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  • Subroutine & GoTo design

    - by sub
    I have a strange question concerning subroutines: As I'm creating a minimal language and I don't want to add high-level loops like while or for I was planning on just adding gotos to keep it Turing-Complete. Now I thought, eww - gotos - I wouldn't want to program in that language if I had to use gotos so often. So I thought about adding subroutines instead. I see the difference as the following: gotos Go to (captain obvious) a previously defined point and continue executing the program from there. Leads to hardly understandable and buggy code, I think that's a fact. subroutines Similiar: You define their starting point somewhere, as you call them the program jumps there - but the subroutine can go back to the point it was called from with return. Okay. Why didn't I just add the more function-like, nice looking subroutines? Because: In order to make return work if I call subroutines from within subroutines from within other subroutines, I'd have to use a stack containing the point where the currently running subroutine came from at top. That would then mean that I would, if I create loops using the subroutines, end up with an extremely memory-eating, overflowing stack with return locations. Not good. Don't think of my subroutines as functions. They are just gotos that return to the point they were called from, they don't actually give back values like the return x; statement in nearly all today's languages. Now to my actual questions: How can I solve the above problem with the stack overflow on loops with subroutines? Do I have to add a separate goto language construct without the return option? Assembler doesn't have loops but as I have seen myJumpPoint:, jnz, jz, retn. That means to me that there must also be a stack containing all the return locations. Am I right with that? What about long running loops then? Don't they overflow the stack/eat memory then? Am I getting the retn symbol in assembler totally wrong? If yes, please explain it to me.

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  • Help with storing/accessing user access roles C# Winforms

    - by user222453
    Hello, firstly I would like to thank you in advance for any assistance provided. I am new to software development and have designed several Client/Server applications over the last 12 months or so, I am currently working on a project that involves a user logging in to gain access to the application and I am looking at the most efficient and "simple" method of storing the users permissions once logged in to the application which can be used throughout restricting access to certain tabs on the main form. I have created a static class called "User" detailed below: static class User { public static int _userID; public static string _moduleName; public static string _userName; public static object[] UserData(object[] _dataRow) { _userID = (int)_dataRow[0]; _userName = (string)_dataRow[1]; _moduleName = (string)_dataRow[2]; return _moduleName; } } When the user logs in and they have been authenticated, I wish to store the _moduleName objects in memory so I can control which tabs on the main form tab control they can access, for example; if the user has been assigned the following roles in the database: "Sales Ledger", "Purchase Ledger" they can only see the relevant tabs on the form, by way of using a Switch - Case block once the login form is hidden and the main form is instantiated. I can store the userID and userName variables in the main form once it loads by means of say for example: Here we process the login data from the user: DataAccess _dal = new DataAccess(); switch (_dal.ValidateLogin(txtUserName.Text, txtPassword.Text)) { case DataAccess.ValidationCode.ConnectionFailed: MessageBox.Show("Database Server Connection Failed!"); break; case DataAccess.ValidationCode .LoginFailed: MessageBox.Show("Login Failed!"); _dal.RecordLogin(out errMsg, txtUserName.Text, workstationID, false); break; case DataAccess.ValidationCode .LoginSucceeded: frmMain frmMain = new frmMain(); _dal.GetUserPrivList(out errMsg,2); //< here I access my DB and get the user permissions based on the current login. frmMain.Show(); this.Hide(); break; default: break; } private void frmMain_Load(object sender, EventArgs e) { int UserID = User._userID; } That works fine, however the _modules object contains mutiple permissions/roles depending on what has been set in the database, how can I store the multiple values and access them via a Switch-Case block? Thank you again in advance.

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  • INNER JOIN code calculated value with SELECT statement

