Search Results

Search found 39082 results on 1564 pages for 'magic function'.

Page 537/1564 | < Previous Page | 533 534 535 536 537 538 539 540 541 542 543 544  | Next Page >

  • Accelerated C++, problem 5-6 (copying values from inside a vector to the front)

    - by Darel
    Hello, I'm working through the exercises in Accelerated C++ and I'm stuck on question 5-6. Here's the problem description: (somewhat abbreviated, I've removed extraneous info.) 5-6. Write the extract_fails function so that it copies the records for the passing students to the beginning of students, and then uses the resize function to remove the extra elements from the end of students. (students is a vector of student structures. student structures contain an individual student's name and grades.) More specifically, I'm having trouble getting the vector.insert function to properly copy the passing student structures to the start of the vector students. Here's the extract_fails function as I have it so far (note it doesn't resize the vector yet, as directed by the problem description; that should be trivial once I get past my current issue.) // Extract the students who failed from the "students" vector. void extract_fails(vector<Student_info>& students) { typedef vector<Student_info>::size_type str_sz; typedef vector<Student_info>::iterator iter; iter it = students.begin(); str_sz i = 0, count = 0; while (it != students.end()) { // fgrade tests wether or not the student failed if (!fgrade(*it)) { // if student passed, copy to front of vector students.insert(students.begin(), it, it); // tracks of the number of passing students(so we can properly resize the array) count++; } cout << it->name << endl; // output to verify that each student is iterated to it++; } } The code compiles and runs, but the students vector isn't adding any student structures to its front. My program's output displays that the students vector is unchanged. Here's my complete source code, followed by a sample input file (I redirect input from the console by typing " < grades" after the compiled program name at the command prompt.) #include <iostream> #include <string> #include <algorithm> // to get the declaration of `sort' #include <stdexcept> // to get the declaration of `domain_error' #include <vector> // to get the declaration of `vector' //driver program for grade partitioning examples using std::cin; using std::cout; using std::endl; using std::string; using std::domain_error; using std::sort; using std::vector; using std::max; using std::istream; struct Student_info { std::string name; double midterm, final; std::vector<double> homework; }; bool compare(const Student_info&, const Student_info&); std::istream& read(std::istream&, Student_info&); std::istream& read_hw(std::istream&, std::vector<double>&); double median(std::vector<double>); double grade(double, double, double); double grade(double, double, const std::vector<double>&); double grade(const Student_info&); bool fgrade(const Student_info&); void extract_fails(vector<Student_info>& v); int main() { vector<Student_info> vs; Student_info s; string::size_type maxlen = 0; while (read(cin, s)) { maxlen = max(maxlen, s.name.size()); vs.push_back(s); } sort(vs.begin(), vs.end(), compare); extract_fails(vs); // display the new, modified vector - it should be larger than // the input vector, due to some student structures being // added to the front of the vector. cout << "count: " << vs.size() << endl << endl; vector<Student_info>::iterator it = vs.begin(); while (it != vs.end()) cout << it++->name << endl; return 0; } // Extract the students who failed from the "students" vector. void extract_fails(vector<Student_info>& students) { typedef vector<Student_info>::size_type str_sz; typedef vector<Student_info>::iterator iter; iter it = students.begin(); str_sz i = 0, count = 0; while (it != students.end()) { // fgrade tests wether or not the student failed if (!fgrade(*it)) { // if student passed, copy to front of vector students.insert(students.begin(), it, it); // tracks of the number of passing students(so we can properly resize the array) count++; } cout << it->name << endl; // output to verify that each student is iterated to it++; } } bool compare(const Student_info& x, const Student_info& y) { return x.name < y.name; } istream& read(istream& is, Student_info& s) { // read and store the student's name and midterm and final exam grades is >> s.name >> s.midterm >> s.final; read_hw(is, s.homework); // read and store all the student's homework grades return is; } // read homework grades from an input stream into a `vector<double>' istream& read_hw(istream& in, vector<double>& hw) { if (in) { // get rid of previous contents hw.clear(); // read homework grades double x; while (in >> x) hw.push_back(x); // clear the stream so that input will work for the next student in.clear(); } return in; } // compute the median of a `vector<double>' // note that calling this function copies the entire argument `vector' double median(vector<double> vec) { typedef vector<double>::size_type vec_sz; vec_sz size = vec.size(); if (size == 0) throw domain_error("median of an empty vector"); sort(vec.begin(), vec.end()); vec_sz mid = size/2; return size % 2 == 0 ? (vec[mid] + vec[mid-1]) / 2 : vec[mid]; } // compute a student's overall grade from midterm and final exam grades and homework grade double grade(double midterm, double final, double homework) { return 0.2 * midterm + 0.4 * final + 0.4 * homework; } // compute a student's overall grade from midterm and final exam grades // and vector of homework grades. // this function does not copy its argument, because `median' does so for us. double grade(double midterm, double final, const vector<double>& hw) { if (hw.size() == 0) throw domain_error("student has done no homework"); return grade(midterm, final, median(hw)); } double grade(const Student_info& s) { return grade(s.midterm, s.final, s.homework); } // predicate to determine whether a student failed bool fgrade(const Student_info& s) { return grade(s) < 60; } Sample input file: Moo 100 100 100 100 100 100 100 100 Fail1 45 55 65 80 90 70 65 60 Moore 75 85 77 59 0 85 75 89 Norman 57 78 73 66 78 70 88 89 Olson 89 86 70 90 55 73 80 84 Peerson 47 70 82 73 50 87 73 71 Baker 67 72 73 40 0 78 55 70 Davis 77 70 82 65 70 77 83 81 Edwards 77 72 73 80 90 93 75 90 Fail2 55 55 65 50 55 60 65 60 Thanks to anyone who takes the time to look at this!

