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• MYSQL JOIN WHERE ISSUES - need some kind of if condition

  - by Breezer

  Hi Well this will be hard to explain but ill do my best The thing is i have 4 tables all with a specific column to relate to eachother. 1 table with users(agent_users) , 1 with working hours(agent_pers), 1 with sold items(agent_stat),1 with project(agent_pro) the user and the project table is irrelevant in the issue at hand but to give you a better understanding why certain tables is included in my query i decided to still mention them =) The thing is that I use 2 pages to insert data to the working hour and the sold items during that time tables, then i have a third page to summarize everything for current month, the query for that is as following: SELECT *, SUM(sv_p_kom),SUM(sv_p_gick),SUM(sv_p_lunch) FROM (( agent_users LEFT JOIN agent_pers ON agent_users.sv_aid = agent_pers.sv_p_uid) LEFT JOIN agent_stat ON agent_pers.sv_p_uid = agent_stat.sv_s_uid) LEFT JOIN agent_pro ON agent_pers.sv_p_pid=agent_pro.p_id WHERE MONTH(agent_pers.sv_p_datum) =7 GROUP BY sv_aname so the problem is now that i dont want sold items from previous months to get included in the data received, i know i could solve that by simple adding in the WHERE part MONTH(agent_stat.sv_s_datum) =7 but then if no items been sold that month no data at all will show up not the time or anything. Any aid on how i could solve this is greatly appreciated. if there's something that's not so clear dont hesitate to ask and ill try my best to answer. after all my english isn't the best out there :P regards breezer

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• Am I going the right way to make login system secure with this simple password salting?

  - by LoVeSmItH

  I have two fields in login table password salt And I have this little function to generate salt function random_salt($h_algo="sha512"){ $salt1=uniqid(rand(),TRUE); $salt2=date("YmdHis").microtime(true); if(function_exists('dechex')){ $salt2=dechex($salt2); } $salt3=$_SERVER['REMOTE_ADDR']; $salt=$salt1.$salt2.$salt3; if(function_exists('hash')){ $hash=(in_array($h_algo,hash_algos()))?$h_algo:"sha512"; $randomsalt=hash($hash,md5($salt)); //returns 128 character long hash if sha512 algorithm is used. }else{ $randomsalt=sha1(md5($salt)); //returns 40 characters long hash } return $randomsalt; } Now to create user password I have following $userinput=$_POST["password"] //don't bother about escaping, i have done it in my real project. $static_salt="THIS-3434-95456-IS-RANDOM-27883478274-SALT"; //some static hard to predict secret salt. $salt=random_salt(); //generates 128 character long hash. $password =sha1($salt.$userinput.$static_salt); $salt is saved in salt field of database and $password is saved in password field. My problem, In function random_salt(), I m having this FEELING that I'm just making things complicated while this may not generate secure salt as it should. Can someone throw me a light whether I m going in a right direction? P.S. I do have an idea about crypt functions and like such. Just want to know is my code okay? Thanks.

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• Is there a definitive reference document for Ruby syntax?

  - by JSW

  I'm searching for a definitive document on Ruby syntax. I know about the definitive documents for the core API and standard library, but what about the syntax itself? For instance, such a document should cover: reserved words, string literals syntax, naming rules for variables/classes/modules, all the conditional statements and their permutations, and so forth. I know there are many books and tutorials, yes, but every one of them is essentially a tutorial, each one having a range of different depth and focus. They will all, by necessity of brevity and narrative flow, omit certain details of the language that the author deems insignificant. For instance, did you know that you can use a case statement without an initial case value, and it will then execute the first true when clause? Any given Ruby book or tutorial may or may not cover that particular lesser-known functionality of the case syntax. It's not discussed in the section in "Programming Ruby" about case statements. But that is just one small example. So far the best documentation I've found is the rubyspec project, which appears to be an attempt to write a complete test suite for the language. That's not bad, but it's a bit hard to use from a practical standpoint as a developer working on my own projects. Am I just missing something or is there really no definitive readable document defining the whole of Ruby syntax?

