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  • PHP get "Application Root" in Xampp on Windows correctly

    - by Michael Mao
    Hi all: I found this thread on StackOverflow about how to get the "Application Root" from inside my web app. However, most of the approaches suggested in that thread can hardly be applied to my Xampp on Windows. Say, I've got a "common.php" which stays inside my web app's app directory: / /app/common.php /protected/index.php In my common.php, what I've got is like this: define('DOCROOT', $_SERVER['DOCUMENT_ROOT']); define('ABSPATH', dirname(__FILE__)); define('COMMONSCRIPT', $_SERVER['PHP_SELF']); After I required the common.php inside the /protected/index.php, I found this: C:/xampp/htdocs //<== echo DOCROOT; C:\xampp\htdocs\comic\app //<== echo ABSPATH /comic/protected/index.php //<== echo COMMONSCRIPT So the most troublesome part is the path delimiters are not universal, plus, it seems all superglobals from the $_SERVER[] asso array, such as $_SERVER['PHP_SELF'], are relative to the "caller" script, not the "callee" script. It seems that I can only rely on dirname(__FILE__) to make sure this always returns an absolute path to the common.php file. I can certainly parse the returning values from DOCROOT and ABSPATH and then calculate the correct "application root". For instance, I can compare the parts after htdocs and substitute all backslashes with slashes to get a unix-like path I wonder is this the right way to handle this? What if I deploy my web app on a LAMP environment? would this environment-dependent approach bomb me out? I have used some PHP frameworks such as CakePHP and CodeIgniter, to be frank, They just work on either LAMP or WAMP, but I am not sure how they approached such a elegant solution. Many thanks in advance for all the hints and suggestions.

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  • iReport / jFreeChart - Combining getItemPaint() override and series colors

    - by barneskd
    I'm attempting to create a bar chart that needs to use specific series colors for N number of categories and a separate color for 1 other category. Here is an example: http://i.imgur.com/1DeCF.png (Sorry, I don't have enough points to embed images yet) In the mockup, Categories 1-3 use a collection of 5 colors to render their series while Category 4 uses a single grey color. My first approach was to override the getItemPaint() method using a customizer class, but I can only figure out how to define a color on the category level, not the series level. Is it possible to define colors on category and/or series levels? Something like, If category != "Category4" Use colors A, B, C, D, and E in category's series Else Use color F in category's series Another thought I had was to combine iReport's Series Colors bar chart property and the getItemPaint() override; that way I could define the 5 colors to use in iReport and use the getItemPaint() override only in the case where the category equals "Category 4". So far I've had no luck combining the two; if the override is defined it overrides iReport's Series Color property.

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  • C#JSON serialization

    - by Bridget the Midget
    I'm trying out the HighStock library for creating stock charts. To fill the chart with data, their example specifies this source. The first parameter is unixtime in milliseconds and the second parameter is the stock closing price. I don't know if this is valid json, but I would argue that the following would be a more appropriate way of writing json. [{"Closing":63.15000,"Date":1262559600000},{"Closing":64.75000,"Date":1262646000000}, ... I guess that I have no other option than to adapt to HighStocks syntax. I could solve this by looping and add correct syntax to a string, but that seems rudimentary. Would it be more wise to serialize C# objects to create my json, and if that's the case - how can I reach the syntax specified in the example? Lets just say this is my c# object: public class Quote { public double Date { get; set; } public decimal Closing { get; set; } } Am I making it unnecessary complex? Should I just format a json string?

