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  • printing out dictionnaires

    - by kyril
    I have a rather specific question: I want to print out characters at a specific place using the \033[ syntax. This is what the code below should do: (the dict cells has the same keys as coords but with either '*' or '-' as value.) coords = {'x'+str(x)+'y'+str(y) : (x,y) for x,y, in itertools.product(range(60), range(20))} for key, value in coords.items(): char = cells[key] x,y = value HORIZ=str(x) VERT=str(y) char = str(char) print('\033['+VERT+';'+HORIZ+'f'+char) However, I noticed that if I put this into a infinite while loop, it does not always prints the same characters at the same position. There are only slight changes, but it deletes some and puts them back in after some loops. I already tried it with lists, and there it seems to behave just fine, so I tend to think it has something todo with the dict, but I can not figure out what it could be. You can see the Problem in a console here: SharedConsole.I am happy for every tip on this matter. On a related topic: After the printing, some changes should be made at the values of the cells dict, but for reason unknown to me, the only the first two rules are executed and the rest is ignored. The rules should test how many neighbours (which is in population) are around the cell and apply the according rule. In my implemention of this I have some kind of weird tumor growth (which should not happen, as if there more than three around they should the cell should die) (see FreakingTumor): if cells_copy [coord] == '-': if population == 3: cells [coord] = '*' if cells_copy [coord] == '*': if population > 3: cells [coord] = '-' elif population <= 1: cells [coord] = '-' elif population == 2 or 3: cells [coord] = '*' I checked the population variable several times, so I am quite sure that is not the matter. I am sorry for the slow consoles. Thanks in advance! Kyril

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  • Firing PropertyChanged event in a complex, nested type in WPF

    - by John
    Hey I have a question about the PropertyChanged vent firing in WPF whne it is used in a complex type. I have a class called DataStore and a list of Departments (an ObservableCollection), and each department again has a list of Products. Properties in the Product class that are changed also affect properties in the Department and DataStore class. How does each Product notify the Department it belongs to, and the DataStore (which is the mother class of all) that one or more of its properties have changed their values? Example: a product has a property NumberSoldToday and is bound. The Department has a property called TotalNumberOfProductsSold: public int TotalNumberOfProductsSold { get { int result = 0; foreach(Product p in this.products) result += p.NumberSoldToday; return result; } } And the data store has a property TotalProductsSold (for all departments): public int TotalProductsSold { get { int result = 0; foreach(Product p in this.deparments) result += p.TotalNumberOfProductsSold; return result; } } If all these properties are bound, and the innermost property changes, it must somehow notify that the value of the other 2 changed as well. How? The only way I can see this happening is to hook up the PropertyChanged event in each class. Th event must also fire when deleting, adding to the collection of products and deparments, respectively. Is there a better, more clever way to do this?

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  • How to get the value of an XML element using Linq even when empty.

    - by Yeodave
    Please excuse my stupidity, I tend to find the traversing XML overly complicated. I am using ASP.NET in VB. I have an XML document which contains all the details of staff in my company... <staff> <staffName>Test Staff</staffName> <staffTitle>Slave</staffTitle> <staffDepartmentName>Finance</staffDepartmentName> <staffOffice>London</staffOffice> <staffEmail>[email protected]</staffEmail> <staffPhone>0207 123 456</staffPhone> <staffNotes>Working hours Mon to Thurs 9.15 - 5.15</staffNotes> <staffBio></staffBio> </staff> As you can see, some nodes do not always contain data for ever member of staff; only Directors have biographies. I access the values like this... For Each staff In ( _ From matches In myXMLFile.Descendants("staff").Descendants("staffName") _ Where matches.Nodes(0).ToString.ToLower.Contains(LCase(search)) _ Order By matches.Value _ Select matches) staffName = staff.Descendants("staffName").Nodes(0).ToString) staffTitle = staff.Descendants("staffTitle").Nodes(0).ToString) staffOffice = staff.Descendants("staffOffice").Nodes(0).ToString) staffEmail = staff.Descendants("staffEmail").Nodes(0).ToString) staffPhone = staff.Descendants("staffPhone").Nodes(0).ToString) staffNotes = staff.Descendants("staffNotes").Nodes(0).ToString) staffBio = staff.Descendants("staffBio").Nodes(0).ToString) ' Do something with that data... Next Once it gets to staffBio I get an error saying "Object reference not set to an instance of an object." obviously because that node does not exist. My question is how can I assign the value to a variable even when it is empty without having to do a conditional check before each assignment?