    Read the article

  • javascript plugin - singleton pattern?

    - by Adam Kiss
    intro Hello, I'm trying to develop some plugin or/*and* object in javascript, which will control some properties over some object. It will also use jQuery, to ease development. idea This is in pseudocode to give you an idea, since I can't really describe it in english with the right words, it's impossible to go and use google to find out what I want to use (and learn). I will have plugin (maybe object?) with some variables and methods: plugin hideshow(startupconfig){ var c, //collection add: function(what){ c += what; }, do: function(){ c.show().hide().stop(); //example code } } and I will use it this way (or sort-of): var p = new Plugin(); p .add($('p#simple')) .add($('p#simple2')) .do(); note I'm not really looking for jQuery plugin tutorials - it's more like usage of singleton pattern in document in javascript, jQuery is mentione only because it will be used to modify dom and simplify selectors, jQuery plugin maybe just for that one little function add. I'm looking for something, that will sit on top of my document and call functions from itselft based on timer, or user actions, or whatever. problems I don't really know where to start with construction of this object/plugin I'm not really sure how to maintain one variable, which is collection of jQuery objects (something like $('#simple, #simple2');) I would maybe like to extedn jQuery with $.fn.addToPlugin to use chaining of objects, but that should be simple (really just each( p.add($(this)); )) I hope I make any sense, ideas, links or advices appreciated.

    Read the article

  • jqueryvalidation no space customization

    - by Ken
    i have a form where the user can update his name and last name. i use jquery validation to validate the form. how can i validate if the user put spaces? here's what i have: <script> $(document).ready(function(){ $('#submit').click(function() { var valid = $("#myform").valid(); if(!valid) { return false; } $.ajax({ type: "POST", url: 'save', data: $('#myform').serialize(), dataType: 'json', cache: false, success: function(result) { // redirect to another page } }); }); }); </script> </head> <body> <form id="myform" method="post" action=""> <fieldset> <legend>update name</legend> <p> <label for="fname">Name</label> <em>*</em><input id="fname" name="fname" size="25" class="required" minlength="2" /> </p> <p> <label for="lname">Last Name</label> <em>*</em><input id="lname" name="lname" size="25" class="required" minlength="2" /> </p> <p> <input id="submit" type="submit" value="Submit"/> </p> </fieldset> </form> thanks

    Read the article

  • More FP-correct way to create an update sql query

    - by James Black
    I am working on access a database using F# and my initial attempt at creating a function to create the update query is flawed. let BuildUserUpdateQuery (oldUser:UserType) (newUser:UserType) = let buf = new System.Text.StringBuilder("UPDATE users SET "); if (oldUser.FirstName.Equals(newUser.FirstName) = false) then buf.Append("SET first_name='").Append(newUser.FirstName).Append("'" ) |> ignore if (oldUser.LastName.Equals(newUser.LastName) = false) then buf.Append("SET last_name='").Append(newUser.LastName).Append("'" ) |> ignore if (oldUser.UserName.Equals(newUser.UserName) = false) then buf.Append("SET username='").Append(newUser.UserName).Append("'" ) |> ignore buf.Append(" WHERE id=").Append(newUser.Id).ToString() This doesn't properly put a , between any update parts after the first, for example: UPDATE users SET first_name='Firstname', last_name='lastname' WHERE id=... I could put in a mutable variable to keep track when the first part of the set clause is appended, but that seems wrong. I could just create an list of tuples, where each tuple is oldtext, newtext, columnname, so that I could then loop through the list and build up the query, but it seems that I should be passing in a StringBuilder to a recursive function, returning back a boolean which is then passed as a parameter to the recursive function. Does this seem to be the best approach, or is there a better one?

