Search Results

Search found 27238 results on 1090 pages for 'local variable'.

Page 867/1090 | < Previous Page | 863 864 865 866 867 868 869 870 871 872 873 874  | Next Page >

• PHP.ini Settings Are Ignored By PHP5.3.5 Running With Windows 7 And Apache 2.2.15

  - by Andy

  I did an install of PHP5.3.5 on Windows 7 Home Premium using the MSI installer download. I got it to overwrite a previous version of PHP5 in C:\php5\ When first testing it, the server failed to start. I fixed this by adding the path to PHP in the Apache2.2 httpd file where the installer had inserted 2 lines of coded pointing to the ini file directory and the PHP DLL but had left out the directory path. After doing this, the server starts ok and I can run phpinfo to view the PHP settings in my web browser on local host. In the phpinfo it states that the loaded configuration file is C:\php5\php.ini as expected. But if I make any changes to the settings, and reboot the server, none of the changes are reflected in phpinfo. Yes, I do refresh the browser window. If I rename the php.ini to something else to make it invisible phpinfo then correctly identifies that there is no php.ini file loaded. So the settings in php.ini are being ignored and some default settings are being used (but I have no idea where these are derived from). As far as I can tell, there are no other php.ini files on my computer. In phpinfo it states that the Configuration File (php.ini) Path is C:\Windows but this is the same as on a Windows XP computer that I work on. And in the windows folder I don't see any php.ini file. In the windows registry, there is no mention of PHP5, and the PATH environment variable starts with C:\php5\; So hopefully someone can suggest how I can get PHP5 to take notice of the C:\php5\php.ini settings. :)

  Read the article

• How to make a self contained jQuery plugin that finds the tallest image height?

  - by Jannis

  I have been trying to make this to be a little jQuery plugin that I can reuse in the future without having to write the following into my actions.js file in full. This works when loaded in the same file where I set the height using my variable tallest. var tallest = null; $('.slideshow img').each(function(index) { if ($(this).height() >= tallest ) { tallest = $(this).height(); } }); $('.slideshow').height(tallest); This works and will cycle through all the items, then set the value of tallest to the greatest height found. The following however does not work: This would be the plugin, loaded from its own file (before the actions.js file that contains the parts using this): (function($){ $.fn.extend({ tallest: function() { var tallest = null; return this.each(function() { if ($(this).height() >= tallest ) { tallest = $(this).height(); } }); } }); })(jQuery); Once loaded I am trying to use it as follows: $('.slideshow img').tallest(); $('.slideshow').height(tallest); However the above two lines return an error of 'tallest is undefined'. How can I make this work? Any ideas would be appreciated. Thinking about this even more the perfect usage of this would be as follows: $('.container').height(tallest('.container item')); But I wouldn't even know where to begin to get this to work in the manner that you pass the object to be measured into the function by adding it into the brackets of the function name. Thanks for reading, Jannis

  Read the article

• c program pointer

  - by sandy101

  Hello , I am trying some programs in c face a problem with this program #include<stdio.h> int main() { int a=9,*x; float b=3.6,*y; char c='a',*z; printf("the value is %d\n",a); printf("the value is %f\n",b); printf("the value is %c\n",c); x=&a; y=&b; z=&c; printf("%u\n",a); printf("%u\n",b); printf("%u\n",c); x++; y++; z++; printf("%u\n",a); printf("%u\n",b); printf("%u\n",c); return 0; } can any one tell me what is the problem with this and i also want to know that when in the above case if the pointer value is incremented then will it over write the previous value address as suppose that the value we got in the above program (without the increment in the pointer value )is 65524 65520 65519 and after the increment the value of the pointer is 65526(as 2 increment for the int ) 65524(as 4 increment for the float ) 65520(as 1 increment for the char variable ) then if in that case will the new pointer address overwrite the content of the previous address and what value be contained at the new address ......plz help

