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  • Is there command-line tool to extract typedef, structure, enumeration, variable, function from a C or C++ file?

    - by FooF
    I am desiring a command-line tool to extract a definition or declaration (typedef, structure, enumeration, variable, or function) from a C or C++ source file. Also a way to replace an existing definition/declaration would be handy (after transforming the extracted definition by a user-submitted script). Is there such generic tool available, or is some resonably close approximation of such a tool? Scriptability and ability to hook-up with user created scripts or programs is of importance here, although I am academically curious of GUI programs too. Open source solutions for Unix/Linux camp are preferred (although I am curious of Windows and OS X tools too). Primary language interests are C and C++ but more generic solution would be even better (I think we do not need super accurate parsing capabilities for finding, extracting and replacing a definition in a program source file). Sample Use Cases (extra - for the curious mind): Given deeply nested structs and variable (array) initializations of these types, suppose there is a need to change a struct definition by adding or reordering fields or rewriting the variable/array definitions in more readable format without introducing errors resulting from manual labor. This would work by extracting the old initializations, then using a script/program to write the new initializations to replace the old ones. For implementing a code browsing tool - extract a definition. Decorative code generation (e.g. logging function entries / returns). Scripted code structuring (e.g. extract this and that thing and put in different place without change - version control commit comment could document the command to perform this operation to make it evident and verifiable that nothing changed). Note about tags: More accurate tag than code-generation would be code-transformation but it does not exist.

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  • Optimizing landing pages

    - by Oleg Shaldybin
    In my current project (Rails 2.3) we have a collection of 1.2 million keywords, and each of them is associated with a landing page, which is effectively a search results page for a given keywords. Each of those pages is pretty complicated, so it can take a long time to generate (up to 2 seconds with a moderate load, even longer during traffic spikes, with current hardware). The problem is that 99.9% of visits to those pages are new visits (via search engines), so it doesn't help a lot to cache it on the first visit: it will still be slow for that visit, and the next visit could be in several weeks. I'd really like to make those pages faster, but I don't have too many ideas on how to do it. A couple of things that come to mind: build a cache for all keywords beforehand (with a very long TTL, a month or so). However, building and maintaing this cache can be a real pain, and the search results on the page might be outdated, or even no longer accessible; given the volatile nature of this data, don't try to cache anything at all, and just try to scale out to keep up with traffic. I'd really appreciate any feedback on this problem.

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  • Why do you program? Why do you do what you do? [closed]

    - by Pirate for Profit
    To me, writing a new program is like a puzzle. Before you write any code for a large system, you have to carefully craft each piece in your mind and imagine how all the pieces will fit together. If you don't, your solution may end up being undefined. What I mean is, I often don't know what I'm doing so I'll come to this site and beg for a code snippet, and then somehow try to hack it into my projects. I started writing GW-Basic when I was around 8 years old. Then it progressed from there, went to california university and did some Python and C++, but really didn't learn anything(college = highsk00l++). I've mostly been self-taught, took awhile to break bad habits and I'd say only in recent years would I consider myself understanding of design patterns and all that stuff (no but honestly procedural dudes, I would not want to design and maintain a large system procedurally, yous crazy). And despite my username, money has NOT been a big motivator. I've gone from job to job, I can usually get the work done perfect very quickly, any delays on my part are understandable (well about as understandable as it gets in the industry). But I ain't gonna work for peanuts because I got mouths to feed. Why do you program? Why do you do what you do?

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  • Multisite Enabling a Table

    - by Joe Fitzgibbons
    I am creating a table (table A) that will have a number of columns(of course) and there will be another table (table B) that holds metadata associated to rows in table A. I am working with a multi site implementation that has one database for the whole shabang. Rows in table A could belong to any number of sites but must belong to at least one. The problem I have is I am not sure what the best practice is for defining what site each row in table A belongs to. I want performance and scalability. There is no finite number of sites going forward. Rows in table A could belong to any number of sites in the future. Right now there are only 3. My initial thoughts are to have a primary site ID in Table A and then metadata in table B will have rows defining additional sites as needed. Another thought is to have a column in Table A for each site and it is a boolean as to wether it belongs to that site. Lastly I have thought about having another table to map rows in Table A to each site. What is the best way to associate rows in a table with any number of sites with performance and scalability in mind?

