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  • What is the best way to parse python script file in C/C++ code

    - by alexpov
    I am embedding python in C/C++ program. What I am trying to do is to parse the python script file from the C/C++ program, break the file to "blocks" so that each "block" is an a valid command in python code. Each block I need to put into std::string. For example: #PythonScript.py import math print "Hello Python" i = 0; while (i < 10): print "i = " , i; i = i + 1; print "GoodBye Python" In this script are 5 different "blocks": the first one is "import math;" the second is "print "Hello Python;" the third is "i = 0;" and the fourth is while (i < 10):\n\tprint "i = " , i;\n\ti = i + 1; My knowledge in python is very basic and I am not familiar with the python code syntax. What is the best way to do this, is there any Python C/C++ API function that supports this? why i need it - for GUI purpose. My program , which is writen in C, uses python to make some calculations. I run from C code , using python C API , python script and what i need is a way to capture python's output in my program. I catch it and evrything is ok, the problem is when the script involves user input. What happens is that i capture python's output after the script is finished , therefore, when there is an input command in the script i get a black screen .... i need to get all the printings before the input command. The first solution i tried is to parss the script to valid commands and run each comand, one after the other , seperatly .... for this i need to pars the script and deside what is a command and what is not ... The question is : what is the best way to do this and if there is somthing that allready does ?

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  • Synchronization of Nested Data Structures between Threads in Java

    - by Dominik
    I have a cache implementation like this: class X { private final Map<String, ConcurrentMap<String, String>> structure = new HashMap...(); public String getValue(String context, String id) { // just assume for this example that there will be always an innner map final ConcurrentMap<String, String> innerStructure = structure.get(context); String value = innerStructure.get(id); if(value == null) { synchronized(structure) { // can I be sure, that this inner map will represent the last updated // state from any thread? value = innerStructure.get(id); if(value == null) { value = getValueFromSomeSlowSource(id); innerStructure.put(id, value); } } } return value; } } Is this implementation thread-safe? Can I be sure to get the last updated state from any thread inside the synchronized block? Would this behaviour change if I use a java.util.concurrent.ReentrantLock instead of a synchronized block, like this: ... if(lock.tryLock(3, SECONDS)) { try { value = innerStructure.get(id); if(value == null) { value = getValueFromSomeSlowSource(id); innerStructure.put(id, value); } } finally { lock.unlock(); } } ... I know that final instance members are synchronized between threads, but is this also true for the objects held by these members? Maybe this is a dumb question, but I don't know how to test it to be sure, that it works on every OS and every architecture.

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  • HTML onmouseover doesn't work to show up text

    - by REALFREE
    I'm trying to show some information on a picture when onmouseover/onmouseout event occurs. What I want to achieve is something like this website does on top selling. My code is like this: <div class="container" onmouseover="$('#info').css('display','block');" onmouseout="$('#info').css('display','none');"> <img src=..."> <div id="info" style="display:none"> ... some text ... </div> </div> So div info block is initially hidden, but when mouse is on a picture I want the information to appear on corresponding picture (with tint background on the image to see text well). But somewhat it doesn't work. I appreciate any suggestion how to approach this problem. Edit: more precisely, the reason why I choose to use inline because I need to show/hide text corresponding to the image(contain unique div id)that user put their mouse on/out. That means I have many div container and each container has unique div id.

