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• How can I get all content within <table></table> tags using a regex?

  - by Bob Dylan

  So I'm writing an application that will do a little screen scrapping. All the pages (about 1000 or so) contain this line: <table border="0" cellspacing="3"> <tr><td>First rows stuff</td></tr> <tr> <td> The data I want is in here <br /> and it's seperated by these annoying <br /> 's. No id's, classes, or even a single <p> tag. Just a bunch of <br /> tags. </td> </tr> </table> So I just need to get the data within the 2nd row out. How can I do this? Should I use a regex or something else?

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• How to have multiple instances of jQuery plugin on single page?

  - by James Skidmore

  I'm writing a simple jQuery plugin, but I'm having trouble being able to use multiple instances on a page. For instance, here is a sample plugin to illustrate my point: (function($) { $.fn.samplePlugin = function(options) { if (typeof foo != 'undefined') { alert('Already defined!'); } else { var foo = 'bar'; } }; })(jQuery); And then if I do this: $(document).ready(function(){ $('#myDiv').samplePlugin({}); // does nothing $('#myDiv2').samplePlugion({}); // alerts "Already defined!" }); This is obviously an over-simplified example to get across the point. So my question is, how do I have two separate instances of the plugin? I'd like to be able to use it across multiple instances on the same page. I'm guessing that part of the problem might be with defining the variables in a global scope. How can I define them unique to that instance of the plugin then? Thank you for your guidance!

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• Insert data in an object to a database.

  - by paul

  I am facing the following design/implementation dilemma. I have a class Customer which is below with getters and setters. I would like to insert the value of the Customer into a "Customer" table of a database. But Customer has an address which is of type "Address". How do I go about inserting this field into the database?(I am using sqlite3). I thought of writing a separate table "Address(customerId,doorNo,city,state,country,pinCode)". But I am having second thoughts about generating the primary key(customerId) which should be same for both the "customer" and "Address" table. Sqlite3 faq states that I can do "Integer Primary Key" to use the field to generate an auto number. But if I do that in customer table, I would have to retrieve the same Id to be used in Address table. This kinda looks wrong to me :-?. There should be an elegant method to solve this. Any ideas would be much appreciated. Thanks in advance. import java.io.*; import java.sql.*; class Customer { private String id; private String name; private Address address; private Connection connection; private ResultSet resultSet; private PreparedStatement preparedStatement; public void insertToDatabase(){ } } class Address{ private String doorNumber; private String streetName; private String cityName; private String districtName; private String stateName; private String countryName; private long pinCode; }

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• Exception error in Erlang

  - by Jim

  So I've been using Erlang for the last eight hours, and I've spent two of those banging my head against the keyboard trying to figure out the exception error my console keeps returning. I'm writing a dice program to learn erlang. I want it to be able to call from the console through the erlang interpreter. The program accepts a number of dice, and is supposed to generate a list of values. Each value is supposed to be between one and six. I won't bore you with the dozens of individual micro-changes I made to try and fix the problem (random engineering) but I'll post my code and the error. The Source: -module(dice2). -export([d6/1]). d6(1) - random:uniform(6); d6(Numdice) - Result = [], d6(Numdice, [Result]). d6(0, [Finalresult]) - {ok, [Finalresult]}; d6(Numdice, [Result]) - d6(Numdice - 1, [random:uniform(6) | Result]). When I run the program from my console like so... dice2:d6(1). ...I get a random number between one and six like expected. However when I run the same function with any number higher than one as an argument I get the following exception... **exception error: no function clause matching dice2:d6(1, [4|3]) ... I know I I don't have a function with matching arguments but I don't know how to write a function with variable arguments, and a variable number of arguments. I tried modifying the function in question like so.... d6(Numdice, [Result]) - Newresult = [random:uniform(6) | Result], d6(Numdice - 1, Newresult). ... but I got essentially the same error. Anyone know what is going on here?

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• How to encrypt/decrypt a file in Java?