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  • Linux: Find all symlinks of a given 'original' file? (reverse 'readlink')

    - by sdaau
    Hi all, Consider the following command line snippet: $ cd /tmp/ $ mkdir dirA $ mkdir dirB $ echo "the contents of the 'original' file" > orig.file $ ls -la orig.file -rw-r--r-- 1 $USER $USER 36 2010-12-26 00:57 orig.file # create symlinks in dirA and dirB that point to /tmp/orig.file: $ ln -s $(pwd)/orig.file $(pwd)/dirA/ $ ln -s $(pwd)/orig.file $(pwd)/dirB/lorig.file $ ls -la dirA/ dirB/ dirA/: total 44 drwxr-xr-x 2 $USER $USER 4096 2010-12-26 00:57 . drwxrwxrwt 20 root root 36864 2010-12-26 00:57 .. lrwxrwxrwx 1 $USER $USER 14 2010-12-26 00:57 orig.file -> /tmp/orig.file dirB/: total 44 drwxr-xr-x 2 $USER $USER 4096 2010-12-26 00:58 . drwxrwxrwt 20 root root 36864 2010-12-26 00:57 .. lrwxrwxrwx 1 $USER $USER 14 2010-12-26 00:58 lorig.file -> /tmp/orig.file At this point, I can use readling to see what is the 'original' (well, I guess the usual term here is either 'target' or 'source', but those in my mind can be opposite concepts as well, so I'll just call it 'original') file of the symlinks, i.e. $ readlink -f dirA/orig.file /tmp/orig.file $ readlink -f dirB/lorig.file /tmp/orig.file ... However, what I'd like to know is - is there a command I could run on the 'original' file, and find all the symlinks that point to it? In other words, something like (pseudo): $ getsymlinks /tmp/orig.file /tmp/dirA/orig.file /tmp/dirB/lorig.file Thanks in advance for any comments, Cheers!

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  • What are your best practices for ensuring the correctness of the reports from SQL?

    - by snezmqd4
    Part of my work involves creating reports and data from SQL Server to be used as information for decision. The majority of the data is aggregated, like inventory, sales and costs totals from departments, and other dimensions. When I am creating the reports, and more specifically, I am developing the SELECTs to extract the aggregated data from the OLTP database, I worry about mistaking a JOIN or a GROUP BY, for example, returning incorrect results. I try to use some "best practices" to prevent me for "generating" wrong numbers: When creating an aggregated data set, always explode this data set without the aggregation and look for any obvious error. Export the exploded data set to Excel and compare the SUM(), AVG(), etc, from SQL Server and Excel. Involve the people who would use the information and ask for some validation (ask people to help to identify mistakes on the numbers). Never deploy those things in the afternoon - when possible, try to take a look at the T-SQL on the next morning with a refreshed mind. I had many bugs corrected using this simple procedure. Even with those procedures, I always worry about the numbers. What are your best practices for ensuring the correctness of the reports?

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  • Form doesn't resize smoothly with a timer event

    - by BDotA
    I have a grid control at the bottom of my form and it can be shown or hidden if user wants to show/hide it. So one way was to well use AutoSize of the form and change the Visuble property of that grid to true or false,... But I thought let's make it a little cooler! so I wanted the form to resize a little more slowly, like a garage door! So I dropped a Timer on the form and started increasing the height of the form little by little while the timer ticks... so something like this when user says show/hide the grid: timer1.Enabled = true; timer1.Start(); and something like this on the timer_click event: this.Height = this.Height + 5; if(this.Height -10 > ErrorsGrid.Bottom ) timer1.Stop(); It kind of works but still not perfect. For example it lags at the very beginning, stop a like a second and then start moving it...So now with this idea in mind what alterations do you suggest I should do to make this thing look and work better?

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  • NHibernate lazy properties behavior?

    - by GeReV
    I've been trying to get NHibernate into development for a project I'm working on at my workplace. Since I have to put a strong emphasis on performance, I've been running a proof-of-concept stress test on an existing project's table with thousands of records, all of which contain a large text column. However, when selecting a collection of these records, the select statement takes a relatively long time to execute; apparently due to the aforementioned column. The first solution that comes to mind is setting this property as lazy: <property name="Content" lazy="true"/> But there seems to be no difference in the SQL generated by NHibernate. My question is, how do lazy properties behave in NHibernate? Is there some kind of type limitations I could be missing? Should I take a different approach altogether? Using HQL's new Class(column1, column2) approach works, but lazy properties sounds like a simpler solution. It's perhaps worth mentioning I'm using NHibernate 2.1.2GA with the Castle DynamicProxy. Thanks!