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  • Determining failing sectors on portable flash memory

    - by Faxwell Mingleton
    I'm trying to write a program that will detect signs of failure for portable flash memory devices (thumb drives, etc). I have seen tools in the past that are able to detect failing sectors and other kinds of trouble on conventional mechanical hard drives, but I fear that flash memory does not have the same kind of predictable low-level access to the hardware due to the internal workings of the storage. Things like wear-leveling and other block-remapping techniques (to skip over 'dead' sectors?) lead me to believe that determining if a flash drive is failing will be difficult at best, if not impossible (short of having constant read failures and device unmounts). Flash drives at their end-of-life should be easy to detect (constant CRC discrepancies during reads and all-out failure). But what about drives that might be failing early? Are there any tell-tale signs like slower throughput speeds that might indicate a flash drive is going to fail much sooner than normal? Along the lines of detecting potentially bad blocks, I had considered attempting random reads/writes to a file close to or exactly the size of the entire volume, but even then is it possible that the drive might report sizes under its maximum capacity to account for 'dead' blocks? In short, is there any way to circumvent or at least detect (algorithmically or otherwise) the use of block-remapping or other life extension techniques for flash memory? Let me end this question by expressing my uncertainty as to whether or not this belongs on serverfault.com . This is definitely a hardware-related question, but I also desire a software solution - preferably one that I can program myself. If this question is misplaced, I will be happy to migrate it to serverfault - but I do need a programming solution. Please let me know if you need clarification :) Thanks!

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  • Firefox drags div like it was an image, javascript event handlers possibly to blame

    - by user281434
    Hi, I'm using this HTML,CSS and Javascript code (in one document together if you want to test it out): <style type="text/css"> #slider_container { width: 200px; height: 30px; background-color: red; display:block; } #slider { width: 20px; height: 30px; background-color: blue; display:block; position:absolute; left:0; } </style> <script type="text/javascript" src="../../js/libs/jquery-1.4.2.min.js"></script> <script type="text/javascript"> $(document).ready(function() { $("#slider").mousedown(function() { $(document).mousemove(function(evnt) { $("#test").html("sliding"); }).mouseup(function() { $("#test").html("not sliding"); $(document).unbind("mousemove mouseup"); });}); }); </script> <div id="test">a</div> <div id="slider_container"> <div id="slider"></div> </div> Everything (surprisingly) works fine in IE, but firefox seems to totally clusterf*ck when this javascript is used. The first "slide" is okay, you drag, it says "sliding", you drop, it says "not sliding". On the second "slide" (or mousedown if you will), firefox suddenly thinks the div is an image or link and wants to drag it around. Screenshot of the dragging: http://i.imgur.com/nPJxZ.jpg Obviously the blue div half-positioned in the red div is the one being dragged. Windows does not capture the cursor when you take a screenshot, but it's a stop sign. Is there someway to prevent this default behaviour?

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  • How upload files to azure in background with Delphi and OmniThread?

    - by mamcx
    I have tried to upload +100 files to azure with Delphi. However, the calls block the main thread, so I want to do this with a async call or with a background thread. This is what I do now (like explained here): procedure TCloudManager.UploadTask(const input: TOmniValue; var output: TOmniValue); var FileTask:TFileTask; begin FileTask := input.AsRecord<TFileTask>; Upload(FileTask.BaseFolder, FileTask.LocalFile, FileTask.CloudFile); end; function TCloudManager.MassiveUpload(const BaseFolder: String; Files: TDictionary<String, String>): TStringList; var pipeline: IOmniPipeline; FileInfo : TPair<String,String>; FileTask:TFileTask; begin // set up pipeline pipeline := Parallel.Pipeline .Stage(UploadTask) .NumTasks(Environment.Process.Affinity.Count * 2) .Run; // insert URLs to be retrieved for FileInfo in Files do begin FileTask.LocalFile := FileInfo.Key; FileTask.CloudFile := FileInfo.Value; FileTask.BaseFolder := BaseFolder; pipeline.Input.Add(TOmniValue.FromRecord(FileTask)); end;//for pipeline.Input.CompleteAdding; // wait for pipeline to complete pipeline.WaitFor(INFINITE); end; However this block too (why? I don't understand).

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  • CFHost DNS Resolution - When is it OK to use synchronous API?