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  • F# passing an operator with arguments to a function

    - by dan
    Can you pass in an operation like "divide by 2" or "subtract 1" using just a partially applied operator, where "add 1" looks like this: List.map ((+) 1) [1..5];; //equals [2..6] // instead of having to write: List.map (fun x-> x+1) [1..5] What's happening is 1 is being applied to (+) as it's first argument, and the list item is being applied as the second argument. For addition and multiplication, this argument ordering doesn't matter. Suppose I want to subtract 1 from every element (this will probably be a common beginners mistake): List.map ((-) 1) [1..5];; //equals [0 .. -4], the opposite of what we wanted 1 is applied to the (-) as its first argument, so instead of (list_item - 1), I get (1 - list_item). I can rewrite it as adding negative one instead of subtracting positive one: List.map ((+) -1) [1..5];; List.map (fun x -> x-1) [1..5];; // this works too I'm looking for a more expressive way to write it, something like ((-) _ 1), where _ denotes a placeholder, like in the Arc language. This would cause 1 to be the second argument to -, so in List.map, it would evaluate to list_item - 1. So if you wanted to map divide by 2 to the list, you could write: List.map ((/) _ 2) [2;4;6] //not real syntax, but would equal [1;2;3] List.map (fun x -> x/2) [2;4;6] //real syntax equivalent of the above Can this be done or do I have to use (fun x -> x/2)? It seems that the closest we can get to the placeholder syntax is to use a lambda with a named argument.

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  • Using pthread to perform matrix multiplication

    - by shadyabhi
    I have both matrices containing only ones and each array has 500 rows and columns. So, the resulting matrix should be a matrix of all elements having value 500. But, I am getting res_mat[0][0]=5000. Even other elements are also 5000. Why? #include<stdio.h> #include<pthread.h> #include<unistd.h> #include<stdlib.h> #define ROWS 500 #define COLUMNS 500 #define N_THREADS 10 int mat1[ROWS][COLUMNS],mat2[ROWS][COLUMNS],res_mat[ROWS][COLUMNS]; void *mult_thread(void *t) { /*This function calculates 50 ROWS of the matrix*/ int starting_row; starting_row = *((int *)t); starting_row = 50 * starting_row; int i,j,k; for (i = starting_row;i<starting_row+50;i++) for (j=0;j<COLUMNS;j++) for (k=0;k<ROWS;k++) res_mat[i][j] += (mat1[i][k] * mat2[k][j]); return; } void fill_matrix(int mat[ROWS][COLUMNS]) { int i,j; for(i=0;i<ROWS;i++) for(j=0;j<COLUMNS;j++) mat[i][j] = 1; } int main() { int n_threads = 10; //10 threads created bcos we have 500 rows and one thread calculates 50 rows int j=0; pthread_t p[n_threads]; fill_matrix(mat1); fill_matrix(mat2); for (j=0;j<10;j++) pthread_create(&p[j],NULL,mult_thread,&j); for (j=0;j<10;j++) pthread_join(p[j],NULL); printf("%d\n",res_mat[0][0]); return 0; }

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  • Is it just me? I find LINQ to XML to be sort of cumbersome, compared to XPath.

    - by Cheeso
    I am a C# programmer, so I don't get to take advantage of the cool XML syntax in VB. Dim itemList1 = From item In rss.<rss>.<channel>.<item> _ Where item.<description>.Value.Contains("LINQ") Or _ item.<title>.Value.Contains("LINQ") Using C#, I find XPath to be easier to think about, easier to code, easier to understand, than performing a multi-nested select using LINQ to XML. Look at this syntax, it looks like Greek swearing: var waypoints = from waypoint in gpxDoc.Descendants(gpx + "wpt") select new { Latitude = waypoint.Attribute("lat").Value, Longitude = waypoint.Attribute("lon").Value, Elevation = waypoint.Element(gpx + "ele") != null ? waypoint.Element(gpx + "ele").Value : null, Name = waypoint.Element(gpx + "name") != null ? waypoint.Element(gpx + "name").Value : null, Dt = waypoint.Element(gpx + "cmt") != null ? waypoint.Element(gpx + "cmt").Value : null }; All the casting, the heavy syntax, the possibility for NullPointerExceptions. None of this happens with XPath. I like LINQ in general, and I use it on object collections and databases, but my first go-round with querying XML led me right back to XPath. Is it just me? Am I missing something? EDIT: someone voted to close this as "not a real question". But it is a real question, stated clearly. The question is: Am I misunderstanding something with LINQ to XML?