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  • Why is the 'var' keyword bad? Or am I just old school?

    - by WaggingSiberian
    Recently I overheard junior developer ask "why do you use 'var' so much?". The mid-level developer responded "I use VAR all the time. I love it! I don't have to figure out the type." I didn't have the time or energy to get into a religious war and hey, I'm still the new guy here :-) I understand var has its place. LINQ comes to mind. But I have also always been told the use of var represents lazy programming and I should just use the correct type to begin with. If it's an int, define it as an int, not a var. When reviewing code, seeing the type makes it easier to follow. My opinion is, it's just lazy but there are exception. Var also reminds me of the VB/VBA variant type. It also had its place. I recall (from many years ago) its usage being less-than-desirable type and it was rather resource hungry. Am I just being stuck in my ways? Should we start using var all the time as my co-worker does?

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  • Processor, OS : 32bit, 64 bit

    - by Sandbox
    I am new to programming and come from a non-CS background (no formal degree). I mostly program winforms using C#. I am confused about 32 bit and 64 bit.... I mean, have heard about 32 bit OS, 32 bit processor and based on which a program can have maximum memory. How it affects the speed of a program. There are lot more questions which keep coming to mind. I tried to go through some Computer Organization and Architecture books. But, either I am too dumb to understand what is written in there or the writers assume that the reader has some CS background. Can someone explain me these things in a plain simple English or point me to something which does that. EDIT: I have read things like In 32-bit mode, they can access up to 4GB memory; in 64-bit mode, they can access much much more....I want to know WHY to all such things. BOUNTY: Answers below are really good....esp one by Martin. But, I am looking at a thorough explanation, but in plain simple English.

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  • Handling Email Bouncebacks in Rails

    - by aressidi
    Hi there, I've built a very basic CRM system for my rails app that allows me to send weekly user activity digests with custom text and create multi-part marketing messages which I can configure and send through a basic admin interface. I'm happy with what I've put together on the send-side of things (minus the fact that I haven't tried to volume test its capabilities), but I'm concerned about how to handle bounce-backs. I came across this plugin with associated scripts: http://github.com/kovyrin/bounces-handler I'm using Google Apps to handle my mail and really don't know enough about Perl to want to mess with the above plugin - I have enough headaches. I'm looking for a simple solution for processing bounce-backs in Rails. All my email will go out from an address like this which will be managed in Google Apps: "[email protected]." What's the best workflow for this? Can anyone post an example solution they're using keeping in mind the fact that I'm using Google Apps for the mail? Any guidance, links, or basic workflow best-practices to handle this would be greatly appreciated. Thanks! -A

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  • How to use iPhone OS 3.2 functionality in an iPhone OS 3.0 app?

    - by mystify
    Problem: My app must run on iPhone OS 3.0. However, there are some features of iPhone OS 3.2 which I really want to use. Just as a little add-on for free. But I don't want to cut off my user base by doing this. Imagine you're an iPhone OS 3.0 thing, and someone gives you a book to read. It has iPhone OS 3.2 instructions. You never learned those. So what do you do? Crash? They would have to be hidden, so you're not bothered. Someone wrote recently on SO: keep in mind that you have to check the version at places in the source code where you like to use the new features and provide alternatives for older os versions So how could I do that? Wouldn't Xcode throw warnings when it finds stuff that isn't linkable from anything anywhere? Would I just check for the OS version and dynamically link - somehow - to whatever stuff I think is cool?

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  • WPF Calling a custom command on a custom control (from a viewmodel?)

    - by user190615
    I want to take a snap of the visual tree of a custom wpf control when the user clicks a button in a toolbar. The control is bound to a viewmodel. I have a BitmapSource dp in the custom control holding the snapped image which is bound to a property on my VM. The BitmapSource dp on the control is updated via a custom command on the control. I've tied the toolbar button's command to call the controls command which updates the BitmapSource. Now the problem is the end result I want is when the user clicks the button, the control updates its image and then the vm offers to save this image. I cant wrap my mind around an mvvm way of doing this. One inelegant solution is that control fires an event after the image is updated which is routed to the viewmodel as a command(command behavior) but then if i want to do something else with the image on some other button click, all the commands bound to the events will fire. All thoughts appreciated. EDIT The command on the control is a RoutedCommand and the commands in my vm are Prism delegate commands.