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  • Space between 2 vertices on a heightmap

    - by Sietse
    First off, I am sorry for the crazy title. I couldn't really think of something else. I am working on a hobby project, it's a infinite world generated with Perlin Noise, Java and LWJGL. But I am having a problem, it is kinda hard to explain, so I made a video: http://youtu.be/D_NUBJZ_5Kw Obviously the problem is the black spaces in between all the pieces of ground. I have no idea what is causing it. I already tried making all the values doubles instead of floats, but that didn't fix it. Here is a piece of code I am using: float height2, height = (float)getHeight(x, y); height2 = (float) ((getHeight(x-1, y+1) + height) / 2); vertexhelper.addVertexColorAndTexture(x, height2, y+1, r, g, b, a, 0f, 1f); height2 = (float) ((getHeight(x+1, y+1) + height) / 2); vertexhelper.addVertexColorAndTexture(x+1, height2, y+1, r, g, b, a, 1f, 1f); height2 = (float) ((getHeight(x+1, y-1) + height) / 2); vertexhelper.addVertexColorAndTexture(x+1, height2, y, r, g, b, a, 1f, 0f); height2 = (float) ((getHeight(x-1, y-1) + height) / 2); vertexhelper.addVertexColorAndTexture(x, height2, y, r, g, b, a, 0f, 0f); I loop through this at the initialization of a chunk with x-16 and y-16. vertexhelper is a class I made that just puts everything in a array. (I am using floats here, but that's after doing the maths, so that shouldn't be a problem) I highly appreciate you reading this.

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  • String generator issue

    - by Andrey
    I want to write a method which returns a string. So far so good. The creation of the string however is quite complicated. I have 3 string lists - the first one has 155 entries, the second one - 9, the third one 21. I want my method if called enough times(155*9*21) to return all the possible combinations of values from the 3 lists (basically this method should keep count on how many times it was called and return only one combination each time). Any ideas how to accomplish that? I have 155*9*22 possible combinations. The first time the method is called it should take List1(0), List2(0), List3(0). After that in the next 21 iterations, the index of the third list is only changed. Once all the elements from the third list have been used increment the index of the second list and so on. Once the method has produced all the possible combinations (155*9*22) I want it to start from the beginning.

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  • How can I create an instance of a class that I can use is more than one place in c#

    - by user1743574
    So I've been working on a class that details students of a university. I have one button that sets the details to a new instance of a class, and another to check if the student passed, through a method in my Class. The problem is that I create an instance of a class in the first button to add the values from what the user input, but I cannot use the second button to access the instance of the class created in the first button. private void button3_Click(object sender, EventArgs e) { Student student1 = new Student(); label1.Text = student1.text(); if (student1.hasPassed() == true) { passfailtextbox.Text = "Pass"; } else { passfailtextbox.Text = "Fail"; } } private void button1_Click(object sender, EventArgs e) { Student student1 = new Student(); student1.FirstName = firstnamebox.Text; student1.SecondName = secondnamebox.Text; student1.DateofBirth = DateTime.Parse(dobtextbox.Text).Date; student1.Course = coursetextbox.Text; student1.MatriculationNumber = int.Parse(matriculationtextbox.Text); student1.YearMark = double.Parse(yearmarktextbox.Text); } public Boolean hasPassed() { if (YearMark < 40) { return false; } else { return true; } } public string text() { return "Student" + " " + firstname + " " + secondname + " " + course + " " + dob.ToString() + " " + matriculationnumber.ToString() + " " + yearmark.ToString() ; }

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  • PHP: Check if 0?

    - by tarnfeld
    Hi, I am using a class which returns me the value of a particular row and cell of an excel spreadsheet. To build up an array of one column I am counting the rows and then looping through that number with a for() loop and then using the $array[] = $value to set the incrementing array object's value. This works great if none of the values in a cell are 0. The class returns me a number 0 so it's nothing to do with the class, I think it's the way I am looping through the rows and then assigning them to the array... I want to carry through the 0 value because I am creating graphs with the data afterwards, here is the code I have. // Get Rainfall $rainfall = array(); for($i=1;$i<=$count;$i++) { if($data->val($i,2) != 'Rainfall') // Check if not the column title { $rainfall[] = $data->val($i,2); } } For your info $data is the excel spreadsheet object and the method $data->val(row,col) is what returns me the value. In this case I am getting data from column 2. Screenshot of spreadsheet http://cl.ly/1Dmy Thanks! All help is very much appreciated!