    - by Jasarien
    I went to the iPhone Developer Tech Talk a few months ago and asked one of the gurus there about the lack of NSHost on the iPhone. Some code I was porting to the iPhone made significant use of NSHost throughout its networking code. I was told that NSHost is on the iPhone, but its private. I was also told that NSHost is a synchronous API and that I shouldn't use it anyway. (If anyone could elaborate on why it shouldn't be used, as a bonus, that'd be great.) I can see the caveats of using synchronous API's on the main thread in that they'll block until complete - and that's never a good thing with network code because there are so many factors that could cause the API to block the thread for a significant amount of time. My solution was to write a wrapper around CFHost's asynchronous resolution functions. The result works quite well, and I'm considering releasing it into the public domain. But my question is this: Say my app only resolves a hostname once per run, during the connecting phase, and then cache's it for the rest of the session. During the time it is resolving, a modal screen is shown telling the user "Connecting" with a nice spinner. Does it really matter whether or not the resolution is asynchronous?? The user has to wait to connect anyway, and the resolution is only done on the first connection. Subsequent connections use the cached result of the resolution. When is it OK to be synchronous and when should things be asynchronous?

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  • Play and Stop in One button

    - by Ardi
    i'm newbie, i'm tried to make play audio play and stop for 1 button only, but i'm in trouble now. if i touch a button when audio is playing, it doesn't stop, even playing audio again and make a double sound. here's my code public class ProjectisengActivity extends Activity{ ImageButton mainkan; MediaPlayer mp; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.test2); mainkan=(ImageButton)findViewById(R.id.imageButton1); mainkan.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v){ go(); } }); public void go(){ mp=MediaPlayer.create(ProjectisengActivity.this, R.raw.test); if(mp.isPlaying()){ mp.stop(); try { mp.prepare(); } catch (IllegalStateException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } mp.seekTo(0); } else { mp.start(); } i'm create for android 3.0 (HoneyComb) thanks for help

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  • Java Concurrency : Synchronized(this) => and this.wait() and this.notify()

    - by jens
    Hello Experts, I would appreciate your help in understand a "Concurrency Example" from: http://forums.sun.com/thread.jspa?threadID=735386 Qute Start: public synchronized void enqueue(T obj) { // do addition to internal list and then... this.notify(); } public synchronized T dequeue() { while (this.size()==0) { this.wait(); } return // something from the queue } Quote End: My Question is: Why is this code valid? = When I synchronize a method like "public synchronized" = then I synchronize on the "Instance of the Object == this". However in the example above: Calling "dequeue" I will get the "lock/monitor" on this Now I am in the dequeue method. As the list is zero, the calling thread will be "waited" From my understanding I have now a deadlock situation, as I will have no chance of ever enquing an object (from an nother thread), as the "dequeue" method is not yet finised and the dequeue "method" holds the lock on this: So I will never ever get the possibility to call "enequeue" as I will not get the "this" lock. Backround: I have exactly the same problem: I have some kind of connection pool (List of Connections) and need to block if all connections are checked. What is the correct way to synchronize the List to block, if size exceeds a limit or is zero? Thank you very much Jens

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  • NetBeans Tips and Tricks

    - by cdmckay
    I just saw an Eclipse tips & tricks post and was wondering if anyone had any tips & tricks for my IDE of choice: NetBeans. Here's a few I know and find to be useful: Removing a package: After you remove a package in NetBeans, it sticks around as a grayed-out package in your Project view. To get rid of that, switch to Files view and delete the directory. Alt-Insert (in Windows) opens up a Generate submenu at your cursor. A nice shortcut for quickly generating getters/setters (among other things). Selecting a chunk of code, right-clicking and then clicking "Refactor Introduce Method" will have NetBeans introduce a method, complete with arguments and return value. Of course you have to make sure the chunk of code only has one return value. Sometimes when you run a build and it crashes, the Java window sticks around at the bottom. I used to just click X until Windows let me End Task, but there's a nicer way to get rid of them. Click "Run Stop Build/Run" and NetBeans will close the window for you. It'll even let you close multiple applications at once. These may seem obvious to grizzled NetBeans developers, but I thought they might be useful for NetBeans newbs like me. Anyone else have any tips/tricks to share? Here are some from the comments: NetBeans allows for code templates. You can even add yours on the Code Templates tab under the Editor settings on the Options window. Some examples: Type sout and hit the tab key as a shorcut for System.out.println("") Type psvm and hit the tab key as a shorcut for public static void main(String args[]) {} Ctrl Shift C: Comments out the selected block of code. Alt Shift F: Formats the selected block of code. Ctrl E: Deletes current line. Ctrl Shift I: Fixes your imports, handy if you've just written a piece of code that needs a lot of packages imported.