  Read the article

• How stop mp3 playing started with audioplayer

  - by bucche

  Hi, My application consists of a table view. row1, row2, row3.... When a cell is touched a different mp3 starts to play (row1.mp3, row2.mp3, row3.mp3....). it works! but i have a problem: i am not able to stop previous mp3, so if i touch a second cell i have 2 mp3s playing... if i touch a third cell i have 3 mp3s and so on... i want to stop mp3 that started before and play mp3 that is related to touched cell... during my tries, i created a variable to show some alerts if the player plays or not and when i am "inside the if" i used [myAudioPlayer stop].. i see the correct alert but mp3 doesn't stop. here is my code - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { NSArray *elementi = [[array objectAtIndex:indexPath.row] componentsSeparatedByString:@"|"]; NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/%@.mp3", [[NSBundle mainBundle] resourcePath],[elementi objectAtIndex:1]]]; NSError *error; myAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error]; myAudioPlayer.numberOfLoops = -1; if (inEsecuzione == 0) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"1" message:@"1" delegate:nil cancelButtonTitle:@"OK"otherButtonTitles:nil]; [alert show]; [alert release]; [myAudioPlayer play]; inEsecuzione = 1; } else { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"2" message:@"2" delegate:nil cancelButtonTitle:@"OK"otherButtonTitles:nil]; [alert show]; [alert release]; [myAudioPlayer stop]; inEsecuzione = 0; } } as i wrote before, i am not able to stop previous mp3

  Read the article

• PHP - uninitialized array offset

  - by kimmothy16

  Hey everyone, I am using PHP to create a form with an array of fields. Basically you can add an unlimited number of 'people' to the form and each person has a first name, last name, and phone number. The form requires that you add a phone number for the first person only. If you leave the phone number field blank on any others, the handler file is supposed to be programmed to use the phone number from the first person. So, my fields are: person[] - a hidden field with a value that is this person's primary key. fname[] - an input field lname[] - an input field phone[] - an input field my form handler looks like this: $people = $_POST['person'] $counter = 0; foreach($people as $person): if(phone[$counter] == '') { // use $phone[0]'s phone number } else { // use $phone[$counter] number } $counter = $counter + 1; endforeach; PHP doesn't like this though, it is throwing me an Notice: Uninitialized string offset error. I debugged it by running the is_array function on people, fname, lname, and phone and it returns true to being an array. I can also manually echo out $phone[2], etc. and get the correct value. I've also ran is_int on the $counter variable and it returned true, so I'm unsure why this isn't working as intended? Any help would be great!

  Read the article

• C++: defining maximum/minimum limits for a class

  - by Luis

  Basically what the title says... I have created a class that models time slots in a variable-granularity daily schedule (where for example the first time slot is 30 minutes, but the second time slot can be 40 minutes); the first available slot starts at (a value comparable to) 1. What I want to do now is to define somehow the maximum and minimum allowable values that this class takes and I have two practical questions in order to do so: 1.- does it make sense to define absolute minimum and maximum in such a way for a custom class? Or better, does it suffice that a value always compares as lower-than any other possible value of the type, given the class's defined relational operators, to be defined the min? (and analogusly for the max) 2.- assuming the previous question has an answer modeled after "yes" (or "yes but ..."), how do I define such max/min? I know that there is std::numeric_limits<> but from what I read it is intended for "numeric types". Do I interpret that as meaning "represented as a number" or can I make a broader assumption like "represented with numbers" or "having a correspondence to integers"? After all, it would make sense to define the minimum and maximum for a date class, and maybe for a dictionary class, but numeric_limits may not be intended for those uses (I don't have much experience with it). Plus, numeric_limits has a lot of extra members and information that I don't know what to make with. If I don't use numeric_limits, what other well-known / widely-used mechanism does C++ offer to indicate the available range of values for a class?

