Search Results

Search found 16947 results on 678 pages for 'kernel programming'.

Page 217/678 | < Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >

  • Does MATLAB perform tail call optimization?

    - by Shea Levy
    I've recently learned Haskell, and am trying to carry the pure functional style over to my other code when possible. An important aspect of this is treating all variables as immutable, i.e. constants. In order to do so, many computations that would be implemented using loops in an imperative style have to be performed using recursion, which typically incurs a memory penalty due to the allocation a new stack frame for each function call. In the special case of a tail call (where the return value of a called function is immediately returned to the callee's caller), however, this penalty can be bypassed by a process called tail call optimization (in one method, this can be done by essentially replacing a call with a jmp after setting up the stack properly). Does MATLAB perform TCO by default, or is there a way to tell it to?

    Read the article

  • Object serialization practical uses?

    - by nash
    How many software projects have you worked on used object serialization? I personally never came across a scenario where object serialization was used. One use case i can think of is, a server software storing objects to disk to save memory. Are there other types of software where object serialization is essential or preferred over a database?

    Read the article

  • Is there a language with native pass-by-reference/pass-by-name semantics, which could be used in mod

    - by Bubba88
    Hi! This is a reopened question. I look for a language and supporting platform for it, where the language could have pass-by-reference or pass-by-name semantics by default. I know the history a little, that there were Algol, Fortran and there still is C++ which could make it possible; but, basically, what I look for is something more modern and where the mentioned value pass methodology is preferred and by default (implicitly assumed). I ask this question, because, to my mind, some of the advantages of pass-by-ref/name seem kind of obvious. For example when it is used in a standalone agent, where copyiong of values is not necessary (to some extent) and performance wouldn't be downgraded much in that case. So, I could employ it in e.g. rich client app or some game-style or standalone service-kind application. The main advantage to me is the clear separation between identity of a symbol, and its current value. I mean when there is no reduntant copying, you know that you're working with the exact symbol/path you have queried/received. And intristing boxing of values will not interfere with the actual logic of program. I know that there is C# ref keyword, but it's something not so intristic, though acceptable. Equally, I realize that pass-by-reference semantics could be simulated in virtually any language (Java as an instant example) and so on.. not sure about pass by name :) What would you recommend - create a something like DSL for such needs wherever it be appropriate; or use some languages that I already know? Maybe, there is something that I'm missing? Thank you!

    Read the article

  • Naming convention in Objective C /C , start with "_"?

    - by Tattat
    Something I see ppl define the variable like this: b2World *_world; b2Body *_body; CCSprite *_ball; instead of b2World *world; b2Body *body; CCSprite *ball; I familiar with the second one, but not the first one. So, I checked the Wikipedia about naming convention: Names beginning with double underscore or an underscore and a capital letter are reserved for implementation (compiler, standard library) and should not be used (e.g. __reserved or _Reserved). So, is that any special meaning which is start with "_"? The wiki page.

    Read the article

  • Socket read() hangs for a while when there is no data to read.

    - by janesconference
    Hi' I'm writing a simple http port forwarder. I read data from port 80, and pass the data to my lighttpd server, on port 8080. As long as I write() data on the socket on port 8080 (forwarding the request) there's no problem, but when I read() data from that socket (forwarding the response), the last read() hangs a lot (about 1 or 2 seconds) before realizing there's no more data and returning 0. I tried to set the socket to non-blocking, but this doesn't work, as sometimes it returns EWOULDBLOCKING even if there's some data left (lighttpd + cgi can be quite slow). I tried to set a timeout with select(), but, as above, a slow cgi could timeout the socket when there's actually some data to transmit. How would you do?

    Read the article

  • (For what) Are Fortran, Cobol and Co. used today?

    - by lamas
    I'm a relatively young programmer and so I don't really know much about languages like Fortran or Cobol that have their origins in the beginning of modern informatics. I'm a bit confused because it seems like there are many people out there saying that these two languages are still very alive and being used all over the world whereas others say the opposite. In addition, it seems like there are only very few questions tagged Fortran or Cobol here on stackoverflow. Can someone "demystify" the situation for me? Who uses these senior languages these days and are they even used anymore? Do you have any experiences with one of the languages or do you know something about their latest developments?