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  • Run a .java file using ProcessBuilder

    - by David K
    I'm a novice programmer working in Eclipse, and I need to get multiple processes running (this is going to be a simulation of a multi-computer system). My initial hackup used multiple threads to multiple classes, but now I'm trying to replace the threads with processes. From my reading, I've gleaned that ProcessBuilder is the way to go. I have tried many many versions of the input you see below, but cannot for the life of me figure out how to properly use it. I am trying to run the .java files I previously created as classes (which I have modified). I eventually just made a dummy test.java to make sure my process is working properly - its only function is to print that it ran. My code for the two files are below. Am I using ProcessBuilder correctly? Is this the correct way to read the output of my subprocess? Any help would be much appreciated. David primary process package Control; import java.io.*; import java.lang.*; public class runSPARmatch { /** * @param args */ public static void main(String args[]) { try { ProcessBuilder broker = new ProcessBuilder("javac.exe","test.java","src\\Broker\\"); Process runBroker = broker.start(); Reader reader = new InputStreamReader(runBroker.getInputStream()); int ch; while((ch = reader.read())!= -1) System.out.println((char)ch); reader.close(); runBroker.waitFor(); System.out.println("Program complete"); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } subprocess package Broker; public class test { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub System.out.println("This works"); } }

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  • IUsable: controlling resources in a better way than IDisposable

    - by Ilya Ryzhenkov
    I wish we have "Usable" pattern in C#, when code block of using construct would be passed to a function as delegate: class Usable : IUsable { public void Use(Action action) // implements IUsable { // acquire resources action(); // release resources } } and in user code: using (new Usable()) { // this code block is converted to delegate and passed to Use method above } Pros: Controlled execution, exceptions The fact of using "Usable" is visible in call stack Cons: Cost of delegate Do you think it is feasible and useful, and if it doesn't have any problems from the language point of view? Are there any pitfalls you can see? EDIT: David Schmitt proposed the following using(new Usable(delegate() { // actions here }) {} It can work in the sample scenario like that, but usually you have resource already allocated and want it to look like this: using (Repository.GlobalResource) { // actions here } Where GlobalResource (yes, I know global resources are bad) implements IUsable. You can rewrite is as short as Repository.GlobalResource.Use(() => { // actions here }); But it looks a little bit weird (and more weird if you implement interface explicitly), and this is so often case in various flavours, that I thought it deserve to be new syntactic sugar in a language.

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  • WPF and Prism View Overlay

    - by Zaheer
    Hi, I need some help with overlaying views using the prism framework.Its a little more complexed than that so let me explain.I could be over-thinking this as well :D i have shell (wpf window) and i have 2 views(A & B - both usercontrols) in a module. when the shell loads it loads view A. On view A i have a button to "popup" view B for some user input. so naturally i would think to some sort of modal window/control, maybe even a popup. however the problem i face with the popup is that when i move the shell the popup remains fixed and it doesnt block events in view A. I've tried disabling view A to stop events being fired and i've also tried to use a to get the view B move with the shell. Only the canvas works but i now need a way to block it tho'. Is there anyway i can overlay a view on top of another view with prism? or how does everyone else create modal popups with prism & wpf? any advise or pointers would be greatly appreciated.