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  • How do I deal with different requests that map to the same response?

    - by daxim
    I'm designing a Web service. The request is idempotent, so I chose the GET method. The response is relatively expensive to calculate and not small, so I want to get caching (on the protocol level) right. (Don't worry about memoisation at my part, I have that already covered; my question here is actually also paying attention to the Web as a whole.) There's only one mandatory parameter and a number of optional parameter with default values if missing. For example, the following two map to the same representation of the response. (If this is a dumb way to go about it the interface, propose something better.) GET /service?mandatory_parameter=some_data HTTP/1.1 GET /service?mandatory_parameter=some_data;optional_parameter=default1;another_optional_parameter=default2;yet_another_optional_parameter=default3 HTTP/1.1 However, I imagine clients do not know this and would treat them separate and therefore waste cache storage. What should I do to avoid violating the golden rule of caching? Make up a canonical form, document it (e.g. all parameters are required after all and need to be sorted in a specific order) and return a client error unless the required form is met? Instead of an error, redirect permanently to the canonical form of a request? Or is it enough to not mind how the request looks like, and just respond with the same ETag for same responses?

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  • counter_cache not updating on the model after save

    - by sehnsucht
    I am using a counter_cache to let MySQL do some of the bookkeeping for me: class Container has_many :items end class Item belongs_to :container, :counter_cache => true end Now, if I do this: container = Container.find(57) item = Item.new item.container = container item.save in the SQL log there will be an INSERT followed by something like: UPDATE `containers` SET `items_count` = COALESCE(`items_count`, 0) + 1 WHERE `containers`.`id` = 57 which is what I expected it to do. However, the container[:items_count] will be stale! ...unless I container.reload to pick up the updated value. Which in my mind sort of defeats part of the purpose of using the :counter_cache in favor of a custom built one, especially since I may not actually want a reload before I try to access the items_count attribute. (My models are pretty code-heavy because of the nature of the domain logic, so I sometimes have to save and create multiple things in one controller call.) I understand I can tinker with callbacks myself but this seems to me a fairly basic expectation of the simple feature. Again, if I have to write additional code to make it fully work, it might as well be easier to implement a custom counter. What am I doing/assuming wrong?

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  • How can I close the output stream after a jsp has been included.

    - by stu
    I have a webpage that makes an ajax call to get some data. That data takes a long time to calculate, so what I did was the first ajax server call returns "loading..." and then the thread goes on to calculate the data and store it in a cache. meanwhile the client javascript checks back every few seconds with another ajax call to see if the cache has been loaded yet. Here's my problem, and it might not be a problem. After the initial ajax to the server call, I do a ...getServletContext().getRequestDispatcher(jsppath).include(request, response); then I use that thread to do the calculations. I don't mind tying up the webserver thread with this, but I want the browser to get the response and not wait for the server to close the socket. I can't tell if the server is closing the socket after the include, but I'm guessing it's not. So how can I forcibly close the stream after I've written out my response, before starting my long calculations? I tried o = response.getOutputStream(); o.close(); but I get an illegal state exception saying that the output stream has already been gotten (presumably by the jsp I'm including) So my qestions: 1) is the webserver closing the socket (I'm guessing not, because you could always include another jsp) 2) if it is as I assume not closing the socket, how do I do that?

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  • Moq basic questions

    - by devoured elysium
    I made the following test for my class: var mock = new Mock<IRandomNumberGenerator>(); mock.Setup(framework => framework.Generate(0, 50)) .Returns(7.0); var rnac = new RandomNumberAverageCounter(mock.Object, 1, 100); rnac.Run(); double result = rnac.GetAverage(); Assert.AreEqual(result, 7.0, 0.1); The problem here was that I changed my mind about what range of values Generate(int min, int max) would use. So in Mock.Setup() I defined the range as from 0 to 50 while later I actually called the Generate() method with a range from 1 to 100. I ran the test and it failed. I know that that is what it's supposed to happen but I was left wondering if isn't there a way to launch an exception or throw in a message when trying to run the method with wrong params. Also, if I want to run this Generate() method 10 times with different values (let's say, from 1 to 10), will I have to make 10 mock setups or something, or is there a special method for it? The best I could think of is this (which isn't bad, I'm just asking if there is other better way): for (int i = 1; i < 10; ++i) { mock.Setup(framework => framework.Generate(1, 100)) .Returns((double)i); }

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  • yet another logic.