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  • Pair equal operator overloading for inserting into set

    - by Petwoip
    I am trying to add a pair<int,int> to a set. If a pair shares the same two values as another in the set, it should not be inserted. Here's my non-working code: typedef std::pair<int, int> PairInt; template<> bool std::operator==(const PairInt& l, const PairInt& r) { return (l.first == r.first && l.second == r.second) || (l.first == r.second && l.second == r.first); } int main() { std::set<PairInt> intSet; intSet.insert(PairInt(1,3)); intSet.insert(PairInt(1,4)); intSet.insert(PairInt(1,4)); intSet.insert(PairInt(4,1)); } At the moment, the (4,1) pair gets added even though there is already a (1,4) pair. The final contents of the set are: (1 3) (1 4) (4 1) and I want it to be (1 3) (1 4) I've tried putting breakpoints in the overloaded method, but they never get reached. What have I done wrong?

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  • How do I access a value of a nested Perl hash?

    - by st
    I am new to Perl and I have a problem that's very simple but I cannot find the answer when consulting my Perl book. When printing the result of Dumper($request); I get the following result: $VAR1 = bless( { '_protocol' => 'HTTP/1.1', '_content' => '', '_uri' => bless( do{\(my $o = 'http://myawesomeserver.org:8081/counter/')}, 'URI::http' ), '_headers' => bless( { 'user-agent' => 'Mozilla/5.0 (X11; U; Linux i686; en; rv:1.9.0.4) Gecko/20080528 Epiphany/2.22 Firefox/3.0', 'connection' => 'keep-alive', 'cache-control' => 'max-age=0', 'keep-alive' => '300', 'accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8', 'accept-language' => 'en-us,en;q=0.5', 'accept-encoding' => 'gzip,deflate', 'host' => 'localhost:8081', 'accept-charset' => 'ISO-8859-1,utf-8;q=0.7,*;q=0.7' }, 'HTTP::Headers' ), '_method' => 'GET', '_handle' => bless( \*Symbol::GEN0, 'FileHandle' ) }, 'HTTP::Server::Simple::Dispatched::Request' ); How can I access the values of '_method' ('GET') or of 'host' ('localhost:8081'). I know that's an easy question, but Perl is somewhat cryptic at the beginning.

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  • Is it a good practice for a .js file to rely on variables declared in the including html

    - by Bozho
    In short: <script type="text/javascript"> var root = '${config.root}'; var userLanguage = '${config.language}'; var userTimezone = '${config.timezone}'; </script> <script type="text/javascript" src="js/scripts.js"></script> And then, in scripts.js, rely on these variables: if (userLanguage == 'en') { .. } The ${..} is simply a placeholder for a value in the script that generates the page. It can be php, jsp, asp, whatever. The point is - it is dynamic, and hence it can't be part of the .js file (which is static). So, is it OK for the static javascript file to rely on these externally defined configuration variables? (they are mainly configuration, of course). Or is it preferred to make the .js file be served dynamically as well (i.e. make it a .php / .jsp, with the proper Content-Type), and have these values defined in there.

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  • Launching and Intent from file and mime type

    - by stonedonkey
    I've reviewed all the similar questions here, but I can't for the life of me figure out what I'm doing wrong. I've written an application that tries to launch various files, sort of a file browser, when a file is clicked it tries to launch the program based on it's associated MIME type or I want it to present the "Choose Application to Launch" dialog. Here's the code I'm using to launch: File file = new File(app.mediaPath() + "/" +_mediaFiles.get(position)); Intent myIntent = new Intent(android.content.Intent.ACTION_VIEW); String extension = android.webkit.MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(file).toString()); String mimetype = android.webkit.MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension); myIntent.setDataAndType(Uri.fromFile(file),mimetype); startActivity(myIntent); This fails and generates a: android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.VIEW dat=file:///file:/mnt/sdcard/roms/nes/Baseball_simulator.nes } Now if I install OI File Manager for instance, it opens instead of this error being thrown, and then if I click the same file from within in it, it launches the approriate dialogs. I have noticed that the MIME type for that particular file fails, but other mime types like .zip do return values. Am I missing something that when the MIME type is null to call a dialog that lets the user select? I've tried other variations of launching the app, including not setting the mime type and only using .setData with no success. The action I want to happen is, a user clicks a file, if it's associated with an application that app launches, if not, the user gets the "Complete action using" dialog with a list of apps. Thanks for any advice.