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  • What is the rationale to non allow overloading of C++ conversions operator with non-member functio

    - by Vicente Botet Escriba
    C++0x has added explicit conversion operators, but they must always be defined as members of the Source class. The same applies to the assignment operator, it must be defined on the Target class. When the Source and Target classes of the needed conversion are independent of each other, neither the Source can define a conversion operator, neither the Target can define a constructor from a Source. Usually we get it by defining a specific function such as Target ConvertToTarget(Source& v); If C++0x allowed to overload conversion operator by non member functions we could for example define the conversion implicitly or explicitly between unrelated types. template < typename To, typename From operator To(const From& val); For example we could specialize the conversion from chrono::time_point to posix_time::ptime as follows template < class Clock, class Duration operator boost::posix_time::ptime( const boost::chrono::time_point& from) { using namespace boost; typedef chrono::time_point time_point_t; typedef chrono::nanoseconds duration_t; typedef duration_t::rep rep_t; rep_t d = chrono::duration_cast( from.time_since_epoch()).count(); rep_t sec = d/1000000000; rep_t nsec = d%1000000000; return posix_time::from_time_t(0)+ posix_time::seconds(static_cast(sec))+ posix_time::nanoseconds(nsec); } And use the conversion as any other conversion. So the question is: What is the rationale to non allow overloading of C++ conversions operator with non-member functions?

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  • Problem with reusing UITableViewCell's

    - by Sheehan Alam
    I have a UITableView that is re-using cells when the user scrolls. Everything appears and scrolls fine, except when the user clicks on an actual row, the highlighted cell displays some text from another cell. I'm not exactly sure why. #define IMAGE_TAG 1111 #define LOGIN_TAG 2222 #define FULL_NAME_TAG 3333 // Customize the appearance of table view cells. - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; STUser *mySTUser = [[[STUser alloc]init]autorelease]; mySTUser = [items objectAtIndex:indexPath.row]; AsyncImageView* asyncImage = nil; UILabel* loginLabel = nil; UILabel* fullNameLabel = nil; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease]; } else { asyncImage = (AsyncImageView *) [cell.contentView viewWithTag:IMAGE_TAG]; loginLabel = (UILabel *) [cell.contentView viewWithTag:LOGIN_TAG]; fullNameLabel = (UILabel *) [cell.contentView viewWithTag:FULL_NAME_TAG]; } // Configure the cell... cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; CGRect frame = CGRectMake(0, 0, 44, 44); asyncImage = [[[AsyncImageView alloc]initWithFrame:frame] autorelease]; asyncImage.tag = IMAGE_TAG; NSURL* url = [NSURL URLWithString:mySTUser.avatar_url_large]; [asyncImage loadImageFromURL:url]; [cell.contentView addSubview:asyncImage]; loginLabel.tag = LOGIN_TAG; CGRect loginLabelFrame = CGRectMake(60, 0, 200, 10); loginLabel = [[[UILabel alloc] initWithFrame:loginLabelFrame] autorelease]; loginLabel.text = [NSString stringWithFormat:@"%@",mySTUser.login]; [cell.contentView addSubview:loginLabel]; fullNameLabel.tag = FULL_NAME_TAG; CGRect fullNameLabelFrame = CGRectMake(60, 20, 200, 10); fullNameLabel = [[[UILabel alloc] initWithFrame:fullNameLabelFrame] autorelease]; fullNameLabel.text = [NSString stringWithFormat:@"%@ %@",mySTUser.first_name, mySTUser.last_name]; //[NSString stringWithFormat:@"%@",mySTUser.login]; [cell.contentView addSubview:fullNameLabel]; return cell; }

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  • Webbased data modelling and management tool

    - by pixeldude
    Is there a web-based tool available, where I am able to... ...define data models (like in a database admin tool) ...fill in data (in custom web forms, not too generic) with basic features like completion ...import data from CSV oder Excel Sheets ...export data to CSV or SQL ...create snapshots of my data models (versions, diff, etc.) ...share my data models ...discuss/collaborate with other people about my data models Well, I can develop something like this in PHP or with Ruby or whatever. But this is such a common task, where the application support could be a lot better. And it would be language and database independent. This would help to maintain data models in different versions and you can maybe share your data models with others, extend it with your team members, etc. There is a website called FreeBase, which allows you to define a data entity model and fill in data, which also has export features, but I need to define my own data model with my own granularity and structure. And it should not be shared in public if I don't want to. How do you solve problems like this yourself?