  Read the article

• Initializing AngularJS service factory style

  - by wisemanIV

  I have a service that retrieves data via REST. I want to store the resulting data in service level variable for use in multiple controllers. When I put all the REST logic directly into controllers everything works fine but when I attempt to move the retrieval / storing of data into a service the controller is not being updated when the data comes back. I've tried lots of different ways of maintain the binding between service and controller. Controller: myApp.controller('SiteConfigCtrl', ['$scope', '$rootScope', '$route', 'SiteConfigService', function ($scope, $rootScope, $route, SiteConfigService) { $scope.init = function() { console.log("SiteConfigCtrl init"); $scope.site = SiteConfigService.getConfig(); } } ]); Service: myApp.factory('SiteConfigService', ['$http', '$rootScope', '$timeout', 'RESTService', function ($http, $rootScope, $timeout, RESTService) { var siteConfig = {} ; RESTService.get("https://domain/incentiveconfig", function(data) { siteConfig = data; }); return { getConfig:function () { console.debug("SiteConfigService getConfig:"); console.debug(siteConfig); return siteConfig; } }; } ]);

  Read the article

• How to inject php code from database into php script ?

  - by luxquarta

  I want to store php code inside my database and then use it into my script. class A { public function getName() { return "lux"; } } // instantiates a new A $a = new A(); Inside my database there is data like "hello {$a->getName()}, how are you ?" In my php code I load the data into a variable $string $string = load_data_from_db(); echo $string; // echoes hello {$a->getName()}, how are you ? So now $string contains "hello {$a-getName()}, how are you ?" {$a-getName()} still being un-interpretated Question: I can't find how to write the rest of the code so that {$a-getName()} gets interpretated "into hello lux, how are you". Can someone help ? $new_string = ?????? echo $new_string; //echoes hello lux, how are you ? Is there a solution with eval() ? (please no debate about evil eval ;)) Or any other solution ?

  Read the article

• RTTI Delphi Create as TValue an n-dimensional matrix.

  - by user558126

  Good day, I had tried to make recurrent function to return a TValue as a n-dimensional. matrix(2D, 3D, 4D...) for example, this procedure will show a n-dimensional matrix(it will list all elements from a n-dimensional matrix as TValue variable): Procedure Show(X:TValue); var i:integer; begin if x.IsArray then begin for i:=0 to x.GetArrayLength-1 do show(x.GetArrayElement(i)); writeln; end else write(x.ToString,' '); end; I don't understand how to create a function to create from a TValue an n-dimensional matrix. For example i need a Function CreateDynArray(Dimensions:array of integer; Kind:TTypeKind):TValue; and the function will return a TValue which is a dynamic array how contain the dimenssions for example: Return=CreateDynArray([2,3],tkInteger); will return a TValue as tkDynArray and if i will show(Return) will list 0 0 0 0 0 0 Thank you very much, and have a nice day!

  Read the article

• Actionscript Enterframe Movement

  - by David

  I am trying to make accelerated movement, but I am running into a problem that, for the life of me, I cannot understand. My class definition: public class Player extends MovieClip { private var stageRef:Stage; private var key:KeyObject; private var acceleration:int = .5; private var curSpeed:int = 0; public function Player(stageRef:Stage) { this.stageRef = stageRef; addEventListener(Event.ENTER_FRAME, enterFrame); key = new KeyObject(stageRef); } public function enterFrame(e:Event) : void { if(key.isDown(key.RIGHT)) { x += 5; } } } This works to move my position in the x direction at a constant rate. However, if I change enterFrame to public function enterFrame(e:Event) : void { if(key.isDown(key.RIGHT)) { x += acceleration; } } No movement occurs. Is there something going on in the event I do not understand? Why is it that I can have x increased by a constant value but not a constant value as defined in a variable in the class? Is it a scope issue?

