Search Results

Search found 11178 results on 448 pages for 'syntax checking'.

Page 387/448 | < Previous Page | 383 384 385 386 387 388 389 390 391 392 393 394  | Next Page >

  • Jquery passing an HTML element into a function

    - by christian
    I have an HTML form where I am going to copy values from a series of input fields to some spans/headings as the user populates the input fields. I am able to get this working using the following code: $('#source').keyup(function(){ if($("#source").val().length == 0){ $("#destinationTitle").text('Sample Title'); }else{ $("#destinationTitle").text($("#source").val()); } }); In the above scenario the html is something like: Sample Title Basically, as the users fills out the source box, the text of the is changed to the value of the source input. If nothing is input in, or the user deletes the values typed into the box some default text is placed in the instead. Pretty straightforward. However, since I need to make this work for many different fields, it makes sense to turn this into a generic function and then bind that function to each 's onkeyup() event. But I am having some trouble with this. My implementation: function doStuff(source,target,defaultValue) { if($(source).val().length == 0){ $(target).text(defaultValue); }else{ $(target).text($(source).val()); } } which is called as follows: $('#source').keyup(function() { doStuff(this, '"#destinationTitle"', 'SampleTitle'); }); What I can't figure out is how to pass the second parameter, the name of the destination html element into the function. I have no problem passing in the element I'm binding to via "this", but can't figure out the destination element syntax. Any help would be appreciated - many thanks!

    Read the article

  • WCF hosting: Can access svc file but cannot go to wsdl link

    - by Impulse
    Hello, I have a WCF service that is hosted in IIS 7.5. I have two servers, one for test and one for production. The service works fine on test server, but on the production server I have the following error. When I access the address http//..../service.svc I can see the default page that says: You have created a service. To test this service, you will need to create a client and use it to call the service. You can do this using the svcutil.exe tool from the command line with the following syntax: svcutil.exe http://..../service.svc?wsdl This will generate a configuration file and a code file that contains the client class. Add the two files to your client application and use the generated client class to call the Service. But when I click the wsdl link, I cannot go to the wsdl page. It returns me to this default web page without any errors. I am suspecting a network/firewall authorization error but does anybody have an experience like this one? All IIS settings are the same for test and production servers. Thank you, Best Regards.

    Read the article

  • How can I speed up a 1800-line PHP include? It's slowing my pageload down to 10sec/view

    - by somerandomguy
    I designed my code to put all important functions in a single PHP file that's now 1800 lines long. I call it in other PHP files--AJAX processors, for example--with a simple "require_once("codeBank.php")". I'm discovering that it takes about 10 seconds to load up all those functions, even though I have nothing more than a few global arrays and a bunch of other functions involved. The main AJAX processor code, for example, is taking 8 seconds just to do a simple syntax verification (whose operational function is stored in codeBank.php). When I comment out the require_once, my AJAX response time speeds up from 10sec to 40ms, so it's pretty clear that PHP's trying to do something with those 1800 lines of functions. That's even with APC installed, which is surprising. What should I do to get my code speed back to the sub-100ms level? Am I failing to get the cache's benefit somehow? Do I need to cut that single function bank file into different pieces? Are there other subtle things that I could be doing to screw up my response time? Or barring all that, what are some tools to dig further into which PHP operations are hitting speed bumps?

    Read the article

  • Stored procedure for generic MERGE

    - by GilliVilla
    I have a set of 10 tables in a database (DB1). And there are 10 tables in another database (DB2) with exact same schema on the same SQL Server 2008 R2 database server machine. The 10 tables in DB1 are frequently updated with data. I intend to write a stored procedure that would run once every day for synchronizing the 10 tables in DB1 with DB2. The stored procedure would make use of the MERGE statement. Now, my aim is to make this as generic and parametrized as possible. That is, accommodate for more tables down the line... and accommodate different source and target DB names. Definitely no hard coding is intended. This is my algorithm so far: Have the database names as parameters Have the first query within the stored procedure... result in giving the names of the 10 tables from a lookup table (this can be 10, 20 or whatever) Have a generic MERGE statement that does the sync for each of the above set of tables (based on primary key?) This is where I need more inputs on. What is the best way to achieve this stored procedure? SQL syntax would be helpful.