    - by sp-1986
    I have the following stored procedure which will generate mon to sun and then creates a temp table with a series of 'weeks' (start and end weeks) : USE [test_staff] GO /****** Object: StoredProcedure [dbo].[sp_timesheets_all_staff_by_week_by_job_grouping_by_site] Script Date: 03/21/2012 09:04:49 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE PROCEDURE [dbo].[sp_timesheets_all_staff_by_week_by_job_grouping_by_site] ( @grouping_ref int, @week_ref int ) AS CREATE TABLE #WeeklyList ( Start_Week date, End_Week date, week_ref int --month_name date ) DECLARE @REPORT_DATE DATETIME, @WEEK_BEGINING VARCHAR(10) SELECT @REPORT_DATE = '2011-01-19T00:00:00' --SELECT @REPORT_DATE = GETDATE() -- should grab the date now. SELECT @WEEK_BEGINING = 'MONDAY' IF @WEEK_BEGINING = 'MONDAY' SET DATEFIRST 1 ELSE IF @WEEK_BEGINING = 'TUESDAY' SET DATEFIRST 2 ELSE IF @WEEK_BEGINING = 'WEDNESDAY' SET DATEFIRST 3 ELSE IF @WEEK_BEGINING = 'THURSDAY' SET DATEFIRST 4 ELSE IF @WEEK_BEGINING = 'FRIDAY' SET DATEFIRST 5 ELSE IF @WEEK_BEGINING = 'SATURDAY' SET DATEFIRST 6 ELSE IF @WEEK_BEGINING = 'SUNDAY' SET DATEFIRST 7 DECLARE @WEEK_START_DATE DATETIME, @WEEK_END_DATE DATETIME --GET THE WEEK START DATE SELECT @WEEK_START_DATE = @REPORT_DATE - (DATEPART(DW, @REPORT_DATE) - 1) --GET THE WEEK END DATE SELECT @WEEK_END_DATE = @REPORT_DATE + (7 - DATEPART(DW, @REPORT_DATE)) PRINT 'Week Start: ' + CONVERT(VARCHAR, @WEEK_START_DATE) PRINT 'Week End: ' + CONVERT(VARCHAR, @WEEK_END_DATE) DECLARE @Interval int = datediff(WEEK,getdate(),@WEEK_START_DATE)+1 --SELECT Start_Week=@WEEK_START_DATE --, End_Week=@WEEK_END_DATE --INTO #WeekList INSERT INTO #WeeklyList SELECT Start_Week=@WEEK_START_DATE, End_Week=@WEEK_END_DATE WHILE @Interval <= 0 BEGIN set @WEEK_START_DATE=DATEADD(WEEK,1,@WEEK_START_DATE) set @WEEK_END_DATE=DATEADD(WEEK,1,@WEEK_END_DATE) INSERT INTO #WeeklyList values (@WEEK_START_DATE,@WEEK_END_DATE) SET @Interval += 1; END SELECT CONVERT(VARCHAR(11), Start_Week, 106) AS 'month_name', CONVERT(VARCHAR(11), End_Week, 106) AS 'End', DATEDIFF(DAY, 0, Start_Week) / 7 AS week_ref -- create the unique week reference number --'VIEW' AS month_name FROM #WeeklyList In this section i am creating the week_ref DATEDIFF(DAY, 0, Start_Week) / 7 AS week_ref -- create the unique week reference number I then need to combine it with this select code: DECLARE @YearString char(3) = CONVERT(char(3), SUBSTRING(CONVERT(char(5), @week_ref), 1, 3)) DECLARE @MonthString char(2) = CONVERT(char(2), SUBSTRING(CONVERT(char(5), @week_ref), 4, 2)) --Convert: DECLARE @Year int = CONVERT(int, @YearString) + 1200 DECLARE @Month int = CONVERT(int, @MonthString) **--THIS FILTERS THE REPORT** SELECT ts.staff_member_ref, sm.common_name, sm.department_name, DATENAME(MONTH, ts.start_dtm) + ' ' + DATENAME(YEAR, ts.start_dtm) AS month_name, ts.timesheet_cat_ref, cat.desc_long AS timesheet_cat_desc, grps.grouping_ref, grps.description AS grouping_desc, ts.task_ref, tsks.task_code, tsks.description AS task_desc, ts.site_ref, sits.description AS site_desc, ts.site_ref AS Expr1, CASE WHEN ts .status = 0 THEN 'Pending' WHEN ts .status = 1 THEN 'Booked' WHEN ts .status = 2 THEN 'Approved' ELSE 'Invalid Status' END AS site_status, ts.booked_time AS booked_time_sum, start_dtm, CONVERT(varchar(20), start_dtm, 108) + ' ' + CONVERT(varchar(20), start_dtm, 103) AS start_dtm_text, booked_time, end_dtm, CONVERT(varchar(20), end_dtm, 108) + ' ' + CONVERT(varchar(20), end_dtm, 103) AS end_dtm_text FROM timesheets AS ts INNER JOIN timesheet_categories AS cat ON ts.timesheet_cat_ref = cat.timesheet_cat_ref INNER JOIN timesheet_tasks AS tsks ON ts.task_ref = tsks.task_ref INNER JOIN timesheet_task_groupings AS grps ON tsks.grouping_ref = grps.grouping_ref INNER JOIN timesheet_sites AS sits ON ts.site_ref = sits.site_ref INNER JOIN vw_staff_members AS sm ON ts.staff_member_ref = sm.staff_member_ref WHERE (ts.status IN (1, 2)) AND (cat.is_leave_category = 0) GROUP BY ts.staff_member_ref, sm.common_name, sm.department_name, DATENAME(MONTH, ts.start_dtm), DATENAME(YEAR, ts.start_dtm), ts.timesheet_cat_ref, cat.desc_long, grps.grouping_ref, grps.description, ts.status, ts.booked_time, ts.task_ref, tsks.task_code, tsks.description, ts.site_ref, sits.description, ts.start_dtm, ts.end_dtm ORDER BY sm.common_name, timesheet_cat_desc, tsks.task_code, site_desc DROP TABLE #WeeklyList GO I want to pass the week_ref into the SELECT statement (refer to comment - THIS FILTERS THE REPORT) but the problem is week_ref isnt a valid column as its derived by code. Any ideas?

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  • How can I position some divs inside an unordered list so they line up with the root element of the l

    - by Ronedog
    I want to position all the divs to line up to the left on the same x coordinate so it looks nice. Notice the picture below, how based on the number of nested categories the div (and its contents) show up at slightly different x coordinates. I need to have the div's line up at exactly the same x coordinate no matter how deeply nested. Note, the bottom most category always has a div for the content, but that div has to be situated inside the last < li . I am using an unordered list to display the menu and thought the best solution would be to grab the root category (Cat 2, and mCat1) and obtain their left offset using jquery, then simply use that value to update the positioning of the div...but I couldn't seem to get it to work just right. I would appreciate any advice or help that you are willing to give. Heres the HTML <ul id="nav> <li>Cat 2 <ul> <li>sub cat2</li> </ul> </li> <li>mCat1 <ul> <li>Subcat A <ul> <li>Subcat A.1 <ul> <li>Annie</li> </ul> </li> </ul> </li> </ul> </li> </ul> Heres some jquery I tried (I have do insert the div inside this .each() loop in order to retrieve some values, but basically, this selector is grabbing the last < li in the menu tree and placing a div after it and that is the div that I want to position. the 245 value was something I was playing around with to see how I could get things to line up, and I know its out of wack, but the problem is still the same no matter what I do: $("#nav li:not(:has(li))").each(function () { var self = $(this); var position = self.offset(); var xLeft = Math.round(position.left)- 245; console.log("xLeft:", xLeft ); self.after( '<div id="' + self.attr('p_node') + '_p_cont_div" class="property_position" style="display:none; left:' + xLeft + 'px;" /> ' ); }); Heres the css: .property_position{ float:left; position: relative; top: 0px; padding-top:5px; padding-bottom:10px; }

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  • Working with Hibernate Queries

    - by jschoen
    I am new to hibernate queries, and trying to get a grasp on how everything works. I am using Hibernate 3 with Netbeans 6.5. I have a basic project set up and have been playing around with how to do everything. I started with essentially a search query. Where the user can enter values into one or more fields. The table would be Person with the columns first_name, middle_name, last_name for the sake of the example. The first way I found was to have a method that took firstName, middleName, and lastName as parameters: Session session = HibernateUtil.getSessionFactory().getCurrentSession(); Transaction tx = session.beginTransaction(); String query = "from Person where (first_name = :firstName or :firstName is null) "+ "and (middle_name = :middleName or :middleName is null) " "and (last_name = :lastname or :lastName is null)"; Query q = session.createQuery(query); q.setString("firstName", firstName); q.setString("middleName", middleName); q.setString("lastName", lastName); List<Person> results = (List<Person>) q.list(); This did not sit well with me, since it seemed like I should not have to write that much, and well, that I was doing it wrong. So I kept digging and found another way: Session session = HibernateUtil.getSessionFactory().getCurrentSession(); Transaction tx = session.beginTransaction(); Criteria crit = session.createCriteria(Person.class); if (firstName != null) { crit.add(Expression.ge("firstName", firstName); } if (middleName != null) { crit.add(Expression.ge("middleName", middleName); } if (lastName != null) { crit.add(Expression.ge("lastName", lastName); } List<Person> results = (List<Person>) crit.list(); So what I am trying to figure out is which way is the preferred way for this type of query? Criteria or Query? Why? I am guessing that Criteria is the preferred way and you should only use Query when you need to write it by hand for performance type reasons. Am I close?