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• How slow are bit fields in C++

  - by Shane MacLaughlin

  I have a C++ application that includes a number of structures with manually controlled bit fields, something like #define FLAG1 0x0001 #define FLAG2 0x0002 #define FLAG3 0x0004 class MyClass { ' ' unsigned Flags; int IsFlag1Set() { return Flags & FLAG1; } void SetFlag1Set() { Flags |= FLAG1; } void ResetFlag1() { Flags &= 0xffffffff ^ FLAG1; } ' ' }; For obvious reasons I'd like to change this to use bit fields, something like class MyClass { ' ' struct Flags { unsigned Flag1:1; unsigned Flag2:1; unsigned Flag3:1; }; ' ' }; The one concern I have with making this switch is that I've come across a number of references on this site stating how slow bit fields are in C++. My assumption is that they are still faster than the manual code shown above, but is there any hard reference material covering the speed implications of using bit fields on various platforms, specifically 32bit and 64bit windows. The application deals with huge amounts of data in memory and must be both fast and memory efficient, which could well be why it was written this way in the first place.

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• Big-O for calculating all routes from GPS data

  - by HH

  A non-critical GPS module use lists because it needs to be modifiable, new routes added, new distances calculated, continuos comparisons. Well so I thought but my team member wrote something I am very hard to get into. His pseudo code int k =0; a[][] <- create mapModuleNearbyDotList -array //CPU O(n) for(j = 1 to n) // O(nlog(m)) for(i =1 to n) for(k = 1 to n) if(dot is nearby) adj[i][j]=min(adj[i][j], adj[i][k] + adj[k][j]); His ideas transformations of lists to tables His worst case time complexity is O(n^3), where n is number of elements in his so-called table. Exception to the last point with Finite structure: O(mlog(n)) where n is number of vertices and m is the amount of neighbour vertices. Questions about his ideas why to waste resources to transform constantly-modified lists to table? Fast? only point where I to some extent agree but cannot understand the same upper limits n for each for-loops -- perhaps he supposed it circular why does the code take O(mlog(n)) to proceed in time as finite structure? The term finite may be wrong, explicit?

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• How to make a calculator in PHP?

  - by Giulio Muscarello

  I want to use PHP to calculate simple algebraic expressions like, 8*(5+1), entered via an <input> tag by a normal user (which means, normal notation: no syntax changes like Multiply(8, Add(5, 1))). Also, it has to show all steps, but that's not hard. The problem, right now, is calculating the value of the expressions. Note: this is what I thought so far, which is quite inefficient but it's a provisory solution. Just replace strings where possible: in our example, recognize the string 5+1 and replace it with 6. Then, loop again, replace (6) with 6, loop again, and replace 8*6 with 48. The code for multiplying, for example, should look like this: for ($a=1; $a < 1000; $a++) { for ($b=1; $b < 1000; $b++) { string_replace($a . '*' . $b, $a*$b, $string); } }

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• How to implement a network protocol?

  - by gotch4

  Here is a generic question. I'm not in search of the best answer, I'd just like you to express your favourite practices. I want to implement a network protocol in Java (but this is a rather general question, I faced the same issues in C++), this is not the first time, as I have done this before. But I think I am missing a good way to implement it. In fact usually it's all about exchanging text messages and some byte buffers between hosts, storing the status and wait until the next message comes. The problem is that I usually end up with a bunch of switch and more or less complex if statements that react to different statuses / messages. The whole thing usually gets complicated and hard to mantain. Not to mention that sometimes what comes out has some "blind spot", I mean statuses of the protocol that have not been covered and that behave in a unpredictable way. I tried to write down some state machine classes, that take care of checking start and end statuses for each action in more or less smart ways. This makes programming the protocol very complicated as I have to write lines and lines of code to cover every possible situation. What I'd like is something like a good pattern, or a best practice that is used in programming complex protocols, easy to mantain and to extend and very readable. What are your suggestions?