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  • Javascript: prototypeal inheritance and the prototype proprity

    - by JanD
    Hi, I have a simple code fragment in JS working with prototype inheritance. function object(o) { function F() {} F.prototype = o; return new F(); } //the following code block has a alternate version var mammal={ color: "brown", getColor: function(){ return this.color; } } var myCat = object(mammal); myCat.meow = function(){return "meow";} that worked fine but adding this: mammal.prototype.kindOf = "predator"; does not. ("mammal.prototype is undefined") Since I guessed that object maybe have no prototype I rewrote it, replacing the var mammal={... block with: function mammal(){ this.color="brown"; this.getColor = function(){return this.color;} } which gave me a bunch of other errors: "Function.prototype.toString called on incompatible object" and if I try to call _myCat.getColor() "myCat.getColor is not a function" Now I am totally confused. After reading Crockford, and Flanagan I did not get the solution for the errors. So it would be great if somebody knows... - why is the prototype undefined in the first example (which is foremost concern; I thought the prototype of explicitly set in the object() function) - why get I these strange errors trying to use the mammal function as prototype object in the object() function?

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  • Javascript: prototypal inheritance and the prototype property

    - by JanD
    Hi, I have a simple code fragment in JS working with prototype inheritance. function object(o) { function F() {} F.prototype = o; return new F(); } //the following code block has a alternate version var mammal = { color: "brown", getColor: function() { return this.color; } } var myCat = object(mammal); myCat.meow = function(){return "meow";} that worked fine but adding this: mammal.prototype.kindOf = "predator"; does not. ("mammal.prototype is undefined") Since I guessed that object maybe have no prototype I rewrote it, replacing the var mammal={... block with: function mammal() { this.color = "brown"; this.getColor = function() { return this.color; } } which gave me a bunch of other errors: "Function.prototype.toString called on incompatible object" and if I try to call _myCat.getColor() "myCat.getColor is not a function" Now I am totally confused. After reading Crockford, and Flanagan I did not get the solution for the errors. So it would be great if somebody knows... - why is the prototype undefined in the first example (which is foremost concern; I thought the prototype of explicitly set in the object() function) - why get I these strange errors trying to use the mammal function as prototype object in the object() function? Edit by the Creator of the Question: These two links helped a lot too: Prototypes_in_JavaScript on the spheredev wiki explains the way the prototype property works relativily simple. What it lacks is some try-out code examples. Some good examples are provided by Morris John's Article. I personally find the explanations are not that easy as in the first link, but still very good. The most difficult part even after I actually got it is really not to confuse the .prototype propery with the internal [[Prototype]] of an object.

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  • Unable to upload large files on FTP using Apache commons-net-3.1

    - by Nitin
    I am trying to upload the one large file ( more than 8 MB) using storeFile(remote, local) method of FTPClient but it results false.It get uploaded with some extra bytes.Following is the code with Output: public class Main { public static void main(String[] args) { FTPClient client = new FTPClient(); FileInputStream fis = null; try { client.connect("208.106.181.143"); client.setFileTransferMode(client.BINARY_FILE_TYPE); client.login("abc", "java"); int reply = client.getReplyCode(); System.out.println("Received Reply from FTP Connection:" + reply); if(FTPReply.isPositiveCompletion(reply)){ System.out.println("Connected Success"); } client.changeWorkingDirectory("/"+"Everbest"+"/"); client.makeDirectory("ETPSupplyChain5.3-EvbstSP3"); client.changeWorkingDirectory("/"+"Everbest"+"/"+"ETPSupplyChain5.3-EvbstSP3"+"/"); FTPFile[] names = client.listFiles(); String filename = "E:\\Nitin\\D-Drive\\Installer.rar"; fis = new FileInputStream(filename); boolean result = client.storeFile("Installer.rar", fis); int replyAfterupload = client.getReplyCode(); System.out.println("Received Reply from FTP Connection replyAfterupload:" + replyAfterupload); System.out.println("result:"+result); for (FTPFile name : names) { System.out.println("Name = " + name); } client.logout(); fis.close(); client.disconnect(); } catch (SocketException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } o/p: Received Reply from FTP Connection:230 Connected Success 32 /Everbest/ETPSupplyChain5.3-EvbstSP3 Received Reply from FTP Connection replyAfterupload:150 result:false