    Read the article

  • How to configure multiple mappings using FluentHibernate?

    - by chris.baglieri
    First time rocking it with NHibernate/Fluent so apologies in advance if this is a naive question. I have a set of Models I want to map. When I create my session factory I'm trying to do all mappings at once. I am not using auto-mapping (though I may if what I am trying to do ends up being more painful than it ought to be). The problem I am running into is that it seems only the top map is taking. Given the code snippet below and running a unit test that attempts to save 'bar', it fails and checking the logs I see NHibernate is trying to save a bar entity to the foo table. While I suspect it's my mappings it could be something else that I am simply overlooking. Code that creates the session factory (note I've also tried separate calls into .Mappings): Fluently.Configure().Database(MsSqlConfiguration.MsSql2008 .ConnectionString(c => c .Server(@"localhost\SQLEXPRESS") .Database("foo") .Username("foo") .Password("foo"))) .Mappings(m => { m.FluentMappings.AddFromAssemblyOf<FooMap>() .Conventions.Add(FluentNHibernate.Conventions.Helpers .Table.Is(x => "foos")); m.FluentMappings.AddFromAssemblyOf<BarMap>() .Conventions.Add(FluentNHibernate.Conventions.Helpers .Table.Is(x => "bars")); }) .BuildSessionFactory(); Unit test snippet: using (var session = Data.SessionHelper.SessionFactory.OpenSession()) { var bar = new Bar(); session.Save(bar); Assert.NotNull(bar.Id); }

    Read the article

  • shell script stopped working --- need to rewrite?

    - by OopsForgotMyOtherUserName
    The script below worked on my Mac OS X. I'm now using Ubuntu OS, and the script is no longer working. I'm wondering if there's something that I need to change here? I did change the first line from #!/bin/bash to #!/bin/sh, but it's still throwing up an error.... Essentially, I get an error when I try to run it: Syntax error: end of file unexpected (expecting ")") #!/bin/sh REMOTE='ftp.example.com' USER='USERNAME' PASSWORD='PASSWORD' CMDFILE='/jtmp/rc.ftp' FTPLOG='/jtmp/ftplog' PATTERN='SampFile*' date > $FTPLOG rm $CMDFILE 2>/dev/null LISTING=$(ftp -in $REMOTE <<EOF user $USER $PASSWORD cd download ls $PATTERN quit EOF ) echo "open $REMOTE" >> $CMDFILE echo "user $USER $PASSWORD" >> $CMDFILE echo "verbose" >> $CMDFILE echo "bin" >> $CMDFILE echo "cd download" >> $CMDFILE for FILE in $LISTING do echo "get $FILE" >> $CMDFILE done echo "quit" >> $CMDFILE ftp -in < $CMDFILE >> $FTPLOG 2>&1 rm $CMDFILE

    Read the article

  • How do I use XPath with a default namespace with no prefix?

    - by Scott Stafford
    What is the XPath (in C# API to XDocument.XPathSelectElements(xpath, nsman) if it matters) to query all MyNodes from this document? <?xml version="1.0" encoding="utf-8"?> <configuration> <MyNode xmlns="lcmp" attr="true"> <subnode /> </MyNode> </configuration I tried /configuration/MyNode which is wrong because it ignores the namespace. I tried /configuration/lcmp:MyNode which is wrong because lcmp is the URI, not the prefix. I tried /configuration/{lcmp}MyNode which failed because Additional information: '/configuration/{lcmp}MyNode' has an invalid token. EDIT: I can't use mgr.AddNamespace("df", "lcmp"); as some of the answerers have suggested. That requires that the XML parsing program know all the namespaces I plan to use ahead of time. Since this is meant to be applicable to any source file, I don't know which namespaces to manually add prefixes for. It seems like {my uri} is the XPath syntax, but Microsoft didn't bother implementing that... true?