    Read the article

  • document.onkeyup triggers when it shouldn't

    - by vonkow
    So I have the following code, which should append 'true' to the div "test" every 25ms as long as key 68 (the d key) is being pressed, right? <html> <body> <div id="test"></div> <script type="text/javascript"> var key=false; var keyDown=function(e) { if (e.keyCode==68) { key=true; } } var keyUp=function(e) { if (e.keyCode==68) { key=false; } } document.onkeydown=keyDown; document.onkeyup=keyUp; var run=function() { document.getElementById('test').appendChild(document.createTextNode(key+'\n')); t = setTimeout('run()', 25); } var t = setTimeout('run()', 25); </script> </body> </html> Save the code, load it in a browser and hold down on the d key. If I'm not crazy, you'll see that it occasionally appends 'false' even though the d key was never released. (I've tried this in FF and Chrome in Linux and Vista). Anybody happen to know why, or have a workaround?

    Read the article

  • Qt/MFC Migration Framework tool: properly exiting DLL?

    - by User
    I'm using the Qt/MFC Migration Framework tool following this example: http://doc.qt.nokia.com/solutions/4/qtwinmigrate/winmigrate-qt-dll-example.html The dll I build is loaded by a 3rd party MFC-based application. The 3rd party app basically calls one of my exported DLL functions to startup my plugin and another function to shutdown my application. Currently I'm doing nothing in my shutdown function. When I load my DLL in the 3rd party app the startup function is called and my DLL starts successfully and I can see my message box. However if I shutdown my plugin and then try to start it again I get the following error: Debug Error! Program: <my 3rd party app> Module: 4.7.1 File: global\qglobal.cpp Line: 2262 ASSERT failure in QWidget: "Widgets must be created in the GUI thread.", file kernel\qwidget.cpp line 1233 (Press Retry to debug the application) Abort Retry Ignore This makes me think I'm not doing something to properly shutdown my plugin. What do I need to do to shut it down properly? UPDATE: http://doc.qt.nokia.com/solutions/4/qtwinmigrate/winmigrate-walkthrough.html says: The DLL also has to make sure that it can be loaded together with other Qt based DLLs in the same process (in which case a QApplication object will probably exist already), and that the DLL that creates the QApplication object remains loaded in memory to avoid other DLLs using memory that is no longer available to the process. So I wonder if there is some problem where I need to somehow keep the original DLL loaded no matter what?

    Read the article

  • I need a true mouseOver...

    - by invertedSpear
    Ok, so mouseOver and RollOver, and their respective outs work great as long as your mouse is actually over the item, or one of it's children. My problem is that I may have another UI component "between" my mouse and the item I want to process the mouse/rollover(maybe a button that is on top of a canvas, but is not a child of the canvas). The mouse is still over the component, there's just something else that it's over at the same time. Any tips or help how to deal with this? Let me know if I'm not being clear enough. Here is a simplified code example detailing my question copy/paste that into your flex/flash builder and you'll see what I mean: <?xml version="1.0" encoding="utf-8"?> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" width="500" height="226" creationComplete="ccInit()"> <mx:Script> <![CDATA[ private function ccInit():void{ myCanv.addEventListener(MouseEvent.ROLL_OVER,handleRollOver); } private function handleRollOver(evt:MouseEvent):void{ myCanv.setStyle("backgroundAlpha",1); myCanv.addEventListener(MouseEvent.ROLL_OUT,handleRollOut); } private function handleRollOut(evt:MouseEvent):void{ myCanv.setStyle("backgroundAlpha",0); myCanv.removeEventListener(MouseEvent.ROLL_OUT,handleRollOut); } ]]> </mx:Script> <mx:Canvas id="myCanv" x="10" y="10" width="480" height="200" borderStyle="solid" borderColor="#000000" backgroundColor="#FFFFFF" backgroundAlpha="0"> </mx:Canvas> <mx:Button x="90" y="50" label="Button" width="327" height="100"/> </mx:Application>

    Read the article

  • .Net Entity objectcontext thread error

    - by Chris Klepeis
    I have an n-layered asp.net application which returns an object from my DAL to the BAL like so: public IEnumerable<SourceKey> Get(SourceKey sk) { var query = from SourceKey in _dataContext.SourceKeys select SourceKey; if (sk.sourceKey1 != null) { query = from SourceKey in query where SourceKey.sourceKey1 == sk.sourceKey1 select SourceKey; } return query.AsEnumerable(); } This result passes through my business layer and hits the UI layer to display to the end users. I do not lazy load to prevent query execution in other layers of my application. I created another function in my DAL to delete objects: public void Delete(SourceKey sk) { try { _dataContext.DeleteObject(sk); _dataContext.SaveChanges(); } catch (Exception ex) { Debug.WriteLine(ex.Message + " " + ex.StackTrace + " " + ex.InnerException); } } When I try to call "Delete" after calling the "Get" function, I receive this error: New transaction is not allowed because there are other threads running in the session This is an ASP.Net app. My DAL contains an entity data model. The class in which I have the above functions share the same _dataContext, which is instantiated in my constructor. My guess is that the reader is still open from the "Get" function and was not closed. How can I close it?