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  • Does Monitor.Wait ensure that fields are re-read?

    - by Marc Gravell
    It is generally accepted (I believe!) that a lock will force any values from fields to be reloaded (essentially acting as a memory-barrier or fence - my terminology in this area gets a bit loose, I'm afraid), with the consequence that fields that are only ever accessed inside a lock do not themselves need to be volatile. (If I'm wrong already, just say!) A good comment was raised here, questioning whether the same is true if code does a Wait() - i.e. once it has been Pulse()d, will it reload fields from memory, or could they be in a register (etc). Or more simply: does the field need to be volatile to ensure that the current value is obtained when resuming after a Wait()? Looking at reflector, Wait calls down into ObjWait, which is managed internalcall (the same as Enter). The scenario in question was: bool closing; public bool TryDequeue(out T value) { lock (queue) { // arbitrary lock-object (a private readonly ref-type) while (queue.Count == 0) { if (closing) { // <==== (2) access field here value = default(T); return false; } Monitor.Wait(queue); // <==== (1) waits here } ...blah do something with the head of the queue } } Obviously I could just make it volatile, or I could move this out so that I exit and re-enter the Monitor every time it gets pulsed, but I'm intrigued to know if either is necessary.

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  • EGODatabase does not retain inserted record

    - by user135775
    Hi Guy! I'm using EGODatabase to process my data. When I tried to insert data into the database which I created with Base and attached to the project, the data that was inserted programmatically will not show up when I restart my app.However the data inserted manually using Base will show up just fine. Following is the code for inserting data into the database: NSString *path = [[NSBundle mainBundle] pathForResource:@"Database" ofType:@"db"]; db = [EGODatabase databaseWithPath:path]; if ([db open]) { NSLog(@"Database is opened successfully!"); } else { NSLog(@"Database is failed to open!"); } NSArray *params = [NSArray arrayWithObjects:[aFeed feedID], [aFeed title], nil]; [db executeUpdate:@"Insert INTO Feed (FeedID, Title) VALUES (?, ?)" parameters:params]; EGODatabaseResult *results = [db executeQuery:@"SELECT * FROM Feed"]; for ( EGODatabaseRow * row in results) { NSLog(@"ID: %@ Title: %@", [row stringForColumn:@"FeedID"], [row stringForColumn:@"Title"]); } I appreciate if anyone can share me a working sample code for EGODatabase. I'm using EGODatabase because I might have multi-threading code that write to the database. Thank in advance.

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  • SQL - Query range between two dates (NON-VBA)

    - by Mohgeroth
    I see various topics on this around stack overflow but none that fit the contect of MS-Access... Given a starting date and an ending date, is there a way through SQL to return records for each given month within the time frame? EG: Between #1/1/2010# and #12/31/2010# results #1/4/2010# #1/11/2010# ..... #12/27/2010# Restrictions MS-Access 2003 :No Case/Loops inside the SQL (IIF statements are good) This is a view only, NO VBA will be used since the data will not be tampered with. Disconnected recordset is my last option. I would prefer to find out theres some way to call your customized functions in the SQL to help return these values... some class stored on a global scope while you iterate through this date range maybe... Is this possible? I see many no's, but if there was a way to pass a value into a function I could find a way to make this work. Sad that I don't have a way to simulate a stored procedure without using a d/c recordset, at least that I know of... any experts out there know a way?

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  • C# cross thread dialogue co-operation

    - by John Attridge
    K I am looking at a primarily single thread windows forms application in 3.0. Recently my boss had a progress dialogue added on a separate thread so the user would see some activity when the main thread went away and did some heavy duty work and locked out the GUI. The above works fine unless the user switches applications or minimizes as the progress form sits top most and will not disappear with the main application. This is not so bad if there are lots of little operations as the event structure of the main form catches up with its events when it gets time so minimized and active flags can be checked and thus the dialog thread can hide or show itself accordingly. But if a long running sql operation kicks off then no events fire. I have tried intercepting the WndProc command but this also appears queued when a long running sql operation is executing. I have also tried picking up the processes, finding the current app and checking various memory values isiconic and the like inside the progress thread but until the sql operation finishes none of these get updated. Removing the topmost causes the dialog to disappear when another app activates but if the main app is then brought back it does not appear again. So I need a way to find out if the other thread is minimized or no longer active that does not involve querying the actual thread as that locks until the sql operation finishes. Now I know that this is not the best way to write this and it would be better to have all the heavy processing on separate threads leaving the GUI free but as this is a huge ancient legacy app the time to re-write in that fashion will not be provided so I have to work with what I have got. Any help is appreciated

