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• Should a new language compiler target the JVM?

  - by Pindatjuh

  I'm developing a new language. My initial target was to compile to native x86 for the Windows platform, but now I am in doubt. I've seen some new languages target the JVM (most notable Scala and Clojure). Ofcourse it's not possible to port every language easily to the JVM; to do so, it may lead to small changes to the language and it's design. So that's the reason behind this doubt, and thus this question: Is targetting the JVM a good idea, when creating a compiler for a new language? Or should I stick with x86? I have experience in generating JVM bytecode. Are there any workarounds to JVM's GC? The language has deterministic implicit memory management. How to produce JIT-compatible bytecode, such that it will get the highest speedup? Is it similar to compiling for IA-32, such as the 4-1-1 muops pattern on Pentium? I can imagine some advantages (please correct me if I'm wrong): JVM bytecode is easier than x86. Like x86 communicates with Windows, JVM communicates with the Java Foundation Classes. To provide I/O, Threading, GUI, etc. Implementing "lightweight"-threads.I've seen a very clever implementation of this at http://www.malhar.net/sriram/kilim/. Most advantages of the Java Runtime (portability, etc.) The disadvantages, as I imagined, are: Less freedom? On x86 it'll be more easy to create low-level constructs, while JVM has a higher level (more abstract) processor. Most disadvantages of the Java Runtime (no native dynamic typing, etc.)

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• Approach for fixing NoClassDefFoundError?

  - by DJC

  I'm seeing this question is getting asked a lot in many different contexts. Perhaps we can set some strategies for locating and fixing it? I'm noobish myself so all I can contribute are horror stories and questions, sorry... It seems this is thrown when a class is visible at compile time but not at run time... how can this happen? In my case I am developing an app that uses the Google APIs, in Eclipse, for the Android platform. I've configured the Project Properties / Java Build Path / Libraries to include the gdata .jars and all is well. When I execute in the emulator I get a force close and the logcat shows a NoClassDefFoundError on a simple new ContactsService("myApp"); I've also tried a new CalendarService("myApp") with the same results. Is it possible or desirable to statically bind at compile time to avoid the problem? How could dynamic binding of an add-on library work in the mobile environment anyway? Either it has to be bound into my .apk or else I need to "install" it? ... hmmm. Advice much appreciated.

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• Passing a var as an argument

  - by Lienau

  On a site I'm making I need to have a progress bar, I found one that suited my needs. By default it will incrementally change the color when a certain percentage is reached (0-30 red, 30-70 orange, etc). My only problem is changing them, I can set them easily with a static number such as 50, but when I try to do it dynamically (ie: 2000*.3 = 600) it fails. I don't know much js/jquery so this is especially difficult for me, if you could help that would be great. I'm pretty sure it's something really simple I'm missing. The code that Fails: var barmax = 2000; var orangeBound = Math.round(barmax * .3); var greenBound = Math.round(barmax * .7); //alert(orangeBound+":"+greenBound); $("#pb1").progressBar({ max: barmax, textFormat: 'fraction', barImage: { 0: 'images/progressbg_red.gif', orangeBound: 'images/progressbg_orange.gif', greenBound: 'images/progressbg_green.gif'} }); The code that works but I can't use because it has to be dynamic: $("#pb1").progressBar({ max: barmax, textFormat: 'fraction', barImage: { 0: 'images/progressbg_red.gif', 600: 'images/progressbg_orange.gif', 1400: 'images/progressbg_green.gif'} }); If you need to see the source, here. Thanks again!

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• Paypal Encrypted Website payments

  - by John Isaacks

  I am trying to integrate a PayPal Website Payments Standard Cart Upload payment type into my shopping cart. I integrated Google Checkout a while back and I did not find it overly confusing as I do paypal. I am getting info on how to encrypt it from here: https://cms.paypal.com/us/cgi-bin/?&cmd=_render-content&content_ID=developer/e_howto_html_encryptedwebpayments#id08A3I0P017Q Paypal says I need to generate a private key and a public certificate using OpenSSL. I went to OpenSSL and downloaded the latest release, which is just a folder containing various files but I see no application I can use, not sure what to do here. Even if I were to get OpenSSL to generate me a private key and public cert, the next step is to download either an MS or Java command line tool to create the encrypted cart ahead of time with the cart-total, tax, etc. which sounds crazy to me, like I am supposed to manually do this prior to every order?? Obviously I do not know the items in the cart the customer is going to buy before hand so I need this to be done on the fly on my website using PHP. But I am completely lost. There has to be a way to setup dynamic secure cart uploads to paypal. Can someone please point me in the right direction?