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  • Squid handling of concurrent cache misses

    - by Oliver H-H
    We're using a Squid cache to off-load traffic from our web servers, ie. it's setup as a reverse-proxy responding to inbound requests before they hit our web servers. When we get blitzed with concurrent requests for the same request that's not in the cache, Squid proxies all the requests through to our web ("origin") servers. For us, this behavior isn't ideal: our origin servers gets bogged down trying to fulfill N identical requests concurrently. Instead, we'd like the first request to proxy through to the origin server, the rest of the requests to queue at the Squid layer, and then all be fulfilled by Squid when the origin server has responded to that first request. Does anyone know how to configure Squid to do this? We've read through the documentation multiple times and thoroughly web-searched the topic, but can't figure out how to do it. We use Akamai too and, interestingly, this is its default behavior. (However, Akamai has so many nodes that we still see lots of concurrent requests in certain traffic spike scenarios, even with Akamai's super-node feature enabled.) This behavior is clearly configurable for some other caches, eg. the Ehcache documentation offers the option "Concurrent Cache Misses: A cache miss will cause the filter chain, upstream of the caching filter to be processed. To avoid threads requesting the same key to do useless duplicate work, these threads block behind the first thread." Some folks call this behavior a "blocking cache," since the subsequent concurrent requests block behind the first request until it's fulfilled or timed-out. Thx for looking over my noob question! Oliver

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  • Form values in a list item

    - by Tri
    Here is the site mock-up I'm working on for my job: http://dev.arm.gov/~noensie/dqhands/cgi-bin/explorer. I'm still a novice in web developing and I need help with placing form values in a list item to pass on to another page. I'd rather not go in great detail the purpose of this website, but in terms of its basic use, select the parameters in the middle column for a request and add it to the list on the right column by pressing on "add request" button when it appears. After the list have been populated, a user would submit the selected requests, which will direct them to another page based on the requests selected (or added to the list, same thing). That last sentence is where I'm having a problem. Right now, each of request in the list in the right column are <li> elements and I assign them attribute values that needed to be passed on to the next page. I tried inserting a hidden input with same values, but I'm still not sure how to utilize that; I'm not even sure using the hidden input is the correct way. Also the "submit request" button is located outside the <form> block. I was going to utilize javascript and jQuery to enable the button to serialize the values in the <form> block, but I don't know quite how to do that. Go ahead and take a look at my javascript code (index.js) and slay me, or, I mean, my code. It's still pretty elementary and short (~260 lines, that's short right?). I will take any help for this problem (as the matter of fact, if you see any other problems or a better way of implementation of something, go ahead and mention that too); tips, advice, code samples, or whatever else you can contribute, it will be greatly appreciated. Tri

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  • Parsing basic math equations for children's educational software?

    - by Simucal
    Inspired by a recent TED talk, I want to write a small piece of educational software. The researcher created little miniature computers in the shape of blocks called "Siftables". [David Merril, inventor - with Siftables in the background.] There were many applications he used the blocks in but my favorite was when each block was a number or basic operation symbol. You could then re-arrange the blocks of numbers or operation symbols in a line, and it would display an answer on another siftable block. So, I've decided I wanted to implemented a software version of "Math Siftables" on a limited scale as my final project for a CS course I'm taking. What is the generally accepted way for parsing and interpreting a string of math expressions, and if they are valid, perform the operation? Is this a case where I should implement a full parser/lexer? I would imagine interpreting basic math expressions would be a semi-common problem in computer science so I'm looking for the right way to approach this. For example, if my Math Siftable blocks where arranged like: [1] [+] [2] This would be a valid sequence and I would perform the necessary operation to arrive at "3". However, if the child were to drag several operation blocks together such as: [2] [\] [\] [5] It would obviously be invalid. Ultimately, I want to be able to parse and interpret any number of chains of operations with the blocks that the user can drag together. Can anyone explain to me or point me to resources for parsing basic math expressions? I'd prefer as much of a language agnostic answer as possible.