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  • cuda 5.0 namespaces for contant memory variable usage

    - by Psypher
    In my program I want to use a structure containing constant variables and keep it on device all long as the program executes to completion. I have several header files containing the declaration of 'global' functions and their respective '.cu' files for their definitions. I kept this scheme because it helps me contain similar code in one place. e.g. all the 'device' functions required to complete 'KERNEL_1' are separated from those 'device' functions required to complete 'KERNEL_2' along with kernels definitions. I had no problems with this scheme during compilation and linking. Until I encountered constant variables. I want to use the same constant variable through all kernels and device functions but it doesn't seem to work. ########################################################################## CODE EXAMPLE ########################################################################### filename: 'common.h' -------------------------------------------------------------------------- typedef struct { double height; double weight; int age; } __CONSTANTS; __constant__ __CONSTANTS d_const; --------------------------------------------------------------------------- filename: main.cu --------------------------------------------------------------------------- #include "common.h" #include "gpukernels.h" int main(int argc, char **argv) { __CONSTANTS T; T.height = 1.79; T.weight = 73.2; T.age = 26; cudaMemcpyToSymbol(d_consts, &T, sizeof(__CONSTANTS)); test_kernel <<< 1, 16 >>>(); cudaDeviceSynchronize(); } --------------------------------------------------------------------------- filename: gpukernels.h --------------------------------------------------------------------------- __global__ void test_kernel(); --------------------------------------------------------------------------- filename: gpukernels.cu --------------------------------------------------------------------------- #include <stdio.h> #include "gpukernels.h" #include "common.h" __global__ void test_kernel() { printf("Id: %d, height: %f, weight: %f\n", threadIdx.x, d_const.height, d_const.weight); } When I execute this code, the kernel executes, displays the thread ids, but the constant values are displayed as zeros. How can I fix this?

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  • Memory Management with returning char* function

    - by RageD
    Hello all, Today, without much thought, I wrote a simple function return to a char* based on a switch statement of given enum values. This, however, made me wonder how I could release that memory. What I did was something like this: char* func() { char* retval = new char; // Switch blah blah - will always return some value other than NULL since default: return retval; } I apologize if this is a naive question, but what is the best way to release the memory seeing as I cannot delete the memory after the return and, obviously, if I delete it before, I won't have a returned value. What I was thinking as a viable solution was something like this void func(char*& in) { // blah blah switch make it do something } int main() { char* val = new char; func(val); // Do whatever with func (normally func within a data structure with specific enum set so could run multiple times to change output) val = NULL; delete val; val = NULL; return 0; } Would anyone have anymore insight on this and/or explanation on which to use? Regards, Dennis M.

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  • Prolog Beginner: How to unify with arithmentic cmparison operators or how to get a set var to range

    - by sixtyfootersdude
    I am new to prolog. I need to write an integer adder that will add numbers between 0-9 to other numbers 0-9 and produce a solution 0-18. This is what I want to do: add(in1, in2, out) :- in1 < 10, in2 < 10, out < 18. I would like to be able to call it like this: To Check if it is a valid addition: ?- add(1,2,3). true ?- add(1,2,4). false With one missing variable: ?- add(X,2,3). 1 ?- add(1,4,X). 5 With multiple missing variables: ?-add(X,Y,Z). % Some output that would make sense. Some examples could be: X=1, Y=1, Z=2 ; X=2, Y=1, Z=3 ...... I realize that this is probably a pretty simplistic question and it is probably very straightforward. However cording to the prolog tutorial I am using: "Unlike unification Arithmetic Comparison Operators operators cannot be used to give values to a variable. The can only be evaluated when every term on each side have been instantiated."