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• How do tools like Hiphop for PHP deal with heterogenous arrays?

  - by Derek Thurn

  I think HipHop for PHP is an interesting tool. It essentially converts PHP code into C++ code. Cross compiling in this manner seems like a great idea, but I have to wonder, how do they overcome the fundamental differences between the two type systems? One specific example of my general question is heterogeneous data structures. Statically typed languages don't tend to let you put arbitrary types into an array or other container because they need to be able to figure out the types on the other end. If I have a PHP array like this: $mixedBag = array("cat", 42, 8.5, false); How can this be represented in C++ code? One option would be to use void pointers (or the superior version, boost::any), but then you need to cast when you take stuff back out of the array... and I'm not at all convinced that the type inferencer can always figure out what to cast to at the other end. A better option, perhaps, would be something more like a union (or boost::variant), but then you need to enumerate all possible types at compile time... maybe possible, but certainly messy since arrays can contain arbitrarily complex entities. Does anyone know how HipHop and similar tools which go from a dynamic typing discipline to a static discipline handle these types of problems?

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• SQL Pivot table error-using variable gives syntax error

  - by Antoni

  Hi my coworker came to me with this error and now I am hooked and trying to figure it out, hope some of the experts can help us! Thanks so much! When I execute Step6 we get this error: Msg 102, Level 15, State 1, Line 4 Incorrect syntax near '@cols'. --Sample of pivot query --Creating Test Table Step1 CREATE TABLE Product(Cust VARCHAR(25), Product VARCHAR(20), QTY INT) GO -- Inserting Data into Table Step2 INSERT INTO Product(Cust, Product, QTY) VALUES('KATE','VEG',2) INSERT INTO Product(Cust, Product, QTY) VALUES('KATE','SODA',6) INSERT INTO Product(Cust, Product, QTY) VALUES('KATE','MILK',1) INSERT INTO Product(Cust, Product, QTY) VALUES('KATE','BEER',12) INSERT INTO Product(Cust, Product, QTY) VALUES('FRED','MILK',3) INSERT INTO Product(Cust, Product, QTY) VALUES('FRED','BEER',24) INSERT INTO Product(Cust, Product, QTY) VALUES('KATE','VEG',3) GO -- Selecting and checking entires in table Step3 SELECT * FROM Product GO -- Pivot Table ordered by PRODUCT Step4 select * FROM ( SELECT * FROM Product) up PIVOT (SUM(QTY) FOR CUST IN ([FRED], [KATE])) AS pvt ORDER BY PRODUCT GO --dynamic pivot???? Step5 DECLARE @cols NVARCHAR(2000) select @cols = STUFF(( SELECT DISTINCT TOP 100 PERCENT '],[' + b.Cust FROM (select top 100 Cust from tblProduct)b ORDER BY '],[' + b.Cust FOR XML PATH('') ), 1, 2, '') + ']' --Show Step6 SELECT * FROM (SELECT * FROM tblProduct) p PIVOT (SUM(QTY) FOR CUST IN (@cols)) as pvt Order by Product

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• mysql and trigger usage question

  - by dhruvbird

  I have a situation in which I don't want inserts to take place (the transaction should rollback) if a certain condition is met. I could write this logic in the application code, but say for some reason, it has to be written in MySQL itself (say clients written in different languages will be inserting into this MySQL InnoDB table) [that's a separate discussion]. Table definition: CREATE TABLE table1(x int NOT NULL); The trigger looks something like this: CREATE TRIGGER t1 BEFORE INSERT ON table1 FOR EACH ROW IF (condition) THEN NEW.x = NULL; END IF; END; I am guessing it could also be written as(untested): CREATE TRIGGER t1 BEFORE INSERT ON table1 FOR EACH ROW IF (condition) THEN ROLLBACK; END IF; END; But, this doesn't work: CREATE TRIGGER t1 BEFORE INSERT ON table1 ROLLBACK; You are guaranteed that: Your DB will always be MySQL Table type will always be InnoDB That NOT NULL column will always stay the way it is Question: Do you see anything objectionable in the 1st method?

