Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 582/809 | < Previous Page | 578 579 580 581 582 583 584 585 586 587 588 589  | Next Page >

• Does "Value Restriction" practically mean that there is no higher order functional programming?

  - by Sadache

  Does "Value Restriction" practically mean that there is no higher order functional programming? I have a problem that each time I try to do a bit of HOP I get caught by a VR error. Example: let simple (s:string)= fun rq->1 let oops= simple "" type 'a SimpleType= F of (int ->'a-> 'a) let get a = F(fun req -> id) let oops2= get "" and I would like to know whether it is a problem of a prticular implementation of VR or it is a general problem that has no solution in a mutable type-infered language that doesn't include mutation in the type system.

  Read the article

• Webservice for serial port devices

  - by camx

  Hi I want to create a remote webservice for an application that is now avaliable only localy. This application controlls three devices (each is controlled separately) connected on serial port. The problem is that I don't know how to take care of passing back information that a device return requested data. For example - I send move command to the motion device (which is very slow and can take a minute or more). Can I just set a big timeout on the client side (and server side) and return for example a true/false if operation is completed or is this a bad idea? Is SOAP with big timeouts ok? And the other question is if Mono on Linux (Ubuntu 9.10, Mono 2.4) is stable enought for making a web service or should I chose Java or some other language? I'm open for recommendations. Thanks for your help!

  Read the article

• Purpose of IF, ELSE, FOR macros ?

  - by psihodelia

  I have a source code of a library which has a lot of strange IF, ELSE, FOR, etc. macros for all common C-keywords instead of using just usual if,else,for,while keywords. These macros are defined like this: #define IF( a) if( increment_if(), a) where increment_if() function is defined so: static __inline void increment_if( void) { // If the "IF" operator comes just after an "ELSE", its counter // must not be incremented. ... //implementation } I don't really understand, what is the purpose of such macros? This library is for a real-time application and I suppose that using such macros must slow-down an application.

  Read the article

• Active Record's SessionScope in BL or DL ?

  - by StupidDeveloper

  Imagine that I have 3 projects: DL, BL and WS. DL contains Active Record implementation with all the mappings, BL has some logic (calling various DL methods) and finally WebService project exposes some BL methods (using some DTO mappings). The questions are: Should I put all data related methods in DL or is it allowed to use SessionScope in BL ? There are some complicated stuff that is right now done on BL. Should/can BL operate on classes-mappings of the Active record? The question is where should be the translation to DTO be made (at the BL level? ) ?

  Read the article

• Execute a method less times possible - PHP

  - by serhio

  I have a site in multiple languages. I have a method that returns me the today currencies in a array. I display that currencies in a table then. // --- en/index.php <?php include_once "../exchangeRates.php"; $currencies = ReadExchangeRates(); // --- fr/index.php <?php include_once "../exchangeRates.php"; $currencies = ReadExchangeRates(); ... // somewhere in the page <td><?php echo $currencies["eur"]["today"]; ?></td> So, every time I load, en/ or fr/ or other language, I request the exchange rates from a external site. Can I optimize this behavior (reading once per day or session)? maybe to store a global variable and check the update date?

  Read the article

• How can I call an executable to run on a separate machine within a program on my own machine (win xp

  - by Mr. H.

  My objective is to write a program which will call another executable on a separate computer(all with win xp) with parameters determined at run-time, then repeat for several more computers, and then collect the results. In short, I'm working on a grid-computing project. The algorithm itself being used is already coded in FORTRAN, but we are looking for an efficient way to run it on many computers at once. I suppose one way to accomplish this would be to upload a script to each computer and then run said script on each computer, all automatically and dependent on my own parameters. But how can I write a program which will write to, upload, and run a script on a separate computer? I had considered GridGain, but the algorithm is already coded and in a different language, so that is ruled out. My current guess at accomplishing this task is using Expect (wiki/Expect), but I have no knowledge of the tool. Any advice appreciated.