  - by Petike

  Hello, I am writing a Java application which can "encrypt" and consequently "decrypt" whatever binary file. I am just a beginner in the "cryptography" area so I would like to write a very simple application for the beginning. For reading the original file, I would probably use the java.io.FileInputStream class to get the "array of bytes" byte originalBytes[] of the file. Then I would probably use some very simple cipher, for example "shift up every byte by 1" and then I would get the "encrypted" bytes byte encryptedBytes[] and let's say that I would also set a "password" for it, for example "123456789". Next, when somebody wants to "decrypt" that file, he has to enter the password ("123456789") first and after that the file could be decrypted (thus "shift down every byte by 1") and consequently saved to the output file via java.io.FileOutputStream I am just wondering how to "store" the password information to the encrypted file so that the decrypting application knows if the entered password and the "real" password equals? Probably it would be silly to add the password (for example the ASCII ordinal numbers of the password letters) to the beginning of the file (before the encrypted data). So my main question is how to store the password information to the encrypted file?

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• Why is JavaMail Transport.send() a static method?

  - by skiphoppy

  I'm revising code I did not write that uses JavaMail, and having a little trouble understanding why the JavaMail API is designed the way it is. I have the feeling that if I understood, I could be doing a better job. We call: transport = session.getTransport("smtp"); transport.connect(hostName, port, user, password); So why is Eclipse warning me that this: transport.send(message, message.getAllRecipients()); is a call to a static method? Why am I getting a Transport object and providing settings that are specific to it if I can't use that object to send the message? How does the Transport class even know what server and other settings to use to send the message? It's working fine, which is hard to believe. What if I had instantiated Transport objects for two different servers; how would it know which one to use? In the course of writing this question, I've discovered that I should really be calling: transport.sendMessage(message, message.getAllRecipients()); So what is the purpose of the static Transport.send() method? Is this just poor design, or is there a reason it is this way?

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• Write raw struct contents (bytes) to a file in C. Confused about actual size written

  - by d11wtq

  Basic question, but I expected this struct to occupy 13 bytes of space (1 for the char, 12 for the 3 unsigned ints). Instead, sizeof(ESPR_REL_HEADER) gives me 16 bytes. typedef struct { unsigned char version; unsigned int root_node_num; unsigned int node_size; unsigned int node_count; } ESPR_REL_HEADER; What I'm trying to do is initialize this struct with some values and write the data it contains (the raw bytes) to the start of a file, so that when I open this file I later I can reconstruct this struct and gain some meta data about what the rest of the file contains. I'm initializing the struct and writing it to the file like this: int esprime_write_btree_header(FILE * fp, unsigned int node_size) { ESPR_REL_HEADER header = { .version = 1, .root_node_num = 0, .node_size = node_size, .node_count = 1 }; return fwrite(&header, sizeof(ESPR_REL_HEADER), 1, fp); } Where node_size is currently 4 while I experiment. The file contains the following data after I write the struct to it: -bash$ hexdump test.dat 0000000 01 bf f9 8b 00 00 00 00 04 00 00 00 01 00 00 00 0000010 I expect it to actually contain: -bash$ hexdump test.dat 0000000 01 00 00 00 00 04 00 00 00 01 00 00 00 0000010 Excuse the newbiness. I am trying to learn :) How do I efficiently write just the data components of my struct to a file?

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• Common Lisp condition system for transfer of control

  - by Ken

  I'll admit right up front that the following is a pretty terrible description of what I want to do. Apologies in advance. Please ask questions to help me explain. :-) I've written ETLs in other languages that consist of individual operations that look something like: // in class CountOperation IEnumerable<Row> Execute(IEnumerable<Row> rows) { var count = 0; foreach (var row in rows) { row["record number"] = count++; yield return row; } } Then you string a number of these operations together, and call The Dispatcher, which is responsible for calling Operations and pushing data between them. I'm trying to do something similar in Common Lisp, and I want to use the same basic structure, i.e., each operation is defined like a normal function that inputs a list and outputs a list, but lazily. I can define-condition a condition (have-value) to use for yield-like behavior, and I can run it in a single loop, and it works great. I'm defining the operations the same way, looping through the inputs: (defun count-records (rows) (loop for count from 0 for row in rows do (signal 'have-value :value `(:count ,count @,row)))) The trouble is if I want to string together several operations, and run them. My first attempt at writing a dispatcher for these looks something like: (let ((next-op ...)) ;; pick an op from the set of all ops (loop (handler-bind ((have-value (...))) ;; records output from operation (setq next-op ...) ;; pick a new next-op (call next-op))) But restarts have only dynamic extent: each operation will have the same restart names. The restart isn't a Lisp object I can store, to store the state of a function: it's something you call by name (symbol) inside the handler block, not a continuation you can store for later use. Is it possible to do something like I want here? Or am I better off just making each operation function explicitly look at its input queue, and explicitly place values on the output queue?

