powerful development platform that modern browsers provide. I encourage you to tinker with Nutshell and let it open your eyes to new possibilities that you may not have considered before. It’s open source. And of course, my company, Nwazet, can help you develop your own custom browser-based direct feedback design tools. This is real visual programming…

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• F# in ASP.NET, mathematics and testing

  - by DigiMortal

  Starting from Visual Studio 2010 F# is full member of .NET Framework languages family. It is functional language with syntax specific to functional languages but I think it is time for us also notice and study functional languages. In this posting I will show you some examples about cool things other people have done using F#. F# and ASP.NET As I am ASP/ASP.NET MVP I am – of course – interested in how people use different languages and technologies with ASP.NET. C# MVP Tomáš Petrícek writes about developing ASP.NET MVC applications using F#. He also shows how to use LINQ To SQL in F# (using F# PowerPack) and provides sample solution and Visual Studio 2010 template for F# MVC web applications. You may also find interesting how you can create controllers in F#. Excellent work, Tomáš! Vladimir Matveev has interesting example about how to use F# and ApplicationHost class to process ASP.NET requests ouside of IIS. This is simple and very straight-forward example and I strongly suggest you to take a look at it. Very cool example is project Strom in Codeplex. Storm is web services testing tool that is fully written on F#. Take a look at this site because Codeplex offers also source code besides binaries. Math Functional languages are strong in fields like mathematics and physics. When I wrote my C# example about BigInteger class I found out that recursive version of Fibonacci algorithm in C# is not performing well. In same time I made same experiment on F# and in F# there were no performance problems with recursive version. You can find F# version of Fibonacci algorithm from Bob Palmer’s blog posting Fibonacci numbers in F#. Although golden spiral is useful for solving many problems I looked for some practical code example and found one. Kean Walmsley published in his Through the Interface blog very interesting posting Creating Fibonacci spirals in AutoCAD using F#. There are also other cool examples you may be interested in. Using numerical components by Extreme Optimization  it is possible to make some numerical integration (quadrature method) using F# (also C# example is available). fsharp.it introduces factorials calculation on F#. Robert Pickering has made very good work on programming The Game of Life in Silverlight and F# – I definitely suggest you to try out this example as it is very illustrative too. Who wants something more complex may take a look at Newton basin fractal example in F# by Jonathan Birge. Testing After some searching and surfing I found out that there is almost everything available for F# to write tests and test your F# code. FsCheck - FsCheck is a port of Haskell's QuickCheck. Important parts of the manual for using FsCheck is almost literally "adapted" from the QuickCheck manual and paper. Any errors and omissions are entirely my responsibility. FsTest - This project is designed to Language Oriented Programming constructs around unit testing and behavior testing in F#. The goal of this project is to create a Domain Specific Language for testing F# code in a way that makes sense for functional programming. FsUnit - FsUnit makes unit-testing with F# more enjoyable. It adds a special syntax to your favorite .NET testing framework. xUnit.NET - xUnit.net is a developer testing framework, built to support Test Driven Development, with a design goal of extreme simplicity and alignment with framework features. It is compatible with .NET Framework 2.0 and later, and offers several runners: console, GUI, MSBuild, and Visual Studio integration via TestDriven.net, CodeRush Test Runner and Resharper. It also offers test project integration for ASP.NET MVC. Getting started Well, as a first thing you need Visual Studio 2010. Then take a look at these resources: F# samples @ MSDN Microsoft F# Developer Center @ MSDN F# Language Reference @ MSDN F# blog F# forums Real World Functional Programming: With Examples in F# and C# (Amazon) Happy F#-ing! :)

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• Java EE 6 Pocket Guide from O'Reilly - Now Available in Paperback and Kindle Edition