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  • Unable to execute stored Procedure using Java and JDBC on SQL server

    - by jwmajors81
    I have been trying to execute a MS SQL Server stored procedure via JDBC today and have been unsuccessful thus far. The stored procedure has 1 input and 1 output parameter. With every combination I use when setting up the stored procedure call in code I get an error stating that the stored procedure couldn't be found. I have provided the stored procedure I'm executing below (NOTE: this is vendor code, so I cannot change it). set ANSI_NULLS ON set QUOTED_IDENTIFIER ON GO ALTER PROC [dbo].[spWCoTaskIdGen] @OutIdentifier int OUTPUT AS BEGIN DECLARE @HoldPolicyId int DECLARE @PolicyId char(14) IF NOT EXISTS ( SELECT * FROM UniqueIdentifierGen (UPDLOCK) ) INSERT INTO UniqueIdentifierGen VALUES (0) UPDATE UniqueIdentifierGen SET CurIdentifier = CurIdentifier + 1 SELECT @OutIdentifier = (SELECT CurIdentifier FROM UniqueIdentifierGen) END The code looks like: CallableStatement statement = connection .prepareCall("{call dbo.spWCoTaskIdGen(?)}"); statement.setInt(1, 0); ResultSet result = statement.executeQuery(); I get the following error: SEVERE: Could not find stored procedure 'dbo.spWCoTaskIdGen'. I have also tried CallableStatement statement = connection .prepareCall("{? = call dbo.spWCoTaskIdGen(?)}"); statement.registerOutParameter(1, java.sql.Types.INTEGER); statement.registerOutParameter(2, java.sql.Types.INTEGER); statement.executeQuery(); The above results in: SEVERE: Could not find stored procedure 'dbo.spWCoTaskIdGen'. I have also tried: CallableStatement statement = connection .prepareCall("{? = call spWCoTaskIdGen(?)}"); statement.registerOutParameter(1, java.sql.Types.INTEGER); statement.registerOutParameter(2, java.sql.Types.INTEGER); statement.executeQuery(); The code above resulted in the following error: Could not find stored procedure 'spWCoTaskIdGen'. Finally, I should also point out the following: I have used the MS SQL Server Management Studio tool and have been able to successfully run the stored procedure. The sql generated to execute the stored procedure is provided below: GO DECLARE @return_value int, @OutIdentifier int EXEC @return_value = [dbo].[spWCoTaskIdGen] @OutIdentifier = @OutIdentifier OUTPUT SELECT @OutIdentifier as N'@OutIdentifier ' SELECT 'Return Value' = @return_value GO The code being executed runs with the same user id that was used in point #1 above. In the code that creates the Connection object I log which database I'm connecting to and the code is connecting to the correct database. Any ideas? Thank you very much in advance.

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  • java NullPointerException when parsing XML

    - by behrk2
    Hi Everyone, I keep receiving a java.lang.NullPointerException while trying to parse out the values of ths tags in the following XML sample: <?xml version="1.0" standalone="yes"?> <autocomplete> <autocomplete_item> <title short="Forrest Gump"></title> </autocomplete_item> <autocomplete_item> <title short="Forrest Landis"></title> </autocomplete_item> <autocomplete_item> <title short="Finding Forrester"></title> </autocomplete_item> <autocomplete_item> <title short="Menotti: The Medium: Maureen Forrester"></title> </autocomplete_item> </autocomplete> Here is my parsing code, can anyone see where I am going wrong? Thanks! public String parse(String element) { Document doc = null; String result = null; DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory .newInstance(); DocumentBuilder docBuilder = null; try { docBuilder = docBuilderFactory.newDocumentBuilder(); } catch (ParserConfigurationException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } docBuilder.isValidating(); try { doc = docBuilder.parse(input); } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } doc.getDocumentElement().normalize(); NodeList list = doc.getElementsByTagName(element); _node = new String(); _element = new String(); for (int i = 0; i < list.getLength(); i++) { Node value = list.item(i).getChildNodes().item(0); _node = list.item(i).getNodeName(); _element = value.getNodeValue(); result = _element; SearchResults searchResults = new SearchResults(); searchResults.setTitles(result); Vector test = searchResults.getTitles(); for (int p = 0; p < test.size(); p++) { System.out.println("STUFF: " + test.elementAt(p)); } }// end for return result; }

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  • Replace HTML entities in a string avoiding <img> tags

    - by Xeos
    I have the following input: Hi! How are you? <script>//NOT EVIL!</script> Wassup? :P LOOOL!!! :D :D :D Which is then run through emoticon library and it become this: Hi! How are you? <script>//NOT EVIL!</script> Wassup? <img class="smiley" alt="" title="tongue, :P" src="ui/emoticons/15.gif"> LOOOL!!! <img class="smiley" alt="" title="big grin, :D" src="ui/emoticons/5.gif"> <img class="smiley" alt="" title="big grin, :P" src="ui/emoticons/5.gif"> <img class="smiley" alt="" title="big grin, :P" src="ui/emoticons/5.gif"> I have a function that escapes HTML entites to prevent XSS. So running it on raw input for the first line would produce: Hi! How are you? &lt;script&gt;//NOT EVIL!&lt;/script&gt; Now I need to escape all the input, but at the same time I need to preserve emoticons in their initial state. So when there is <:-P emoticon, it stays like that and does not become &lt;:-P. I was thinking of running a regex split on the emotified text. Then processing each part on its own and then concatenating the string together, but I am not sure how easily can Regex be bypassed? I know the format will always be this: [<img class="smiley" alt="] [empty string] [" title="] [one of the values from a big list] [, ] [another value from the list (may be matching original emoticon)] [" src="ui/emoticons/] [integer from Y to X] [.gif">] Using the list MAY be slow, since I need to run that regex on text that may have 20-30-40 emoticons. Plus there may be 5-10-15 text messages to process. What could be an elegant solution to this? I am ready to use third-party library or jQuery for this. PHP preprocessing is possible as well.

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  • Corner Cases, Unexpected and Unusual Matlab

    - by Mikhail
    Over the years, reading others code, I encountered and collected some examples of Matlab syntax which can be at first unusual and counterintuitive. Please, feel free to comment or complement this list. I verified it r2006a. set([], 'Background:Color','red') Matlab is very forgiving sometimes. In this case, setting properties to an array of objects works also with nonsense properties, at least when the array is empty. myArray([1,round(end/2)]) This use of end keyword may seem unclean but is sometimes very handy instead of using length(myArray). any([]) ~= all([]) Surprisigly any([]) returns false and all([]) returns true. And I always thought that all is stronger then any. EDIT: with not empty argument all() returns true for a subset of values for which any() returns true (e.g. truth table). This means that any() false implies all() false. This simple rule is being violated by Matlab with [] as argument. Loren also blogged about it. Select(Range(ExcelComObj)) Procedural style COM object method dispatch. Do not wonder that exist('Select') returns zero! [myString, myCell] Matlab makes in this case an implicit cast of string variable myString to cell type {myString}. It works, also if I would not expect it to do so. [double(1.8), uint8(123)] => 2 123 Another cast example. Everybody would probably expect uint8 value being cast to double but Mathworks have another opinion. a = 5; b = a(); It looks silly but you can call a variable with round brackets. Actually it makes sense because this way you can execute a function given its handle. a = {'aa', 'bb' 'cc', 'dd'}; Surprsisingly this code neither returns a vector nor rises an error but defins matrix, using just code layout. It is probably a relict from ancient times. set(hobj, {'BackgroundColor','ForegroundColor'},{'red','blue'}) This code does what you probably expect it to do. That function set accepts a struct as its second argument is a known fact and makes sense, and this sintax is just a cell2struct away. Equvalence rules are sometimes unexpected at first. For example 'A'==65 returns true (although for C-experts it is self-evident). About which further unexpected/unusual Matlab features are you aware?