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  • Flexible CMS for non-programmers

    - by Bunkerbewohner
    Hello! I'm looking for a content management system that allows creating single pages out of predefined blocks flexibly. For example I have a "product" block that is used to show producs on a page and it may appear numerous times on one page with different contents. But I also might wanna use it on different pages. Also I have simply generic blocks like multiple column text blocks (1 col, 2 col etc.) where I just want to insert this kind of structure into the page and enter any text. So I'm looking for a cms with someething like a building block / module concept for contents. I'm already searching the web but there are so many CMSs that I can't look into every one. So if anyone knows a solution that might be right for me, please tell me! Technology-wise it just has to run on Linux. If it's OpenSource / free that's great, but I might also pay for it, if it offers the features I want. Thanks for any hints in advance!

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  • Debug NAudio MP3 reading difference?

    - by Conrad Albrecht
    My code using NAudio to read one particular MP3 gets different results than several other commercial apps. Specifically: My NAudio-based code finds ~1.4 sec of silence at the beginning of this MP3 before "audible audio" (a drum pickup) starts, whereas other apps (Windows Media Player, RealPlayer, WavePad) show ~2.5 sec of silence before that same drum pickup. The particular MP3 is "Like A Rolling Stone" downloaded from Amazon.com. Tested several other MP3s and none show any similar difference between my code and other apps. Most MP3s don't start with such a long silence so I suspect that's the source of the difference. Debugging problems: I can't actually find a way to even prove that the other apps are right and NAudio/me is wrong, i.e. to compare block-by-block my code's results to a "known good reference implementation"; therefore I can't even precisely define the "error" I need to debug. Since my code reads thousands of samples during those 1.4 sec with no obvious errors, I can't think how to narrow down where/when in the input stream to look for a bug. The heart of the NAudio code is a P/Invoke call to acmStreamConvert(), which is a Windows "black box" call which I can't think how to error-check. Can anyone think of any tricks/techniques to debug this?

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  • strategy for choosing proper object and proper method

    - by zerkms
    in the code below at first if statements block (there will be more than just "worker" condition, joined with else if) i select proper filter_object. After this in the same conditional block i select what filter should be applied by filter object. This code is silly. public class Filter { public static List<data.Issue> fetch(string type, string filter) { Filter_Base filter_object = new Filter_Base(filter); if (type == "worker") { filter_object = new Filter_Worker(filter); } else if (type == "dispatcher") { filter_object = new Filter_Dispatcher(filter); } List<data.Issue> result = new List<data.Issue>(); if (filter == "new") { result = filter_object.new_issues(); } else if (filter == "ended") { result = filter_object.ended_issues(); } return result; } } public class Filter_Base { protected string _filter; public Filter_Base(string filter) { _filter = filter; } public virtual List<data.Issue> new_issues() { return new List<data.Issue>(); } public virtual List<data.Issue> ended_issues() { return new List<data.Issue>(); } } public class Filter_Worker : Filter_Base { public Filter_Worker(string filter) : base(filter) { } public override List<data.Issue> new_issues() { return (from i in data.db.GetInstance().Issues where (new int[] { 4, 5 }).Contains(i.RequestStatusId) select i).Take(10).ToList(); } } public class Filter_Dispatcher : Filter_Base { public Filter_Dispatcher(string filter) : base(filter) { } } it will be used in some kind of: Filter.fetch("worker", "new"); this code means, that for user that belongs to role "worker" only "new" issues will be fetched (this is some kind of small and simple CRM). Or another: Filter.fetch("dispatcher", "ended"); // here we get finished issues for dispatcher role Any proposals on how to improve it?