  - by arungupta

  Hot off the press ... Java EE 6 Pocket Guide from 'OReilly Media is now available in Paperback and Kindle Edition. Here are the book details: Release Date: Sep 21, 2012 Language: English Pages: 208 Print ISBN: 978-1-4493-3668-4 | ISBN 10:1-4493-3668-X Ebook ISBN:978-1-4493-3667-7 | ISBN 10:1-4493-3667-1 The book provides a comprehensive summary of the Java EE 6 platform. Main features of different technologies from the platform are explained and accompanied by tons of samples. A chapter is dedicated to Managed Beans, Servlets, Java Persistence API, Enterprise JavaBeans, Contexts and Dependency Injection, JavaServer Faces, SOAP-Based Web Services, RESTful Web Services, Java Message Service, and Bean Validation in that format. Many thanks to Markus Eisele, John Yeary, and Bert Ertman for reviewing and providing valuable comments. This book was not possible without their extensive feedback! This book was mostly written by compiling my blogs, material from 2-day workshops, and several hands-on workshops around the world. The interactions with users of different technologies and whiteboard discussions with different specification leads helped me understand the technology better. Many thanks to them for helping me be a better user! The long international flights during my travel around the world proved extremely useful for authoring the content. No phone, no email, no IM, food served on the table, power outlet = a perfect recipe for authoring ;-) Markus wrote a detailed review of the book. He was one of the manuscript reviewers of the book as well and provided valuable guidance. Some excerpts from his blog: It covers the basics you need to know of Java EE 6 and gives good examples of all relevant parts. ... This is a pocket guide which is comprehensively written. I could follow all examples and it was a good read overall. No complicated constructs and clear writing. ... GO GET IT! It is the only book you probably will need about Java EE 6! It is comprehensive, wonderfully written and covers everything you need in your daily work. It is not a complete reference but provides a great shortcut to the things you need to know. To me it is a good beginners guide and also works as a companion for advanced users. Here is the first tweet feedback ... Jeff West was super prompt to place the first pre-order of my book, pretty much the hour it was announced. Thank you Jeff! @mike_neck posted the very first tweet about the book, thanks for that! The book is now available in Paperback and Kindle Edition from the following websites: O'Reilly Media (Ebook, Print & Ebook, Print) Amazon.com (Kindle Edition and Paperback) Barnes and Noble Overstock (1% off Amazon) Buy.com Booktopia.com Tower Books Angus & Robertson Shopping.com Here is how I can use your help: Help spread the word about the book If you bought a Paperback or downloaded Kindle Edition, then post your review here. If you have not bought, then you can buy it at amazon.com and multiple other websites mentioned above. If you are coming to JavaOne, you'll have an opportunity to get a free copy at O'Reilly's booth on Monday (October 1) from 2-3pm. And you can always buy it from the JavaOne Bookstore. I hope you enjoy reading it and learn something new from it or hone your existing skills. As always, looking forward to your feedback!

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• I love it when a plan comes together

  - by DavidWimbush

  I'm currently working on an application so that our Marketing department can produce most of their own mailing lists without my having to get involved. It was all going well until I got stuck on the bit where the actual SQL query is generated but a rummage in Books Online revealed a very clean solution using some constructs that I had previously dismissed as pointless. Typically we want to email every customer who is in any of the following n groups. Experience shows that a group has the following definition: <people who have done A> [(AND <people who have done B>) | (OR <people who have done C>)] [APART FROM <people who have done D>] When doing these by hand I've been using INNER JOIN for the AND, UNION for the OR, and LEFT JOIN + WHERE D IS NULL for the APART FROM. This would produce two quite different queries: -- Old OR select  A.PersonID from  (   -- A   select  PersonID   from  ...   union  -- OR   -- C   select  PersonID   from  ...   ) AorC   left join  -- APART FROM   (   select  PersonID   from  ...   ) D on D.PersonID = AorC.PersonID where  D.PersonID is null -- Old AND select  distinct main.PersonID from  (   -- A   select  PersonID   from  ...   ) A   inner join  -- AND   (   -- B   select  PersonID   from  ...   ) B on B.PersonID = A.PersonID   left join  -- APART FROM   (   select  PersonID   from  ...   ) D on D.PersonID = A.PersonID where  D.PersonID is null But when I tried to write the code that can generate the SQL for any combination of those (along with all the variables controlling what each SELECT did and what was in all the optional bits of each WHERE clause) my brain started to hurt. Then I remembered reading about the (then new to me) keywords INTERSECT and EXCEPT. At the time I couldn't see what they added but I thought I would have a play and see if they might help. They were perfect for this. Here's the new query structure: -- The way forward select  PersonID from  (     (       (       -- A       select  PersonID       from  ...       )       union      -- OR        intersect  -- AND       (       -- B/C       select  PersonID       from  ...       )     )     except     (     -- D     select  PersonID     from  ...     )   ) x I can easily swap between between UNION and INTERSECT, and omit B, C, or D as necessary. Elegant, clean and readable - pick any 3! Sometimes it really pays to read the manual.