    - by Sunil
    I'm working on a research problem out of curiosity and I don't know how to program the logic that I've in mind. Let me explain it to you : I've 4 vectors say for example, v1 = 1 1 1 1 v2 = 2 2 2 2 v3 = 3 3 3 3 v4 = 4 4 4 4 Now what I want to do is to add them combination-wise. i.e v12 = v1+v2 v13 = v1+v3 v14 = v1+v4 v23 = v2+v3 v24 = v2+v4 v34 = v3+v4 Till this step it is just fine. The problem/trick is now, at the end of each iteration I give the obtained vectors into a black box function and it returns only few of the vectors say v12, v13 and v34. Now, I want to add each of these vectors one vector from v1,v2,v3,v4 which it hasn't added before. For example v3 and v4 hasn't been added to v12 so I want to create v123 and v124. similarly for all the vectors like, v12 should become : v123 = v12+v3 v124 = v12+v4 v13 should become : v132 // this should not occur because I already have v123 v134 = v13+v4; v14,v23 and v24 cannot be considered because it was deleted in the black box function so all we have in our hands to work with is v12,v13 and v34. v34 should become : v341 // cannot occur because we have 134 v342 = v34+v2 It is important that I do not do all at one step at the start like for example I can do (4 choose 3) 4C3 and finish it off but I want to do it step by step at each iteration. I've asked a modified version of this question before (without including the black box function) and got answers here. Can anybody tell me how to do it when the black box function is included ? A modification of the previous answer would also be great. Thanks in advance.

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  • How to check whether a default browser is opened in the operating system (Java)?

    - by stempel1984
    Hi, I am newbie here. During my work, I faced an interesting problem. I need to: check whether a default html browser is opened; check whether the browser is minimized/maximized (simply, a window's state); get an url address typed in the browser. If any of these conditions is not met, I have to open the browser in a maximized view with a desired url address. I primarily wanted to do all this in Java, but it came to my mind that I should employ many techniques/technologies and combine them appropriately to complete the functionality. But, which ones? That's the problem. I just recalled Windows API, but I'm not sure if it is of any help... Some users on another forum suggested that I should consider JNI (no experience at all)... I only know how to open a default browser (e.g. with use of the 'browse(URI uri)' method of the 'java.awt.Desktop' class) - that's too little to be proud of. Please give me some hints, maybe links to reasonable discussions, I would greatly appreciate any suggestions how to approach the problem.

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  • C++ - Totally suspend windows application

    - by HardCoder1986
    Hello! I am developing a simple WinAPI application and started from writing my own assertion system. I have a macro defined like ASSERT(X) which would make pretty the same thing as assert(X) does, but with more information, more options and etc. At some moment (when that assertion system was already running and working) I realized there is a problem. Suppose I wrote a code that does some action using a timer and (just a simple example) this action is done while handling WM_TIMER message. And now, the situation changes the way that this code starts throwing an assert. This assert message would be shown every TIMER_RESOLUTION milliseconds and would simply flood the screen. Options for solving this situation could be: 1) Totally pause application running (probably also, suspend all threads) when the assertion messagebox is shown and continue running after it is closed 2) Make a static counter for the shown asserts and don't show asserts when one of them is already showing (but this doesn't pause application) 3) Group similiar asserts and show only one for each assert type (but this also doesn't pause application) 4) Modify the application code (for example, Get / Translate / Dispatch message loop) so that it suspends itself when there are any asserts. This is good, but not universal and looks like a hack. To my mind, option number 1 is the best. But I don't know any way how this can be achieved. What I'm seeking for is a way to pause the runtime (something similiar to Pause button in the debugger). Does somebody know how to achieve this? Also, if somebody knows an efficient way to handle this problem - I would appreciate your help. Thank you.