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  • sql foreign keys

    - by Paul Est
    I was create tables with the syntax in phpmyadmin: DROP TABLE IF EXISTS users; DROP TABLE IF EXISTS info; CREATE TABLE users ( user_id int unsigned NOT NULL auto_increment, email varchar(100) NOT NULL default '', pwd varchar(32) NOT NULL default '', isAdmin int(1) unsigned NOT NULL, PRIMARY KEY (user_id) ) TYPE=INNODB; CREATE TABLE info ( info_id int unsigned NOT NULL auto_increment, first_name varchar(100) NOT NULL default '', last_name varchar(100) NOT NULL default '', address varchar(300) NOT NULL default '', zipcode varchar(100) NOT NULL default '', personal_phone varchar(100) NOT NULL default '', mobilephone varchar(100) NOT NULL default '', faxe varchar(100) NOT NULL default '', email2 varchar(100) NOT NULL default '', country varchar(100) NOT NULL default '', sex varchar(1) NOT NULL default '', birth varchar(1) NOT NULL default '', email varchar(100) NOT NULL default '', PRIMARY KEY (info_id), FOREIGN KEY (email) REFERENCES users(email) ON UPDATE CASCADE ON DELETE CASCADE ) TYPE=INNODB; But shows the error "#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'TYPE=INNODB' at line 11 " If i remove the TYPE=INNODB in the end of create the tables, it will show the error "#1005 - Can't create table 'curriculo.info' (errno: 150) ".

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  • TSQL to insert an ascending value

    - by David Neale
    I am running some SQL that identifies records which need to be marked for deletion and to insert a value into those records. This value must be changed to render the record useless and each record must be changed to a unique value because of a database constraint. UPDATE Users SET Username = 'Deleted' + (ISNULL( Cast(SELECT RIGHT(MAX(Username),1) FROM Users WHERE Username LIKE 'Deleted%') AS INT) ,0) + 1 FROM Users a LEFT OUTER JOIN #ADUSERS b ON a.Username = 'AVSOMPOL\' + b.sAMAccountName WHERE (b.sAMAccountName is NULL AND a.Username LIKE 'AVSOMPOL%') OR b.userAccountControl = 514 This is the important bit: SET Username = 'Deleted' + (ISNULL( Cast(SELECT RIGHT(MAX(Username),1) FROM Users WHERE Username LIKE 'Deleted%') AS INT) ,0) + 1 What I've tried to do is have deleted records have their Username field set to 'Deletedxxx'. The ISNULL is needed because there may be no records matching the SELECT RIGHT(MAX(Username),1) FROM Users WHERE Username LIKE 'Deleted%' statement and this will return NULL. I get a syntax error when trying to parse this (Msg 156, Level 15, State 1, Line 2 Incorrect syntax near the keyword 'SELECT'. Msg 102, Level 15, State 1, Line 2 Incorrect syntax near ')'. I'm sure there must be a better way to go about this, any ideas?

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  • Python: Best way to check for Python version in program that uses new language features?

    - by Mark Harrison
    If I have a python script that requires at least a particular version of python, what is the correct way to fail gracefully when an earlier version of python is used to launch the script? How do I get control early enough to issue an error message and exit? For example, I have a program that uses the ternery operator (new in 2.5) and "with" blocks (new in 2.6). I wrote a simple little interpreter-version checker routine which is the first thing the script would call ... except it doesn't get that far. Instead, the script fails during python compilation, before my routines are even called. Thus the user of the script sees some very obscure synax error tracebacks - which pretty much require an expert to deduce that it is simply the case of running the wrong version of python. update I know how to check the version of python. The issue is that some syntax is illegal in older versions of python. Consider this program: import sys if sys.version_info < (2, 4): raise "must use python 2.5 or greater" else: # syntax error in 2.4, ok in 2.5 x = 1 if True else 2 print x When run under 2.4, I want this result $ ~/bin/python2.4 tern.py must use python2.5 or greater and not this result: $ ~/bin/python2.4 tern.py File "tern.py", line 5 x = 1 if True else 2 ^ SyntaxError: invalid syntax (channeling for a coworker)