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• actionscript-3: refactor interface inheritance to get rid of ambiguous reference error

  - by maxmc

  hi! imagine there are two interfaces arranged via composite pattern, one of them has a dispose method among other methods: interface IComponent extends ILeaf { ... function dispose() : void; } interface ILeaf { ... } some implementations have some more things in common (say an id) so there are two more interfaces: interface ICommonLeaf extends ILeaf { function get id() : String; } interface ICommonComponent extends ICommonLeaf, IComponent { } so far so good. but there is another interface which also has a dispose method: interface ISomething { ... function dispose() : void; } and ISomething is inherited by ICommonLeaf: interface ICommonLeaf extends ILeaf, ISomething { function get id() : String; } As soon as the dispose method is invoked on an instance which implements the ICommonComponent interface, the compiler fails with an ambiguous reference error because ISomething has a method called dispose and ILeaf also has a dispose method, both living in different interfaces (IComponent, ISomething) within the inheritace tree of ICommonComponent. I wonder how to deal with the situation if the IComponent, the ILeaf and the ISomething can't change. the composite structure must also work for for the ICommonLeaf & ICommonComponent implementations and the ICommonLeaf & ICommonComponent must conform to the ISomething type. this might be an actionscript-3 specific issue. i haven't tested how other languages (for instance java) handle stuff like this.

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• jQuery image hover color overlay

  - by Ryan Max

  I can't seem to find any examples of this having been done anywhere on the internet before but here is what I am going to attempt to do...I'm trying to go about the cleanest possible way of laying this out. So I have an image gallery where the images are all different sizes. I want to make it so that when you mouseover the image, it turns a shade of orange. Just a simple hover effect. I want to do this without using an image swap, otherwise I'd have to create an orange colored hover-image for each individual gallery image, I'd like this to be a bit more dynamic. My plan is just to position an empty div over the image absolutely with a background color, width and height 100% and opacity: 0. Then using jquery, on mouseover I'd have the opacity fade to 0.3 or so, and fade back to zero on mouseout. My question is, what would be the best way to layout the html and css to do this efficiently and cleanly. Here's a brief, but incomplete setup: <li> <a href="#"> <div class="hover">&nbsp;</div> <img src="images/galerry_image.png" /> </a> </li> .hover { width: 100%; height: 100%; background: orange; opacity: 0; }

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• AnyCPU/x86/x64 for C# application and it's C++/CLI dependency

  - by Soonts

  I'm Windows developer, I'm using Microsoft visual studio 2008 SP1. My developer machine is 64 bit. The software I'm currently working on is managed .exe written in C#. Unfortunately, I was unable to solve the whole problem solely in C#. That's why I also developed a small managed DLL in C++/CLI. Both projects are in the same solution. My C# .exe build target is "Any CPU". When my C++ DLL build target is "x86", the DLL is not loaded. As far as I understood when I googled, the reason is C++/CLI language, unlike other .NET languages, compiles to the native code, not managed code. I switched the C++ DLL build target to x64, and everything works now. However, AFAIK everything will stop working as soon as my client will install my product on a 32-bit OS. I have to support Windows Vista and 7, both 32 and 64 bit versions of each of them. I don't want to fall back to 32 bits. That 250 lines of C++ code in my DLL is only 2% of my codebase. And that DLL is only used in several places, so in the typical usage scenario it's not even loaded. My DLL implements two COM objects with ATL, so I can't use "/clr:safe" project setting. Is there way to configure the solution and the projects so that C# project builds "Any CPU" version, the C++ project builds both 32 bit and 64 bit versions, then in the runtime when the managed .EXE is starting up, it uses either 32-bit DLL or 64-bit DLL depending on the OS? Or maybe there's some better solution I'm not aware of? Thanks in advance!