  Read the article

• problem with implementing a simple work queue

  - by John Deerikio

  Hi all, I am having troubles with implementing a simple work queue. Doing some analysis, I am facing a subtle problem. The work queue is backed by a regular linked list. The code looks like this (simplified): 0. while (true) 1. while (enabled == true) 2. acquire lock on the list and get the next action to be executed (blocking operation) (store it in a local variable) 3. execute the action (outside the lock on the list on previous line) 4. get lock on this work queue 5. wait until this work queue has been notified (triggered when setEnabled(true) has been callled) The setEnabled(e) operation looks like this (simplified): enabled = e if (enabled == true) acquire lock on this work queue and do notify() Although this works, there is a condition in which a deadlock occurs. It happens in the following rare situation: while an action is being executed, setEnabled(false) is called just before step (4) is entered, setEnabled(true) is called now step (5) keeps waiting forever, because this work queue has already been notified How do I solve this? I have been looking at this for some time, but I cannot come up with a solution. Please note I am fairly new to thread synchronization. Thanks a lot.

  Read the article

• Disabling repeating keyboard down event in as3

  - by psy-sci

  now I'm trying to make the keyboard events to stop repeating. My idea was to have a true and false condition for when the key is pressed so that it wont repeat if the key is down already. //Mouse Event Over keyCButton.addEventListener(MouseEvent.MOUSE_OVER, function(){gotoAndStop(2)}); //Variable var Qkey:uint = 81; //Key Down Event stage.addEventListener(KeyboardEvent.KEY_DOWN, keydown); var soundplayed = false; function keydown(event:KeyboardEvent){ if (event.keyCode==Qkey) { this.soundplayed=true;} } if (this.soundplayed==false){ gotoAndPlay(3); } else {} //Key Up Event stage.addEventListener(KeyboardEvent.KEY_UP, keyup); function keyup(event:KeyboardEvent){ if (event.keyCode==Qkey) { this.soundplayed=true; gotoAndStop(1); } } doing this just turns off the key event I think i need to add a "&& keyDown..." to "if (this.soundplayed==true)" but i dont know how to do it without getting errors here is the keyboard player i'm trying to fix http://soulseekrecords.org/psysci/animation/piano.html

  Read the article

• Recursive Enumeration in Java

  - by Harm De Weirdt

  Hello everyone. I still have a question about Enumerations. Here's a quick sketch of the situation. I have a class Backpack that has a Hashmap content with as keys a variable of type long, and as value an ArrayList with Items. I have to write an Enumeration that iterates over the content of a Backpack. But here's the catch: in a Backpack, there can also be another Backpack. And the Enumeration should also be able to iterate over the content of a backpack that is in the backpack. (I hope you can follow, I'm not really good at explaining..) Here is the code I have: public Enumeration<Object> getEnumeration() { return new Enumeration<Object>() { private int itemsDone = 0; //I make a new array with all the values of the HashMap, so I can use //them in nextElement() Collection<Long> keysCollection = getContent().keySet(); Long [] keys = keysCollection.toArray(new Long[keysCollection.size()]); public boolean hasMoreElements() { if(itemsDone < getContent().size()) { return true; }else { return false; } } public Object nextElement() { ArrayList<Item> temporaryList= getContent().get(keys[itemsDone]); for(int i = 0; i < temporaryList.size(); i++) { if(temporaryList.get(i) instanceof Backpack) { return temporaryList.get(i).getEnumeration(); }else { return getContent().get(keys[itemsDone++]); } } } }; Will this code work decently? It's just the "return temporaryList.get(i).getEnumeration();" I'm worried about. Will the users still be able to use just the hasMoreElemens() and nextElement() like he would normally do? Any help is appreciated, Harm De Weirdt

  Read the article

• Approaches for animating a C# property over time?