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  • How can I use functools.partial on multiple methods on an object, and freeze parameters out of order

    - by Joseph Garvin
    I find functools.partial to be extremely useful, but I would like to be able to freeze arguments out of order (the argument you want to freeze is not always the first one) and I'd like to be able to apply it to several methods on a class at once, to make a proxy object that has the same methods as the underlying object except with some of its methods parameter being frozen (think of it as generalizing partial to apply to classes). I've managed to scrap together a version of functools.partial called 'bind' that lets me specify parameters out of order by passing them by keyword argument. That part works: >>> def foo(x, y): ... print x, y ... >>> bar = bind(foo, y=3) >>> bar(2) 2 3 But my proxy class does not work, and I'm not sure why: >>> class Foo(object): ... def bar(self, x, y): ... print x, y ... >>> a = Foo() >>> b = PureProxy(a, bar=bind(Foo.bar, y=3)) >>> b.bar(2) Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: bar() takes exactly 3 arguments (2 given) I'm probably doing this all sorts of wrong because I'm just going by what I've pieced together from random documentation, blogs, and running dir() on all the pieces. Suggestions both on how to make this work and better ways to implement it would be appreciated ;) One detail I'm unsure about is how this should all interact with descriptors. Code follows. from types import MethodType class PureProxy(object): def __init__(self, underlying, **substitutions): self.underlying = underlying for name in substitutions: subst_attr = substitutions[name] if hasattr(subst_attr, "underlying"): setattr(self, name, MethodType(subst_attr, self, PureProxy)) def __getattribute__(self, name): return getattr(object.__getattribute__(self, "underlying"), name) def bind(f, *args, **kwargs): """ Lets you freeze arguments of a function be certain values. Unlike functools.partial, you can freeze arguments by name, which has the bonus of letting you freeze them out of order. args will be treated just like partial, but kwargs will properly take into account if you are specifying a regular argument by name. """ argspec = inspect.getargspec(f) argdict = copy(kwargs) if hasattr(f, "im_func"): f = f.im_func args_idx = 0 for arg in argspec.args: if args_idx >= len(args): break argdict[arg] = args[args_idx] args_idx += 1 num_plugged = args_idx def new_func(*inner_args, **inner_kwargs): args_idx = 0 for arg in argspec.args[num_plugged:]: if arg in argdict: continue if args_idx >= len(inner_args): # We can't raise an error here because some remaining arguments # may have been passed in by keyword. break argdict[arg] = inner_args[args_idx] args_idx += 1 f(**dict(argdict, **inner_kwargs)) new_func.underlying = f return new_func

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  • C++ print out a binary search tree

    - by starcorn
    Hello, Got nothing better to do this Christmas holiday, so I decided to try out making a binary search tree. I'm stuck with the print function. How should the logic behind it work? Since the tree is already inserting it in a somewhat sorted order, and I want to print the tree from smallest values to the biggest. So I need to travel to the furthest left branch of the tree to print the first value. Right, so after that how do I remember the way back up, do I need to save the previous node? A search in wikipedia gave me an solution which they used stack. And other solutions I couldn't quite understand how they've made it, so I'm asking here instead hoping someone can enlight me. I also wonder my insert function is OK. I've seen other's solution being smaller. void treenode::insert(int i) { if(root == 0) { cout << "root" << endl; root = new node(i,root); } else { node* travel = root; node* prev; while(travel) { if(travel->value > i) { cout << "travel left" << endl; prev = travel; travel = travel->left; } else { cout << "travel right" << endl; prev = travel; travel = travel->right; } } //insert if(prev->value > i) { cout << "left" << endl; prev->left = new node(i); } else { cout << "right" << endl; prev->right = new node(i); } } } void treenode::print() { node* travel = root; while(travel) { cout << travel->value << endl; travel = travel->left; } }

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  • Error using `loess.smooth` but not `loess` or `lowess`

    - by Sandy
    I need to smooth some simulated data, but occasionally run into problems when the simulated ordinates to be smoothed are mostly the same value. Here is a small reproducible example of the simplest case. > x <- 0:50 > y <- rep(0,51) > loess.smooth(x,y) Error in simpleLoess(y, x, w, span, degree, FALSE, FALSE, normalize = FALSE, : NA/NaN/Inf in foreign function call (arg 1) loess(y~x), lowess(x,y), and their analogue in MATLAB produce the expected results without error on this example. I am using loess.smooth here because I need the estimates evaluated at a set number of points. According to the documentation, I believe loess.smooth and loess are using the same estimation functions, but the former is an "auxiliary function" to handle the evaluation points. The error seems to come from a C function: > traceback() 3: .C(R_loess_raw, as.double(pseudovalues), as.double(x), as.double(weights), as.double(weights), as.integer(D), as.integer(N), as.double(span), as.integer(degree), as.integer(nonparametric), as.integer(order.drop.sqr), as.integer(sum.drop.sqr), as.double(span * cell), as.character(surf.stat), temp = double(N), parameter = integer(7), a = integer(max.kd), xi = double(max.kd), vert = double(2 * D), vval = double((D + 1) * max.kd), diagonal = double(N), trL = double(1), delta1 = double(1), delta2 = double(1), as.integer(0L)) 2: simpleLoess(y, x, w, span, degree, FALSE, FALSE, normalize = FALSE, "none", "interpolate", control$cell, iterations, control$trace.hat) 1: loess.smooth(x, y) loess also calls simpleLoess, but with what appears to be different arguments. Of course, if you vary enough of the y values to be nonzero, loess.smooth runs without error, but I need the program to run in even the most extreme case. Hopefully, someone can help me with one and/or all of the following: Understand why only loess.smooth, and not the other functions, produces this error and find a solution for this problem. Find a work-around using loess but still evaluating the estimate at a specified number of points that can differ from the vector x. For example, I might want to use only x <- seq(0,50,10) in the smoothing, but evaluate the estimate at x <- 0:50. As far as I know, using predict with a new data frame will not properly handle this situation, but please let me know if I am missing something there. Handle the error in a way that doesn't stop the program from moving onto the next simulated data set. Thanks in advance for any help on this problem.

