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  • Scala Tuple Deconstruction

    - by dbyrne
    I am new to Scala, and ran across a small hiccup that has been annoying me. Initializing two vars in parallel works great: var (x,y) = (1,2) However I can't find a way to assign new values in parallel: (x,y) = (x+y,y-x) //invalid syntax I end up writing something like this: val xtmp = x+y; y = x-y; x = xtmp I realize writing functional code is one way of avoiding this, but there are certain situations where vars just make more sense. I have two questions: 1) Is there a better way of doing this? Am I missing something? 2) What is the reason for not allowing true parallel assignment?

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  • Java method get the inheriting type

    - by DrDro
    I have several classes that extend C and I would need a method that accepts any argument of type C. But in this method I would like to know if I'm dealing with A or B. * public A extends C public B extends C public void goForIt(C c)() If I cast how can I retrieve the type in a clean way (I just read using getClass or instanceof is often not the best way). PS: Fell free to edit an explicit title. *Sorry but I can't type closing braces

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  • How to sanely read and dump structs to disk when some fields are pointers?

    - by bp
    Hello, I'm writing a FUSE plugin in C. I'm keeping track of data structures in the filesystem through structs like: typedef struct { block_number_t inode; filename_t filename; //char[SOME_SIZE] some_other_field_t other_field; } fs_directory_table_item_t; Obviously, I have to read (write) these structs from (to) disk at some point. I could treat the struct as a sequence of bytes and do something like this: read(disk_fd, directory_table_item, sizeof(fs_directory_table_item_t)); ...except that cannot possibly work as filename is actually a pointer to the char array. I'd really like to avoid having to write code like: read(disk_df, *directory_table_item.inode, sizeof(block_number_t)); read(disk_df, directory_table_item.filename, sizeof(filename_t)); read(disk_df, *directory_table_item.other_field, sizeof(some_other_field_t)); ...for each struct in the code, because I'd have to replicate code and changes in no less than three different places (definition, reading, writing). Any DRYer but still maintainable ideas?

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  • Defining a class with specific style dynamically in jQuery

    - by Acorn
    Is it possible to define a class with specific style attributes dynamically with jQuery, rather than setting the style of all elements with that class? I could set the attributes of the class at the end of the script once all the elements have been created, but is that the best way to go about it? If I define the style of the class with $('.class').css('property','value'); at the beginning of the script, nothing would happen because the elements with class .class haven't been created yet, right?

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  • sp_help with wildcards

    - by serhio
    There is a command in SqlServer sp_help 'table_name' (table_name or other stuff) Is there a possibility to use it when you don't know the whole table name, with wildcards or something like this: sp_help admin_%

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  • Proper indentation for Python multiline strings

    - by ensnare
    What is the proper indentation for Python multiline strings within a function? def method: string = """line one line two line three""" or def method: string = """line one line two line three""" or something else? It looks kind of weird to have the string hanging outside the function in the first example. Thanks.

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  • PHP Array To Class Static Public Values.

    - by what
    I want to make a class that has all the values of an array as a static object in that class. For example: $vars=array(... );//some array with actual values $Class_code='class MyClass{'; for($i=0; $i<count($vars); $i++){ $Class_code.='static public $'.strval($vars[i]).';'; } eval($Class_code.'}'); /* When I echo the line above it says that the vars for MyClass (MyClass::vars) are missing even with strval(). */ So, how can I get $vars[i] to be a string if strval didn't work?

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  • How big can I make an Android application's canvas in terms of pixels?

    - by user279112
    I've determined an estimate of the size of my Android emulator's screen in pixels, although I think its resolution can be changed to other numbers. Quite frankly though that doesn't eliminate the general problem of not knowing how many pixels on each axis I have to work with on my Android applications in general. The main problem I'm trying to solve is this: How do I make sure I don't use a faulty resolution on Android applications if I want to keep things' sizes constant (so that if the application screen shrinks, for instances, objects will still show up just as big - there just won't be as many of them being shown) if I wish to do this with a single universal resolution for each program? Failing that, how do I make sure everything's alright if I try to do everything the same way with maybe a few different pre-set resolutions? Mainly it seems like a relevant question that must be answered before I can come across a complete answer for the general problem is how big can I always make my application in pixels, NOT regarding if and when a user resizes the application's screen to something smaller than the maximum size permitted by the phone and its operating system. I really want to try to keep this simple. If I were doing this for a modern desktop, for instance, I know that if I design the application with a 800x600 canvas, the user can still shrink the application to the point they're not doing themselves any favors, but at least I can basically count on it working right and not being too big for the monitor or something. Is there such a magic resolution for Android, assuming that I'm designing for API levels 3+ (Android 1.5+)? Thanks

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  • How to redirect to the current page with form in php?

    - by garcon1986
    Hello, I tried to redirect to the current page with form in my php application. Now i have met a problem. <form name="myform" action="?page=matching" method="GET"> <input id="match_button" type="submit" name="button" value="button" onClick="func_load3()" /> </form> action="?page=matching" means the current page, because i use the single entry in my php application. With the code upon, When i click the button, it redirects to the homepage. And I tried to use: <form name="myform" action="<?php echo $_SERVER['PHP_SELF']; ?>" method="GET"> but it still doesn't work. So i have to ask for help from you. Do you have any ideas about that? How to fix it? Thanks in advance.