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• parsing the output of the 'w' command?

  - by Blackbinary

  I'm writing a program which requires knowledge of the current load on the system, and the activity of any users (it's a load balancer). This is a university assignment, and I am required to use the w command. I'm having a hard time parsing this command because it is very verbose. Any suggestions on what I can do would be appreciated. This is a small part of the program, and I am free to use whatever method i like. The most condensed version of w which still has the information I require is `w -u -s -f' which produces this: 10:13:43 up 9:57, 2 users, load average: 0.00, 0.00, 0.00 USER TTY IDLE WHAT fsm tty7 22:44m x-session-manager fsm pts/0 0.00s w -u -s -f So out of that, I am interested in the first number after load average and the smallest idle time (so i will need to parse them all). My background process will call w, so the fact that w is the lowest idle time will not matter (all i will see is the tty time). Do you have any ideas? Thanks (I am allowed to use alternative unix commands, like grep, if that helps).

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• Multiple Inheritence with same Base Classes in Python

  - by Jordan Reiter

  I'm trying to wrap my head around multiple inheritance in python. Suppose I have the following base class: class Structure(object): def build(self, *args): print "I am building a structure!" self.components = args And let's say I have two classes that inherit from it: class House(Structure): def build(self, *args): print "I am building a house!" super(House, self).build(*args) class School(Structure): def build(self, type="Elementary", *args): print "I am building a school!" super(School, self).build(*args) Finally, a create a class that uses multiple inheritance: class SchoolHouse(School, House): def build(self, *args): print "I am building a schoolhouse!" super(School, self).build(*args) Then, I create a SchoolHouse object and run build on it: >>> sh = SchoolHouse() >>> sh.build("roof", "walls") I am building a schoolhouse! I am building a house! I am building a structure! So I'm wondering -- what happened to the School class? Is there any way to get Python to run both somehow? I'm wondering specifically because there are a fair number of Django packages out there that provide custom Managers for models. But there doesn't appear to be a way to combine them without writing one or the other of the Managers as inheriting from the other one. It'd be nice to just import both and use both somehow, but looks like it can't be done? Also I guess it'd just help to be pointed to a good primer on multiple inheritance in Python. I have done some work with Mixins before and really enjoy using them. I guess I just wonder if there is any elegant way to combine functionality from two different classes when they inherit from the same base class.

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• How can I perform this query between related tables without using UNION?

  - by jeremy

  Suppose I have two separate tables that I watch to query. Both of these tables has a relation with a third table. How can I query both tables with a single, non UNION based query? I want the result of the search to rank the results by comparing a field on each table. Here's a theoretical example. I have a User table. That User can have both CDs and books. I want to find all of that user's books and CDs with a single query matching a string ("awesome" in this example). A UNION based query might look like this: SELECT "book" AS model, name, ranking FROM book WHERE name LIKE 'Awesome%' UNION SELECT "cd" AS model, name, ranking FROM cd WHERE name LIKE 'Awesome%' ORDER BY ranking DESC How can I perform a query like this without the UNION? If I do a simple left join from User to Books and CDs, we end up with a total number of results equal to the number of matching cds timse the number of matching books. Is there a GROUP BY or some other way of writing the query to fix this?