    Read the article

  • How to update attributes without valitation

    - by Brian Roisentul
    I've got a model with its validations, and I found out that I can't update an attribute without validating the object before. I already tried to add on => :create syntax at the end of each validation line, but I got the same results. My announcement model have the following validations: validates_presence_of :title validates_presence_of :description validates_presence_of :announcement_type_id validate :validates_publication_date validate :validates_start_date validate :validates_start_end_dates validate :validates_category validate :validates_province validates_length_of :title, :in => 6..255, :on => :save validates_length_of :subtitle, :in => 0..255, :on => :save validates_length_of :subtitle, :in => 0..255, :on => :save validates_length_of :place, :in => 0..50, :on => :save validates_numericality_of :vacants, :greater_than_or_equal_to => 0, :only_integer => true validates_numericality_of :price, :greater_than_or_equal_to => 0, :only_integer => true My rake task does the following: task :announcements_expiration => :environment do announcements = Announcement.expired announcements.each do |a| #Gets the user that owns the announcement user = User.find(a.user_id) puts a.title + '...' a.state = 'deactivated' if a.update_attributes(:state => a.state) puts 'state changed to deactivated' else a.errors.each do |e| puts e end end end This throws all the validation exceptions for that model, in the output. Does anybody how to update an attribute without validating the model?

    Read the article

  • crash when using stl vector at instead of operator[]

    - by Jamie Cook
    I have a method as follows (from a class than implements TBB task interface - not currently multithreading though) My problem is that two ways of accessing a vector are causing quite different behaviour - one works and the other causes the entire program to bomb out quite spectacularly (this is a plugin and normally a crash will be caught by the host - but this one takes out the host program as well! As I said quite spectacular) void PtBranchAndBoundIterationOriginRunner::runOrigin(int origin, int time) const // NOTE: const method { BOOST_FOREACH(int accessMode, m_props->GetAccessModes()) { // get a const reference to appropriate vector from member variable // map<int, vector<double>> m_rowTotalsByAccessMode; const vector<double>& rowTotalsForAccessMode = m_rowTotalsByAccessMode.find(accessMode)->second; if (origin != 129) continue; // Additional debug constrain: I know that the vector only has one non-zero element at index 129 m_job->Write("size: " + ToString(rowTotalsForAccessMode.size())); try { // check for early return... i.e. nothing to do for this origin if (!rowTotalsForAccessMode[origin]) continue; // <- this works if (!rowTotalsForAccessMode.at(origin)) continue; // <- this crashes } catch (...) { m_job->Write("Caught an exception"); // but its not an exception } // do some other stuff } } I hate not putting in well defined questions but at the moment my best phrasing is : "WTF?" I'm compiling this with Intel C++ 11.0.074 [IA-32] using Microsoft (R) Visual Studio Version 9.0.21022.8 and my implementation of vector has const_reference operator[](size_type _Pos) const { // subscript nonmutable sequence #if _HAS_ITERATOR_DEBUGGING if (size() <= _Pos) { _DEBUG_ERROR("vector subscript out of range"); _SCL_SECURE_OUT_OF_RANGE; } #endif /* _HAS_ITERATOR_DEBUGGING */ _SCL_SECURE_VALIDATE_RANGE(_Pos < size()); return (*(_Myfirst + _Pos)); } (Iterator debugging is off - I'm pretty sure) and const_reference at(size_type _Pos) const { // subscript nonmutable sequence with checking if (size() <= _Pos) _Xran(); return (*(begin() + _Pos)); } So the only difference I can see is that at calls begin instead of simply using _Myfirst - but how could that possibly be causing such a huge difference in behaviour?

    Read the article

  • What's the best way to get a bunch of rows from MySQL if you have an array of integer primary keys?