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• Servlet Security question about j_security_check, j_username and j_password

  - by Nitesh Panchal

  Hello, I used jdbcRealm in my web application and it's working fine. I defined all constraints also in my web.xml. Like all pages of url pattern /Admin/* should be accessed by only admin. I have a login form with uses standard j_security_check, j_username and j_password. Now, when i type Admin/home.jsf it rightly redirects me login.jsf and there when i type the password i am redirected to home.jsf. This works alright but problem comes i directly go to login.jsf and then type password and username. This time it again redirects me to login.jsf. Is there any way through which i can specify which page to go when successful login is there? I need to specify different different pages for different roles. For Admin, it is /Admin/home.jsf for general users it is /General/home.jsf because login form is shared between different type of users. Where do i specify all these things? Secondly, i want to have a remember me checkbox at the end of login form. How do i do this? By default, it is submitted to j_security_check servlet and i have no control over its execution. Please help. This doesn't seem so hard but looks like i am missing something.

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• strcmp() but with 0-9 AFTER A-Z? (C/C++)

  - by Aaron

  For reasons I completely disagree with but "The Powers (of Anti-Usability) That Be" continue to decree despite my objections, I have a sorting routine which does basic strcmp() compares to sort by its name. It works great; it's hard to get that one wrong. However, at the 11th hour, it's been decided that entries which begin with a number should come AFTER entries which begin with a letter, contrary to the ASCII ordering. They cite the EBCDIC standard has numbers following letters so the prior assumption isn't a universal truth, and I have no power to win this argument... but I digress. Therein lies my problem. I've replaced all appropriate references to strcmp with a new function call nonstd_strcmp, and now need to implement the modifications to accomplish the sort change. I've used a FreeBSD source as my base: http://freebsd.active-venture.com/FreeBSD-srctree/newsrc/libkern/strncmp.c.html if (n == 0) return (0); do { if (*s1 != *s2++) return (*(const unsigned char *)s1 - *(const unsigned char *)(s2 - 1)); if (*s1++ == 0) break; } while (--n != 0); return (0); I guess I might need to take some time away to really think about how it should be done, but I'm sure I'm not the only one who's experienced the brain-deadness of just-before-release spec changes.

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• Perl, strings, floats, unit testing and regexps!

  - by Chris R

  OK, as a preface this question potentially is 'stupider' than my normal level of question - however this problem has been annoying me for the last few days so I'll ask it anyway. I'll give a mock example of what my problem is so I can hope to generalize it to my current problem. #!/usr/bin/perl -w use strict; use Test::More 'no_plan'; my $fruit_string = 'Apples cost $1.50'; my ($fruit, $price) = $fruit_string =~ /(\w+)s cost \$(\d+\.\d+)/; # $price += 0; # Uncomment for Great Success is ($price, 1.50, 'Great Success'); Now when this is run I get the message # Failed test 'Great Success' # got: '1.50' # expected: '1.5' To make the test work - I either uncomment the commented line, or use is ($price, '1.50', 'Great Success'). Both options do not work for me - I'm testing a huge amount of nested data using Test::Deep and cmp_deeply. My question is, how can you extract a double from a regexp then use it immediately as a double - or if there is a better way altogether let me know - and feel free to tell me to take up gardening or something lol, learning Perl is hard.

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• How to learn a C++ GUI library effectively?

  - by Chan

  Hello everyone, I have many options for GUI in my head while searching in stackoverflow, but these are what I chose among others: Qt gtkmm GTK+ I used GTK+ couple years ago, and I felt so painful when using C API without string object and containers. I prefer C++ style, I then switched to C++ gtkmm, but the documentation was bad at that time. I found no help when encountering an issue. Now I want to give a hard try for Qt4, but I really want to know how to learn a GUI librarie effectively. With core C++, I usually pick up a problem and try to solve it in different ways using that particular technique, functionality. On the other hand, after skimming through the documentation from Qt site, I don't think this way of studying is applicable, since the GUI classes and APIs are so much bigger. Plus I'm still in school, so I won't have much time to play all the day long with it. How do you guys learn GUI before? Can anyone share some experiences how they learn thing, that would be an invaluable input for me! Best regards, Chan Nguyen

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• Combining two-part SQL query into one query