  Read the article

• Delphi 7 WriteProcessMemory

  - by Tprice88

  This is my Working Code DriftMul:=99; WriteProcessMemory(HandleWindow, ptr($4E709C), @DriftMul, 2, Write); I want to Convert it without using a variable but it wont work Below is just an Example of what i want to do. WriteProcessMemory(HandleWindow, ptr($4E709C), ptr(99), 2, Write); Does anyone know a way to make this work with using a variable??? I am able to program in a few languages and every language i use their is a way to to do this. The reason i want to do this is because i am gonna be making a big program that does alot of writing of different values and it will save me around 300+ lines. Below is an Example in c++ i was using. WriteProcessMemory(hProcess, (void*)0x4E709C, (void*)(PBYTE)"\x20", 1, NULL);

  Read the article

• Looking for suggestions about an architecture of a MultiThreaded app.

  - by Dimitri

  Hello everyone. I am looking to develop a multithreaded application that will be running in unconditional loop and processing high volume of data. High volume is 2000+ records per minute. Processing will involve data retrieval, calculations and data updates. I need the application to perform so that there is virtually no back log, meaning i need to be able to finish up all of the 2000 points in one minute or even faster. Our current implementation features a multithreaded application that is spawn multiple times (from 10 to 20) and we are noticing that it's not handling data as expected and i even feel that instances of the application compete with each other for processor time and eventually if not slowing, not benefiting each other for sure. I would like to know what would be the best approach: have a single instance running but maximize threads that can run simultaneously? or is there other ways i don't know? I'm open to suggestions. Thank you in advance

  Read the article

• Regex for xml parsing

  - by ogmios

  What is your opinon about following regexes - is it correct? To find element with spcific and required attribute "<(" + elem_name + ")(\s+(?:[^<]?\s+)" + attr_name + "\s*=\s*(['\"])((?:(?!\3).))\3[^<])(.*?)" To find element with spcific but optional attribute "<(" + elem_name + ")(\s*|\s+(?:[^<]?\s+)(?:" + attr_name + "\s*=\s*(['\"])((?:(?!\3).))\3)?[^<])(.*?)" Pleas not another answer "use existing xml parser". Question is - are the regexes proper or not? This is specific situation - C language in embedded system and xml is not well-formed (cannot be fixed - does not depend on me). Xml have specified schema and no problem with namespaces etc. exists.

  Read the article

• How to add response headers based on Content-type; getting Content-type before the response is commi

  - by Bozho

  I want to set the Expires header for all image/* and text/css. I'm doing this in a Filter. However: before calling chain.doFilter(..) the Content-type is not yet "realized" after calling chain.doFilter(..) the Content-type is set, but so is content-length, which forbids adding new headers (at least in Tomcat implementation) I can use the extensions of the requested resource, but since some of the css files are generated by richfaces by taking them from inside jar-files, the name of the file isn't x.css, but is /xx/yy/zz.xcss/DATB/.... So, is there a way to get the Content-type before the response is committed.

  Read the article

• Design question?

  - by Mohamed

  I am building music app, where user can do several tasks including but not limited to listening song, like song, recommend song to a friend and extra. currently I have this model: class Activity(models.Model): activity = models.TextField() user = models.ForeignKey(User) date = models.DateTimeField(auto_now=True) so far I thought about two solutions. 1. saving a string to database. e.g "you listened song xyz" 2. create a dictionary about the activity and save to the database using pickle or json. e.g. dict_ = {"activity_type":"listening", "song":song_obj} I am leaning to the second implementation, but not quite sure. so what do you think about those two methods? do you know better way to achieve the goal?

  Read the article

• DDD Infrastructure services

  - by Zygimantas

  Hello, I am learning DDD and I am a little bit lost in Infrastructure layer: As I understand, "all good DDD applications" should have 4 layers: Presentation, Application, Domain and Infrastructure. Database should be accessed using Repositories. Repository interfaces should be in Domain layer and repository implementation - in Infrastructure (reference http://stackoverflow.com/questions/693221/ddd-where-to-keep-domain-interfaces-the-infrastructure). Application, Domain and Infrastructure layer should/may have services (reference www.lostechies.com/blogs/jimmy_bogard/archive/2008/08/21/services-in-domain-driven-design.aspx), in example EmailService in Infrastructure layer which sends Email messages. BUT, inside Infrastructure layer we have repository implementations, which are used to access database. So, in this case, repositories are database services? What is the difference between Infrastructure service and repository? Thanks in advance!

  Read the article

• Is it legal for a C++ reference to be NULL?