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• Combining cache methods - memcache/disk based

  - by Industrial

  Hi! Here's the deal. We would have taken the complete static html road to solve performance issues, but since the site will be partially dynamic, this won't work out for us. What we have thought of instead is using memcache + eAccelerator to speed up PHP and take care of caching for the most used data. Here's our two approaches that we have thought of right now: Using memcache on all<< major queries and leaving it alone to do what it does best. Usinc memcache for most commonly retrieved data, and combining with a standard harddrive-stored cache for further usage. The major advantage of only using memcache is of course the performance, but as users increases, the memory usage gets heavy. Combining the two sounds like a more natural approach to us, even though the theoretical compromize in performance. Memcached appears to have some replication features available as well, which may come handy when it's time to increase the nodes. What approach should we use? - Is it stupid to compromize and combine the two methods? Should we insted be focusing on utilizing memcache and instead focusing on upgrading the memory as the load increases with the number of users? Thanks a lot!

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• (x86) Assembler Optimization

  - by Pindatjuh

  I'm building a compiler/assembler/linker in Java for the x86-32 (IA32) processor targeting Windows. High-level concepts of a "language" (in essential a Java API for creating executables) are translated into opcodes, which then are wrapped and outputted to a file. The translation process has several phases, one is the translation between languages: the highest-level code is translated into the medium-level code which is then translated into the lowest-level code (probably more than 3 levels). My problem is the following; if I have higher-level code (X and Y) translated to lower-level code (x, y, U and V), then an example of such a translation is, in pseudo-code: x + U(f) // generated by X + V(f) + y // generated by Y (An easy example) where V is the opposite of U (compare with a stack push as U and a pop as V). This needs to be 'optimized' into: x + y (essentially removing the "useless" code) My idea was to use regular expressions. For the above case, it'll be a regular expression looking like this: x:(U(x)+V(x)):null, meaning for all x find U(x) followed by V(x) and replace by null. Imagine more complex regular expressions, for more complex optimizations. This should work on all levels. What do you suggest? What would be a good approach to optimize in these situations?

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• Output reformatted text within a file included in a JSP

  - by javanix

  I have a few HTML files that I'd like to include via tags in my webapp. Within some of the files, I have pseudo-dynamic code - specially formatted bits of text that, at runtime, I'd like to be resolved to their respective bits of data in a MySQL table. For instance, the HTML file might include a line that says: Welcome, [username]. I want this resolved to (via a logged-in user's data): Welcome, [email protected]. This would be simple to do in a JSP file, but requirements dictate that the files will be created by people who know basic HTML, but not JSP. Simple text-tags like this should be easy enough for me to explain to them, however. I have the code set up to do resolutions like that for strings, but can anyone think of a way to do it across files? I don't actually need to modify the file on disk - just load the content, modify it, and output it w/in the containing JSP file. I've been playing around with trying to load the files into strings via the apache readFileToString, but I can't figure out how to load files from a specific folder within the webapp's content directory without hardcoding it in and having to worry about it breaking if I deploy to a different system in the future.

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• Variable amount of columns returned in mysqli prepared statement

  - by manyxcxi

  I have a situation where a dynamic query is being generated that could select anywhere from 1 to over 300 different columns across multiple tables. It currently works fine just doing a query, however the issue I'm running into in using a prepared statement is that I do not know how to handle the fact that I don't know how many columns I will be asking for each time and therefor don't know how to process the results. The reason I believe a bind statement will help is because once this query is run once, it will most likely (though not always) be run again with the exact same parameters. Currently I have something like this: $rows = array(); $this->statement = $this->db->prepare($query); $this->statement->bind_param('i',$id); $this->statement->execute(); $this->statement->bind_result($result); while($this->statement->fetch()) { $rows[] = $result; } I know this doesn't work as I want it to, my question is how do I get the data back out of the query. Is it possible to bring the columns back in an associative array by column name, like a standard mysqli query?

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• Groovy / Scala / Java under the hood

  - by Jack

  I used Java for like 6-7 years, then some months ago I discovered Groovy and started to save a lot of typing.. then I wondered how certain things worked under the hood (because groovy performance is really poor) and understood that to give you dynamic typing every Groovy object is a MetaClass object that handles all the things that the JVM couldn't handle by itself. Of course this introduces a layer in the middle between what you write and what you execute that slows down everything. Then somedays ago I started getting some infos about Scala. How these two languages compare in their byte code translations? How much things they add to the normal structure that it would be obtained by plain Java code? I mean, Scala is static typed so wrapper of Java classes should be lighter, since many things are checked during compile time but I'm not sure about the real differences of what's going inside. (I'm not talking about the functional aspect of Scala compared to the other ones, that's a different thing) Can someone enlighten me? From WizardOfOdds it seems like that the only way to get less typing and same performance would be to write an intermediate translator that translates something in Java code (letting javac compile it) without alterating how things are executed, just adding synctatic sugar withour caring about other fallbacks of the language itself.