  - by user332523

  Hello, I have a SQL query that I'm currently solving by doing two queries. I am wondering if there is a way to do it in a single query that makes it more efficient. Consider two tables: Transaction_Entries table and Transactions, each one defined below: Transactions - id - reference_number (varchar) Transaction_Entries - id - account_id - transaction_id (references Transactions table) Notes: There are multiple transaction entries per transaction. Some transactions are related, and will have the same reference_number string. To get all transaction entries for Account X, then I would do SELECT E.*, T.reference_number FROM Transaction_Entries E JOIN Transactions T ON (E.transaction_id=T.id) where E.account_id = X The next part is the hard part. I want to find all related transactions, regardless of the account id. First I make a list of all the unique reference numbers I found in the previous result set. Then for each one, I can query all the transactions that have that reference number. Assume that I hold all the rows from the previous query in PreviousResultSet UniqueReferenceNumbers = GetUniqueReferenceNumbers(PreviousResultSet) // in Java foreach R in UniqueReferenceNumbers // in Java SELECT * FROM Transaction_Entries where transaction_id IN (SELECT * FROM Transactions WHERE reference_number=R Any suggestions how I can put this into a single efficient query?

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• How to link different Servlet together?

  - by Harry Pham

  First of all, I did not use Spring MVC. :) :) Just want to get it out first. Now what I have is different JSP pages that making calls to different Servlets. All the pieces work great individually but I kind of need to link them together. If all of jsp pages make GET request then it would be easy, since I would just pass a type via the web address, and on my servlet side, I would just enumerated through all the parameter, determine which type is it, and delegate to the right servlet. But not all jsp pages make GET request, some make POST request via form. Let see example A.jsp $.getJSON('GenericServlet?type=A', ... GenericServlet.java String type = request.getParameter("type"); if(type.equals("A")){ //Somehow delegate to Servlet A (Not sure how to do that yet :)) } but in B.jsp I would have something like this B.jsp <form action="GenericServlet" method="post"> <table border=0 cellspacing=10 cellpadding=0> <tr> <td>User Name:</td> <td><input type="text" name="username" size=22/></td> </tr> <tr> <td>Password:</td> <td><input type="password" name="password" size=22/></td> </tr> </table> <input type="submit" value="Create User" /> </form> It kind of hard for me to determine in GenericServlet.java that this need to go to servletB

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• How to create view model without sorting collections in memory.

  - by Chevex

  I have a view model (below). public class TopicsViewModel { public Topic Topic { get; set; } public Reply LastReply { get; set; } } I want to populate an IQueryable<TopicsViewModel> with values from my IQueryable<Topic> collection and IQueryable<Reply> collection. I do not want to use the attached entity collection (i.e. Topic.Replies) because I only want the last reply for that topic and doing Topic.Replies.Last() loads the entire entity collection in memory and then grabs the last one in the list. I am trying to stay in IQueryable so that the query is executed in the database. I also don't want to foreach through topics and query replyRepository.Replies because looping through IQueryable<Topic> will start the lazy loading. I'd prefer to build one expression and have all the leg work done in the lower layers. I have the following: IQueryable<TopicsViewModel> topicsViewModel = from x in topicRepository.Topics from y in replyRepository.Replies where y.TopicID == x.TopicID orderby y.PostedDate ascending select new TopicsViewModel { Topic = x, LastReply = y }; But this isn't working. Any ideas how I can populate an IQueryable or IEnumerable of TopicsViewModel so that it queries the database and grabs topics and that topic's last reply? I am trying really hard to avoid grabbing all replies related to that topic. I only want to grab the last reply. Thank you for any insight you have to offer.

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• Need a better way to execute console commands from python and log the results

  - by Wim Coenen

  I have a python script which needs to execute several command line utilities. The stdout output is sometimes used for further processing. In all cases, I want to log the results and raise an exception if an error is detected. I use the following function to achieve this: def execute(cmd, logsink): logsink.log("executing: %s\n" % cmd) popen_obj = subprocess.Popen(\ cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) (stdout, stderr) = popen_obj.communicate() returncode = popen_obj.returncode if (returncode <> 0): logsink.log(" RETURN CODE: %s\n" % str(returncode)) if (len(stdout.strip()) > 0): logsink.log(" STDOUT:\n%s\n" % stdout) if (len(stderr.strip()) > 0): logsink.log(" STDERR:\n%s\n" % stderr) if (returncode <> 0): raise Exception, "execute failed with error output:\n%s" % stderr return stdout "logsink" can be any python object with a log method. I typically use this to forward the logging data to a specific file, or echo it to the console, or both, or something else... This works pretty good, except for three problems where I need more fine-grained control than the communicate() method provides: stdout and stderr output can be interleaved on the console, but the above function logs them separately. This can complicate the interpretation of the log. How do I log stdout and stderr lines interleaved, in the same order as they were output? The above function will only log the command output once the command has completed. This complicates diagnosis of issues when commands get stuck in an infinite loop or take a very long time for some other reason. How do I get the log in real-time, while the command is still executing? If the logs are large, it can get hard to interpret which command generated which output. Is there a way to prefix each line with something (e.g. the first word of the cmd string followed by :).