  - by Mario Fritsch

  I'm currently trying to animate a bunch of public properties on certain objects. Usually they are of type float or vectors of floats (the type is known at compile-time). I want to be able to: assign a static value to them (MyObject.Duration = 10f;) or assign a random value to them by specifying a minimum and maximum value and optionally also a weight (MyObject.Duration = new RandomFloat(5f, 20f, 2f);) or "bind" this property to the property of another object (think of a child object binding some of its properties to its parent object, like its color or size or sth.) or assign sort of a keyframe animation to them, specifying a variable number of keyframes with timecode and the property's value at that specific point in time as well as information about how to interpolate between these frames The keyframes should be able to accept random values for each frame, both for the time and the property's value. What would be a practical approach for this kind of system? Currently I'm thinking about polymorphism: implement a base class or interface with a public Value-property and/or GetValue(float time)-method and then creating different sub classes like StaticValue, RandomValue, BindingValue and AnimatedValue implementing this base class or interface. Doesn't seem very elegant, though, and the initialization of even simple objects becomes a bit tedious. Another idea would be to implement these properties just as regular floats or vectors and create special "Modifier"-types binding to these properties. To retrieve the "real" value of the property, I'd first call any Modifier bound to the property, which would in turn update the actual object's property for me to retrieve later on. That would most likely mean using reflection at some point, which could be quite bad for performance as I'll probably have thousands of properties to update dozens of times per second. Any suggestions on this? Being a novice I'm (hopefully) missing some far more elegant and/or practical solution than I'm already playing around with :( Edit: Probably should have mentioned this earlier, but WPF isn't an option - it's not available on all targetted platforms, so I can't rely on it. I'm aware of its powerful databinding and animation capabilities, but I need to roll my own (or find some other lightweight alternative meeting my needs).

  Read the article

• Should I pass a SqlDataReader by reference or not when passing it out to multiple threads.

  - by deroby

  Hi all, being new to c# I've run into this 'conundrum' when passing around a SqlDataReader between different threads. Without going into too much detail, the idea is to have a main thread fetching data from the database (a large recordset) and then have a helper-task run through this record by record and doing some stuff based upon the contents of this. There is no feedback to the recordset, it simply wades through until no records are left. This works fine, but given the nature of the job at hand it should be possible to have this job spread over different threads (CPUs) to maximize throughput (the order of execution is of no significance). The question then becomes, when I pass this recordset in a SqlDataReader, do I have to use ref or not ? It kind of boils down to the question : if I pass the object around without specifying ref, won't it create new copies in memory and have records processed n times ? Or, don't I risk having the record-position being moved forward while not all fields have been fully read yet ? The latter seems more like a 'data racing' issue and probably is covered by the lock()ing mechanism (or not?). My initial take on the problem was that it doesn't really hurt passing the variable using ref, yet as a colleague put it : "you only need ref when you're doing something wrong" =) Additionally using ref restricts me from applying a Using() construction too which isn't very nice either. I thus create a "basic" project that tackles the same approach but without the ref notation. Tests so far show that it works flawlessly on a Core2Duo (2cpu) using any number of threads, yet I'm still a bit wary... What do you experts think about this ? Use ref or not ? You can find the test-project here as it seems I can't upload it to this question directly ?!? ps: it's just a test-project and I'm new to c#, so please be gentle on me when breaking down the code =P

  Read the article

• C# XML node with colon

  - by Sticky

  Hi, my code attempts to grab data from the RSS feed of a website. It grabs the nodes fine, but when attempting to grab the data from a node with a colon, it crashes and gives the error "Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function." The code is shown below: WebRequest request = WebRequest.Create("http://buypoe.com/external.php?type=RSS2&lastpost=true"); WebResponse response = request.GetResponse(); StringBuilder sb = new StringBuilder(""); System.IO.StreamReader rssStream = new System.IO.StreamReader(response.GetResponseStream(), System.Text.Encoding.GetEncoding("utf-8")); XmlDocument rssDoc = new XmlDocument(); rssDoc.Load(rssStream); XmlNodeList rssItems = rssDoc.SelectNodes("rss/channel/item"); for (int i = 0; i < 5; i++) { XmlNode rssDetail; rssDetail = rssItems.Item(i).SelectSingleNode("dc:creator"); if (rssDetail != null) { user = rssDetail.InnerText; } else { user = ""; } } I understand that I need to define the namespace, but am unsure how to do this. Help would be appreciated.