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  • Copy vector of values to vector of pairs in one line

    - by Kirill V. Lyadvinsky
    I have the following types: struct X { int x; X( int val ) : x(val) {} }; struct X2 { int x2; X2() : x2() {} }; typedef std::pair<X, X2> pair_t; typedef std::vector<pair_t> pairs_vec_t; typedef std::vector<X> X_vec_t; I need to initialize instance of pairs_vec_t with values from X_vec_t. I use the following code and it works as expected: int main() { pairs_vec_t ps; X_vec_t xs; // this is not empty in the production code ps.reserve( xs.size() ); { // I want to change this block to one line code. struct get_pair { pair_t operator()( const X& value ) { return std::make_pair( value, X2() ); } }; std::transform( xs.begin(), xs.end(), back_inserter(ps), get_pair() ); } return 0; } What I'm trying to do is to reduce my copying block to one line with using boost::bind. This code is not working: for_each( xs.begin(), xs.end(), boost::bind( &pairs_vec_t::push_back, ps, boost::bind( &std::make_pair, _1, X2() ) ) ); I know why it is not working, but I want to know how to make it working without declaring extra functions and structs?

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  • CUDA: When to use shared memory and when to rely on L1 caching?

    - by Roger Dahl
    After Compute Capability 2.0 (Fermi) was released, I've wondered if there are any use cases left for shared memory. That is, when is it better to use shared memory than just let L1 perform its magic in the background? Is shared memory simply there to let algorithms designed for CC < 2.0 run efficiently without modifications? To collaborate via shared memory, threads in a block write to shared memory and synchronize with __syncthreads(). Why not simply write to global memory (through L1), and synchronize with __threadfence_block()? The latter option should be easier to implement since it doesn't have to relate to two different locations of values, and it should be faster because there is no explicit copying from global to shared memory. Since the data gets cached in L1, threads don't have to wait for data to actually make it all the way out to global memory. With shared memory, one is guaranteed that a value that was put there remains there throughout the duration of the block. This is as opposed to values in L1, which get evicted if they are not used often enough. Are there any cases where it's better too cache such rarely used data in shared memory than to let the L1 manage them based on the usage pattern that the algorithm actually has?

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  • XSL-FO: Static content AND Flow content in Region-Body: Possible?

    - by Peterdk
    I have the following problem: I need to use XSLFO to generate a 2-column multipage document. Problem is: I need to have a vertical line between the 2 columns. Since XSLFO does not seem to specify a option for creating such a divider, I need to manually put it there. I was thinking of using a static rotated blockcontainer with a leader in it. However, it looks like it's not possible to use static-content on the same region as where the flow content comes. <fo:layout-master-set> <fo:simple-page-master page-width="170mm" page-height="222mm" master-name="page" > <fo:region-body region-name="xsl-region-body" margin-top="2mm" margin-bottom="2mm" margin-left="10mm" margin-right="10mm" column-count="2" column-gap="5mm" /> </fo:simple-page-master> </fo:layout-master-set> <fo:page-sequence master-reference="page"> <fo:static-content flow-name="xsl-region-body" ><!-- This gives a error --> <fo:block>test</fo:block> </fo:static-content> <fo:flow flow-name="xsl-region-body"> <xsl:apply-templates/> </fo:flow> </fo:page-sequence> Results in (XEP): [error] Duplicate identifier: flow-name="xsl-region-body". Property 'flow-name' should be unique within 'fo:page-sequence'. Are there any methods to place static content on the main region when also flow content is placed there? Or: Is there a way to define the divider that divides a 2-column layout?

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