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• Given 4 objects, how to figure out whether exactly 2 have a certain property

  - by Cocorico

  Hi guys! I have another question on how to make most elegant solution to this problem, since I cannot afford to go to computer school right so my actual "pure programming" CS knowledge is not perfect or great. This is basically an algorhythm problem (someone please correct me if I am using that wrong, since I don't want to keep saying them and embarass myself) I have 4 objects. Each of them has an species property that can either be a dog, cat, pig or monkey. So a sample situation could be: object1.species=pig object2.species=cat object3.species=pig object4.species=dog Now, if I want to figure out if all 4 are the same species, I know I could just say: if ( (object1.species==object2.species) && (object2.species==object3.species) && (object3.species==object4.species) ) { // They are all the same animal (don't care WHICH animal they are) } But that isn't so elegant right? And if I suddenly want to know if EXACTLY 3 or 2 of them are the same species (don't care WHICH species it is though), suddenly I'm in spaghetti code. I am using Objective C although I don't know if that matters really, since the most elegant solution to this is I assume the same in all languages conceptually? Anyone got good idea? Thanks!!

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• What techniques can be used to detect so called "black holes" (a spider trap) when creating a web crawler?

  - by Tom

  When creating a web crawler, you have to design somekind of system that gathers links and add them to a queue. Some, if not most, of these links will be dynamic, which appear to be different, but do not add any value as they are specifically created to fool crawlers. An example: We tell our crawler to crawl the domain evil.com by entering an initial lookup URL. Lets assume we let it crawl the front page initially, evil.com/index The returned HTML will contain several "unique" links: evil.com/somePageOne evil.com/somePageTwo evil.com/somePageThree The crawler will add these to the buffer of uncrawled URLs. When somePageOne is being crawled, the crawler receives more URLs: evil.com/someSubPageOne evil.com/someSubPageTwo These appear to be unique, and so they are. They are unique in the sense that the returned content is different from previous pages and that the URL is new to the crawler, however it appears that this is only because the developer has made a "loop trap" or "black hole". The crawler will add this new sub page, and the sub page will have another sub page, which will also be added. This process can go on infinitely. The content of each page is unique, but totally useless (it is randomly generated text, or text pulled from a random source). Our crawler will keep finding new pages, which we actually are not interested in. These loop traps are very difficult to find, and if your crawler does not have anything to prevent them in place, it will get stuck on a certain domain for infinity. My question is, what techniques can be used to detect so called black holes? One of the most common answers I have heard is the introduction of a limit on the amount of pages to be crawled. However, I cannot see how this can be a reliable technique when you do not know what kind of site is to be crawled. A legit site, like Wikipedia, can have hundreds of thousands of pages. Such limit could return a false positive for these kind of sites. Any feedback is appreciated. Thanks.

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• How can i know what TextView was clickbale?

  - by sgiro

  Hello, i have one doubt. I have an iteration of TextViews, and what i want is when i click in one TextView , i want stop the iteration and open a web, who can i know what TextView as been click on? i have this code: Iterator<TextView> it = text.iterator(); while(it.hasNext()){ test = it.next(); test.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { //mWebView = (WebView) findViewById(R.id.webview); mWebView.setWebViewClient(new WebViewClient() { @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { view.loadUrl(url); return true; } }); mWebView.getSettings().setJavaScriptEnabled(true); mWebView.loadUrl(url); } }); // condition to stop the iteration when i click on TextView } And what i want is the condition to stop the iteration when i click on the TextView that i want see, i try using some methods that are in the TextView and don't work. Anyone can help me? I have the iteration of TextViews because i want to do this dynamic, and i don't know the TextView who as click, and i want to know what TextView was click to stop the iteration, because if i don't stop this, for example if i have 3 TextView they will open the same web. Thanks and forgive my English

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• How to I pass parameters to Ruby/Python scripts from inside PHP?