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  • Book recommendation for Silverlight

    - by Mathias Weyel
    Hi there, yet another question for recommendations for a book on Silverlight. I look for a book that covers the UI and styling and, if possible, custom drawing and graphics. Very important for me is the style of the book - it should focus on the actual programming and not on where to click in Visual Studio to get things done. Let's take a fictional example for proper usage of the DataGrid control: Bad: To use the data grid, drag it from the toolbox onto the control. You can change the background color by clicking on “Background” in the properties. To define custom columns, click on columns and edit them in the configuration window that opens. Good: To use the DataGrid, you need a reference to the blah dll and declare the namespace in the XAML like this (blah), the data model should be like blah and if you want to define how the columns look like, you need to define them like this (more blah). And if you want to do this in C# because you for whatever reason aren’t able or willing to use XAML, this would look like blah. Bonus points for coverage of topics like how to manage resources (images/fonts) and internationalization. There are quite some snippets on how to do that on the internet but somehow each of them looks like they work but are not a proper way of doing it. cheers Mathias

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  • concatenate string and running index into string within a loop

    - by user331706
    To use a given graphic package I need to define, book and fill histogram. How can I get the name of the histogram which is a string to concatenate with 2 integer as a string ( hts_i_j ) in 3 for loop instead. That has to be done in c++ See the exemple below to define TH1F* hts_5_53; TH1F* hts_5_54; …… TH1F* hts_5_69; to book hts_5_53= HDir.make("hts_5_53")," Title", 100,0.,100.); hts_5_54-HDir.make("hts_5_54")," Title", 100,0.,100.); …… hts_16_69-HDir.make("hts_16_69")," Title", 100,0.,100.); to fill hts_5_53-Fill(f) hts_5_54-Fill(f) …… hts_16_69-Fill(f) Instead I would like to define, book and fill in 3 for loops. e.g . for(int i=5, i<17, ++i){ for(int j=53, j<70, ++j){ hts_i_j } } how can I get the string hts to concatenate with the indices ( i,j) in a simple short way while defining, booking and filling in 3 for loop instead

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  • Windows Phone app: Binding data in a UserControl which is contained in a ListBox

    - by Alexandros Dafkos
    I have an "AddressListBox" ListBox that contains "AddressDetails" UserControl items, as shown in the .xaml file extract below. The Addresses collection is defined as ObservableCollection< Address Addresses and Street, Number, PostCode, City are properties of the Address class. The binding fails, when I use the "{Binding property}" syntax shown below. The binding succeeds, when I use the "dummy" strings in the commented-out code. I have also tried "{Binding Path=property}" syntax without success. Can you suggest what syntax I should use for binding the data in the user controls? <ListBox x:Name="AddressListBox" DataContext="{StaticResource dataSettings}" ItemsSource="{Binding Path=Addresses, Mode=TwoWay}"> <ListBox.ItemTemplate> <DataTemplate> <!-- <usercontrols:AddressDetails AddressRoad="dummy" AddressNumber="dummy2" AddressPostCode="dummy3" AddressCity="dummy4"> </usercontrols:AddressDetails> --> <usercontrols:AddressDetails AddressRoad="{Binding Street}" AddressNumber="{Binding Number}" AddressPostCode="{Binding PostCode}" AddressCity="{Binding City}"> </usercontrols:AddressDetails> </DataTemplate> </ListBox.ItemTemplate> </ListBox>

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  • Unboxing to unknown type