    Read the article

  • C# property definition

    - by Sunny
    For C# properties, I can do this: public class Employee{ public string Name { get; private set; } public Employee(string name){ Name = name; } } which means that the Name property can be set within the class Employee & can be read publicly. But, if I want to restrict the set to only within the constructors of the Employee class, I need to do: public class Employee{ public readonly string Name = String.Empty; public Employee(string name){ Name = name; } } But, for this case, I had to change the property to a field. Is there any reason this is not possible/allowed in C#: public class Employee{ public string Name { get; private readonly set; } public Employee(string name){ Name = name; } } IMO this will allow us to have properties which can be set only in the constructor & does not require us to change properties to fields... Thanks!

    Read the article

  • How do I handle partial write completions from overlapped I/O using I/O Completion Ports

    - by Poni
    On Windows I/O completion ports, say I do this: void function() { WSASend("1111"); // A WSASend("2222"); // B WSASend("3333"); // C } If I got a "write-complete" that says 3 bytes of WSASend() A were sent, is it possible that right after that I'll get a "write-complete" that tells me that some or all of B & C were sent, or will TCP will hold them until I re-issue a WSASend() call with the rest of A's data? Or will TCP complete it automatically?

    Read the article

  • IP address problem

    - by mavric
    I built a TicTacToe game application (I'm using TCP protocol) that consist of server and client (that run two times to represent the 2 opponents). I have a problem and I can't find the solution for it, that is why I'm asking this question. the problem is : when the client try to connect the server on my machine, it never connect because of the IP address(obtained from the support tab from the local area connection in my windows) of my machine isn't correct. I tried to obtain my IP address from websites that told you your IP but I doesn't work. I have a problem to determine my IP address that any machine can connect to me from anywhere. p.s. I'm using router to connect the internet. thanks.

    Read the article

  • Is selling a "website screen scraper" illegal?

    - by Yatendra Goel
    I have coded a "website screen scraper" and want to sell it commercially. I know that webpages scraped by the screen scraper are restricted to be scraped by the webmaser of that website. The robots.txt file of the website says that its webpages must not be scraped. So my question is whether selling that screen scraper is a crime or using that screen scraper is a crime in legal terms. I know that this question is related to law but I thought the software experts on SO must also have answer to this question.

    Read the article

  • Is key 'chord' functionality provided by Win32/.net?

    - by John
    Several MS apps support the concept of chords, like "CTRL+X,Y" which means "holding down CTRL, press X, then Y". Is this a bespoke thing they (and other companies) implement, or is it built into any APIs? It would be nice to be able to set up event handlers or accelerators based on chords rather than write code to do it.

    Read the article

  • Generate an image / thumbnail of a webpage using X/Gui-less linux

    - by dassouki
    There are a lot of solutions out there on generating a thumbnail or an image preview of a webpage. Some of these are websites like websnapshots, windows libraries such as PHP's imagegrabscreen (only works on windows), and KDE's wkhtml. Many more do exist. However, I'm looking for a GUI-less solution. Something I can create an API around and link it to php or python. I'm comfortable with python, php, C, and shell. This is a personal project, so I'm not interested in commercial applications as I'm aware of their existence. Any ideas?

    Read the article

  • Visual Studio 2010 Language Support

    - by inspectorG4dget
    Hello SO, I want to be able to develop code using Visual Studio 2010. I just got VS2010 and I'm not able to get the languages I want on it. The main reason that I'm asking this is that I'm trying to migrate to ONE IDE that does it all for me. Thus far eclipse has been doing a good job, but I've been informed that VS2010 is better and I'm trying to get into the groove of that standard So my question is two-fold. I am not able to find a complete list of languages supported by VS2010. What are these languages? How can I get VS2010 support for: a. Python/IronPython b. C/C++/C#/XNA c. Java My Googling has given me no promising/definitive results. I'd really appreciate any help.

    Read the article

  • How to number the ls output in unix?

    - by Snehal
    I am trying to write a file with format - "id file_absolute_path" which basically lists down all the files recursively in a folder and give an identifier to each file listed like 1,2,3,4. I can get the absolute path of the files recursively using the following command: ls -d -1 $PWD/**/*/* However, I am unable to give an identifier from the output of the ls command. I am sure this can be done using awk, but can't seem to solve it.

    Read the article

  • Please Help me add up the elements for this structure in Scheme/Lisp

    - by kunjaan
    I have an input which is of this form: (((lady-in-water . 1.25) (snake . 1.75) (run . 2.25) (just-my-luck . 1.5)) ((lady-in-water . 0.8235294117647058) (snake . 0.5882352941176471) (just-my-luck . 0.8235294117647058)) ((lady-in-water . 0.8888888888888888) (snake . 1.5555555555555554) (just-my-luck . 1.3333333333333333))) (context: the word denotes a movie and the number denotes the weighted rating submitted by the user) I need to add all the quantity and return a list which looks something like this ((lady-in-water 2.5) (snake 2.5) (run 2.25) (just-myluck 2.6)) How do I traverse the list and all the quantities? I am really stumped. Please help me. Thanks.