    Read the article

  • jquery: set variable based on one class from an element that has more than one class

    - by John
    Hi I'm trying to make a table who's columns and rows highlight on hover (I realise there are jquery plugins out there that will do this, but I'm trying to learn, so thought I'd have a stab at doing it for myself.) Here's what I've got so far: $('th:not(.features), td:not(.features)').hover(highlight); function highlight(){ $('th.highlightCol, td.highlightCol').removeClass('highlightCol'); var col = $(this).attr('class'); $('.' + col).addClass('highlightCol'); }; $('tr').hover(highlightRowOn, highlightRowOff); function highlightRowOn(){ $(this).children('td:not(.highlightCol)').addClass('highlightRow'); }; function highlightRowOff(){ $(this).children('td:not(.highlightCol)').removeClass('highlightRow'); }; This works fine apart from one problem: Each 'td' has a class specific to it's column (package1, package2, package3, package4). It is this that gets passed to the variable (col) to add the class 'highlightCol' to a column when one of its 'td's are hovered on. However, If you move the cursor to a new column along a highlighted row, the 'td' you land on has two classes (highlightedRow and package* ). These both get passed to the variable and as a result the new column does not receive the correct class to highlight. Is there a way for me to target just the 'package* ' class and pass that to the variable while ignoring the 'highlightedRow' class? I hope that's not too jumbled for someone to make sense of and many thanks for any help offered.

    Read the article

  • How can I modify a scalar reference passed to a subroutine reference

    - by Mark
    I have a function to convert documents into different formats, which then calls another function based on the type document. It's pretty straight forward for everything aside from HTML documents which require a bit of cleaning up, and that cleaning up is different based on where it's come from. So I had the idea that I could pass a reference to a subroutine to the convert function so the caller has the opportunity to modify the HTML, kinda like so (I'm not at work so this isn't copy-and-pasted): package Converter; ... sub convert { my ($self, $filename, $coderef) = @_; if ($filename =~ /html?$/i) { $self->_convert_html($filename, $coderef); } } sub _convert_html { my ($self, $filename, $coderef) = @_; my $html = $self->slurp($filename); $coderef->(\$html); #this modifies the html $self->save_to_file($filename, $html); } which is then called by: Converter->new->convert("./whatever.html", sub { s/<html>/<xml>/i }); I've tried a couple of different things along these lines but I keep on getting 'Use of uninitialized value in substitution (s///)'. Is there any way of doing what I'm trying to do? Thanks

    Read the article

  • jQuery ajax post failing in asp

    - by Dave Kiss
    hey guys, this might be really stupid, but hopefully someone can help. I'm trying to post to an external script using ajax so i can mail the data, but for some reason my data is not making it to the script. $(document).ready(function() { $("#submitContactForm").click(function () { $('#loading').append('<img src="http://www.xxxxxxxx.com/demo/copyshop/images/loading.gif" alt="Currently Loading" id="loadingComment" />'); var name = $('#name').val(); var email = $('#email').val(); var comment = $('#comment').val(); var dataString = 'name='+ name + '&email=' + email + '&comment=' + comment; $.ajax({ url: 'http://www.xxxxx.com/demo/copyshop/php/sendmail.php', type: 'POST', data: '?name=Dave&[email protected]&comment=hiiii', success: function(result) { $('#loading').append('success'); } }); return false; }); }); the php script is simple (for now - just wanted to make sure it worked) <?php $name = $_POST['name']; $email = $_POST['email']; $comment = $_POST['comment']; $to = '[email protected]'; $subject = 'New Contact Inquiry'; $message = $comment; mail($to, $subject, $message); ?> the jquery is embedded in an .aspx page (a language i'm not familiar with) but is posting to a php script. i'm receiving emails properly but there is no data inside. am i missing something? i tried to bypass the variables in this example, but its still not working thanks

    Read the article

  • jQuery ajax delete script not actually deleting.