  Read the article

• Writing a plist

  - by iOS-Newbie

  I am trying to test out writing a dictionary to a plist. The following code does not report any errors, but I cannot find any trace of the file that I supposed wrote. Here is the code snippet: NSDictionary *myDictionary = [NSDictionary dictionaryWithObjectsAndKeys: @"First letter of the alphabet", @"A", @"Second letter of the alphabet", @"B", @"Third letter of the alphabet", @"C", nil ]; I can see the dictionary contents displayed properly with either method calls: NSLog(@"Here is my partial dictionary %@", myDictionary); for (NSString *key in myDictionary) NSLog(@"here it is again %@ %@", key, [myDictionary objectForKey:key]); The following code displays the "succeeded" message when the program is run repeatedly if ([myDictionary writeToFile: @"myDictionary" atomically:YES ] == NO) NSLog(@"write to file failed"); else NSLog(@"write to file succeeded"); even when changing the atomically: argument to NO to not write a temporary file. However, when I search my current directory, or even my entire Mac, I cannot find any file called "myDictionary.plist" or any file with the string "myDictionary". Isn't the path variable "@myDictionary" supposed to represent the file at the current directory, i.e. where the class executable resides?

  Read the article

• passing string to a AJAX/JSON function

  - by Mikey1980

  I’m having trouble getting a AJAX/JSON function to work correctly. I had this function grabbing value from a drop down box but now I want to use an anchor tag to set it's value. I thought it would be easy to just use the onClick event to pass string to the function I was using for the drop down box but it doesn’t do anything. I’m stumped! Here how I set it up: 1st I add an onClick event… <a href="<?php echo Settings::get('app.webroot'); ?>?view=schedule&action=questions" onmouseout="MM_swapImgRestore();" onmouseover="MM_swapImage('bre','','template/images/schedule/bre_f2.gif',1) onclick="assignCallType('testing')";> 2nd I check main.js.php function assignCallType(type) { alert(type); //just for debugging new Request.JSON({ url: "ajax.php", onSuccess: function(rtndata,txt){ if (rtndata['STATUS'] != 'OK') alert('Error assigning call type to call'); }, onFailure: function (xhr) { alert('Error assigning call type to call'); } }).get({ 'action': 'assignCallType', 'call_type': type }); } 3rd Ajax.php: the variable is back in PHP and values don’t get added to the db, but I also didn’t get the alert from main.js.php if ($_GET['action'] == "assignCallType") { if ($USER->isInsideSales()) { $call_type = $_GET['call_type']; $_SESSION['callinfo']->setCallType($call_type); $_SESSION['callinfo']->save($callid); echo json_encode(array('STATUS'=>'OK')); } else { echo json_encode(array('STATUS'=>'DENIED')); } } Any idea where I am going wrong. The only difference between this and the working drop down is how the function was called, I used onchange="assignCallType(this.value)".

  Read the article

• Simple average calculation

  - by sasquatch90

  I'm trying to write program calculating average of given numbers stored in an array. Amount of numbers should be not more than 100, and user should input them until a !int variable is given : #include <iostream> #include <conio.h> using namespace std; double average(int tab[], int i){ int sum=0; for(int j=0; j<i; ++j){ sum+=tab[j]; } return (double)sum/i; } int main() { int tab[100]; int n=0; int number=0; do { if(n < 100){ cout << "Give " << n+1 << " number : "; cin >> number; tab[n]=number; number=0; ++n; } else{ break; } } while( !isdigit(number) ); cout << average(tab, n) << endl; getch(); return 0; } Why after giving char, it prints me 'Give n number:' for all empty cells of my array ? It should end and use only given numbers.