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  • Reporting Services as PDF through WebRequest in C# 3.5 "Not Supported File Type"

    - by Heath Allison
    I've inherited a legacy application that is supposed to grab an on the fly pdf from a reporting services server. Everything works fine up until the point where you try to open the pdf being returned and adobe acrobat tells you: Adobe Reader could not open 'thisStoopidReport'.pdf' because it is either not a supported file type or because the file has been damaged(for example, it was sent as an email attachment and wasn't correctly decoded). I've done some initial troubleshooting on this. If I replace the url in the WebRequest.Create() call with a valid pdf file on my local machine ie: @"C:temp/validpdf.pdf") then I get a valid PDF. The report itself seems to work fine. If I manually type the URL to the reporting services report that should generate the pdf file I am prompted for user authentication. But after supplying it I get a valid pdf file. I've replace the actual url,username,userpass and domain strings in the code below with bogus values for obvious reasons. WebRequest request = WebRequest.Create(@"http://x.x.x.x/reportServer?/reports/reportNam&rs:format=pdf&rs:command=render&rc:parameters=blahblahblah"); int totalSize = 0; request.Credentials = new NetworkCredential("validUser", "validPass", "validDomain"); request.Timeout = 360000; // 6 minutes in milliseconds. request.Method = WebRequestMethods.Http.Post; request.ContentLength = 0; WebResponse response = request.GetResponse(); Response.Clear(); BinaryReader reader = new BinaryReader(response.GetResponseStream()); Byte[] buffer = new byte[2048]; int count = reader.Read(buffer, 0, 2048); while (count > 0) { totalSize += count; Response.OutputStream.Write(buffer, 0, count); count = reader.Read(buffer, 0, 2048); } Response.ContentType = "application/pdf"; Response.Cache.SetCacheability(HttpCacheability.Private); Response.CacheControl = "private"; Response.Expires = 30; Response.AddHeader("Content-Disposition", "attachment; filename=thisStoopidReport.pdf"); Response.AddHeader("Content-Length", totalSize.ToString()); reader.Close(); Response.Flush(); Response.End();

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  • Linked List Design

    - by Jim Scott
    The other day in a local .NET group I attend the following question came up: "Is it a valid interview question to ask about Linked Lists when hiring someone for a .NET development position?" Not having a computer sciense degree and being a self taught developer my response was that I did not feel it was appropriate as I in 5 years of developer with .NET had never been exposed to linked lists and did not hear any compeling reason for a use for one. However the person commented that it is a very common interview question so I decided when I left that I would do some reasearch on linked lists and see what I might be missing. I have read a number of posts on stack overflow and various google searches and decided the best way to learn about them was to write my own .NET classes to see how they worked from the inside out. Here is my class structure Single Linked List Constructor public SingleLinkedList(object value) Public Properties public bool IsTail public bool IsHead public object Value public int Index public int Count private fields not exposed to a property private SingleNode firstNode; private SingleNode lastNode; private SingleNode currentNode; Methods public void MoveToFirst() public void MoveToLast() public void Next() public void MoveTo(int index) public void Add(object value) public void InsertAt(int index, object value) public void Remove(object value) public void RemoveAt(int index) Questions I have: What are typical methods you would expect in a linked list? What is typical behaviour when adding new records? For example if I have 4 nodes and I am currently positioned in the second node and perform Add() should it be added after or before the current node? Or should it be added to the end of the list? Some of the designs I have seen explaining things seem to expose outside of the LinkedList class the Node object. In my design you simply add, get, remove values and know nothing about any node object. Should the Head and Tail be placeholder objects that are only used to define the head/tail of the list? I require my Linked List be instantiated with a value which creates the first node of the list which is essentially the head and tail of the list. Would you change that ? What should the rules be when it comes to removing nodes. Should someone be able to remove all nodes? Here is my Double Linked List Constructor public DoubleLinkedList(object value) Properties public bool IsHead public bool IsTail public object Value public int Index public int Count Private fields not exposed via property private DoubleNode currentNode; Methods public void AddFirst(object value) public void AddLast(object value) public void AddBefore(object existingValue, object value) public void AddAfter(object existingValue, object value) public void Add(int index, object value) public void Add(object value) public void Remove(int index) public void Next() public void Previous() public void MoveTo(int index)

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  • RCP applicatoon activities

    - by Peter
    I have a problem with my RCP application. First, I defined an activity in my plugin.xml: <extension point="org.eclipse.ui.activities"> <activity id="myproject.view.input.activity" name="myproject.view.input.activity"> <enabledWhen> <with variable="myproject.view.input.active"> <equals value="ENABLED"> </equals> </with> </enabledWhen> </activity> <activityPatternBinding activityId="myproject.view.input.activity" pattern="myproject.gui/myproject.view.input"> </activityPatternBinding> Then i defined my SourceProvider: <extension point="org.eclipse.ui.services"> <sourceProvider provider="myproject.util.CommandState"> <variable name="myproject.view.input.active" priorityLevel="workbench"> </variable> And, finally, my CommandState class: public class CommandState extends AbstractSourceProvider { public final static String OUTPUT_VIEW = "myproject.view.input.active"; // then goes some others variables, i just skip them // .... public final static String [] ACTIONS = {OUTPUT_VIEW /*and all others variables*/}; public final static String ENABLED = "ENABLED"; public final static String DISENABLED = "DISENABLED"; private final Map <String, String> currentState = new HashMap <String, String> (); @Override public void dispose() { } @Override public String[] getProvidedSourceNames() { return ACTIONS; } @Override public Map <String, String> getCurrentState() { return currentState; } public void setEnabled(boolean enabled, String [] commands) { String value = enabled ? ENABLED : DISENABLED; for (String command : commands) { currentState.put(command, value); fireSourceChanged(ISources.WORKBENCH, command, value); } } } In my Login window, application checks user permissions, and enable or disable views, commands, etc. with setEnabled method of CommandState. For commands it works fine, they are enabling or disabling correctly. But when i try to disable view and open perspective, that contains that view (myproject.view.input), it opened without that view, but also throws exception: !STACK 1 org.eclipse.ui.PartInitException: Could not create view: myproject.view.input at org.eclipse.ui.internal.ViewFactory.createView(ViewFactory.java:158) I can show full stacktrace if anyone want. I tried to debug my application and before i open my perspective whith that view, i checked currentState of my CommandState source provider, and all seemes to be ok: all variables values are correct and myproject.view.input.active = DISABLED Can anyone say, why exception is thrown? Thanks for any help. Sorry for big post and bad language