    - by werm
    I have a little personal webapp that I'm working on. I have a link that, when clicked, is supposed to make an ajax call to a php that is supposed to delete that info from a database. For some unknown reason, it won't actually delete the row from the database. I've tried everything I know, but still nothing. I'm sure it's something incredibly easy... Here are the scripts involved. Database output: $sql = "SELECT * FROM bookmark_app"; foreach ($dbh->query($sql) as $row) { echo '<div class="box" id="',$row['id'],'"><img src="images/avatar.jpg" width="75" height="75" border="0" class="avatar"/> <div class="text"><a href="',$row['url'],'">',$row['title'],'</a><br/> </div> /*** Click to delete ***/ <a href="?delete=',$row['id'],'" class="delete">x</a></div> <div class="clear"></div>'; } $dbh = null; Ajax script: $(document).ready(function() { $("a.delete").click(function(){ var element = $(this); var noteid = element.attr("id"); var info = 'id=' + noteid; $.ajax({ type: "GET", url: "includes/delete.php", data: info, success: function(){ element.parent().eq(0).fadeOut("slow"); } }); return false; }); }); Delete code: include('connect.php'); //delete.php?id=IdOfPost if($_GET['id']){ $id = $_GET['id']; //Delete the record of the post $delete = mysql_query("DELETE FROM `db` WHERE `id` = '$id'"); //Redirect the user header("Location:xxxx.php"); }

    Read the article

  • Jquery Show Fields depending on Select Menu value but on page load

    - by Tim
    Hello, This question refers to the question http://stackoverflow.com/questions/835259/jquery-show-hide-fields-depening-on-select-value <select id="viewSelector"> <option value="0">-- Select a View --</option> <option value="view1">view1</option> <option value="view2">view2</option> <option value="view3">view3</option> </select> <div id="view1"> <!-- content --> </div> <div id="view2a"> <!-- content --> </div> <div id="view2b"> <!-- content --> </div> <div id="view3"> <!-- content --> </div> $(document).ready(function() { $.viewMap = { '0' : $([]), 'view1' : $('#view1'), 'view2' : $('#view2a, #view2b'), 'view3' : $('#view3') }; $('#viewSelector').change(function() { // hide all $.each($.viewMap, function() { this.hide(); }); // show current $.viewMap[$(this).val()].show(); }); }); When I select the 2nd item in the menu it shows the corresponding field. The exception to this is when the on page load the select menu already has the 2nd menu item selected, the field does not show. As you may be able to tell, I am new to jquery and could definetly use some help with adjusting this code so that the selected item's field is shown on page load. Thanks, Tim

    Read the article

  • Assigning console.log to another object (Safari issue)

    - by Trevor Burnham
    I wanted to keep my logging statements as short as possible while preventing console from being accessed when it doesn't exist; I came up with the following solution: var _ = {}; if (console) { _.log = console.debug; } else { _.log = function() { } } To me, this seems quite elegant, and it works great in Firefox 3.6 (including preserving the line numbers that make console.debug more useful than console.log). But it doesn't work in Safari 4. (Haven't tested in other browsers yet.) If I follow the above with console.debug('A') _.log('B'); the first statement works fine in both browsers, but the second generates a "TypeError: Type Error" in Safari. Is this just a difference between how Firebug and the Safari Web Developer Tools implement console? If so, it is VERY annoying on Apple's part. (I get the same results in both browsers if I bind the console function to a prototype and then instantiate, rather than binding it directly to the object.) I could, of course, just call console.debug from an anonymous function assigned to _.log, but then I'd lose my line numbers. Any other ideas?

    Read the article

  • Simple Prototype.js code to select multiple elements with the same classname

    - by stephemurdoch
    I have one link with an id of "link", and I use the javascript below to open that link up in a modalbox: #In my template I have: <a href="some/path" id="link">link</a> #Then in my application.js file I have: document.observe('dom:loaded', function() { $('login-link').observe('click', function(event) { event.stop(); Modalbox.show(this.href,{title: 'some title', width: 500}); }); }) Since id's must be unique, this javascript only works for one element per page so I use it to observe my login-link and it has served me well. Until now. I want to use the same javascript to observe multiple links which have classnames instead of id's as below: <a href="link/to/some/stuff" class="link">link 1</a> <a href="link/to/some/other/stuff" class="link">link 2</a> When I do this, I can't get any of the links to open in a modalbox. If I change the class to an id for each link, then I can get the first link in the list to open in a modalbox. I've tried to use the '$$' notation to build an array of links in my javascript (shown below) but if I do that, then none of the links open correctly #document.observe method removed for display purposes $$('link').observe('click', function(event) { event.stop(); Modalbox.show(this.href,{title: 'some title', width: 500} ); }); My javascript skills obviously suck. Does anyone know how to fix the problem?

    Read the article

  • How to access and run field events from extension js?