    - by Evan P.
    I have a MySQL table with an auto-incremented integer primary key. I want to get a bunch of rows from the table based on an array of integers I have in memory in my program. The array ranges from a handful to about 1000 items. What's the most efficient query syntax to get the rows? I can think of a few: "SELECT * FROM thetable WHERE id IN (1, 2, 3, 4, 5)" (this is what I do now) "SELECT * FROM thetable where id = 1 OR id = 2 OR id = 3" Multiple queries of the form "SELECT * FROM thetable WHERE id = 1". Probably the most friendly to the query cache, but expensive due to having lots of query parsing. A union, like "SELECT * FROM thetable WHERE id = 1 UNION SELECT * FROM thetable WHERE id = 2 ..." I'm not sure if MySQL caches the results of each query; it's also the most verbose format. I think using the NoSQL interface in MySQL 5.6+ would be the most efficient way to do this, but I'm not yet up to MySQL 5.6.

    Read the article

  • how to do validations when composing object of a class in other class ?

    - by haansi
    Hi, I have an IPAddress class which has one property named ip and in its setter I am validating data coming and if data is invalid it throws an error. (Its code is as the following): private string ip; public string IP { get { return ip; } set { string PartsOfIP = value.Split('.'); if (PartsOfIP.Length == 4) { foreach (string part in PartsOfIP) { int a = 0; bool result = int.TryParse(part, out a); if (result != true) { throw new Exception("Invalid IP"); } else { ip = value; } } } else { throw new Exception("Invalid IP"); } } In User Class I want to compose an object of IPAddress class. I am doing validations for properties of User in User class and validations of Ip in IPAddress class. My question is how I will compose IPAddress object in UserClass and what will be syntax for this ? If I again mention get and set here with IPAddress object in User class will my earlier mentioned (in IPAddress class) getter and setter work ? plz advice me in details thanks

    Read the article

  • JavaScript audio not playing outside of jQuery function

    - by user1814016
    I know the question title doesn't make much sense, but I can't think of a better way to put it. I am a newbie to jQuery and I'm using this code to fade in a <div> and play a sound: $(document).ready(function(){ $('#speech').fadeIn('medium', function() { play('msg_appear'); var sptx = $('<p class="stext">').text('There is nothing here.'); $('#speech').append(sptx); $('.stext').typeOut({marker: '', delay: 22}); }); }); This code runs fine however the sound plays after the fade-in is complete. I wanted it to play while it was fading in, so I tried placing the play() call outside of the fade-in function like this: $(document).ready(function(){ play('msg_appear'); $('#speech').fadeIn('medium', function() { However, now it's not playing at all. There's no errors on the JavaScript console so I'm unsure if it's a syntax error, and probably something obvious, but I don't know what. play() is a function I found to play audio, here it is if it matters at all. I placed it in the same file the above code is; right above the $(document).ready(). function play(sound) { if (window.HTMLAudioElement) { var snd = new Audio(''); if(snd.canPlayType('audio/ogg')) { snd = new Audio(sound + '.ogg'); } else if(snd.canPlayType('audio/mp3')) { snd = new Audio(sound + '.mp3'); } snd.play(); } else { alert('HTML5 Audio is not supported by your browser!'); } }

    Read the article

  • jQuery code not executing when DOM is ready

    - by Ben
    I have written a simple jQuery script that changes the hash tag of a link. I do this because I am using IntenseDebate comments in Wordpress but the comment link still links replaced id of the old comments. I'm using jQuery so that if javascript is enabled, the user can click on the comments link and it will take them to the IntenseDebate comments. If its not enabled it will take them to the traditional comments (because IntenseDebate requires javascript to function). The issue I'm having lies in this script to change the hash tag at the end of the link. Currently the URL "someurl.com/#respond" but I need the script to change it to "someurl.com/#comments". What is happening is that the script doesn't work, however I believe my syntax is correct so I decided to try copying and pasting the code into Firebug's console and the code executed perfectly. I could see that the link I was trying to change was now correct, and I could click on it and it worked as I desired. So what I don't understand is why the code is not executing when it is supposed to. I am using $(document).ready() and I have other jQuery on the page that executes just fine. I even tested it on a simple HTML page away from all the problems that might be caused by Wordpress and I received the same result. Does anyone know why this might be happening? Here is my code (I am using noConflict because Wordpress makes use of other frameworks): jQuery.noConflict(); jQuery(document).ready(function($) { $("a[href$='respond']").each(function() { this.href = this.href.replace("respond", "comments"); }); })(jQuery); Thanks very much for your help!