    Read the article

  • How to find minimum weight with maximum cost in 0-1 Knapsack algorithm?

    - by Nitin9791
    I am trying to solve a spoj problem Party Schedule the problem statement is- You just received another bill which you cannot pay because you lack the money. Unfortunately, this is not the first time to happen, and now you decide to investigate the cause of your constant monetary shortness. The reason is quite obvious: the lion's share of your money routinely disappears at the entrance of party localities. You make up your mind to solve the problem where it arises, namely at the parties themselves. You introduce a limit for your party budget and try to have the most possible fun with regard to this limit. You inquire beforehand about the entrance fee to each party and estimate how much fun you might have there. The list is readily compiled, but how do you actually pick the parties that give you the most fun and do not exceed your budget? Write a program which finds this optimal set of parties that offer the most fun. Keep in mind that your budget need not necessarily be reached exactly. Achieve the highest possible fun level, and do not spend more money than is absolutely necessary. Input The first line of the input specifies your party budget and the number n of parties. The following n lines contain two numbers each. The first number indicates the entrance fee of each party. Parties cost between 5 and 25 francs. The second number indicates the amount of fun of each party, given as an integer number ranging from 0 to 10. The budget will not exceed 500 and there will be at most 100 parties. All numbers are separated by a single space. There are many test cases. Input ends with 0 0. Output For each test case your program must output the sum of the entrance fees and the sum of all fun values of an optimal solution. Both numbers must be separated by a single space. Example Sample input: 50 10 12 3 15 8 16 9 16 6 10 2 21 9 18 4 12 4 17 8 18 9 50 10 13 8 19 10 16 8 12 9 10 2 12 8 13 5 15 5 11 7 16 2 0 0 Sample output: 49 26 48 32 now I know that it is an advance version of 0/1 knapsack problem where along with maximum cost we also have to find minimum weight that is less than a a given weight and have maximum cost. so I have used dp to solve this problem but still get a wrong awnser on submission while it is perfectly fine with given test cases. My code is typedef vector<int> vi; #define pb push_back #define FOR(i,n) for(int i=0;i<n;i++) int main() { //freopen("input.txt","r",stdin); while(1) { int W,n; cin>>W>>n; if(W==0 && n==0) break; int K[n+1][W+1]; vi val,wt; FOR(i,n) { int x,y; cin>>x>>y; wt.pb(x); val.pb(y); } FOR(i,n+1) { FOR(w,W+1) { if(i==0 || w==0) { K[i][w]=0; } else if (wt[i-1] <= w) { if(val[i-1] + K[i-1][w-wt[i-1]]>=K[i-1][w]) { K[i][w]=val[i-1] + K[i-1][w-wt[i-1]]; } else { K[i][w]=K[i-1][w]; } } else { K[i][w] = K[i-1][w]; } } } int a1=K[n][W],a2; for(int j=0;j<W;j++) { if(K[n][j]==a1) { a2=j; break; } } cout<<a2<<" "<<a1<<"\n"; } return 0; } Could anyone suggest what am I missing??

    Read the article

  • How do you pronounce "Enum"?

    - by Davy8
    In the spirit of this question how do you pronounce Enum? Tagging as subjective and community wiki obviously. I've heard E-Nuhm and E-Nnoom any others? Edit: Looks like we have a winner. Thought it'd be a closer race since most of the people at my work use the 2nd one.

    Read the article

  • Using static variable in function vs passing variable from caller

    - by Patrick
    I have a function which spawns various types of threads, one of the thread types needs to be spawned every x seconds. I currently have it like this: bool isTime( Time t ) { return t >= now(); } void spawner() { while( 1 ) { Time t = now(); if( isTime( t ) )//is time is called in more than one place in the real function { launchthread() t = now() + offset; } } } but I'm thinking of changing it to: bool isTime() { static Time t = now(); if( t >= now() ) { t = now() + offset; return true; } return false; } void spawner() { if( isTime() ) launchthread(); } I think the second way is neater but I generally avoid statics in much the same way I avoid global data; anyone have any thoughts on the different styles?

    Read the article

< Previous Page | 213 214 215 216 217 218 219 220 221 222 223 224  | Next Page >