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• Visual Studio 2010 Best Practices

  - by Etienne Tremblay

  I’d like to thank Packt for providing me with a review version of Visual Studio 2010 Best Practices eBook. In fairness I also know the author Peter having seen him speak at DevTeach on many occasions.  I started by looking at the table of content to see what this book was about, knowing that “best practices” is a real misnomer I wanted to see what they were.  I really like the fact that he starts the book by really saying they are not really best practices but actually recommend practices.  As a Team Foundation Server user I found that chapter 2 was more for the open source crowd and I really skimmed it.  The portion on Branching was well documented, although I’m not a fan of the testing branch myself, but the rest was right on. The section on merge remote changes (bring the outside to you) paradigm is really important and was touched on. Chapter 3 has good solid practices on low level constructs like generics and exceptions. Chapter 4 dives into architectural practices like decoupling, distributed architecture and data based architecture.  DTOs and ORMs are touched on briefly as is NoSQL. Chapter 5 is about deployment and is really a great primer on all the “packaging” technologies like Visual Studio Setup and Deployment (depreciated in 2012), Click Once and WIX the major player outside of commercial solutions.  This is a nice section on how to move from VSSD to WIX this is going to be important in the coming years due to the fact that VS 2012 doesn’t support VSSD. In chapter 6 we dive into automated testing practices, including test coverage, mocking, TDD, SpecDD and Continuous Testing.  Peter covers all those concepts really nicely albeit succinctly. Being a book on recommended practices I find this is really good. I really enjoyed chapter 7 that gave me a lot of great tips to enhance my Visual Studio “experience”.  Tips on organizing projects where good.  Also even though I knew about configurations I like that he put that in there so you can move all your settings to another machine, a lot of people don’t know about that. Quick find and Resharper are also briefly covered.  He touches on macros (depreciated in 2012).  Finally he touches on Continuous Integration a very important concept in today’s ALM landscape. Chapter 8 is all about Parallelization, threads, Async, division of labor, reactive extensions.  All those concepts are touched on and again generalized approaches to those modern problems are giving.       Chapter 9 goes into distributed apps, the most used and accepted practice in the industry for .NET projects the chapter tackles concepts like Scalability, Messaging and Cloud (the flavor of the month of distributed apps, although I think this will stick ;-)).  He also looks a protocols TCP/UDP and how to debug distributed apps.  He touches on logging and health monitoring. Chapter 10 tackles recommended practices for web services starting with implementing WCF services, which goes into all sort of goodness like how to host in IIS or self-host.  How to manual test WCF services, also a section on authentication and authorization.  ASP.NET Web services are also touched on in that chapter All in all a good read, nice tips and accepted practices.  I like the conciseness of the subjects and Peter touches on a lot of things in this book and uses a lot of the current technologies flavors to explain the concepts.   Cheers, ET

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• Indexing data from multiple tables with Oracle Text

