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  • Unpacking tuple types in Scala

    - by jpalecek
    I was just wondering, can I decompose a tuple type into its components' types in Scala? I mean, something like this trait Container { type Element } trait AssociativeContainer extends Container { type Element <: (Unit, Unit) def get(x : Element#First) : Element#Second }

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  • Java - Console-like web applet.

    - by Dean
    Hey, I've been developing an application in the windows console with Java, and want to put it online in all of its console-graphics-glory. Is there a simple web applet API I can use to port my app over? I'm just using basic System.out and System.in functionality, but I'm happy to rebuild my I/O wrappers. I think something along these lines would be a great asset to any beginning Java developers who want to put their work online.

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  • Recursive query question - break rows into columns?

    - by Stew
    I have a table "Families", like so FamilyID PersonID Relationship ----------------------------------------------- F001 P001 Son F001 P002 Daughter F001 P003 Father F001 P004 Mother F002 P005 Daughter F002 P006 Mother F003 P007 Son F003 P008 Mother and I need output like FamilyID PersonID Father Mother ------------------------------------------------- F001 P001 P003 P004 F001 P002 P003 P004 F001 P003 F001 P004 F002 P005 P006 F002 P006 F003 P007 P008 F003 P008 In which the PersonID of the Father and Mother for a given PersonID are listed (if applicable) in separate columns. I know this must be a relatively trivial query to write (and therefore to find instructions for), but I can't seem to come up with the right search terms. Searching "SQL recursive queries" has gotten me closest, but I can't quite translate those methods to what I'm trying to do here. I'm trying to learn, so multiple methods are welcome, as is vocabulary I should read up on. Thanks!

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  • Any difference in compiler behavior for each of these snippets?

    - by HotHead
    Please consider following code: 1. uint16 a = 0x0001; if(a < 0x0002) { // do something } 2. uint16 a = 0x0001; if(a < uint16(0x0002)) { // do something } 3. uint16 a = 0x0001; if(a < static_cast<uint16>(0x0002)) { // do something } 4. uint16 a = 0x0001; uint16 b = 0x0002; if(a < b) { // do something } What compiler does in backgorund and what is the best (and correct) way to do above testing? p.s. sorry, but I couldn't find the better title :) EDIT: values 0x0001 and 0x0002 are only example. There coudl be any 2 byte value instead. Thank you in advance!

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  • How does jQuery .data() work?

    - by kazanaki
    My Javascript knowledge is pretty limited. Instead of asking several javascript questions I got the "message" from Stack overflow and started using jQuery right away in order to save me some time. However several times I do not undestand the "magic" behind jQuery and I would love to learn the details. I want to use .data() in my application. The examples are very helpful. I do not understand however WHERE these values are stored. I inspect the webpage with Firebug and as soon as .data() saves an object to a dom element, I do not see any change in Firebug (either HTML or Dom tabs). I tried to look at jQuery source, but it is very advanced for my Javascript knowledge and I lost myself. So the question is: Where do the values stored by jQuery.data() actually go? Can I inspect/locate/list/debug them using a tool?

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  • Python doesn't work properly when I execute a script after using Right Click >> Command Prompt Here

    - by Dominic Bou-Samra
    This is a weird bug. I know it's something funky going on with my PATH variable, but no idea how to fix it. If I have a script C:\Test\test.py and I execute it from within IDLE, it works fine. If I open up Command Prompt using Runcmd.exe and navigate manually it works fine. But if I use Windows 7's convenient Right Click on folder Command Prompt Here then type test.py it fails with import errors. I also cannot just type "python" to reach a python shell session if I use the latter method above. Any ideas?

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  • How to extract only part of string in PHP?

    - by shin
    I have a following string and I want to extract image123.jpg. ..here_can_be_any_length "and_here_any_length/image123.jpg" and_here_also_any_length image123 can be any length (newimage123456 etc) and with extension of jpg, jpeg, gif or png. I assume I need to use preg_match, but I am not really sure how to code it. Any help will be appreciated. Thanks in advance.

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  • How do you setLayoutParams() for an ImageView?

    - by DeadTime
    I want to set the LayoutParams for an ImageView but cant seem to find out the proper way to do it. I can only find documentation in the API for the various ViewGroups, but not an ImageView. Yet the ImageView seems to have this functionality. This code doesn't work... myImageView.setLayoutParams(new ImageView.LayoutParams(30,30)); How do I do it?

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  • Validating age field

    - by Marcelo
    Hi people, I'm trying to validate an age field in a form but I'm having some problem. First I tried to make sure that the field will not be send empty. I don't know JavaScript so I searched some scripts and adapted them to this: function isInteger (s) { var i; if (isEmpty(s)) if (isInteger.arguments.length == 1) return 0; else return (isInteger.arguments[1] == true); for (i = 0; i < s.length; i++) { var c = s.charAt(i); if (!isDigit(c)) return false; } return true; } function isEmpty(s) { return ((s == null) || (s.length == 0)) } function validate_required(field,alerttxt) { with (field) { if (value==null||value=="") { alert(alerttxt);return false; } else { return true; } } } function validate_form(thisform) { with (thisform) { if ((validate_required(age,"Age must be filled out!")==false) || isInteger(age,"Age must be and int number")==false)) {email.focus();return false;} } } //html part <form action="doador.php" onsubmit="return validate_form(this)" method="post"> It's working fine for empty fields, but if I type any letters or characters in age field, it'll be sent and saved a 0 in my database. Can anyone help me? Sorry for any mistake in English, and thanks in anvance for your help.