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  • Data not transfred from form to mysql table (updating of data is not happening)

    - by Jimson
    Hi all and thanks in advance to all for this I tired and was unable to find the answer i am looking for an answer. my problem is that i am unable to update the values enterd in the form. I have attached all the files i'm using MYSQL database to fetch data. what happens is that i'm able to add and delete records from form using ajax and PHP scripts to MYSQL database, but i am not able to update data which was retrived from database. the file structure is as follows index.php is a file with ajax functions where it displays form for adding new data to MYSQL using save.php file and list of all records are view without refrishing page (calling load-list.php to view all records from index.php works fine, and save.php to save data from form) - *Delete*is an ajax function called from index.php to delete record from mysql database (function calling delete.php works fine) - Update is an ajax function called from index.php to update data using update-form.php by retriving specific record from mysql tabel, (works fine) Problem lies in updating data from update-form.php to update.php (in which update query is wrriten for mysql) i had tried in many ways at last i had figured out that data is not being transfred from update-form.php to update.php there is a small problem in jquery ajax function where it is not transfering data to update.php page. can any one correct this ????? i will be greatfull to them..... please find the link below for all files link to get my form files

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  • PropertyPlaceholderConfigurer works from Maven command line, but not from Eclipse?

    - by HDave
    I have Eclipse configured to use an external maven instance. Nonetheless I have an integration test that runs fine from the command line, but fails from within Eclipse. The error is a class Spring application context bean error: Cannot convert value of type [java.lang.String] to required type The culprit it a bean that sets property values using a PropertyPlaceholderConfigurer. <!-- property settings for non-JNDI database connections --> <bean id="placeholderConfigUuid" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" /> <property name="location" value="classpath:database.properties" /> <property name="placeholderPrefix" value="$DS{" /> </bean> I know which bean is failing because it appears in the stack trace and because when I replace the $DS{hibernate.dialect} with a static value it works. I have two questions: 1) Since M2Eclipse is using the same Maven setup as the command line, why does one work and the other fail? 2) How to fix this? I really like the ability to run a single jUnit test from within Eclipse on demand.

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  • How to send and retrieve in the controller

    - by user281180
    I have the folowing code in my view, however, I can see that I don`t have the values in the controller. What is wrong? In the view I have, <% using (Html.BeginForm()) {%> <%=Html.TextBox("Addresses[0].Line1") %> <%=Html.TextBox("Addresses[0].Line2")%> <%=Html.TextBox("Addresses[1].Line1")%> <%=Html.TextBox("Addresses[1].Line2")%> <input type="submit" name="submitForm" value="Save products" /> <% } %> My classes are as follows: public class Customer { public string FirstName { get; set; } public string Lastname { get; set; } public List<Address> Addresses { get; set; } public Customer() { Addresses = new List<Address>(); } } public class Address { public int Line1 { get; set; } public int Line2 { get; set; } } My controller as follows: public ActionResult Index() { return View(); } [HttpPost] public ActionResult Index(Customer customer) { return View(); }

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  • Permuting output of a tree of closures

    - by yan
    This a conceptual question on how one would implement the following in Lisp (assuming Common Lisp in my case, but any dialect would work). Assume you have a function that creates closures that sequentially iterate over an arbitrary collection (or otherwise return different values) of data and returns nil when exhausted, i.e. (defun make-counter (up-to) (let ((cnt 0)) (lambda () (if (< cnt up-to) (incf cnt) nil)))) CL-USER> (defvar gen (make-counter 3)) GEN CL-USER> (funcall gen) 1 CL-USER> (funcall gen) 2 CL-USER> (funcall gen) 3 CL-USER> (funcall gen) NIL CL-USER> (funcall gen) NIL Now, assume you are trying to permute a combinations of one or more of these closures. How would you implement a function that returns a new closure that subsequently creates a permutation of all closures contained within it? i.e.: (defun permute-closures (counters) ......) such that the following holds true: CL-USER> (defvar collection (permute-closures (list (make-counter 3) (make-counter 3)))) CL-USER> (funcall collection) (1 1) CL-USER> (funcall collection) (1 2) CL-USER> (funcall collection) (1 3) CL-USER> (funcall collection) (2 1) ... and so on. The way I had it designed originally was to add a 'pause' parameter to the initial counting lambda such that when iterating you can still call it and receive the old cached value if passed ":pause t", in hopes of making the permutation slightly cleaner. Also, while the example above is a simple list of two identical closures, the list can be an arbitrarily-complicated tree (which can be permuted in depth-first order, and the resulting permutation set would have the shape of the tree.). I had this implemented, but my solution wasn't very clean and am trying to poll how others would approach the problem. Thanks in advance.