    - by Robert
    I'm trying to figure out syntax that supports unboxing an integral type (short/int/long) to its intrinsic type, when the type itself is unknown. Here is a completely contrived example that demonstrates the concept: // Just a simple container that returns values as objects struct DataStruct { public short ShortVale; public int IntValue; public long LongValue; public object GetBoxedShortValue() { return LongValue; } public object GetBoxedIntValue() { return LongValue; } public object GetBoxedLongValue() { return LongValue; } } static void Main( string[] args ) { DataStruct data; // Initialize data - any value will do data.LongValue = data.IntValue = data.ShortVale = 42; DataStruct newData; // This works if you know the type you are expecting! newData.ShortVale = (short)data.GetBoxedShortValue(); newData.IntValue = (int)data.GetBoxedIntValue(); newData.LongValue = (long)data.GetBoxedLongValue(); // But what about when you don't know? newData.ShortVale = data.GetBoxedShortValue(); // error newData.IntValue = data.GetBoxedIntValue(); // error newData.LongValue = data.GetBoxedLongValue(); // error } In each case, the integral types are consistent, so there should be some form of syntax that says "the object contains a simple type of X, return that as X (even though I don't know what X is)". Because the objects ultimately come from the same source, there really can't be a mismatch (short != long). I apologize for the contrived example, it seemed like the best way to demonstrate the syntax. Thanks.

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  • python: help defining/installing simple script to setup machine-specific information

    - by Jason S
    (This is related to scons but I think most of the following should be fairly general to python) I would like to define a python file/library that I put in a Well-Known Place somewhere on my computer that I can use to define machine-specific paths, and was looking for help on how to do this well, since I'm a beginner to Python & really only use it for my scons work. scons uses a SConstruct file which can execute python code. What I would like to do is something like this: My SConstruct file would contain this at the beginning: defaultEnv = JJJJJ.getMachineSpecificPaths() or (do both of these syntaxes work?) import JJJJJ defaultEnv = getMachineSpecificPaths() I define a JJJJJ.py file somewhere installed in the python dir which contains the following def getMachineSpecificPaths(): ... does something here, I don't know what ... that reads a file machine-specific-paths.txt (maybe it has the code Ross Rogers mentioned in my other question) located in the same directory as JJJJJ.py containing the following: machine-specific-paths.txt TI_C28_ROOT C:/appl/ti/ccs/?4.1.1/ccsv4/tools/co?mpiler/c2000 JSDB c:/bin/jsdb/jsdb.exe PYTHON_PATH c:/appl/python/2.6.4 The thing is, I don't really know much about the conventions in Python about where you put system-wide libraries and files. This is probably really simple to get right but I don't know how.

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  • PHP and Gettext not work on my server!

    - by NeoNmaN
    i have this site ( http://rssbot.dk/en/ ) i try to get gettext to work so my english, sweiden and norway site can comming up. Bot i can't get it to work, what have i doe wrong? this is my config code // define constants ( defualt - danish ) $lang = 'da_DA'; $lang_short = ''; $lang_prefix = 'da'; if ( isset( $_GET['lang'] ) ) { switch( $_GET['lang'] ) { case 'en': $lang = 'en_EN'; $lang_short = 'en/'; $lang_prefix = 'en'; break; case 'se': $lang = 'se_SE'; $lang_short = 'se/'; $lang_prefix = 'se'; break; case 'no': $lang = 'no_NO'; $lang_short = 'no/'; $lang_prefix = 'no'; break; } } define( 'LANG', $lang_short ); define( 'LANG_PREFIX', $lang_prefix ); putenv("LC_ALL=". $lang ); bindtextdomain('messages', ROOT .'lang/'); and my path is /var/www/rssbot.dk/lang/ folder. shut i make chmod right or? i hob to can be helpet

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  • Case class copy() method abstraction.

    - by Joa Ebert
    I would like to know if it is possible to abstract the copy method of case classes. Basically I have something like sealed trait Op and then something like case class Push(value: Int) extends Op and case class Pop() extends Op. The first problem: A case class without arguments/members does not define a copy method. You can try this in the REPL. scala> case class Foo() defined class Foo scala> Foo().copy() <console>:8: error: value copy is not a member of Foo Foo().copy() ^ scala> case class Foo(x: Int) defined class Foo scala> Foo(0).copy() res1: Foo = Foo(0) Is there a reason why the compiler makes this exception? I think it is rather unituitive and I would expect every case class to define a copy method. The second problem: I have a method def ops: List[Op] and I would like to copy all ops like ops map { _.copy() }. How would I define the copy method in the Op trait? I get a "too many arguments" error if I say def copy(): this.type. However, since all copy() methods have only optional arguments: why is this incorrect? And, how do I do that correct? By making another method named def clone(): this.type and write everywhere def clone() = copy() for all the case classes? I hope not.