  - by Roger

  Hi, everybody. I need to turn HTML into equivalent Markdown-structured text. From what I could discover, I have only two good choices: Python: Aaron Swartz's html2text.py Ruby: Singpolyma's html2markdown.rb As I am programming in PHP, I need to pass the HTML code, call the Ruby/Python Script and receive the output back. I started creating a simple test just to know if my server was configured to run both languages. PHP code: echo exec('./hi.rb'); Ruby code: #!/usr/bin/ruby puts "Hello World!" It worked fine and I am ready to go to the next step. Unfortunately, all I know is that the function is Ruby works like this: HTML2Markdown.new('<h1>HTMLcode</h1>').to_s I don't know how to make PHP pass the string (with the HTML code) to Ruby nor how to make the ruby script receive the variable and pass it back to PHP (after have parsed it into Markdown). Believe it or not: I know less of Python. A folk made a similar question here ("how to call ruby script from php?") but with no practical information to my case. Any help would be a joy - thanks. Rogério Madureira. atipico.com.br

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• Transitioning from desktop app written in C++ to a web-based app

  - by Karim

  We have a mature Windows desktop application written in C++. The application's GUI sits on top of a windows DLL that does most of the work for the GUI (it's kind of the engine). It, too, is written in C++. We are considering transitioning the Windows app to be a web-based app for various reasons. What I would like to avoid is having to writing the CGI for this web-based app in C++. That is, I would rather have the power of a 4G language like Python or a .NET language for creating the web-based version of this app. So, the question is: given that I need to use a C++ DLL on the backend to do the work of the app what technology stack would you recommend for sitting between the user's browser and are C++ dll? We can assume that the web server will be Windows. Some options: Write a COM layer on top of the windows DLL which can then be access via .NET and use ASP.NET for the UI Access the export DLL interface directly from .NET and use ASP.NET for the UI. Write a custom Python library that wraps the windows DLL so that the rest of the code can be written. Write the CGI using C++ and a C++-based MVC framework like Wt Concerns: I would rather not use C++ for the web framework if it can be avoided - I think languages like Python and C# are simply more powerful and efficient in terms of development time. I'm concerned that my mixing managed and unmanaged code with one of the .NET solutions I'm asking for lots of little problems that are hard to debug (purely anecdotal evidence for that) Same is true for using a Python layer. Anything that's slightly off the beaten path like that worries me in that I don't have much evidence one way or the other if this is a viable long term solution.

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• Web development: Haskell or Scheme

  - by Robert E. Lester

  I would like to to choose one of these languages for building web applications. I'm not interested in framework per say, but have the following needs: Rapid development. Easy to scale. Strong community for the web. Quick and easy to deploy. I'm very familiar with Haskell, and have some familiarity with scheme (in particular PLT). Scheme appeals to me as good candidate for web development due to it's simple syntax which is homogenous across libraries. I state this despite my subjective opinion that Haskell is a 'cleaner' language. Haskell web apps seem to require learning and building a patchwork of different combinator libraries. On the plus side, I realise this can be quite expressive, although I'd prefer to eliminate impedance mismatches where possible. While scheme-plt looks to be a good fit, I can find but one example of it being used in the "real world". Haskell doesn't seem to fair too much better here, but there seems to be a bigger community behind the web side. Please help me make up my mind. For the most part I'm interested in real-world use cases.

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• How to make safe frequent DataSource switches for AbstractRoutingDataSource?

  - by serg555

  I implemented Dynamic DataSource Routing for Spring+Hibernate according to this article. I have several databases with same structure and I need to select which db will run each specific query. Everything works fine on localhost, but I am worrying about how this will hold up in real web site environment. They are using some static context holder to determine which datasource to use: public class CustomerContextHolder { private static final ThreadLocal<CustomerType> contextHolder = new ThreadLocal<CustomerType>(); public static void setCustomerType(CustomerType customerType) { Assert.notNull(customerType, "customerType cannot be null"); contextHolder.set(customerType); } public static CustomerType getCustomerType() { return (CustomerType) contextHolder.get(); } public static void clearCustomerType() { contextHolder.remove(); } } It is wrapped inside some ThreadLocal container, but what exactly does that mean? What will happen when two web requests call this piece of code in parallel: CustomerContextHolder.setCustomerType(CustomerType.GOLD); //<another user will switch customer type here to CustomerType.SILVER in another request> List<Item> goldItems = catalog.getItems(); Is every web request wrapped into its own thread in Spring MVC? Will CustomerContextHolder.setCustomerType() changes be visible to other web users? My controllers have synchronizeOnSession=true. How to make sure that nobody else will switch datasource until I run required query for current user? Thanks.