    Read the article

  • MySQL PHP | "SELECT FROM table" using "alphanumeric"-UUID. Speed vs. Indexed Integer / Indexed Char

    - by dropson
    At the moment, I select rows from 'table01' using: SELECT * FROM table01 WHERE UUID = 'whatever'; The UUID column is a unique index. I know this isn't the fastest way to select data from the database, but the UUID is the only row-identifier that is available to the front-end. Since I have to select by UUID, and not ID, I need to know what of these two options I should go for, if say the table consists of 100'000 rows. What speed differences would I look at, and would the index for the UUID grow to large, and lag the DB? Get the ID before doing the "big" select 1. $id = "SELECT ID FROM table01 WHERE UUID = '{alphanumeric character}'"; 2. $rows = SELECT * FROM table01 WHERE ID = $id; Or keep it the way it is now, using the UUID. 1. SELECT FROM table01 WHERE UUID '{alphanumeric character}'; Side note: All new rows are created by checking if the system generated uniqueid exists before trying to insert a new row. Keeping the column always unique. The "example" table. CREATE TABLE Table01 ( ID int NOT NULL PRIMARY KEY, UUID char(15), name varchar(100), url varchar(255), `date` datetime ) ENGINE = InnoDB; CREATE UNIQUE INDEX UUID ON Table01 (UUID);

    Read the article

  • Determing if an unordered vector<T> has all unique elements

    - by Hooked
    Profiling my cpu-bound code has suggested I that spend a long time checking to see if a container contains completely unique elements. Assuming that I have some large container of unsorted elements (with < and = defined), I have two ideas on how this might be done: The first using a set: template <class T> bool is_unique(vector<T> X) { set<T> Y(X.begin(), X.end()); return X.size() == Y.size(); } The second looping over the elements: template <class T> bool is_unique2(vector<T> X) { typename vector<T>::iterator i,j; for(i=X.begin();i!=X.end();++i) { for(j=i+1;j!=X.end();++j) { if(*i == *j) return 0; } } return 1; } I've tested them the best I can, and from what I can gather from reading the documentation about STL, the answer is (as usual), it depends. I think that in the first case, if all the elements are unique it is very quick, but if there is a large degeneracy the operation seems to take O(N^2) time. For the nested iterator approach the opposite seems to be true, it is lighting fast if X[0]==X[1] but takes (understandably) O(N^2) time if all the elements are unique. Is there a better way to do this, perhaps a STL algorithm built for this very purpose? If not, are there any suggestions eek out a bit more efficiency?

    Read the article

  • MSSQL 2008 - Bit Param Evaluation alters Execution Plan

    - by Nathanial Woolls
    I have been working on migrating some of our data from Microsoft SQL Server 2000 to 2008. Among the usual hiccups and whatnot, I’ve run across something strange. Linked below is a SQL query that returns very quickly under 2000, but takes 20 minutes under 2008. I have read quite a bit on upgrading SQL server and went down the usual paths of checking indexes, statistics, etc. before coming to the conclusion that the following statement, found in the WHERE clause, causes the execution plan for the steps that follow this statement to change dramatically: And ( @bOnlyUnmatched = 0 -- offending line Or Not Exists( The SQL statements and execution plans are linked below. A coworker was able to rewrite a portion of the WHERE clause using a CASE statement, which seems to “trick” the optimizer into using a better execution plan. The version with the CASE statement is also contained in the linked archive. I’d like to see if someone has an explanation as to why this is happening and if there may be a more elegant solution than using a CASE statement. While we can work around this specific issue, I’d like to have a broader understanding of what is happening to ensure the rest of the migration is as painless as possible. Zip file with SQL statements and XML execution plans Thanks in advance!