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  • Handles Comparison: empty classes vs. undefined classes vs. void*

    - by Nawaz
    Microsoft's GDI+ defines many empty classes to be treated as handles internally. For example, (source GdiPlusGpStubs.h) //Approach 1 class GpGraphics {}; class GpBrush {}; class GpTexture : public GpBrush {}; class GpSolidFill : public GpBrush {}; class GpLineGradient : public GpBrush {}; class GpPathGradient : public GpBrush {}; class GpHatch : public GpBrush {}; class GpPen {}; class GpCustomLineCap {}; There are other two ways to define handles. They're, //Approach 2 class BOOK; //no need to define it! typedef BOOK *PBOOK; typedef PBOOK HBOOK; //handle to be used internally //Approach 3 typedef void* PVOID; typedef PVOID HBOOK; //handle to be used internally I just want to know the advantages and disadvantages of each of these approaches. One advantage with Microsoft's approach is that, they can define type-safe hierarchy of handles using empty classes, which (I think) is not possible with the other two approaches. What else? EDIT: One advantage with the second approach (i.e using incomplete classes) is that we can prevent clients from dereferencing the handles (that means, this approach appears to support encapsulation strongly, I suppose). The code would not even compile if one attempts to dereference handles. What else?

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  • Truly declarative language?

    - by gjvdkamp
    Hi all, Does anyone know of a truly declarative language? The behaviour I'm looking for is kind of what Excel does, where I can define variables and formulas, and have the formula's result change when the input changes (without having set the answer again myself) The behaviour I'm looking for is best shown with this pseudo code: X = 10 // define and assign two variables Y = 20; Z = X + Y // declare a formula that uses these two variables X = 50 // change one of the input variables ?Z // asking for Z should now give 70 (50 + 20) I've tried this in a lot of languages like F#, python, matlab etc, but every time i try this they come up with 30 instead of 70. Wich is correct from an imperative point of view, but i'm looking for a more declerative behaviour if you know what i mean. And this is just a very simple calculation. When things get more difficult it should handle stuff like recursion and memoization automagically. The code below would obviously work in C# but it's just so much code for the job, i'm looking for something a bit more to the point without all that 'technical noise' class BlaBla{ public int X {get;set;} // this used to be even worse before 3.0 public int Y {get;set;} public int Z {get{return X + Y;}} } static void main(){ BlaBla bla = new BlaBla(); bla.X = 10; bla.Y = 20; // can't define anything here bla.X = 50; // bit pointless here but I'll do it anyway. Console.Writeline(bla.Z);// 70, hurray! } This just seems like so much code, curly braces and semicolons that add nothing. Is there a language/ application (apart from Exel) that does this? Maybe I'm no doing it right in the mentioned langauges, or I've completely missed an app that does just this. I prototyped a language/ application that does this (along with some other stuff) and am thinking of productizing it. I just can't believe it's not there yet. Don't want to waste my time. Thanks in advance, Gert-Jan

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  • Best practices for JQuery namespaces + general purpose utility functions

    - by Armchair Bronco
    What are some current "rules of thumb" for implementing JQuery namespaces to host general purpose utility functions? I have a number of JavaScript utility methods scattered in various files that I'd like to consolidate into one (or more) namespaces. What's the best way to do this? I'm currently looking at two different syntaxes, listed in order of preference: //****************************** // JQuery Namespace syntax #1 //****************************** if (typeof(MyNamespace) === "undefined") { MyNamespace = {}; } MyNamespace.SayHello = function () { alert("Hello from MyNamespace!"); } MyNamespace.AddEmUp = function (a, b) { return a + b; } //****************************** // JQuery Namespace syntax #2 //****************************** if (typeof (MyNamespace2) === "undefined") { MyNamespace2 = { SayHello: function () { alert("Hello from MyNamespace2!"); }, AddEmUp: function (a, b) { return a + b; } }; } Syntax #1 is more verbose but it seems like it would be easier to maintain down the road. I don't need to add commas between methods, and I can left align all my functions. Are there other, better ways to do this?