  Read the article

• Self referencing userdata and garbage collection

  - by drtwox

  Because my userdata objects reference themselves, I need to delete and nil a variable for the garbage collector to work. Lua code: obj = object:new() -- -- Some time later obj:delete() -- Removes the self reference obj = nil -- Ready for collection C Code: typedef struct { int self; // Reference to the object // Other members and function references removed } Object; // Called from Lua to create a new object static int object_new( lua_State *L ) { Object *obj = lua_newuserdata( L, sizeof( Object ) ); // Create the 'self' reference, userdata is on the stack top obj->self = luaL_ref( L, LUA_REGISTRYINDEX ); // Put the userdata back on the stack before returning lua_rawgeti( L, LUA_REGISTRYINDEX, obj->self ); // The object pointer is also stored outside of Lua for processing in C return 1; } // Called by Lua to delete an object static int object_delete( lua_State *L ) { Object *obj = lua_touserdata( L, 1 ); // Remove the objects self reference luaL_unref( L, LUA_REGISTRYINDEX, obj->self ); return 0; } Is there some way I can set the object to nil in Lua, and have the delete() method called automatically? Alternatively, can the delete method nil all variables that reference the object? Can the self reference be made 'weak'?

  Read the article

• Why does this Haskell code produce the "infinite type" error?

  - by Charlie Flowers

  I am new to Haskell and facing a "cannot construct infinite type" error that I cannot make sense of. In fact, beyond that, I have not been able to find a good explanation of what this error even means, so if you could go beyond my basic question and explain the "infinite type" error, I'd really appreciate it. Here's the code: intersperse :: a -> [[a]] -> [a] -- intersperse '*' ["foo","bar","baz","quux"] -- should produce the following: -- "foo*bar*baz*quux" -- intersperse -99 [ [1,2,3],[4,5,6],[7,8,9]] -- should produce the following: -- [1,2,3,-99,4,5,6,-99,7,8,9] intersperse _ [] = [] intersperse _ [x] = x intersperse s (x:y:xs) = x:s:y:intersperse s xs And here's the error trying to load it into the interpreter: Prelude :load ./chapter.3.ending.real.world.haskell.exercises.hs [1 of 1] Compiling Main ( chapter.3.ending.real.world.haskell.exercises.hs, interpreted ) chapter.3.ending.real.world.haskell.exercises.hs:147:0: Occurs check: cannot construct the infinite type: a = [a] When generalising the type(s) for `intersperse' Failed, modules loaded: none. Thanks. EDIT: Thanks to the responses, I have corrected the code and I also have a general guideline for dealing with the "infinite type" error in Haskell: Corrected code intersperse _ [] = [] intersperse _ [x] = x intersperse s (x:xs) = x ++ s:intersperse s xs What the problem was: My type signature states that the second parameter to intersperse is a list of lists. Therefore, when I pattern matched against "s (x:y:xs)", x and y became lists. And yet I was treating x and y as elements, not lists. Guideline for dealing with the "infinite type" error: Most of the time, when you get this error, you have forgotten the types of the various variables you're dealing with, and you have attempted to use a variable as if it were some other type than what it is. Look carefully at what type everything is versus how you're using it, and this will usually uncover the problem.