  - by BCS

  A while back I ran into a bug the looked something like this: void fn(int &i) { printf(&i == NULL ? "NULL\n" : "!NULL\n"); } int main() { int i; int *ip = NULL; fn(i); // prints !NULL fn(*ip); // prints NULL return 0; } More recently, I ran into this comment about C++ references: [References arguments make] it clear, unlike with pointers, that NULL is not a possible value. But, as show above, NULL is a possible value. So where is the error? In the language spec? (Unlikely.) Is the compiler in error for allowing that? Is that coding guide in error (or a little ambiguous)? Or am I just wandering into the minefield known as undefined behavior?

  Read the article

• Validation of method parameters

  - by Anton Tsivarev

  I have a RESTful web service. For implementation using JAX-RS (Jersey). Have the following method: public void foo (@PathParam ("name") String uuid) { ... } I need to do validation of input parameters. And if data invalid throw WebApplicationException. I added my custom annotation CheckUuid (extends ): public void foo (@PathParam ("name") @CheckUuid String uuid) { ... } Is it possible to do validation using annotations on a stage when the method chosen, but not yet called? For example using PreProcessInterceptor?

  Read the article

• Write a recursive function in C that converts a number into a string

  - by user3501779

  I'm studying software engineering, and came across this exercise: it asks to write a recursive function in C language that receives a positive integer and an empty string, and "translates" the number into a string. Meaning that after calling the function, the string we sent would contain the number but as a string of its digits. I wrote this function, but when I tried printing the string, it did print the number I sent, but in reverse. This is the function: void strnum(int n, char *str) { if(n) { strnum(n/10, str+1); *str = n%10 + '0'; } } For example, I sent the number 123 on function call, and the output was 321 instead of 123. I also tried exchanging the two lines within the if statement, and it still does the same. I can't figure out what I did wrong. Can someone help please? NOTE: Use of while and for loop statements is not allowed for the exercise.

  Read the article

• Simple iPhone tally method question

  - by Rob

  Just trying to create a simple method that counts up 1 on the tally when the button is pressed. My knowledge is extremely limited and I am pretty sure that my problem is somewhere in the method implementation: -(IBAction) updateTally:(id) sender { NSString *text; int total = 0; total = total + 1; text=[[NSString alloc] initWithFormat: @"%i", total]; lblTally.text = text; } I have done the necessary interface declarations for the lblTally UILabel and the updateTally method. I suspect that there is some sort of an NSString/int/%i/%@ mixup that I am making but I'm not sure how to fix it. When I run the program as it currently is it displays a 0 in the lblTally label field on the iphone. When I press the button it then displays a 1 in that field. However, if I continue to press the button - nothing happens.

  Read the article

• Determine phone number based on time zone?

  - by Zachary Burt

  I have a (potentially international) phone number. It may or may not have a country code prefix. Does anyone know of a database that will help me map phone number = time zone? I would even just like to map phone number = country, since I can probably create country = time zone by scraping existing data on the web. This is a more complicated problem than it looks; for example, how do I know if it's a US-based number -- e.g. is it a USA area code, or an international country calling code? Any language is fine; I can port it.

  Read the article

• Processing XML file with Huge data

  - by Manish Dhanotiya

  Hi,be m I am working on an application which has below requiements - 1. Download a ZIP file from a server. 2. Uncompress the ZIP file, get the content (which is in XML format) from this file into a String. 3. Pass this content into another method for parsing and further processing. Now, my concerns here is the XML file may be of Huge size say like '100MB', and my JVM has memory of only 512 MB, so how can I get this content into Chunks and pass for Parsing and then insert the data into PL/SQL tables. Since there can be multiple requests running at the same time and considering 512MB of memory what will be the best possible to process this. How I can get the data into Chunks and pass it as Stream for XML parsing. I googled on this, but didnt find any implementation. :( Thanks,

  Read the article

• Interface issue

  - by peter

  i added a property 'WrmVersion' in interface IResourcePolicy but i am not getting those thing in the implementation side means here it should come in the List view data. means SubItems.Add(((IResourcePolicy)Data).WrmVersion is not getting This is the interface public interface IResourcePolicy { DataVersion WrmVersion { get; set; } bool ResourcePolicyEnabled { get; set; } } i am implementing it in public new IResourcePolicy Data { get { return (IResourcePolicy)base.Data; } } protected override void OnUpdate() { if(Data != null) { Text = base.Data.Name; if(SubItems.Count == 1) { SubItems.Add(((IResourcePolicy)Data).ResourcePolicyEnabled.ToString()); }

  Read the article

• Java Synchronized Write Block

  - by ikurtz

  im new to java and i have a question regarding Synchronized. i have the following code for writing to network (simple implementation for now): public void networkSendData(byte[] data){ try { out.write(data); out.flush(); } catch (IOException e) { } } i was wondering if there is a need for block level Synchronized here as im am writing the whole data at once. or is there a chance for race condition? i ask because the data to write is coming for multiple sources. thank you.