  - by Roger Ford

  It's well known that Oracle Text indexes perform best when all the data to be indexed is combined into a single index. The query select * from mytable where contains (title, 'dog') 0 or contains (body, 'cat') 0 will tend to perform much worse than select * from mytable where contains (text, 'dog WITHIN title OR cat WITHIN body') 0 For this reason, Oracle Text provides the MULTI_COLUMN_DATASTORE which will combine data from multiple columns into a single index. Effectively, it constructs a "virtual document" at indexing time, which might look something like: <title>the big dog</title> <body>the ginger cat smiles</body> This virtual document can be indexed using either AUTO_SECTION_GROUP, or by explicitly defining sections for title and body, allowing the query as expressed above. Note that we've used a column called "text" - this might have been a dummy column added to the table simply to allow us to create an index on it - or we could created the index on either of the "real" columns - title or body. It should be noted that MULTI_COLUMN_DATASTORE doesn't automatically handle updates to columns used by it - if you create the index on the column text, but specify that columns title and body are to be indexed, you will need to arrange triggers such that the text column is updated whenever title or body are altered. That works fine for single tables. But what if we actually want to combine data from multiple tables? In that case there are two approaches which work well: Create a real table which contains a summary of the information, and create the index on that using the MULTI_COLUMN_DATASTORE. This is simple, and effective, but it does use a lot of disk space as the information to be indexed has to be duplicated. Create our own "virtual" documents using the USER_DATASTORE. The user datastore allows us to specify a PL/SQL procedure which will be used to fetch the data to be indexed, returned in a CLOB, or occasionally in a BLOB or VARCHAR2. This PL/SQL procedure is called once for each row in the table to be indexed, and is passed the ROWID value of the current row being indexed. The actual contents of the procedure is entirely up to the owner, but it is normal to fetch data from one or more columns from database tables. In both cases, we still need to take care of updates - making sure that we have all the triggers necessary to update the indexed column (and, in case 1, the summary table) whenever any of the data to be indexed gets changed. I've written full examples of both these techniques, as SQL scripts to be run in the SQL*Plus tool. You will need to run them as a user who has CTXAPP role and CREATE DIRECTORY privilege. Part of the data to be indexed is a Microsoft Word file called "1.doc". You should create this file in Word, preferably containing the single line of text: "test document". This file can be saved anywhere, but the SQL scripts need to be changed so that the "create or replace directory" command refers to the right location. In the example, I've used C:\doc. multi_table_indexing_1.sql : creates a summary table containing all the data, and uses multi_column_datastore Download link / View in browser multi_table_indexing_2.sql : creates "virtual" documents using a procedure as a user_datastore Download link / View in browser

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• Programmatically creating scrollview(s) from custom component in android

  - by jaapbeetstra

  I'm trying to build a compound control in Android, containing (among other things) a ScrollView. Things go wrong when I try to view the control in Eclipse, crashing with a NullPointerException after the error message: "Parser is not a BridgeXmlBlockParser". Stacktrace: java.lang.NullPointerException at android.view.View.<init>(View.java:1720) at android.view.ViewGroup.<init>(ViewGroup.java:277) at android.widget.FrameLayout.<init>(FrameLayout.java:83) at android.widget.ScrollView.<init>(ScrollView.java:128) at android.widget.ScrollView.<init>(ScrollView.java:124) at android.widget.ScrollView.<init>(ScrollView.java:120) at my.compound.control.StringPicker.onMeasure(StringPicker.java:46) ... I've traced the error to the following conditions: The NPE is thrown because a Context.obtainStyledAttributes() call returns null when the attrs argument passed is null. This only applies to the BridgeContext implementation used in Eclipse, which expects attrs to be an instance of the BridgeXmlBlockParser. The attrs argument is null because I create the ScrollView using the (Context) constructor. There is a workaround of course, which is passing the attrs I receive when Eclipse constructs the compound control, but I don't want all the attributes set on the compound control to apply to my inner control. Am I doing something wrong, is this a bug in Android Eclipse, ...?

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