  Read the article

• How I May Have Taken A Wrong Path in Programming

  - by Ygam

  I am in a major stump right now. I am a BSIT graduate, but I only started actual programming less than a year ago. I observed that I have the following attitude in programming: I tend to be more of a purist, scorning unelegant approaches to solving problems using code I tend to look at anything in a large scale, planning everything before I start coding, either in simple flowcharts or complex UML charts I have a really strong impulse on refactoring my code, even if I miss deadlines or prolong development times I am obsessed with good directory structures, file naming conventions, class, method, and variable naming conventions I tend to always want to study something new, even, as I said, at the cost of missing deadlines I tend to see software development as something to engineer, to architect; that is, seeing how things relate to each other and how blocks of code can interact (I am a huge fan of loose coupling) i.e the OOP thinking I tend to combine OOP and procedural coding whenever I see fit I want my code to execute fast (thus the elegant approaches and refactoring) This bothers me because I see my colleagues doing much better the other way around (aside from the fact that they started programming since our first year in college). By the other way around I mean, they fire up coding, gets the job done much faster because they don't have to really look at how clean their codes are or how elegant their algorithms are, they don't bother with OOP however big their projects are, they mostly use web APIs, piece them together and voila! Working code! CLients are happy, they get paid fast, at the expense of a really unmaintainable or hard-to-read code that lacks structure and conventions, or slow executions of certain actions (which the common reasoning against would be that internet connections are much faster these days, hardware is more powerful). The excuse I often receive is clients don't care about how you write the code, but they do care about how long you deliver it. If it works then all is good. Now, did my "purist" approach to programming may have been the wrong way to start programming? Should I just dump these purist concepts and just code the hell up because I have seen it: clients don't really care how beautifully coded it is?

  Read the article

• Setting <td> value using jquery

  - by timk

  Hello, I have the div structure shown below. For the second <td> in the table i want to replace &nbsp; with a hyperlink whose href attribute is stored in the variable myLink. How can i do this with jquery ? Please help. Thank You. <div class="pbHeader"> <table cellspacing="0" cellpadding="0" border="0"> <tbody> <tr> <td class="pbTitle"> <h2 class="mainTitle">Transfer Membership</h2> </td> <td> &nbsp; </td> </tr> </tbody> </table> </div>

  Read the article

• summing functions handles in matlab

  - by user552231

  Hi I am trying to sum two function handles, but it doesn't work. for example: y1=@(x)(x*x); y2=@(x)(x*x+3*x); y3=y1+y2 The error I receive is "??? Undefined function or method 'plus' for input arguments of type 'function_handle'." This is just a small example, in reality I actually need to iteratively sum about 500 functions that are dependent on each other. EDIT The solution by Clement J. indeed works but I couldn't manage to generalize this into a loop and ran into a problem. I have the function s=@(x,y,z)((1-exp(-x*y)-z)*exp(-x*y)); And I have a vector v that contains 536 data points and another vector w that also contains 536 data points. My goal is to sum up s(v(i),y,w(i)) for i=1...536 Thus getting one function in the variable y which is the sum of 536 functions. The syntax I tried in order to do this is: sum=@(y)(s(v(1),y,z2(1))); for i=2:536 sum=@(y)(sum+s(v(i),y,z2(i))) end

  Read the article

• Safari and Chrome back button changes hidden and submit values in forms

  - by OverClocked

  The following problem happens on both Safari and Chrome, so probably a WebKit issue. Page A: a page that requires you to login to see, contains a form that has a type=submit button, with name=submit, and value=a Page B: some other page Page C: ask user to login page, contains a form with a type=submit button, with name=submit and value=c User visits page A, then page B. Then idles and the user's login session times out. User hits back button to go back to page A. Browser redirects user to page C. On Safari and Chrome, when C is rendered, the form on page C has the type=submit button, name=submit, but value shows up as "a". If you reload while on page C, "c" appears as the value of the name=submit button. The same problem appears with type=hidden input fields; when user hits back button, their values are also changed to some other value from some other form. Also, this problem also shows up w/o the redirect, with just submit then back. In this case the previous page renders with incorrect values for hidden and submit CGI variables. So far the only fix I can come up with is use Javascript to reset the type=hidden and type=submit variable values, after page C loads, to make sure the values are correct. But that's not clean and universally applicable. Short of WebKit fixing this error, has anyone ran into a better workaround? Thanks.

  Read the article

< Previous Page | 863 864 865 866 867 868 869 870 871 872 873 874  | Next Page >