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  • perl DateTime now() problem

    - by Sergey Sinkovskiy
    Having this script use DateTime; use DateTime::Format::Strptime; my $p = DateTime::Format::Strptime->new(pattern => '%F %T', time_zone => 'local'); my $dt1 = DateTime->now(time_zone=>'local')->set_time_zone('UTC'); my $dt2 = $p->parse_datetime('2010-10-23 14:10:02')->set_time_zone('UTC'); print Dumper($dt1->hms); print Dumper($dt2->hms); print Dumper($dt1 > $dt2); The problem is that $dt1 is off by 1 hour. Like $VAR1 = '12:09:55'; $VAR1 = '11:10:02'; $VAR1 = 1; If I remove set_time_zone('UTC') in both cases - dumped values are okay. My feel is that somewhere DST is taken into account unnecessarily, but can't find out. Update: I dumped $dt-time_zone-name and $dt-offset for both and that's what i get. $VAR1 = 'Europe/Kiev'; $VAR1 = 7200; $VAR1 = 'Europe/Kiev'; $VAR1 = 10800; How this could be possible?

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  • MySQL Join/Comparison on a DATETIME column (<5.6.4 and > 5.6.4)

    - by Simon
    Suppose i have two tables like so: Events ID (PK int autoInc), Time (datetime), Caption (varchar) Position ID (PK int autoinc), Time (datetime), Easting (float), Northing (float) Is it safe to, for example, list all the events and their position if I am using the Time field as my joining criteria? I.e.: SELECT E.*,P.* FROM Events E JOIN Position P ON E.Time = P.Time OR, even just simply comparing a datetime value (taking into consideration that the parameterized value may contain the fractional seconds part - which MySQL has always accepted) e.g. SELECT E.* FROM Events E WHERE E.Time = @Time I understand MySQL (before version 5.6.4) only stores datetime fields WITHOUT milliseconds. So I would assume this query would function OK. However as of version 5.6.4, I have read MySQL can now store milliseconds with the datetime field. Assuming datetime values are inserted using functions such as NOW(), the milliseconds are truncated (<5.6.4) which I would assume allow the above query to work. However, with version 5.6.4 and later, this could potentially NOT work. I am, and only ever will be interested in second accuracy. If anyone could answer the following questions would be greatly appreciated: In General, how does MySQL compare datetime fields against one another (consider the above query). Is the above query fine, and does it make use of indexes on the time fields? (MySQL < 5.6.4) Is there any way to exclude milliseconds? I.e. when inserting and in conditional joins/selects etc? (MySQL 5.6.4) Will the join query above work? (MySQL 5.6.4) EDIT I know i can cast the datetimes, thanks for those that answered, but i'm trying to tackle the root of the problem here (the fact that the storage type/definition has been changed) and i DO NOT want to use functions in my queries. This negates all my work of optimizing queries applying indexes etc, not to mention having to rewrite all my queries. EDIT2 Can anyone out there suggest a reason NOT to join on a DATETIME field using second accuracy?

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  • How can I pass a hash to a Perl subroutine?

    - by Vishalrix
    In one of my main( or primary) routines,I have two or more hashes. I want the subroutine foo() to recieve these possibly-multiple hashes as distinct hashes. Right now I have no preference if they go by value, or as references. I am struggling with this for the last many hours and would appreciate help, so that I dont have to leave perl for php! ( I am using mod_perl, or will be) Right now I have got some answer to my requirement, shown here From http://forums.gentoo.org/viewtopic-t-803720-start-0.html # sub: dump the hash values with the keys '1' and '3' sub dumpvals { foreach $h (@_) { print "1: $h->{1} 3: $h->{3}\n"; } } # initialize an array of anonymous hash references @arr = ({1,2,3,4}, {1,7,3,8}); # create a new hash and add the reference to the array $t{1} = 5; $t{3} = 6; push @arr, \%t; # call the sub dumpvals(@arr); I only want to extend it so that in dumpvals I could do something like this: foreach my %k ( keys @_[0]) { # use $k and @_[0], and others } The syntax is wrong, but I suppose you can tell that I am trying to get the keys of the first hash ( hash1 or h1), and iterate over them. How to do it in the latter code snippet above?

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