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  • Query Results Not Expected

    - by E-Madd
    I've been a CF developer for 15 years and I've never run into anything this strange or frustrating. I've pulled my hair out for hours, googled, abstracted, simplified, prayed and done it all in reverse. Can you help me? A cffunction takes one string argument and from that string I build an array of "phrases" to run a query with, attempting to match a location name in my database. For example, the string "the republic of boulder" would produce the array: ["the","republic","of","boulder","the republic","the republic of","the republic of boulder","republic of","republic of boulder","of boulder"]. Another cffunction uses the aforementioned cffunction and runs a cfquery. A query based on the previously given example would be... select locationid, locationname, locationaliasname from vwLocationsWithAlias where LocationName in ('the','the republic','the republic of','republic','republic of','republic of boulder','of','of boulder','boulder') or LocationAliasName in ('the','the republic','the republic of','republic','republic of','republic of boulder','of','of boulder','boulder') This returns 2 records... locationid - locationname - locationalias 99 - 'Boulder' - 'the republic' 68 - 'Boulder' - NULL This is good. Works fine and dandy. HOWEVER... if the string is changed to "the republic", resulting in the phrases array ["the","republic","the republic"] which is then used to produce the query... select locationid, locationname, locationaliasname from vwLocationsWithAlias where LocationName in ('the','the republic','republic') or LocationAliasName in ('the','the republic','republic') This returns 0 records. Say what?! OK, just to make sure I'm not involuntarily HIGH I run that very same query in my SQL console against the same database in the cf datasource. 1 RECORD! locationid - locationname - locationalias 99 - 'Boulder' - 'the republic' I can even hard-code that sql within the same cffunction and get that one result, but never from the dynamically generated SQL. I can get my location phrases from another cffunction of a different name that returns hard-coded array values and those work, but never if the array is dynamically built. I've tried removing cfqueryparams, triple-checking my datatypes, datasource setups, etc., etc., etc. NO DICE WTF!? Is this an obscure bug? Am I losing my mind? I've tried everything I can think of and others (including Ray Camden) can think of. ColdFusion 8 (with all the latest hotfixes) SQL Server 2005 (with all the greatest service packs) Windows 2003 Server (with all the latest updates, service packs and nightly MS voodoo)

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  • How would you organize this Javascript?

    - by Anurag
    How do you usually organize complex web applications that are extremely rich on the client side. I have created a contrived example to indicate the kind of mess it's easy to get into if things are not managed well for big apps. Feel free to modify/extend this example as you wish - http://jsfiddle.net/NHyLC/1/ The example basically mirrors part of the comment posting on SO, and follows the following rules: Must have 15 characters minimum, after multiple spaces are trimmed out to one. If Add Comment is clicked, but the size is less than 15 after removing multiple spaces, then show a popup with the error. Indicate amount of characters remaining and summarize with color coding. Gray indicates a small comment, brown indicates a medium comment, orange a large comment, and red a comment overflow. One comment can only be submitted every 15 seconds. If comment is submitted too soon, show a popup with appropriate error message. A couple of issues I noticed with this example. This should ideally be a widget or some sort of packaged functionality. Things like a comment per 15 seconds, and minimum 15 character comment belong to some application wide policies rather than being embedded inside each widget. Too many hard-coded values. No code organization. Model, Views, Controllers are all bundled together. Not that MVC is the only approach for organizing rich client side web applications, but there is none in this example. How would you go about cleaning this up? Applying a little MVC/MVP along the way? Here's some of the relevant functions, but it will make more sense if you saw the entire code on jsfiddle: /** * Handle comment change. * Update character count. * Indicate progress */ function handleCommentUpdate(comment) { var status = $('.comment-status'); status.text(getStatusText(comment)); status.removeClass('mild spicy hot sizzling'); status.addClass(getStatusClass(comment)); } /** * Is the comment valid for submission */ function commentSubmittable(comment) { var notTooSoon = !isTooSoon(); var notEmpty = !isEmpty(comment); var hasEnoughCharacters = !isTooShort(comment); return notTooSoon && notEmpty && hasEnoughCharacters; } // submit comment $('.add-comment').click(function() { var comment = $('.comment-box').val(); // submit comment, fake ajax call if(commentSubmittable(comment)) { .. } // show a popup if comment is mostly spaces if(isTooShort(comment)) { if(comment.length < 15) { // blink status message } else { popup("Comment must be at least 15 characters in length."); } } // show a popup is comment submitted too soon else if(isTooSoon()) { popup("Only 1 comment allowed per 15 seconds."); } });

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  • Coldfusion Components:- The argument passed to the function is not of type numeric

    - by salim.vali
    Hi I have a simple form form.cfm:- <cfset Registr = createObject("component", "forms.Registr") /> <cfset setFoo = createObject('component','forms.Registr).putNUsr(username,password,rating) /> <form name="regFrm" action="#cgi.script_name#" method="post" onsubmit="submitform();" > <tr><td>Username:</td> <td><input type="text" name=" Username" value="#form. Username#" ></td></tr> <tr><td>Password:</td> <td><input class="" type="password" name="password" value="#form.password#" ></td></tr> <tr><td>Rate:</td> <select name="rating" > <option value="" ></option> <cfloop query="qGetReting"> <option value="#rating_id#" <cfif form. rating eq prof_id>selected</cfif> >#rating#</option> </cfloop> </select> </td> </tr> </form> Now there is this cfc called Registr.cfc in the "forms" folder which has an insert-function called 'putNUsr'the code for 'Registr.cfc' is as follows. <cfcomponent> <cffunction name="putNUsr" returntype="void" displayname="" output="no"> <cfargument name="password" type="string" required="true"> <cfargument name="rating" type="numeric" required="true"> <cfargument name="username" type="string" required="true"> <cfquery datasource="#application.xyz#" name="q_putNUsr"> insert into users (username , password , rating) values( <cfqueryparam value="#arguments. username#" cfsqltype="CF_SQL_VARCHAR" />, <cfqueryparam value="#arguments.password#" cfsqltype="CF_SQL_VARCHAR" />, <cfqueryparam value="#arguments.rating#" cfsqltype="CF_SQL_INTEGER" ) </cfquery> </cffunction> </cfcomponent> I am able to populate the DB with the data if I do not use the form field "rating" which is numeric. Else i am getting the error as follows:- The RATING argument passed to the putNUsr function is not of type numeric. If the component name is specified as a type of this argument, it is possible that either a definition file for the component cannot be found or is not accessible. KINDLY HELP -S Vali

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  • What are the basics of dealing with user input events in Android?