    Read the article

  • How to lazy load a data structure (python)

    - by Anton Geraschenko
    I have some way of building a data structure (out of some file contents, say): def loadfile(FILE): return # some data structure created from the contents of FILE So I can do things like puppies = loadfile("puppies.csv") # wait for loadfile to work kitties = loadfile("kitties.csv") # wait some more print len(puppies) print puppies[32] In the above example, I wasted a bunch of time actually reading kitties.csv and creating a data structure that I never used. I'd like to avoid that waste without constantly checking if not kitties whenever I want to do something. I'd like to be able to do puppies = lazyload("puppies.csv") # instant kitties = lazyload("kitties.csv") # instant print len(puppies) # wait for loadfile print puppies[32] So if I don't ever try to do anything with kitties, loadfile("kitties.csv") never gets called. Is there some standard way to do this? After playing around with it for a bit, I produced the following solution, which appears to work correctly and is quite brief. Are there some alternatives? Are there drawbacks to using this approach that I should keep in mind? class lazyload: def __init__(self,FILE): self.FILE = FILE self.F = None def __getattr__(self,name): if not self.F: print "loading %s" % self.FILE self.F = loadfile(self.FILE) return object.__getattribute__(self.F, name) What might be even better is if something like this worked: class lazyload: def __init__(self,FILE): self.FILE = FILE def __getattr__(self,name): self = loadfile(self.FILE) # this never gets called again # since self is no longer a # lazyload instance return object.__getattribute__(self, name) But this doesn't work because self is local. It actually ends up calling loadfile every time you do anything.

    Read the article

  • Mongodb update: how to check if an update succeeds or fails?

    - by zmg
    I think the title pretty much says it all. I'm working with Mongodb in PHP using the pecl driver. My updates are working great, but I'd like to build some error checking into my funciton(s). I've tried using lastError() in a pretty simple function: function system_db_update_object($query, $values, $database, $collection) { $connection = new Mongo(); $collection = $connection->$database->$collection; $connection->$database->resetError(); //Added for debugging $collection->update( $query, array('$set' => $values)); //$errorArray = $connection->$database->lastError(); var_dump($connection->$database->lastError());exit; // Var dump and /Exit/ } But pretty much regardless of what I try to update (whether it exists or not) I get these same basic results: array(4) { ["err"]=> NULL ["updatedExisting"]=> bool(true) ["n"]=> float(1) ["ok"]=> float(1) } Any help or direction would be greatly appreciated.

    Read the article

  • How to query an .NET assembly's required framework (not CLR) version?

    - by Bonfire Burns
    Hi, we are using some kind of plug-in architecture in one of our products (based on .NET). We have to consider our customers or even 3rd party devs writing plug-ins for the product. The plug-ins will be .NET assemblies that are loaded by our product at run-time. We have no control about the quality or capabilities of the external plug-ins (apart from checking whether they implement the correct interfaces). So we need to implement some kind of safety check while loading the plug-ins to make sure that our product (and the hosting environment) can actually host the plug-in or deliver a meaningful error message ("The plug-in your are loading needs .NET version 42.42 - the hosting system is only on version 33.33."). Ideally the plug-ins would do this check internally, but our experience regarding their competence is so-so and in any case our product will get the blame, so we want to make sure that this "just works". Requiring the plug-in developers to provide the info in the metadata or to explicitly provide the information in the interface is considered "too complicated". I know about the Assembly.ImageRuntimeVersion property. But to my knowledge this tells me only the needed CLR version, not the framework version. And I don't want to check all of the assembly's dependencies and match them against a table of "framework version vs. available assemblies". Do you have any ideas how to solve this in a simple and maintainable fashion? Thanks & regards, Bon