    - by Dan Roberts
    I have an extension that helps in submitting forms automatically for a process at work. We are running into a problem with dual select boxes where one option is selected and then that selection changes another field's options. Since setting an option selected property to true doesn't trigger the field's onchange event I am trying to do so through code. The problem I've run into is that if I try to access or run functions on the field object from the extension, I get the error Error: uncaught exception: [Exception... "Component is not available" nsresult: "0x80040111 (NS_ERROR_NOT_AVAILABLE)" location: "JS frame :: chrome://webformsidebar/content/webformsidebar.js :: WebFormSidebar_FillProcess :: line 499" data: no] the line causing the error is... if (typeof thisField.onchange === 'function') The line right before it works just fine... thisField.options[t].selected=true; ...so I'm not sure why this is resulting in such an error. What surprises me most I guess is that checking for the existence of the function leads to an error. It feels like the problem is related to the code running in the context of the extension instead of the browser window document. If so, is there any way to call a function in the browser window context instead? Do I need to actually inject code into the page somehow? Any other ideas? Thanks

    Read the article

  • Can PHP dissect its own syntax?

    - by Nathan Long
    Can PHP dissect its own syntax? For example, I'd like to write a function that takes in an input like $object->attribute and says to itself: OK, he's giving me $foo->bar, which means he must think that $foo is an object that has a property called bar. Before I try accessing bar and potentially get a 'Trying to get property of non-object' error, let me check whether $foo is even an object. The end goal is to echo a value if it is set, and fail silently if not. I want to avoid repetition like this: <input value="<? if(is_object($foo) && is_set($foo->bar)){ echo $foo->bar; }?> "/> ...and to avoid writing a function that does the above, but has to have the object and attribute passed in separately, like this: <input value="<? echoAttribute($foo,'bar') ?>" /> ...but to instead write something which: preserves the object-attribute syntax is flexible: can also handle array keys or regular variables Like this: <input value="<? echoIfSet($foo->bar); ?> /> <input value="<? echoIfSet($baz['buzz']); ?> /> <input value="<? echoIfSet($moo); ?> /> But this all depends on PHP being able to tell me "what kind of thing am I asking for when I say $object->attribute or $array[$key]", so that my function can handle each according to its own type. Is this possible?

    Read the article

  • Binding type variables that only occur in assertions

    - by Giuseppe Maggiore
    Hi! I find it extremely difficult to describe my problem, so here goes nothing: I have a bunch of assertions on the type of a function. These assertions rely on a type variable that is not used for any parameter of the function, but is only used for internal bindings. Whenever I use this function it does not compile because, of course, the compiler has no information from which to guess what type to bind my type variable. Here is the code: {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances, UndecidableInstances, FlexibleContexts, EmptyDataDecls, ScopedTypeVariables, TypeOperators, TypeSynonymInstances #-} class C a a' where convert :: a -> a' class F a b where apply :: a -> b class S s a where select :: s -> a data CInt = CInt Int instance S (Int,String) Int where select (i,_) = i instance F Int CInt where apply = CInt f :: forall s a b . (S s a, F a b) => s -> b f s = let v = select s :: a y = apply v :: b in y x :: Int x = f (10,"Pippo") And here is the generated error: FunctorsProblems.hs:21:4: No instances for (F a Int, S (t, [Char]) a) arising from a use of `f' at FunctorsProblems.hs:21:4-17 Possible fix: add an instance declaration for (F a Int, S (t, [Char]) a) In the expression: f (10, "Pippo") In the definition of `x': x = f (10, "Pippo") Failed, modules loaded: none. Prelude>

    Read the article

  • Javascript force GC collection? / Forcefully free object?

    - by plash
    I have a js function for playing any given sound using the Audio interface (creating a new instance for every call). This works quite well, until about the 32nd call (sometimes less). This issue is directly related to the release of the Audio instance. I know this because I've allowed time for the GC in Chromium to run and it will allow me to play another 32 or so sounds again. Here's an example of what I'm doing: <html><head> <script language="javascript"> function playSound(url) { snd = new Audio(url); snd.play(); delete snd; snd = null; } </script> </head> <body> <a href="#" onclick="playSound('blah.mp3');">Play sound</a> </body></html> I also have this, which works well for pages that have less than 32 playSound calls: var AudioPlayer = { cache: {}, play: function(url) { if (!AudioPlayer.cache[url]) AudioPlayer.cache[url] = new Audio(url); AudioPlayer.cache[url].play(); } }; But this will not work for what I want to do (dynamically replace a div with other content (from separate files), which have even more sounds on them - 1. memory usage would easily skyrocket, 2. many sounds will never play). I need a way to release the sound immediately. Is it possible to do this? I have found no free/close/unload method for the Audio interface. The pages will be viewed locally, so the constant loading of sounds is not a big factor at all (and most sounds are rather short).