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• What is different about C++ math.h abs() compared to my abs()

  - by moka

  I am currently writing some glsl like vector math classes in c++, and I just implemented an abs() function like this: template<class T> static inline T abs(T _a) { return _a < 0 ? -_a : _a; } I compared its speed to the default c++ abs from math.h like this: clock_t begin = clock(); for(int i=0; i<10000000; ++i) { float a = abs(-1.25); }; clock_t end = clock(); unsigned long time1 = (unsigned long)((float)(end-begin) / ((float)CLOCKS_PER_SEC/1000.0)); begin = clock(); for(int i=0; i<10000000; ++i) { float a = myMath::abs(-1.25); }; end = clock(); unsigned long time2 = (unsigned long)((float)(end-begin) / ((float)CLOCKS_PER_SEC/1000.0)); std::cout<<time1<<std::endl; std::cout<<time2<<std::endl; Now the default abs takes about 25ms while mine takes 60. I guess there is some low level optimisation going on. Does anybody know how math.h abs works internally? The performance difference is nothing dramatic, but I am just curious!

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• Using Subsonic 3.0 Advanced Templates

  - by umit

  Hi all, I've been trying to use Subsonic Advanced Templates in a project for a while but most of the time I find myself writing a Stored Procedure as I can't find a proper way of doing it in code. Subsonic created corresponding objects for my DB tables and for foreign keys it created IQueryable fields inside each object. These fields are not loaded by default and a new SQL query is executed when you access them. 1- Is there a way to get all data in one query (deep load)? Also these fields can not be assigned. So when I want to create an object in a maintenance page, I can't put all the data into this object before saving it in DB: Post post = new Post(); //get photos for this post IList<PostPhoto> postPhotos = GetPostPhotos(); post.PostPhotos = postPhotos; 2- Is it possible to have one Post object with all fields set from user input? Think of the Post object above and assume I've successfully assigned its fields. Now I need to save it to the DB. 3- Is using BatchQuery the only way to do it in one query? If I have 4 photos in PostPhotos field; 2 of them previously saved and 2 of them new, can I use the Update method to handle both the adding and updating of these photos? Any ideas or links are appreciated. Cheers...

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• forcing stack w/i 32bit when -m64 -mcmodel=small

  - by chaosless

  have C sources that must compile in 32bit and 64bit for multiple platforms. structure that takes the address of a buffer - need to fit address in a 32bit value. obviously where possible these structures will use natural sized void * or char * pointers. however for some parts an api specifies the size of these pointers as 32bit. on x86_64 linux with -m64 -mcmodel=small tboth static data and malloc()'d data fit within the 2Gb range. data on the stack, however, still starts in high memory. so given a small utility _to_32() such as: int _to_32( long l ) { int i = l & 0xffffffff; assert( i == l ); return i; } then: char *cp = malloc( 100 ); int a = _to_32( cp ); will work reliably, as would: static char buff[ 100 ]; int a = _to_32( buff ); but: char buff[ 100 ]; int a = _to_32( buff ); will fail the assert(). anyone have a solution for this without writing custom linker scripts? or any ideas how to arrange the linker section for stack data, would appear it is being put in this section in the linker script: .lbss : { *(.dynlbss) *(.lbss .lbss.* .gnu.linkonce.lb.*) *(LARGE_COMMON) } thanks!

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• Visual Studio - Edit source code located in a database

  - by mfeingold

  I am building something similar to Server Explorer for Apache CouchDB. One of the things necessary is to be able to edit CouchDB view definitions which in CouchDB are JavaScript functions. How can I trick Visual Studio into using my object to retrieve and save the content of the JavaScript function but still use the rest of it - I am happy with editor itself and have no intention of writing my own Editor/Language Service, etc. The latter would be much bigger effort than what this project warrants Edit After more digging I am still stuck. Here is what I know: IVsUIShellOpenDocument interface provides a method OpenStandardEditor which can be used to open the standard Visual Studio editor. As one of the parameters this method takes a Pointer to the IUnknown interface of the document data object. This object is supposed to implement several interfaces described in many places all over the MSDN. Visual Studio SDK also provides a 'sample' implementation of the document data object VsTextBufferClass. I can create an instance of this class and when I pass the pointer to the instance to the OpenStandardEditor I can see my editor and it seems to work ok. When I try to implement my own class implementing the same interfaces (IVsTextBuffer, VsTextBuffer, IVsTextLines) OpenStandardEditor method returns success, but VS bombs out on call editor.Show() with an access violation. My suspicion is that VsTextBufferClass also implements some other interface(s) but not in C# way but rather in the good old COM way. I just do not know which one(s). Any thoughts?