    Read the article

  • Attempt to use a while loop for the 'next' arg of a for loop generates #arg error

    - by JerryK
    Am attempting to teach myself to program using Tcl. The task i've set myself to motivate my learning of Tcl is to solve the 8 queens problem. My approach to creating a program is to successively 'prototype' a solution. I have asked an earlier question related to the correctly laying out the nested for loops and received a helpful answer. To my dismay I find that the next development of my code creates the same interpreter error : "wrong # args" I have been careful to have an open brace at the end of the line preceding the while loop command. I've also tried to put the arguments of the whileloop in braces. This generates a different error. I have sincerely tried to understand the Tcl syntax man page - not too successfully - suggested by the answerer of my earlier question. Here is the code set allowd 1 set notallowd 0 for {set r1p 1} {$r1p <= 8} {incr r1p } { puts "1st row q placed at $r1p" ;# re-initialize r2 'free for q placemnt' array after every change of r1 q pos: for {set i 1 } {$i <= 8} {incr i} { set r2($i) $allowd } for { set r2($r1p) $notallowd ; set r2([expr $r1p-1]) $notallowd ; set r2([expr $r1p+1]) $notallowd ; set r2p 1} {$r2p <= 8} { ;# 'next' arg of r2 forloop will be a whileloop : while r2($r2p)== $notallowd incr r2p } { puts "2nd row q placed at $r2p" ;# end of 'commnd' arg of r2 forloop } } Where am I going wrong? EDIT : to provide clear reply @slebetman As stated in my text, I did brace the arguments of the whileloop (indeed that was how i first wrote the code) below is exactly the layout of the r2 forloop tried: for { set r2($r1p) $notallowd ; set r2([expr $r1p-1]) $notallowd ; set r2([expr $r1p+1]) $notallowd ; set r2p 1} {$r2p <= 8} { ;# 'next' arg of r2 forloop will be a whileloop : while { r2($r2p)== $notallowd } { incr r2p } } { puts "2nd row q placed at $r2p" ;# end of 'commnd' arg of r2 forloop } but this generates the fatal interpreter error : "unknown math function 'r2' while compiling while { r2($r2p .... "

    Read the article

  • Java : Inner class of an interface (from google guice)

    - by bsreekanth
    Hello, I was going through the source of google guice, and found an unfamiliar piece of code. It would be great learning if someone can clarify it. I have very basic understanding of inner classes, as they keep the implementation details close to the public interface. Otherwise the inner class may pollute the namespace. Now, I see the below lines at public static final Scope SINGLETON = new Scope() { public <T> Provider<T> scope(final Key<T> key, final Provider<T> creator) { return new Provider<T>() { ......... } It assign an inner class instance to the static variable, but Scope is an interface defined as (at) public interface Scope Is it possible to instantiate the interface?? or is it a succinct syntax for an anonymous implementation of an interface?? If anyone can explain what the author is intended by multiple nested classes above (Scope and Provider), and why it make sense to implement this way, it would help me to understand. thanks.

    Read the article

  • Efficient mapping of game entity positions in Java

    - by byte
    In Java (Swing), say I've got a 2D game where I have various types of entities on the screen, such as a player, bad guys, powerups, etc. When the player moves across the screen, in order to do efficient checking of what is in the immediate vicinity of the player, I would think I'd want indexed access to the things that are near the character based on their position. For example, if player 'P' steps onto element 'E' in the following example... | | | | | | | | | |P| | | | |E| | | | | | | | | ... would be to do something like: if(player.getPosition().x == entity.getPosition().x && entity.getPosition.y == thing.getPosition().y) { //do something } And thats fine, but that implies that the entities hold their positions, and therefor if I had MANY entities on the screen I would have to loop through all possible entities available and check each ones position against the player position. This seems really inefficient especially if you start getting tons of entities. So, I would suspect I'd want some sort of map like Map<Point, Entity> map = new HashMap<Point, Entity>(); And store my point information there, so that I could access these entities in constant time. The only problem with that approach is that, if I want to move an entity to a different point on the screen, I'd have to search through the values of the HashMap for the entity I want to move (inefficient since I dont know its Point position ahead of time), and then once I've found it remove it from the HashMap, and re-insert it with the new position information. Any suggestions or advice on what sort of data structure / storage format I ought to be using here in order to have efficient access to Entities based on their position, as well as Position's based on the Entity?