    Read the article

  • Authentication using cookie key with asynchronous callback

    - by greg
    I need to write authentication function with asynchronous callback from remote Auth API. Simple authentication with login is working well, but authorization with cookie key, does not work. It should checks if in cookies present key "lp_login", fetch API url like async and execute on_response function. The code almost works, but I see two problems. First, in on_response function I need to setup secure cookie for authorized user on every page. In code user_id returns correct ID, but line: self.set_secure_cookie("user", user_id) does't work. Why it can be? And second problem. During async fetch API url, user's page has loaded before on_response setup cookie with key "user" and the page will has an unauthorized section with link to login or sign on. It will be confusing for users. To solve it, I can stop loading page for user who trying to load first page of site. Is it possible to do and how? Maybe the problem has more correct way to solve it? class BaseHandler(tornado.web.RequestHandler): @tornado.web.asynchronous def get_current_user(self): user_id = self.get_secure_cookie("user") user_cookie = self.get_cookie("lp_login") if user_id: self.set_secure_cookie("user", user_id) return Author.objects.get(id=int(user_id)) elif user_cookie: url = urlparse("http://%s" % self.request.host) domain = url.netloc.split(":")[0] try: username, hashed_password = urllib.unquote(user_cookie).rsplit(',',1) except ValueError: # check against malicious clients return None else: url = "http://%s%s%s/%s/" % (domain, "/api/user/username/", username, hashed_password) http = tornado.httpclient.AsyncHTTPClient() http.fetch(url, callback=self.async_callback(self.on_response)) else: return None def on_response(self, response): answer = tornado.escape.json_decode(response.body) username = answer['username'] if answer["has_valid_credentials"]: author = Author.objects.get(email=answer["email"]) user_id = str(author.id) print user_id # It returns needed id self.set_secure_cookie("user", user_id) # but session can's setup

    Read the article

  • Loop over Json using Jquery

    - by mayanna
    Below is my Json Data received from Ajax response. { "error": { "errorCode": "0001", "errorText": "SUCCESS" }, "responselist": [ { "count": 2, "event": [ { "startDate": null, "eventId": 1234, "eventName": "Interview", "modifiedUser": "User", "eventTypeCode": "1", "eventVenue": null, "eventSpecialInst": "isnsdf", "eventStatusCode": "OP", "eventLangCode": "Eng", "eventDesc": "sdfsadfsd", "fromEmailId": "[email protected]", "rsvpDeadline": 5, "canceledInd": "yes", "canceldEmailText": "sdfasdfasdfasfasdfasdfasdf", "daysToWaitlistLastCall": 5, "daysToReminderAdmin": 6, "daysToReminderEvent": 3, "daysToReminderInvitation": 2, "endDate": null, "venueAddrLine1": null, "venueAddrLine2": null, "venueAddrLine3": null, "cityCode": null, "stateCode": null, "appId": null, "modifiedDate": "2010-12-16", "countryCode": null, "zipCode": null, "user_id": null, "updateFlag": "R" }, { "startDate": null, "eventId": 4321, "eventName": "Seasonal Hiring", "modifiedUser": "User", "eventTypeCode": "1", "eventVenue": null, "eventSpecialInst": "isnsdf", "eventStatusCode": "OP", "eventLangCode": "Eng", "eventDesc": "sdfsadfsd", "fromEmailId": "[email protected]", "rsvpDeadline": 5, "canceledInd": "yes", "canceldEmailText": "sdfasdfasdfasfasdfasdfasdf", "daysToWaitlistLastCall": 5, "daysToReminderAdmin": 6, "daysToReminderEvent": 3, "daysToReminderInvitation": 2, "endDate": null, "venueAddrLine1": "KFC", "venueAddrLine2": "The Forum", "venueAddrLine3": "Koramangala", "cityCode": "Bangalore", "stateCode": "Karnataka", "appId": null, "modifiedDate": "2010-12-16", "countryCode": "India", "zipCode": "560040", "user_id": null, "updateFlag": "R" } ] } ] } Using below code to extract information inside event object. But I am not able to do it. Need guidance. $.ajax({ url:"<%=request.getContextPath()%>/service/showInvitedEvents/21", dataType:"json", success: function(jsonData) { alert("Inside response success"); $.each(jsonData.responselist.event,function(i,item) $.each(Employees,function(i,item) { alert('Iteration is' + i); var teventName = item.eventName; var teventVenue = item.eventVenue; var tstartDate = item.startDate; var tendDate = item.endDate; var tstarend = tstartDate +" - "+ tendDate ; $("#eventTable tbody").append("<tr><td><a id="+teventName+i+" href=<%=request.getContextPath()%>/service/session/1234>"+teventName+"</a></td><td>"+teventVenue+"</td><td>"+tstarend+"</td></tr>"); });

    Read the article

  • Why am I getting a syntax error after my Json result?