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  • feeding input to a java process from a batch file

    - by YGL
    If I have a simple java program that processes lines of text from standard input, then I can run it with the following script: @Echo off java Test < file.txt pause exit The script redirects lines of input from a separate file. Is there a way that I can avoid having to use an extra file? Or is this the easiest way? Thanks.

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  • NZEC Run time Error Occured

    - by madan
    import math def gen_caller(a): for z in a: x,y=z if x==1: x=2 if y>=x and y-x<=100000: for i in range(x,y+1): flag=0 for j in range(2,(long(math.sqrt(i))+1)): if(i%j==0): flag=1 break if flag==0: print i print "" n=(int(raw_input())) gen_caller([[(long(raw_input())) for j in range(0,2)] for i in range(0,n) if n<=10])

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  • initializing a vector of custom class in c++

    - by Flamewires
    Hey basically Im trying to store a "solution" and create a vector of these. The problem I'm having is with initialization. Heres my class for reference class Solution { private: // boost::thread m_Thread; int itt_found; int dim; pfn_fitness f; double value; std::vector<double> x; public: Solution(size_t size, int funcNo) : itt_found(0), x(size, 0.0), value(0.0), dim(30), f(Eval_Functions[funcNo]) { for (int i = 1; i < (int) size; i++) { x[i] = ((double)rand()/((double)RAND_MAX))*maxs[funcNo]; } } Solution() : itt_found(0), x(31, 0.0), value(0.0), dim(30), f(Eval_Functions[1]) { for (int i = 1; i < 31; i++) { x[i] = ((double)rand()/((double)RAND_MAX))*maxs[1]; } } Solution operator= (Solution S) { x = S.GetX(); itt_found = S.GetIttFound(); dim = S.GetDim(); f = S.GetFunc(); value = S.GetValue(); return *this; } void start() { value = f (dim, x); } /* plus additional getter/setter methods*/ } Solution S(30, 1) or Solution(2, 5) work and initalizes everything, but I need X of these solution objects. std::vector<Solution> Parents(X) will create X solutions with the default constructor and i want to construct using the (int, int) constructor. Is there any easy(one liner?) way to do this? Or would i have to do something like: size_t numparents = 10; vector<Solution> Parents; Parents.reserve(numparents); for (int i = 0; i<(int)numparents; i++) { Solution S(31, 0); Parents.push_back(S); }

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  • C#- Console Program Ideas for Noob

    - by user335932
    So, Im a beginning C# programmer. I know basic syntax and simple things like if statements and loops(methods and classes too). I've only used console apps right now havent bothered with windows forms yet. So any simple app ideas that introduce new things important for C# programming. Also, NO tutorials. I want to make all by myself.

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  • Should I invest time in learning Java language these days? (question from a greenhorn)

    - by dave-keiture
    Hi experts, Assuming you've already had a chance to look through the lambda syntax proposed for Java7 (and the other things that have happened with Java, after Oracle has bought Sun + obvious problems in Java Community Process), what do you think is the future of Java language? Should I, as a Java greenhorn, invest time in learning Java language (not talking about the core JVM, which definitely will survive anything, and worth investments), or concentrate on Scala, Groovy, or other hybrid languages on the JVM platform (I've came into Java world from PHP/Ruby). Thanks in advance.

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  • MySQL " identify storage engine statement"

    - by sammysmall
    This IS NOT a Homework question! While building my current student database project I realized that I may want to identify comprehensive information about a database design in the future. More-so if I am fortunate enough to get a job in this field and were handed a database project how could I break down certain elements for identification... In all of my previous designs I have been using MySQL Community Server (GPL) 5.1.42, I thought (duh) that I was using the MyISAM based on most of my text-book instruction and MySQL 5.0 Reference Manual :: 13 Storage Engines :: 13.1 The MyISAM Storage Engine I determined that this was in fact incorrect for this version and the use of "SHOW ENGINES" at the console... No problem, figured out why they have "versions" the need to pay attention to what version is being used, and the need for a means to determine what I am about to mess up "if" I do not pay attention to detail... Q1. Specifically what statement will identify the version used by someone elses initial database creation? (since I created my own databases I know what version I used) Q2. Specifically what statement will identify the storage engine that the developer used when creating the database. (I specified a particular database in my collection then tried SHOW Engine, did not work, then tried to just get the metadata from one table in that database: mysql SELECT duck_cust, table_type, engine - FROM INFORMATION_SCHEMA.tables - WHERE table_schema = 'tp' - ORDER BY table_type ASC, table_name DESC; as this was not really what I wanted (and did not work) I am looking for some direction from the pros... Q3. (If you really have the inclination to continue helping) If I were to access a database from an earlier/later "version" are there backward/forward compatibility issues for maintaining/updating data between versions? Please and Thank you in advance for your time and efforts! sammysmall

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  • Is there any good (eazy, small) sample of working with google openid? (php)

    - by Ole Jak
    Is there any good (eazy to understend, small - not lotof code lines) sample of working with google openid? (php) - What I need is to see how to get users name from google openId ; a good way of how to integrate openid into my current users DB (tooday in DB I have table user with name and pass)? and how to get any Idea about if useris currently loged in from this computer with openId?