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• Widget host app with custom view - onClick is not triggered in the app widget.

  - by Dennis K

  I'm writing an app that will host widgets. The app has custom view (which probably is the source of issue). I obtain AppWidgetHostView like this private AppWidgetHostView widget; ... AppWidgetProviderInfo appWidgetInfo = mAppWidgetManager.getAppWidgetInfo(appWidgetId); widget = mAppWidgetHost.createView(this, appWidgetId, appWidgetInfo); widget.setAppWidget(appWidgetId, appWidgetInfo); mView.addWidget(widget, appWidgetInfo); mView.addWidget() basically just remembers this AppWidgetHostView instance and then draws it directly onto canvas. Visually everything is fine - I can see the actual widget. But the issue is with reacting on UI events. Please advise what needs to be done in the parent view in order to correctly trigger handlers in the widgets like onClick(). Notes: I used standard widgets which normally react on click events. None worked. I also created my own test widget with listener (via views.setOnClickPendingIntent(R.id.appwidget_text, pending);) and onClick() is successfully triggered if the widget is added on Homescreen, but doesn't work in my app. mView correctly detects click event and I tried to call widget.performClick() there, which returns false meaning onClickListener is not registered in the widget. But according to source mAppWidgetHost.createView() would call updateAppWidget which would register its onClick listener.. Please advise where to look at. Thanks

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• Syntax error beyond end of program

  - by a_m0d

  I am experimenting with writing a toy compiler in ocaml. Currently, I am trying to implement the offside rule for my lexer. However, I am having some trouble with the ocaml syntax (the compiler errors are extremely un-informative). The code below (33 lines of it) causes an error on line 34, beyond the end of the source code. I am unsure what is causing this error. open Printf let s = (Stack.create():int Stack.t); let rec check x = ( if Stack.is_empty s then Stack.push x s else if Stack.top s < x then ( Stack.push x s; printf "INDENT\n"; ) else if Stack.top s > x then ( printf "DEDENT\n"; Stack.pop s; check x; ) else printf "MATCHED\n"; ); let main () = ( check 0; check 4; check 6; check 8; check 5; ); let _ = Printexc.print main () Ocaml output: File "lexer.ml", line 34, characters 0-0: Error: Syntax error Can someone help me work out what the error is caused by and help me on my way to fixing it?

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• Where can a self-teacher learn general good programming habits and conventions?

  - by lucid

  A few mistakes and general childishness in early adulthood have left me in a situation where I work a menial job, with no possibility (in the near future) of attending school. I aspire to one day work in the programming field (gaming specifically), after proving myself on the indie end of things. I've gotten very confident in C++, java, and python, and I find I'm able to solve any problem I want either from previous experience, or from scouring the web for help. The solutions work, and with each attempt they become more readable, maintainable, and extensible. But this is because I'm learning from mistakes and bad programming and design habits I feel I might have avoided with actual schooling. General tips like: "if it's hard to read or getting long, or you're writing it twice, it should be in one or more functions." or "design all your classes before you start coding, so you don't have to rewrite classes later when you discover an unforeseen dependency" Is there a good book or website for learning general good programming practices and design habits? Also, naming and format conventions. I realize sometimes development houses have their own conventions, but things like "Classes in python usually have the first letter of each word capitalized". I'd like to be able to show some source code to a potential employer, and be prepared when for what's expected on a team. Is there some central database of naming and formatting conventions somewhere? Also, feel free to give any thoughts on whether or not the self-teach, garner some indie sales, use them as your resume' route is realistic

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• How do I use InputType=numberDecimal with the "phone" soft keypad?