    - by user279112
    Hello. I thought I had understood this question, but something is quite wrong here. When the user (me, so far) tries to press keys, nothing really happens, and I am having a lot of trouble understanding what it is that I've missed. Consider this before I present some code to help clarify my problem: I am using Android's Lunar Lander example to make my first "real" Android program. In that example, of course, there exist a class LunarView, and class nested therein LunarThread. In my code the equivalents of these classes are Graphics and GraphicsThread, respectively. Also I can make sprite animations in 2D just fine on Android. I have a Player class, and let's say GraphicsThread has a Player member referred to as "player". This class has four coordinates - x1, y1, x2, and y2 - and they define a rectangle in which the sprite is to be drawn. I've worked it out so that I can handle that perfectly. Whenever the doDraw(Canvas canvas) method is invoked, it'll just look at the values of those coordinates and draw the sprite accordingly. Now let's say - and this isn't really what I'm trying to do with the program - I'm trying to make the program where all it does is display the Player sprite at one location of the screen UNTIL the FIRST time the user presses the Dpad's left button. Then the location will be changed to another set position on the screen, and the sprite will be drawn at that position for the rest of the program invariably. Also note that the GraphicsThread member in Graphics is called "thread", and that the SurfaceHolder member in GraphicsThread is called "mSurfaceHolder". So consider this method in class Graphics: @Override public boolean onKeyDown(int keyCode, KeyEvent msg) { return thread.keyDownHandler(keyCode, msg); } Also please consider this method in class GraphicsThread: boolean keyDownHandler(int keyCode, KeyEvent msg) { synchronized (mSurfaceHolder) { if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) { player.x1 = 100; player.y1 = 100; player.x2 = 120; player.y2 = 150; } } return true; } Now then assuming that player's coordinates start off as (200, 200, 220, 250), why won't he do anything different when I press Dpad: Left? Thanks!

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  • Any simple approaches for managing customer data change requests for global reference files?

    - by Kelly Duke
    For the first time, I am developing in an environment in which there is a central repository for a number of different industry standard reference data tables and many different customers who need to select records from these industry standard reference data tables to fill in foreign key information for their customer specific records. Because these industry standard reference files are utilized by all customers, I want to reserve Create/Update/Delete access to these records for global product administrators. However, I would like to implement a (semi-)automated interface by which specific customers could request record additions, deletions or modifications to any of the industry standard reference files that are shared among all customers. I know I need something like a "data change request" table specifying: user id, user request datetime, request type (insert, modify, delete), a user entered text explanation of the change request, the user request's current status (pending, declined, completed), admin resolution datetime, admin id, an admin entered text description of the resolution, etc. What I can't figure out is how to elegantly handle the fact that these data change requests could apply to dozens of different tables with differing table column definitions. I would like to give the customer users making these data change requests a convenient way to enter their proposed record additions/modifications directly into CRUD screens that look very much like the reference table CRUD screens they don't have write/delete permissions for (with an additional text explanation and perhaps request priority field). I would also like to give the global admins a tool that allows them to view all the outstanding data change requests for the users they oversee sorted by date requested or user/date requested. Upon selecting a data change request record off the list, the admin would be directed to another CRUD screen that would be populated with the fields the customer users requested for the new/modified industry standard reference table record along with customer's text explanation, the request status and the text resolution explanation field. At this point the admin could accept/edit/reject the requested change and if accepted the affected industry standard reference file would be automatically updated with the appropriate fields and the data change request record's status, text resolution explanation and resolution datetime would all also be appropriately updated. However, I want to keep the actual production reference tables as simple as possible and free from these extraneous and typically null customer change request fields. I'd also like the data change request file to aggregate all data change requests across all the reference tables yet somehow "point to" the specific reference table and primary key in question for modification & deletion requests or the specific reference table and associated customer user entered field values in question for record creation requests. Does anybody have any ideas of how to design something like this effectively? Is there a cleaner, simpler way I am missing? Thank you so much for reading.

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  • how can I get data in the table cell that is checked after submit

    - by arnold
    can someone give me help, please. here's my basic html <form action="addSomething.php" method="POST"> <table> <tr> <th>Add Data</th> <th>Description</th> <th>Quantity</th> </tr> <tr> <td><input type="checkbox" name="data[]" value="sample1" /> </td> <td class="desc">Newbie</td> <td>2</td> </tr> <tr> <td><input type="checkbox" name="data[]" value="sample1" /> </td> <td class="desc">Pro</td> <td>1</td> </tr> <tr> <td><input type="checkbox" name="data[]" value="sample1"/> </td> <td class="desc" > Master </td> <td>1</td> </tr> <br/> <input type="submit" name="add" value="SUBMIT"/> ..... how can I get the one with the class "desc" and the column for quantity that is checked after submitting the form because the only I can add when querying in mysql is the value of checkbox but I want also the value of the data in "Description" column and "Quantity" column In my addSomething.php the code I have is if(isset($_POST['add'])) { foreach($_POST['data'] as $value) { $sql = "INSERT INTO tablename (column1) VALUES('$value');" //query stuff } } what I will do , Any hints guys?

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  • Creating a column of RadioButtons in Adobe Flex

    - by adnan
    I am having an un-predictable behavior of creating radio buttons in advancedDataGrid column using itemRenderer. Similar kind of problem has been reported at http://stackoverflow.com/questions/112036/creating-a-column-of-radiobuttons-in-adobe-flex. I tried to use the same procedure i.e. bind every radio button selectedValue and value attributes with the property specified in the property of the associated bean but still facing the problem. The button change values! The selected button becomes deselected, and unselected ones become selected. Here is the code of my advancedDataGrid: <mx:AdvancedDataGrid id="adDataGrid_rptdata" width="100%" height="100%" dragEnabled="false" sortableColumns="false" treeColumn="{action}" liveScrolling="false" displayItemsExpanded="true" > <mx:dataProvider> <mx:HierarchicalData source="{this.competenceCollection}" childrenField="competenceCriteria"/> </mx:dataProvider> <mx:columns> <mx:AdvancedDataGridColumn headerText="" id="action" dataField="criteriaName" /> <mx:AdvancedDataGridColumn headerText="Periode 1" dataField="" width="200"> <mx:itemRenderer> <mx:Component> <mx:HBox horizontalAlign="center" width="100%" verticalAlign="middle"> <mx:RadioButton name="period1" value="{data}" selected="{data.period1}" group="{data.radioBtnGrpArray[0]}" visible="{data.showRadioButton}" /> </mx:HBox> </mx:Component> </mx:itemRenderer> </mx:AdvancedDataGridColumn> <mx:AdvancedDataGridColumn headerText="Periode 2" dataField="" width="200"> <mx:itemRenderer> <mx:Component> <mx:HBox horizontalAlign="center" width="100%" verticalAlign="middle"> <mx:RadioButton name="period2" value="{data}" selected="{data.period2}" group="{data.radioBtnGrpArray[1]}" visible="{data.showRadioButton}" /> </mx:HBox> </mx:Component> </mx:itemRenderer> </mx:AdvancedDataGridColumn> <mx:AdvancedDataGridColumn headerText="Periode 3" dataField="" width="200"> <mx:itemRenderer> <mx:Component> <mx:HBox horizontalAlign="center" width="100%" verticalAlign="middle"> <mx:RadioButton name="period3" value="{data}" selected="{data.period3}" group="{data.radioBtnGrpArray[2]}" visible="{data.showRadioButton}" /> </mx:HBox> </mx:Component> </mx:itemRenderer> </mx:AdvancedDataGridColumn> </mx:columns> </mx:AdvancedDataGrid> Any work around is highly appreciated in this regard!