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• Looking for fast, minimal, preferrably free disc cloning software [closed]

  - by Dave

  We have to test our application installation and functionality on many Windows operating system versions and languages (XP, Vista, Win7; English, Spanish, Portuguese, etc; 32-bit & b4-bit.) While we can do much of this in virtual machines, we have noticed that VM's sometimes hide problems, or raise false bugs. So, we need to do "bare metal" OS installation for much of our testing. I have been using Acronis True Image for the past year, and am not impressed. It often gives random errors which require a reboot, and is really slow. For example, when trying to restore an image, it goes through a "Locking partition" cycle about three times (once after you click OK on each step of the wizard), each of which can take 5 minutes to complete. This all happens BEFORE it actually starts the image copy, which is sometimes quick (3-5 minutes), sometimes long (hours). The size of all of our images are roughly the same, so that is not related. So, anyway, I'm looking to switch to something else: I only need very basic functionality--just creating images of entire discs, and then restoring those images onto the exact same hard drive at a later date. That's it. I'm not opposed to paying for a good piece of software, but if there is something free out there that does the job well, that would be a preference. My OS on which the imaging software would run is Windows Vista, but a bootable media (into a Linux flavor) would be fine also, as long as its quick to use and reliable. Recommendations? (Also, moderators, if this should be a CW, I'll be happy to mark it as such; unclear about the rules there.)

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• How to create a chart from mysql data?

  - by user187580

  Hello, I have some data and want to create some dynamic charts. I have looked on Google visualisation api .. It looks great but the problem is I am not very familiar with it. Any ideas, how I can set the data.setValue from mysql data. <script type='text/javascript'> google.load('visualization', '1', {'packages': ['geomap']}); google.setOnLoadCallback(drawMap); function drawMap() { var data = new google.visualization.DataTable(); data.addRows(6); data.addColumn('string', 'Country'); data.addColumn('number', 'Popularity'); data.setValue(0, 0, 'Germany'); data.setValue(0, 1, 200); data.setValue(1, 0, 'United States'); data.setValue(1, 1, 300); data.setValue(2, 0, 'Brazil'); data.setValue(2, 1, 400); data.setValue(3, 0, 'Canada'); data.setValue(3, 1, 500); data.setValue(4, 0, 'France'); data.setValue(4, 1, 600); data.setValue(5, 0, 'RU'); data.setValue(5, 1, 700); var options = {}; options['dataMode'] = 'regions'; var container = document.getElementById('map_canvas'); var geomap = new google.visualization.GeoMap(container); geomap.draw(data, options); }; </script> I can create chart using some other methods but just interested in using Google Visualisation API. Thanks.

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• Building a CMS in PHP: Development tools

  - by TRiG

  I'm planning to build a CMS in PHP and MySQL, mainly for my own amusement and education. (Though who knows, I may come up with something useful and cool. Anything's possible.) I'll be asking questions about code architecture etc. later. For now, I'm more interested in development tools. So far, all my playing with code has been done on a web server, and I've edited over FTP. I was thinking it might be quicker to use a localhost. Also, that way, I could use version control (which I've never done before). So, A. How do I set up a localhost server with many subdomains on an Ubuntu 9.10 computer. Is XAMPP for Linux the way to go, or should I use a standard Apache distro? (Or another webserver altogether?) For that matter, is it possible to set up more than one webserver on the same computer, and to use them for different localhost subdomains? B. How do I set up a version control thingy covering all the code (which will be on several subdomains of localhost, and in a few shared folders)? I've read Joel Spolsky's HgInt tutorial, and it makes Mercurial look good. And simple, especially if you're working on your own. C. Should I continue to use gEdit to write HTML/CSS/JS/PHP, or is there a better free editor out there for these languages?

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