  - by Adam Dunn

  For an EditText box, the user should only be entering valid numbers, so I am using android:inputType="numberDecimal". Unfortunately, the soft keyboard that Android brings up has numbers only along the top row, while the next three rows have various other symbols (dollar sign, percent sign, exclamation mark, space, etc). Since the numberDecimal only accepts numbers 0-9, negative sign, and decimal point, it would make more sense to use the "phone" soft keyboard (0-9 in a 3x3 grid, plus some other symbols). This would make the buttons larger and easier to hit (since it's a 4x4 grid rather than a 10x4 grid in the same screen area). Unfortunately, using android:inputType="phone" allows non-numeric characters such as parentheses I have attempted to use android:inputType="numberDecimal|phone", but the numberDecimal aspect of the bit flag seems to be ignored. I have also tried using android:inputType="phone" in combination with android:digits="0123456789-.", but that still allows multiple negative signs or decimal points (inputType="number" has really good error checking for things like that, and won't let the user even type it in). I have also tried using android:inputType="phone" in the xml layout file, while using a DigitsKeyListener in the java code, but then that just uses the default number soft keyboard (the one that has numbers only along top row) (it appears to set InputType.TYPE_CLASS_NUMBER, which voids the InputType.TYPE_CLASS_PHONE set by the xml layout). Writing a custom IME wouldn't work, since the user would have to select the IME as a global option outside the app. Is there any way to use the "phone" style soft keyboard while also using the "number" restrictions on what is entered?

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• Thread Safety of C# List<T> for readers

  - by ILIA BROUDNO

  I am planning to create the list once in a static constructor and then have multiple instances of that class read it (and enumerate through it) concurrently without doing any locking. In this article http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx MS describes the issue of thread safety as follows: Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe. A List can support multiple readers concurrently, as long as the collection is not modified. Enumerating through a collection is intrinsically not a thread-safe procedure. In the rare case where an enumeration contends with one or more write accesses, the only way to ensure thread safety is to lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization. The "Enumerating through a collection is intrinsically not a thread-safe procedure." Statement is what worries me. Does this mean that it is thread safe for readers only scenario, but as long as you do not use enumeration? Or is it safe for my scenario?

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• how to clear XFixes regions

  - by ~buratinas

  Hi, I'm writing some low level code for X11 platform. To achieve best data copying performance I use XFixes/XDamage extensions. How can I clear the contents of XFixes region after one refresh cycle? Or do they clean themselves after I use XFixesSetPictureClipRegion? My code is something like that: Display xdpy; XShamPixmap pixmap_; XFixesRegion region_; damage_event_callback(damage_geometry_t geometry, XDamage damage,...) { unsigned curr_region = XFixesCreateRegion(xdpy, 0, 0); XDamageSubtract(xdpy, damage, None, curr_region); XFixesTranslateRegion( xdpy, curr_region, geometry.left(), geometry.top() ); XFixesUnionRegion (xdpy, region_, region_, curr_region); } process_damage_events(...) { XFixesSetPictureClipRegion( xdpy, pixmap_, 0, 0, region_); XCopyArea (xdpy, window_->id(), pixmap_, XDefaultGC(xdpy, XDefaultScreen(xdpy)), 0,0,width(),height(),0,0); /*Should clear region_ here */ ... } Currently I clear the region by deleting and recreating, but I guess it's not the best way to do that.

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• Vim - show diff on commit in mercurial;

  - by JackLeo

  In my .hgrc I can provide an editor or a command to launch an editor with options on commit. I want to write a method or alias that launches $ hg ci, it would not only open up message in Vim, but also would split window and there print out $ hg diff. I know that I can give parameters to vim by using +{command} option. So launching $ vim "+vsplit" does the split but any other options goes to first opened window. So I assume i need a specific function, yet I have no experience in writing my own Vim scripts. The script should: Open new vertical split with empty buffer (with vnew possibly) In empty buffer launch :.!hg diff Set empty buffer file type as diff :set ft=diff I've written such function: function! HgCiDiff() vnew :.!hg diff set ft=diff endfunction And in .hgrc I've added option: editor = vim "+HgCiDiff()" It kind of works, but I would like that splited window would be in right side (now it opens up in left) and mercurial message would be focused window. Also :wq could be setted as temporary shortcut to :wq<CR>:q! (having an assumption that mercurial message is is focused). Any suggestions to make this a bit more useful and less chunky? UPDATE: I found vim split guide so changing vnew with rightbelow vnew opens up diff on the right side.