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  • What is NSString in struct?

    - by 4thSpace
    I've defined a struct and want to assign one of its values to a NSMutableDictionary. When I try, I get a EXC_BAD_ACCESS. Here is the code: //in .h file typedef struct { NSString *valueOne; NSString *valueTwo; } myStruct; myStruct aStruct; //in .m file - (void)viewDidLoad { [super viewDidLoad]; aStruct.valueOne = @"firstValue"; } //at some later time [myDictionary setValue:aStruct.valueOne forKey:@"key1"]; //dies here with EXC_BAD_ACCESS This is the output in debugger console: (gdb) p aStruct.valueOne $1 = (NSString *) 0xf41850 Is there a way to tell what the value of aStruct.valueOne is? Since it is an NSString, why does the dictionary have such a problem with it? ------------- EDIT ------------- This edit is based on some comments below. The problem appears to be in the struct memory allocation. I have no issues assigning the struct value to the dictionary in viewDidLoad, as mentioned in one of the comments. The problem is that later on, I run into an issue with the struct. Just before the error, I do: po aStruct.oneValue Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_PROTECTION_FAILURE at address: 0x00000000 0x9895cedb in objc_msgSend () The program being debugged was signaled while in a function called from GDB. GDB has restored the context to what it was before the call. To change this behavior use "set unwindonsignal off" Evaluation of the expression containing the function (_NSPrintForDebugger) will be abandoned. This occurs just before the EXC_BAD_ACCESS: NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; [formatter setDateFormat:@"MM-dd-yy_HH-mm-ss-A"]; NSString *date = [formatter stringFromDate:[NSDate date]]; [formatter release]; aStruct.valueOne = date; So the memory issue is most likely in my releasing of formatter. The date var has no retain. Should I instead be doing NSString *date = [[formatter stringFromDate:[NSDate date]] retain]; Which does work but then I'm left with a memory leak.

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  • How does MySQL's ORDER BY RAND() work?

    - by Eugene
    Hi, I've been doing some research and testing on how to do fast random selection in MySQL. In the process I've faced some unexpected results and now I am not fully sure I know how ORDER BY RAND() really works. I always thought that when you do ORDER BY RAND() on the table, MySQL adds a new column to the table which is filled with random values, then it sorts data by that column and then e.g. you take the above value which got there randomly. I've done lots of googling and testing and finally found that the query Jay offers in his blog is indeed the fastest solution: SELECT * FROM Table T JOIN (SELECT CEIL(MAX(ID)*RAND()) AS ID FROM Table) AS x ON T.ID >= x.ID LIMIT 1; While common ORDER BY RAND() takes 30-40 seconds on my test table, his query does the work in 0.1 seconds. He explains how this functions in the blog so I'll just skip this and finally move to the odd thing. My table is a common table with a PRIMARY KEY id and other non-indexed stuff like username, age, etc. Here's the thing I am struggling to explain SELECT * FROM table ORDER BY RAND() LIMIT 1; /*30-40 seconds*/ SELECT id FROM table ORDER BY RAND() LIMIT 1; /*0.25 seconds*/ SELECT id, username FROM table ORDER BY RAND() LIMIT 1; /*90 seconds*/ I was sort of expecting to see approximately the same time for all three queries since I am always sorting on a single column. But for some reason this didn't happen. Please let me know if you any ideas about this. I have a project where I need to do fast ORDER BY RAND() and personally I would prefer to use SELECT id FROM table ORDER BY RAND() LIMIT 1; SELECT * FROM table WHERE id=ID_FROM_PREVIOUS_QUERY LIMIT 1; which, yes, is slower than Jay's method, however it is smaller and easier to understand. My queries are rather big ones with several JOINs and with WHERE clause and while Jay's method still works, the query grows really big and complex because I need to use all the JOINs and WHERE in the JOINed (called x in his query) sub request. Thanks for your time!

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  • angular, try to display object in ng-repeat fails

    - by Simone M
    i'm writing an mobile application in javascript with angularJS and ionicframework (last beta v.11), i create dinamically an object and want to display all objects inside in a ng-repeat. Why nr-repeat don't display anything? This is screen from my object: I use this code for put values in scope: $scope.distanceSuppliers = myCar; And this is the code in html: <ion-item ng-repeat="(id, supplier) in distanceSuppliers"> <div class="items item-button-right" ng-click="openDetails(id)"> {{supplier.name}}<br /> {{supplier.address}}<br /> </div> </ion-item> This is my complete code for JS: .controller('suppliers', function($scope, cw_db, $ionicPopup, $ionicActionSheet, appdelegate, $rootScope, $firebase, $location, $ionicLoading, cw_position) { $ionicLoading.show({ template: 'Updating data..' }); var geocoder; var tot = 0; var done = 0; geocoder = new google.maps.Geocoder(); cw_db.getData(cw_db.getSuppliers(), "", function(suppliers) { cw_position.getPosition(function (error, position) { suppliers.on('value', function(supp) { $scope.distanceSuppliers = {}; tot = 0; done = 0; supp.forEach(function(childSnapshot) { tot++; var childData = childSnapshot.val(); if (childData.address) { calculateDistance(childData, position.coords.latitude, position.coords.longitude); } }); }); $ionicLoading.hide(); }); }); function calculateDistance(childData, usrLat, usrLon) { var service = new google.maps.DistanceMatrixService(); service.getDistanceMatrix( { origins: [new google.maps.LatLng(usrLat, usrLon)], destinations: [childData.address], travelMode: google.maps.TravelMode.DRIVING, unitSystem: google.maps.UnitSystem.METRIC, avoidHighways: false, avoidTolls: false }, function(response, status) { if (status != google.maps.DistanceMatrixStatus.OK) { alert('Error was: ' + status); } else { done++; var results = response.rows[0].elements; childData.distance = results[0].distance.value; $scope.distanceSuppliers.push(childData); if (done == tot) { console.log($scope.distanceSuppliers); } } }); } $scope.openDetails = function(index) { //appdelegate.setCallId(index); //$location.path("/app/supplierDetails"); } }) what's wrong?

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