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  • Implement a custom editor in Visual Studio 2008 or 2010

    - by David Montgomery
    Hi, I'm trying to find documentation on how one would go about creating a custom editor plug-in for VS2008 or VS2010. The file syntax I want to edit is from a tool called TemplateMaschine by Stefan Sarstedt. An example of the template syntax: <%@ Assembly Name="System.Xml" %> <%@ Import NameSpace="System.Xml" %> <%@ Import NameSpace="System.Collections" %> <%@ Argument Name="className" Type="string" %> <%@ Argument Name="attributes" Type="ArrayList" %> public class <%=className%> { <% foreach(string attr in attributes) { %> public string <%=attr%>; <% } %> } The most important editor features for me would be real-time syntax checking and code completion. If we could get those features, it would save us THOUSANDS of man-hours. Failing to incorporate a custom editor into Studio, maybe there is some open source text editor project out there that might be easy to extend for my purposes? I've looked a little at Eclipse, but I would think code completion won't be an option (also, my Java stinks). Another possibility might be extending the SharpDevelop text editor component. Ideas and suggestions welcome!

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  • C++ Multiple inheritance with interfaces?

    - by umanga
    Greetings all, I come from Java background and I am having difficulty with multiple inheritance. I have an interface called IView which has init() method.I want to derive a new class called PlaneViewer implementing above interface and extend another class. (QWidget). My implementation is as: IViwer.h (only Header file , no CPP file) : #ifndef IVIEWER_H_ #define IVIEWER_H_ class IViewer { public: //IViewer(); ///virtual //~IViewer(); virtual void init()=0; }; #endif /* IVIEWER_H_ */ My derived class. PlaneViewer.h #ifndef PLANEVIEWER_H #define PLANEVIEWER_H #include <QtGui/QWidget> #include "ui_planeviewer.h" #include "IViewer.h" class PlaneViewer : public QWidget , public IViewer { Q_OBJECT public: PlaneViewer(QWidget *parent = 0); ~PlaneViewer(); void init(); //do I have to define here also ? private: Ui::PlaneViewerClass ui; }; #endif // PLANEVIEWER_H PlaneViewer.cpp #include "planeviewer.h" PlaneViewer::PlaneViewer(QWidget *parent) : QWidget(parent) { ui.setupUi(this); } PlaneViewer::~PlaneViewer() { } void PlaneViewer::init(){ } My questions are: Is it necessary to declare method init() in PlaneViewer interface also , because it is already defined in IView? 2.I cannot complie above code ,give error : PlaneViewer]+0x28): undefined reference to `typeinfo for IViewer' collect2: ld returned 1 exit status Do I have to have implementation for IView in CPP file?

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  • IDE framework for a dynamic language?

    - by Kevin Reid
    Let's say I have a super-wonderful new programming language, and I want there to be an IDE for it. What IDE platform/framework could I use to get this done efficiently? I mean things like: Collection of files in a project, searching them, tabbed/split editors etc. — the basics. Syntax highlighting and auto-indent/reformatting. Providing the user interface for code completion — hit tab, get a list (I'll have to implement the necessary partial evaluation myself (it's a dynamic language)). This is the feature I'm most wishing for. Built-in parser framework which is good at recovering from the sort of syntax errors occurring in code that is in the middle of being edited would be helpful. In-editor annotation of syntax/runtime error locations fed back from the language runtime. REPL (interactive evaluator) interaction with the same completion as in the editor. This system should be Linux/Mac/Windows cross-platform (in that priority order). Being implemented in Java (or rather, accepting language plugins written in Java) is possibly useful, but anything else is worth a try too.

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