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• Implementing list position locator in C++?

  - by jfrazier

  I am writing a basic Graph API in C++ (I know libraries already exist, but I am doing it for the practice/experience). The structure is basically that of an adjacency list representation. So there are Vertex objects and Edge objects, and the Graph class contains: list<Vertex *> vertexList list<Edge *> edgeList Each Edge object has two Vertex* members representing its endpoints, and each Vertex object has a list of Edge* members representing the edges incident to the Vertex. All this is quite standard, but here is my problem. I want to be able to implement deletion of Edges and Vertices in constant time, so for example each Vertex object should have a Locator member that points to the position of its Vertex* in the vertexList. The way I first implemented this was by saving a list::iterator, as follows: vertexList.push_back(v); v->locator = --vertexList.end(); Then if I need to delete this vertex later, then rather than searching the whole vertexList for its pointer, I can call: vertexList.erase(v->locator); This works fine at first, but it seems that if enough changes (deletions) are made to the list, the iterators will become out-of-date and I get all sorts of iterator errors at runtime. This seems strange for a linked list, because it doesn't seem like you should ever need to re-allocate the remaining members of the list after deletions, but maybe the STL does this to optimize by keeping memory somewhat contiguous? In any case, I would appreciate it if anyone has any insight as to why this happens. Is there a standard way in C++ to implement a locator that will keep track of an element's position in a list without becoming obsolete? Much thanks, Jeff

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• PHP form processing - how to capture text from field that has variable Name/ID

  - by user80151

  I have a form that has a field pulled from the database as a dropdown. I need to get the text selected in the dropdown but I don't know in advance what the field ID will be. This is basically just a form that has already been generated. I don't need to pull anything from the database, it's already on this page. All I need to do is get the form information and email it, no writing to the database. I know how to do the _Request for the other fields based on the ID but I'm not sure how to do this one. The ID changes. It can be ID=1, ID-2, etc. I need to do something like: _REQUEST form element where ID is LIKE "ID[*]" or something similar. Any suggestions or links to tutorials? Here are a couple samples of what the dropdown renders on the page: <div class="wrapperAttribsOptions"> <h4 class="optionName back"><label class="attribsSelect" for="attrib- 1">Model</label></h4> <div class="back"> <select name="id[1]" id="attrib-1"> <option value="45">VC3-4C</option> <option value="1">VC3-4PG</option> <option value="3">VC3-4SG</option> <div class="wrapperAttribsOptions"> <h4 class="optionName back"><label class="attribsSelect" for="attrib-14">SPK Model</label></h4> <div class="back"> <select name="id[14]" id="attrib-14"> <option value="43">SPK-4</option> <option value="44">SPK-8</option> </select> TIA

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• SCJP Book, IO section: Is this a typo or is there a reason it would look like this?

  - by iamchuckb

  My question is about line 4, where the new PrintWriter is created with the constructor taking the FileWriter fw as a parameter. I don't understand the use of chaining the BufferedWriter bw to FileWriter if it isn't used later on in the actual writing. Can Java apply chaining in a way that bw still somehow affects the rest of the program? 16. try { 17. FileWriter fw = new FileWriter(test); 18. BufferedWriter bw = new BufferedWriter(fw, 1024); 19. PrintWriter out = new PrintWriter(fw); 20. out.println("<html><body><h1>"); 21. out.println(args[0]); 22. out.println("</h1></body></html>"); 23. out.close(); 24. bw.close(); 25. fw.close(); 26. }catch(IOException e) { 27. e.printStackTrace(); 28. } I think it is probably a typo and they meant to use bw as the parameter for PrintWriter out but like the title says, I'm new to this. Thanks to all in advance.

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