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  • python regex of a date in some text

    - by Horace Ho
    How can I find as many date patterns as possible from a text file by python? The date pattern is defined as: dd mmm yyyy ^ ^ | | +---+--- spaces where: dd is a two digit number mmm is three-character English month name (e.g. Jan, Mar, Dec) yyyy is four digit year there are two spaces as separators Thanks!

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  • Haskell Ord instance with a Set

    - by mvid
    I have some code that I would like to use to append an edge to a Node data structure: import Data.Set (Set) import qualified Data.Set as Set data Node = Vertex String (Set Node) deriving Show addEdge :: Node -> Node -> Node addEdge (Vertex name neighbors) destination | Set.null neighbors = Vertex name (Set.singleton destination) | otherwise = Vertex name (Set.insert destination neighbors) However when I try to compile I get this error: No instance for (Ord Node) arising from a use of `Set.insert' As far as I can tell, Set.insert expects nothing but a value and a set to insert it into. What is this Ord?

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  • ajax code error in aspx page

    - by peter
    where do i put the code in aspx page if i want to display hover menu,,if i put anywhere in aspx page its throwing errors the code is <ajaxToolkit:HoverMenuExtender ID="hme2" runat="Server" TargetControlID="GridView1" PopupControlID="PopupMenu" HoverCssClass="popupHover" PopupPosition="Left" OffsetX="0" OffsetY="0" PopDelay="50" /> errors like unrecoganized tag filter 'ajaxToolkit' ,,,this name contain upper case character which is not allowed,,like that

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  • Understanding Device Contexts

    - by Smashery
    As a relative newcomer to MFC, I see Device Contexts (DCs) a lot. I vaguely understand that it's something to do with drawing, but the specifics are not very well explained anywhere that I can find. What does creating a "compatible Device Context" mean, and why is it important? What does SelectObject do, and how must I make a DC compatible first?

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  • Learning Haskell maps, folds, loops and recursion

    - by Darknight
    I've only just dipped my toe in the world of Haskell as part of my journey of programming enlightenment (moving on from, procedural to OOP to concurrent to now functional). I've been trying an online Haskell Evaluator. However I'm now stuck on a problem: Create a simple function that gives the total sum of an array of numbers. In a procedural language this for me is easy enough (using recursion) (c#) : private int sum(ArrayList x, int i) { if (!(x.Count < i + 1)) { int t = 0; t = x.Item(i); t = sum(x, i + 1) + t; return t; } } All very fine however my failed attempt at Haskell was thus: let sum x = x+sum in map sum [1..10] this resulted in the following error (from that above mentioned website): Occurs check: cannot construct the infinite type: a = a -> t Please bear in mind I've only used Haskell for the last 30 minutes! I'm not looking simply for an answer but a more explanation of it. Thanks in advanced.

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  • Why the "mutable default argument fix" syntax is so ugly, asks python newbie

    - by Cawas
    Now following my series of "python newbie questions" and based on another question. Go to http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html#other-languages-have-variables and scroll down to "Default Parameter Values". There you can find the following: def bad_append(new_item, a_list=[]): a_list.append(new_item) return a_list def good_append(new_item, a_list=None): if a_list is None: a_list = [] a_list.append(new_item) return a_list So, question here is: why is the "good" syntax over a known issue ugly like that in a programming language that promotes "elegant syntax" and "easy-to-use"? Why not just something in the definition itself, that the "argument" name is attached to a "localized" mutable object like: def better_append(new_item, a_list=[].local): a_list.append(new_item) return a_list I'm sure there would be a better way to do this syntax, but I'm also almost positive there's a good reason to why it hasn't been done. So, anyone happens to know why?

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  • jQuery attribute question

    - by Nick Simone
    I'm trying to select a series of divs one at a time. I'm sure theres a better way to do this, but I gave them all unique rels and I'm using the rels to select them one at a time. I want to move them over the width of the div, then animate it dropping down the screen. What I have is: $(document).ready(function(){ var totalbricks = 7; var index = 2; $(".brick").animate({top:"600px"}); while(index < totalbricks) { var postion = 45*index; $(".brick[rel='+index+']").css('left', postion+'px'); $(".brick[rel='+index+']").animate({top:"600px"}); index++; } }); All the divs are in a container div. Jquery docs say, 'Variables can be used using the following syntax: [name='" +MyVar+ "']' What am I doing wrong? Here is the HTML that is being used by the jQuery <body> <div id="container"> <div id="canvas"> <div class="brick" rel="1"> </div> <div class="brick" rel="2"> </div> <div class="brick" rel="3"> </div> <div class="brick" rel="4"> </div> <div class="brick" rel="5"> </div> <div class="brick" rel="6"> </div> <div class="brick" rel="7"> </div> </div> </div> </body>

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