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  • How to access child div elements under a given condition with javascript?

    - by hlovdal
    My main question is to calculate the last alert message, but any other information is also welcome. I am trying to learn javascript (to use with greasemonkey later), but I am struggling a bit to grasp the DOM and how to process it. <html> <head> <script type="text/javascript"> function my_test() { var elements = document.getElementsByTagName("div"); // prints "found [object HTMLCollection] with length 8" alert("found " + elements + " with length " + elements.length); // prints "0:[object HTMLDivElement]" alert("0:" + elements[0]); // how to calculate the following? alert("for intereting one is AAAA and three is CCCC"); } </script> </head> <body> <div class="interesing"> <div class="one">AAAA</div> <div class="two">BBBB</div> <div class="three">CCCC</div> </div> <div class="boring"> <div class="one">1111</div> <div class="two">2222</div> <div class="three">3333</div> </div> <input type="button" onclick="my_test()" value="my test" </body> </html> So elements is now an array of elements and I can access each of them individually. But where can I find what methods/properties these elements have?

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  • New desktop GUI developer; can choose any platform...

    - by alexantd
    I'm planning a client-server product for a tiny, low-volume, high-cost vertical market. One of the components of the product will be a desktop application, simple to moderate in complexity, for data entry and uploading to a central server from remote PCs and/or Macs via SOAP. The server is a Java web app. Customers will be choosing their platform (Windows or Mac) based on what the client app runs on, so my options are wide-open here. However, I will be developing on a Mac and have a strong allergy to MS-specific technologies (sorry). The app will not need to run on any non-desktop-computer devices and I have total freedom to say it will support X but not Y or Z without any negative consequences (quite the luxury, to be sure). I have a lot of experience in server-side development but very little in desktop GUI stuff, and am evaluating my options on the client - basically what do I want to commit to learning over the next 6+ months. I have server-side Java experience as well as a brief dabble in iPhone development, which went OK. Overall I'm looking for: Ease of learning & development IDE support Healthy surrounding ecosystem (libraries, tools, help, etc.) Quality documentation My options as I see them, in rough order of how I'm currently mentally ranking them: Java Swing Cocoa Java SWT JavaFX Adobe AIR XULRunner Am I leaving anything out?

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  • How should I parse this simple text file in Java?

    - by Winston
    I have a text file that looks like this: grn129 agri- ac-214 ahss hud114 ahss lov1150 ahss lov1160 ahss lov1170 ahss lov1210 ahss What is the best way to parse this file using Java if I want to create a HashMap with the first column as the key and the second column as the value. Should I use the Scanner class? Try to read in the whole file as a string and split it? What is the best way?

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  • Error in connection in ruby.

    - by piemesons
    require 'rubygems' require 'mysql' db = Mysql.connect('localhost', 'root', '', 'mohit') //db.rb:4: undefined method `connect' for Mysql:Class (NoMethodError) //undefined method `real_connect' for Mysql:Class (NoMethodError) db.query("CREATE TABLE people ( id integer primary key, name varchar(50), age integer)") db.query("INSERT INTO people (name, age) VALUES('Chris', 25)") begin query = db.query('SELECT * FROM people') puts "There were #{query.num_rows} rows returned" query.each_hash do |h| puts h.inspect end rescue puts db.errno puts db.error end error i am geting is: undefined method `connect' for Mysql:Class (NoMethodError) OR undefined method `real_connect' for Mysql:Class (NoMethodError) EDIT return value of Mysql.methods ["private_class_method", "inspect", "name", "tap", "clone", "public_methods", "object_id", "__send__", "method_defined?", "instance_variable_defined?", "equal?", "freeze", "extend", "send", "const_defined?", "methods", "ancestors", "module_eval", "instance_method", "hash", "autoload?", "dup", "to_enum", "instance_methods", "public_method_defined?", "instance_variables", "class_variable_defined?", "eql?", "constants", "id", "instance_eval", "singleton_methods", "module_exec", "const_missing", "taint", "instance_variable_get", "frozen?", "enum_for", "private_method_defined?", "public_instance_methods", "display", "instance_of?", "superclass", "method", "to_a", "included_modules", "const_get", "instance_exec", "type", "<", "protected_methods", "<=>", "class_eval", "==", "class_variables", ">", "===", "instance_variable_set", "protected_instance_methods", "protected_method_defined?", "respond_to?", "kind_of?", ">=", "public_class_method", "to_s", "<=", "const_set", "allocate", "class", "new", "private_methods", "=~", "tainted?", "__id__", "class_exec", "autoload", "untaint", "nil?", "private_instance_methods", "include?", "is_a?"] return value of Mysql.methods(false) is []... blank array

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