    - by Mike
    I'm using Json to retrieve data from a database, construct some html, and put it to the page, but I'm getting a syntax error after my tag, which is the last tag in the string from my php file. PHP if($QString == ""){ $query = "SELECT * FROM categories"; $result = mysql_query($query); while($row = mysql_fetch_array($result, MYSQL_ASSOC)) { $categories="<a href=" . '"' . "?catID=" . $row['catID'] . '"' . ">" . $row['CatName'] . "</a><br>"; echo $_GET['jsoncallback'] . $categories; } } jQuery var jSon = {}; $(function(){ jQuery.jSon.getjSon(); }); jQuery.jSon = { getjSon : function () { $.getJSON('http://host6.spellnet.net/links/list.php?jsoncallback=?', function(json) { eval(json.data); }); } Any Help would be greatly appreciated. I'm getting closer and closer.

    Read the article

  • jQuery addClass() not running before jQuery.ajax()

    - by Josh
    I'm trying to have a button that onclick will apply a class loading (sets cursor to "wait") to the body, before making a series of ajax requests. Code is: $('#addSelected').click(function(){ $('body').addClass('loading'); var products = $(':checkbox[id^=add_]:checked'); products.each(function(){ var prodID = $(this).attr('id').replace('add_', ''); var qty = $('#qty_' + prodID).val(); if($('#prep_' + prodID).val()) { prodID += ':' + $('#prep_' + prodID).val(); } // Have to use .ajax rather than .get so we can use async:false, otherwise // product adds happen in parallel, causing data to be lost. $.ajax({ url: '<?=base_url()?>basket/update/' + prodID + '/' + qty, async: false, beforeSend: function(){ $('body').addClass('loading'); } }); }); }); I've tried doing $('body').addClass('loading'); both before the requests, and as a beforeSend callback, but there is no difference. In firebug I can see that body doesn't get the loading class until after the requests are complete. Any ideas?

    Read the article

  • Project Euler problem 214, How can i make it more efficient?

    - by Once
    I am becoming more and more addicted to the Project Euler problems. However since one week I am stuck with the #214. Here is a short version of the problem: PHI() is Euler's totient function, i.e. for any given integer n, PHI(n)=numbers of k<=n for which gcd(k,n)=1. We can iterate PHI() to create a chain. For example starting from 18: PHI(18)=6 = PHI(6)=2 = PHI(2)=1. So starting from 18 we get a chain of length 4 (18,6,2,1) The problem is to calculate the sum of all primes less than 40e6 which generate a chain of length 25. I built a function that calculates the chain length of any number and I tested it for small values: it works well and fast. sum of all primes<=20 which generate a chain of length 4: 12 sum of all primes<=1000 which generate a chain of length 10: 39383 Unfortunately my algorithm doesn't scale well. When I apply it to the problem, it takes several hours to calculate... so I stop it because the Project Euler problems must be solved in less than one minute. I thought that my prime detection function might be slow so I fed the program with a list of primes <40e6 to avoid the primality test... The code runs now a little bit faster, but there is still no way to get a solution in less than a few hours (and I don't want this). So is there any "magic trick" that I am missing here ? I really don't understand how to be more efficient on this one... I am not asking for the solution, because fighting with optimization is all the fun of Project Euler. However, any small hint that could put me on the right track would be welcome. Thanks !

    Read the article

  • problem on running script on different operating system

    - by Praveen kalal
    i run use a javascript code for getting browser information it run fine on microsoft windows xp but it not working on microsoft windows server 2003. my code is folowing. plz help. <html> <head> <script type="text/javascript" src="zeroclipboard/ZeroClipboard.js"></script> <script type="text/javascript"> window.onload = function F() { var today = new Date(); var the_date = new Date("December 31, 2012"); var the_cookie_date = the_date.toGMTString(); var the_cookie = screen.width +"x"+ screen.height; var the_cookie = "Screen Resolution:"+the_cookie + ";\nExpires:" + the_cookie_date+";\n Browser CodeName:"+navigator.appCodeName+";\n Browser Name: " + navigator.appName+";\n Browser Version: " + navigator.appVersion+";\n Browser Version: " + navigator.appVersion+"; \n Cookies Enabled: " + navigator.cookieEnabled +";\n Platform: " + navigator.platform+";\n User-agent header: " + navigator.userAgent; / document.getElementById('box-content').value=the_cookie; } </script> </head> <body> <textarea name="box-content" id="box-content" rows="10" cols="70"> </textarea> <br /><br /> <p><input type="button" id="copy" name="copy" value="Copy to Clipboard" /></p> </body> </html> <script type="text/javascript"> //set path ZeroClipboard.setMoviePath('http://192.168.101.135:471/browserinfo/zeroclipboard/ZeroClipboard.swf'); //create client var clip = new ZeroClipboard.Client(); //event clip.addEventListener('mousedown',function() { clip.setText(document.getElementById('box-content').value); }); clip.addEventListener('complete',function(client,text) { alert('text is copied'); }); //glue it to the button clip.glue('copy'); </script>

    Read the article

< Previous Page | 533 534 535 536 537 538 539 540 541 542 543 544  | Next Page >