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  • Strangest LINQ to SQL case I have ever seen

    - by kubaw
    OK, so this is the strangest issue in .net programming I have ever seen. It seems that object fields are serialized in .net web services in order of field initialization. It all started with Flex not accepting SOAP response from .net web service. I have found out that it was due to the order of serialized fields was statisfying the order of fields in declared serializable class. It had something to do with generic lists and LINQ to SQL but I can't find out what. This one is really hard to reproduce. Example to get the idea: [Serializable] public class SomeSample { public int A; public int B; public int C; } I was querying some data tables within asmx web service using linq and returning list of SomeSample objects: var r = (from ...... select new SomeSample { A = 1, C = 3 }).ToList(); Now the list was once more iterated and B field was applied some value (ex. 2). However the returned soap envelope contained following excerpt: <A>1</A><C>3</C><B>2</B> Please notice the order of serialization. If I initially initialized all fields: var r = (from ...... select new SomeSample { A = 1, B = 2, C = 3 }).ToList(); object was serialized in correct order. I must add, that in both cases the debugger shows exactly the same content of "r" variable. Am I losing my mind or is this normal behavior? Thanks in advance.

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  • slidepanel/hover help

    - by Josh
    I'm trying to create a menu navigation system from the top of the page. I want it so when I hover over the link, it drops down (the link drops down; so it'd be as if there was a whole field being hidden beyond the 0px mark) with the related field. I've gotten it to work, somehow but it still isn't right. A few issues are: when I hover over .drop_slide and then if I choose to close it by hovering back over the .drop_slide it does as it's told, which is "slide, slide". I'm interested in rectifying this issue so it doesn't do that, however I just don't know how. The idea is to have multiple links in the .slide, so I need it to be constantly open while the user mouses over the other links. Should this be created in one field? If so, how would I do that with a drop down in mind? Am I approaching this completely wrong? Lol. Should I be researching into .animate? I've been looking at it actually, but I can't get anything to grow negatively. Say; marginTop: -85px or something. ANY help is appreciated, thanks! $(document).ready(function(){ function slide() { $("#panel").slideToggle("slow"); } $(".drop_slide").hover(slide, stop); $("#panel").hover(stop, slide); });

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  • How to create a timer the right way?

    - by mystify
    I always have an class which needs to set up a timer for as long as the object is alive. Typically an UIView which does some animation. Now the problem: If I strongly reference the NSTimer I create and invalidate and release the timer in -dealloc, the timer is never invalidated or released because -dealloc is never called, since the run loop maintains a strong reference to the target. So what can I do? If I cant hold a strong ref to the timer object, this is also bad because maybe I need a ref to it to be able to stop it. And a weak ref on a object is not good, because maybe i'm gonna access it when it's gone. So better have a retain on what I want to keep around. How are you guys solving this? must the superview create the timer? is that better? or should i really just make a weak ref on it and keep in mind that the run loop holds a strong ref on my timer for me, as long as it's not invalidated?

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  • Making more recent items more likely to be drawn

    - by bobo
    There are a few hundred of book records in the database and each record has a publish time. In the homepage of the website, I am required to write some codes to randomly pick 10 books and put them there. The requirement is that newer books need to have higher chances of getting displayed. Since the time is an integer, I am thinking like this to calculate the probability for each book: Probability of a book to be drawn = (current time - publish time of the book) / ((current time - publish time of the book1) + (current time - publish time of the book1) + ... (current time - publish time of the bookn)) After a book is drawn, the next round of the loop will minus the (current time - publish time of the book) from the denominator and recalculate the probability for each of the remaining books, the loop continues until 10 books have been drawn. Is this algorithm a correct one? By the way, the website is written in PHP. Feel free to suggest some PHP codes if you have a better algorithm in your mind. Many thanks to you all.

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  • How do I code a tree of objects in Haskell with pointers to parent and children?

    - by axilmar
    I've got the following problem: I have a tree of objects of different classes where an action in the child class invalidates the parent. In imperative languages, it is trivial to do. For example, in Java: public class A { private List<B> m_children = new LinkedList<B>(); private boolean m_valid = true; public void invalidate() { m_valid = false; } public void addChild(B child) { m_children.add(child); child.m_parent = this; } } public class B { public A m_parent = null; private int m_data = 0; public void setData(int data) { m_data = 0; m_parent.invalidate(); } } public class Main { public static void main(String[] args) { A a = new A(); B b = new B(); b.setData(0); //invalidates A } } How do I do the above in Haskell? I cannot wrap my mind around this, since once I construct an object in Haskell, it cannot be changed. I would be much obliged if the relevant Haskell code is posted.

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