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• OnConnect event not firing when using TClientSocket inside a TThread on non-blocking mode

  - by mathematician1975

  I am trying to make use of Borlands TClientSocket component in non-blocking mode inside a multithreaded C++ Windows application. I am creating multiple threads (classes derived from TThread), each of which creates its own TClientSocket object. I then assign member functions of the thread class to act as event handlers for the OnConnect, OnDisconnect and OnSocketError events of the socket. The problem I am having here is that whenever I call the TClientSocket::Open() function from within the TThread::Execute() function, the OnConnect event never fires. However, When I call the Open() function from the VCL thread prior to the TThread::Execute() function getting called, all of the events fire and I can use the thread-socket combination as I would like. Now I have not read anything in documentation that says that TClientSocket should not be used in non-blocking mode when used inside a thread, but it appears to me that there is perhaps something wrong conceptually in the way I am trying to use this class. Borland documentation is quite poor on the subject and these components have now been deprecated so reliable information is hard to come by. Despite being deprecated I have to use them as there is no alternative in the Builder 6 package I have. Can anyone please advise me if there is a right/wrong way to use TThread and a non-blocking TClientSocket in combination. I have never had problems using it as part of the VCL thread and never had problems using TServerSocket before and I really cannot understand why some events are not firing.

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• Wrapping text and div as a unit

  - by mathee

  I have the following that I would like wrapped as units. <div class='tag-box'> <a href=#>Axe Committee</a> <div class='circle'><a href=#>x</a></div> </div> The CSS for these classes are: .tag-box { display:inline; } .circle { display:inline; padding-left:4px; padding-right:4px; background:rgb(196,15,24); /*dark red*/ -moz-border-radius:10px; -webkit-border-radius:10px; } .circle a { font-size:10px; text-decoration:none; color:#fff; position:relative; top:-2px; } I can have upwards of 20 or 30 of these tag-boxes displayed inline. The problem is that the wrapping will break the words from each other or even break the red circle from the link. This makes it hard to differentiate which circle belongs to which link. (In the future, each circle corresponds to a different action with respect to the link.) See below. How do I prevent this kind of wrapping from occurring?

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• How can I change the tags/css class of some dynamic text based on output from a helper?

  - by Angela

  I have a repeated line which outputs something like: Call John Jones in -3 days (status) I have a helper called show_status(contact,email) which will output whether that particular email had been sent to that particular contact. If it is "sent," then that entire line should show up as "strike out." Similarly, if the number of days is -3 (<0), the line should be formatted in red. Here's my hack, but there must be a cleaner way to put the logic into the controller? I hard-code a value that wraps around the lines I want formatted, and assign the value based on a separate call to the same helper: <% for call in @campaign.calls %> <% if !show_call_status(@contact,call).blank? %> <%= strike_start = '<s>'%> <%= strike_end = '</s>' %> <% end %> <p> <%= strike_start %> <%= link_to call.title, call_path(call) %> on <%= (@contact.date_entered + call.days).to_s(:long) %> in <%= interval_email(@contact,call) %> days <%= make_call(@contact,call) %> <span class='status'><%= show_call_status(@contact,call) %></span> <%= strike_end %> </p> <% end %> I guess what I'd like to do is not have the if statement in the View. Not sure how to do this.