  Read the article

• script only works in IE

  - by Alex

  I have the following JavaScript for show running line: <script type="text/javascript" language="javascript"> //Change script's width (in pixels) var marqueewidth=800 //Change script's height (in pixels, pertains only to NS) var marqueeheight=20 //Change script's scroll speed (larger is faster) var speed=3 //Change script's contents var marqueecontents='You text here' if (document.all) document.write('<marquee scrollAmount='+speed+' style="width:'+marqueewidth+'">'+marqueecontents+'</marquee>') function regenerate(){ window.location.reload() } function regenerate2(){ if (document.layers){ setTimeout("window.onresize=regenerate",450) intializemarquee() } } function intializemarquee(){ document.cmarquee01.document.cmarquee02.document.write('<nobr>'+marqueecontents+'</nobr>') document.cmarquee01.document.cmarquee02.document.close() thelength=document.cmarquee01.document.cmarquee02.document.width scrollit() } function scrollit(){ if (document.cmarquee01.document.cmarquee02.left>=thelength*(-1)){ document.cmarquee01.document.cmarquee02.left-=speed setTimeout("scrollit()",100) } else{ document.cmarquee01.document.cmarquee02.left=marqueewidth scrollit() } } window.onload=regenerate2 </script> What should I change in script to make it work in FF and Chrome? Thanks

  Read the article

• C++ boost thread id and Singleton

  - by aaa

  hi. Sorry to flood so many questions this week. I assume thread index returned by thread.get_id is implementation specific. In case of the pthreads, is index reused? IE, if thread 0 runs and joins, is thread launched afterwords going to have a different ID? the reason I ask this is a need to implement Singleton pattern with a twist: each thread gets its own instance. I know it sounds very crazy, but threads control hardware (cuda) which does not permit device memory sharing. What is a good way to implement such pattern?

  Read the article

• Unique visitor counting in ASP.NET MVC

  - by Max

  I'd like to do visitor tracking similar to how stackoverflow does it.. By reading through numerous posts, I've figured out some details already: Count only 1 IP hit per 15 minutes (if anonymous) Count only 1 unique user-Login (per day?) Now that leaves the question of the real implementation.. Should I log the two factors live into a table (and increase count) | IP | timestamp | pageurl | Or do the counting AFTERWARDS (e.g. using IIS log files - which don't include the user, right? I know there're some similar posts outside, but NONE really has a great solution in my opinion yet..

  Read the article

• Windows Phone: Updating backend datastore (via web service) while keeping UI very responsive

  - by will

  I am developing a Windows Phone app where users can update a list. Each update, delete, add etc need to be stored in a database that sits behind a web service. As well as ensuring all the operations made on the phone end up in the cloud, I need to make sure the app is really responsive and the user doesn’t feel any lag time whatsoever. What’s the best design to use here? Each check box change, each text box edit fires a new thread to contact the web service? Locally store a list of things that need to be updated then send to the server in batch every so often (what about the back button)? Am I missing another even easier implementation? Thanks in advance,

  Read the article

• Is there a design pattern for this ?

  - by ytrewq

  I have a component that needs to call a specific service depending on the input it receives. So my component has to look at the input and based on a configuration that says "for this input call this service with this data" needs to call the proper service. The services have a common signature method and a specific one (each). I thought about an abstract class that includes the signatures for all three methods. The implementation for the two services will override all three methods (throwing NotImplementedException for the methods that are not supported by current service). A component that could be initialized with a map (that for each input type will have the type of the service to be called) will also be defined. Do you have a better approach to cope this scenario ?

  Read the article

< Previous Page | 578 579 580 581 582 583 584 585 586 587 588 589  | Next Page >