    Read the article

  • T-SQL: how to sort table rows based on 2 columns

    - by Criss Nautilus
    I'm quite stuck with this problem for sometime now.. How do I sort column A depending on the contents of Column B? I have this sample: ID count columnA ColumnB 12 1 A B 13 2 C D 14 3 B C I want to sort it like this: ID count ColumnA ColumnB 12 1 A B 14 3 B C 13 2 C D so I need to sort the rows if the previous row of ColumnB = the next row of ColumnA I'm thinking a loop? but can't quite imagine how it will work... I was thinking it will go like this (maybe) SELECT a.ID, a.ColumnA, a.ColumnB FROM TableA WITH a (NOLOCK) LEFT JOIN TableA b WITH (NOLOCK) ON a.ID = b.ID and a.counts = b.counts Where a.columnB = b.ColumnA the above code isn't working though and I was thinking more on the lines of... DECLARE @counts int = 1 DECLARE @done int = 0 --WHILE @done = 0 BEGIN SELECT a.ID, a.ColumnA, a.ColumnB FROM TableA WITH a (NOLOCK) LEFT JOIN TableA b WITH (NOLOCK) ON a.ID = b.ID and a.counts = @counts Where a.columnB = b.ColumnA set @count = @count +1 END If this was a C code, would be easier for me but t-sql's syntax is making it a bit harder for a noobie like me.

    Read the article

  • What C# container is most resource-efficient for existence for only one operation?

    - by ccornet
    I find myself often with a situation where I need to perform an operation on a set of properties. The operation can be anything from checking if a particular property matches anything in the set to a single iteration of actions. Sometimes the set is dynamically generated when the function is called, some built with a simple LINQ statement, other times it is a hard-coded set that will always remain the same. But one constant always exists: the set only exists for one single operation and has no use before or after it. My problem is, I have so many points in my application where this is necessary, but I appear to be very, very inconsistent in how I store these sets. Some of them are arrays, some are lists, and just now I've found a couple linked lists. Now, none of the operations I'm specifically concerned about have to care about indices, container size, order, or any other functionality that is bestowed by any of the individual container types. I picked resource efficiency because it's a better idea than flipping coins. I figured, since array size is configured and it's a very elementary container, that might be my best choice, but I figure it is a better idea to ask around. Alternatively, if there's a better choice not out of resource-efficiency but strictly as being a better choice for this kind of situation, that would be nice as well.

    Read the article

  • How to write curiously recurring templates with more than 2 layers of inheritance?

    - by Kyle
    All the material I've read on Curiously Recurring Template Pattern seems to one layer of inheritance, ie Base and Derived : Base<Derived>. What if I want to take it one step further? #include <iostream> using std::cout; template<typename LowestDerivedClass> class A { public: LowestDerivedClass& get() { return *static_cast<LowestDerivedClass*>(this); } void print() { cout << "A\n"; } }; template<typename LowestDerivedClass> class B : public A<LowestDerivedClass> { public: void print() { cout << "B\n"; } }; class C : public B<C> { public: void print() { cout << "C\n"; } }; int main() { C c; c.get().print(); // B b; // Intentionally bad syntax, // b.get().print(); // to demonstrate what I'm trying to accomplish return 0; } How can I rewrite this code to compile without errors (and output "C\nB\n")?

    Read the article

< Previous Page | 383 384 385 386 387 388 389 390 391 392 393 394  | Next Page >