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• Handling close-to-impossible collisions on should-be-unique values

  - by balpha

  There are many systems that depend on the uniqueness of some particular value. Anything that uses GUIDs comes to mind (eg. the Windows registry or other databases), but also things that create a hash from an object to identify it and thus need this hash to be unique. A hash table usually doesn't mind if two objects have the same hash because the hashing is just used to break down the objects into categories, so that on lookup, not all objects in the table, but only those objects in the same category (bucket) have to be compared for identity to the searched object. Other implementations however (seem to) depend on the uniqueness. My example (that's what lead me to asking this) is Mercurial's revision IDs. An entry on the Mercurial mailing list correctly states The odds of the changeset hash colliding by accident in your first billion commits is basically zero. But we will notice if it happens. And you'll get to be famous as the guy who broke SHA1 by accident. But even the tiniest probability doesn't mean impossible. Now, I don't want an explanation of why it's totally okay to rely on the uniqueness (this has been discussed here for example). This is very clear to me. Rather, I'd like to know (maybe by means of examples from your own work): Are there any best practices as to covering these improbable cases anyway? Should they be ignored, because it's more likely that particularly strong solar winds lead to faulty hard disk reads? Should they at least be tested for, if only to fail with a "I give up, you have done the impossible" message to the user? Or should even these cases get handled gracefully? For me, especially the following are interesting, although they are somewhat touchy-feely: If you don't handle these cases, what do you do against gut feelings that don't listen to probabilities? If you do handle them, how do you justify this work (to yourself and others), considering there are more probable cases you don't handle, like a supernonva?

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• Is there a table of OpenGL extensions, versions, and hardware support somewhere?

  - by Thomas

  I'm looking for some resource that can help me decide what OpenGL version my game needs at minimum, and what features to support through extensions. Ideally, a table of the following format: 1.0 1.1 1.2 1.2.1 1.3 ... multitexture - ARB ARB core core texture_float - EXT EXT ARB ARB ... (Not sure about the values I put in, but you get the idea.) The extension specs themselves, at opengl.org, list the minimum OpenGL version they need, so that part is easy. However, many extensions have been accepted and became core standard in subsequent OpenGL versions, but it is very hard to find when that happened. The only way I could find is to compare the full OpenGL standards document for each version. On a related note, I would also very much like to know which extensions/features are supported by which hardware, to help me decide what features I can safely use in my game, and which ones I need to make optional. For example, a big honkin' table like this: MAX_TEXTURE_IMAGE_UNITS MAX_VERTEX_TEXTURE_IMAGE_UNITS ... GeForce 6xxx 8 4 GeForce 7xxx 16 8 ATi x300 8 4 ... (Again, I'm making the values up.) The table could list hardware limitations from glGet but also support for particular extensions, and limitations of such extension support (e.g. what floating-point texture formats are supported in hardware). Any pointers to these or similar resources would be hugely appreciated!

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• How do you use stl's functions like for_each?

  - by thomas-gies

  I started using stl containers because they came in very handy when I needed functionality of a list, set and map and had nothing else available in my programming environment. I did not care much about the ideas behind it. STL documentations were only interesting up to the point where it came to functions, etc. Then I skipped reading and just used the containers. But yesterday, still being relaxed from my holidays, I just gave it a try and wanted to go a bit more the stl way. So I used the transform function (can I have a little bit of applause for me, thank you). From an academic point of view it really looked interesting and it worked. But the thing that boroughs me is that if you intensify the use of those functions, you need 10ks of helper classes for mostly everything you want to do in your code. The hole logic of the program is sliced in tiny pieces. This slicing is not the result of god coding habits. It's just a technical need. Something, that makes my life probably harder not easier. And I learned the hard way, that you should always choose the simplest approach that solves the problem at hand. And I can't see what, for example, the for_each function is doing for me that justifies the use of a helper class over several simple lines of code that sit inside a normal loop so that everybody can see what is going on. I would like to know, what you are thinking about my concerns? Did you see it like I do when you started working this way and have changed your mind when you got used to it? Are there benefits that I overlooked? Or do you just ignore this stuff as I did (and will go an doing it, probably). Thanks. PS: I know that there is a real for_each loop in boost. But I ignore it here since it is just a convenient way for my usual loops with iterators I guess.

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• How to refresh/redraw the screen (not the program window)

  - by mohrphium

  I'm having a bit of a hard time figuring out, how to remove a drawn ellipse after it has been drawn somewhere else. I need a circle to follow my mouse all the time and this is all the program should do. I get the mousepositions and draw my circle but how can I remove the last one? #include <Windows.h> #include <iostream> void drawRect(int a1, int a2){ HDC screenDC = ::GetDC(0); //Draw circle at mouse position ::Ellipse(screenDC, a1, a2+5, a1+9, a2+14); ::ReleaseDC(0, screenDC); //::InvalidateRect(0, NULL, TRUE); //<- I tried that but then everything flickers //Also, the refresh rate is not fast enough... still some circles left } int main(void) { int a1; int a2; bool exit=false; while (exit!=true) { POINT cursorPos; GetCursorPos(&cursorPos); float x = 0; x = cursorPos.x; float y = 0; y = cursorPos.y; a1=(int)cursorPos.x; a2=(int)cursorPos.y; drawRect(a1, a2); } } I am working with graphics and all that stuff for the first time. Im kinda stuck here... once again. Thanks.

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• How would I instruct extconf.rb to use additional g++ optimization flags, and which are advisable?

  - by mohawkjohn

  I'm using Rice to write a C++ extension for a Ruby gem. The extension is in the form of a shared object (.so) file. This requires 'mkmf-rice' instead of 'mkmf', but the two (AFAIK) are pretty similar. By default, the compiler uses the flags -g -O2. Personally, I find this kind of silly, since it's hard to debug with any optimization enabled. I've resorted to editing the Makefile to take out the flags I don't like (e.g., removing -fPIC -shared when I need to debug using main() instead of Ruby's hooks). But I figure there's got to be a better way. I know I can just do $CPPFLAGS += " -DRICE" to add additional flags. But how do I remove things without editing the Makefile directly? A secondary question: what optimizations are safe for shared objects loaded by Ruby? Can I do things like -funroll-loops? What do you all recommend? It's a scientific computing project, so the faster the better. Memory is not much of an issue. Many thanks!

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• Java queue and multi-dimention array question? [Beginner level]

  - by javaLearner.java

  First of all, this is my code (just started learning java): Queue<String> qe = new LinkedList<String>(); qe.add("b"); qe.add("a"); qe.add("c"); qe.add("d"); qe.add("e"); My question: Is it possible to add element to the queue with two values, like: qe.add("a","1"); // where 1 is integer So, that I know element "a" have value 1. If I want to add a number let say "2" to element a, I will have like a = 3. If this cant be done, what else in java classes that can handle this? I tried to use multi-dimention array, but its kinda hard to do the queue, like pop, push etc. (Maybe I am wrong) How to call specific element in the queue? Like, call element a, to check its value. [Note] Please don't give me links that ask me to read java docs. I was reading, and I still dont get it. The reason why I ask here is because, I know I can find the answer faster and easier.

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• C# Retrieving Data From XML File

  - by Christopher MacKinnon

  I seem to be having a problem with retrieving XML values with C#, which I know it is due to my very limited knowledge of C# and .XML. I was given the following XML file <PowerBuilderRunTimes> <PowerBuilderRunTime> <Version>12</Version> <Files> <File>EasySoap110.dll</File> <File>exPat110.dll</File> <File>pbacc110.dll</File> </File> </PowerBuilderRunTime> </PowerBuilderRunTimes> I am to process the XML file and make sure that each of the files in the exist in the folder (that's the easy part). It's the processing of the XML file that I have having a hard time with. Here is what I have done thus far: var runtimeXml = File.ReadAllText(string.Format("{0}\\{1}", configPath, Resource.PBRuntimes)); var doc = XDocument.Parse(runtimeXml); var topElement = doc.Element("PowerBuilderRunTimes"); var elements = topElement.Elements("PowerBuilderRunTime"); foreach (XElement section in elements) { //pbVersion is grabbed earlier. It is the version of PowerBuilder if( section.Element("Version").Value.Equals(string.Format("{0}", pbVersion ) ) ) { var files = section.Elements("Files"); var fileList = new List<string>(); foreach (XElement area in files) { fileList.Add(area.Element("File").Value); } } } My issue is that the String List is only ever populated with one value, "EasySoap110.dll", and everything else is ignored. Can someone please help me, as I am at a loss.

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