Search Results

Search found 18096 results on 724 pages for 'let me be'.

Page 41/724 | < Previous Page | 37 38 39 40 41 42 43 44 45 46 47 48  | Next Page >

• Simple .HTACCESS Passing Variables

  - by Willie Murray III

  Let's says I have a classifieds site which has a URL structure similar to the one which I have listed below: Ex. http://takarat.com/openclassifieds/?category=iphone&location=tennessee This is what shows up when I click "tennessee" as the location and then click on "iphone" as the category. Now let's say this site has a search box and I wanted a URL which comes up after using this search box to show up as opposed to the previous URL. Let's say that whenever I search for the word "iphone" while WITHIN the iphone CATEGORY the following link shows up: Iphone SEARCH Ex. http://takarat.com/openclassifieds/?s=iphone&category=iphone&location=tennessee Ok, I want THAT iphone SEARCH to come up whenever anyone clicks Tennessee Iphone..How would I do this [by the way, I want this to be dynamic so that I can use the code for different combinations of locations and products etc..I want the code to use the CATEGORY name to conduct the search basically]? I believe that this will involve "Passing varibles" from the original link... I am new to programming so I may have my terminology wrong. Any help would be appreciated. Thanks in advance. TURN THIS: takarat.com/openclassifieds/?category=iphone[var 1]&location=tennessee[var2] INTO THIS: takarat.com/openclassifieds/?s=iphone[var 1]&category=iphone[var 1]&location=tennessee[var2]

  Read the article

• Confused over behavior of List.mapi in F#

  - by James Black

  I am building some equations in F#, and when working on my polynomial class I found some odd behavior using List.mapi Basically, each polynomial has an array, so 3*x^2 + 5*x + 6 would be [|6, 5, 3|] in the array, so, when adding polynomials, if one array is longer than the other, then I just need to append the extra elements to the result, and that is where I ran into a problem. Later I want to generalize it to not always use a float, but that will be after I get more working. So, the problem is that I expected List.mapi to return a List not individual elements, but, in order to put the lists together I had to put [] around my use of mapi, and I am curious why that is the case. This is more complicated than I expected, I thought I should be able to just tell it to make a new List starting at a certain index, but I can't find any function for that. type Polynomial() = let mutable coefficients:float [] = Array.empty member self.Coefficients with get() = coefficients static member (+) (v1:Polynomial, v2:Polynomial) = let ret = List.map2(fun c p -> c + p) (List.ofArray v1.Coefficients) (List.ofArray v2.Coefficients) let a = List.mapi(fun i x -> x) match v1.Coefficients.Length - v2.Coefficients.Length with | x when x < 0 -> ret :: [((List.ofArray v1.Coefficients) |> a)] | x when x > 0 -> ret :: [((List.ofArray v2.Coefficients) |> a)] | _ -> [ret]

  Read the article

• How to create an Universal Binary for iTunes Connect Distribution?

  - by balexandre

  I created an app that was rejected because Apple say that my App was not showing the correct iPad window and it was showing the same iPhone screen but top left aligned. Running on simulator, I get my App to show exactly what it should, a big iPad View. my app as Apple referees that is showing on device: my app running the simulator (50% zoom only): my code in the Application Delegate is the one I published before - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // The default have the line below, let us comment it //MainViewController *aController = [[MainViewController alloc] initWithNibName:@"MainView" bundle:nil]; // Our main controller MainViewController *aController = nil; // Is this OS 3.2.0+ ? #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 30200 if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) // It's an iPad, let's set the MainView to our MainView-iPad aController = [[MainViewController alloc] initWithNibName:@"MainView-iPad" bundle:nil]; else // This is a 3.2.0+ but not an iPad (for future, when iPhone/iPod Touch runs with same OS than iPad) aController = [[MainViewController alloc] initWithNibName:@"MainView" bundle:nil]; #else // It's an iPhone/iPod Touch (OS < 3.2.0) aController = [[MainViewController alloc] initWithNibName:@"MainView" bundle:nil]; #endif // Let's continue our default code self.mainViewController = aController; [aController release]; mainViewController.view.frame = [UIScreen mainScreen].applicationFrame; [window addSubview:[mainViewController view]]; [window makeKeyAndVisible]; return YES; } on my target info I have iPhone/iPad My question is, how should I build the app? Use Base SDK iPhone Simulator 3.1.3 iPhone Simulator 3.2 my Active Configuration is Distribution and Active Architecture is arm6 Can anyone that already published app into iTunes Connect explain me the settings? P.S. I followed the Developer Guideline on Building and Installing your Development Application that is found on Creating and Downloading Development Provisioning Profiles but does not say anything regarding this, as I did exactly and the app was rejected.

  Read the article

• How to setup Lucene search for a B2B web app?

  - by Bill Paetzke

  Given: 5000 databases (spread out over 5 servers) 1 database per client (so you can infer there are 1000 clients) 2 to 2000 users per client (let's say avg is 100 users per client) Clients (databases) come and go every day (let's assume most remain for at least one year) Let's stay agnostic of language or sql brand, since Lucene (and Solr) have a breadth of support The Question: How would you setup Lucene search so that each client can only search within its database? How would you setup the index(es)? Would you need to add a filter to all search queries? If a client cancelled, how would you delete their (part of the) index? (this may be trivial--not sure yet) Possible Solutions: Make an index for each client (database) Pro: Search is faster (than one-index-for-all method). Indices are relative to the size of the client's data. Con: I'm not sure what this entails, nor do I know if this is beyond Lucene's scope. Have a single, gigantic index with a database_name field. Always include database_name as a filter. Pro: Not sure. Maybe good for tech support or billing dept to search all databases for info. Con: Search is slower (than index-per-client method). Flawed security if query filter removed. For Example: Joel Spolsky said in Podcast #11 that his hosted web app product, FogBugz On-Demand, uses Lucene. He has thousands of on-demand clients. And each client gets their own database. His situation is quite similar to mine. Although, he didn't elaborate on the setup (particularly indices); hence, the need for this question. One last thing: I would also accept an answer that uses Solr (the extension of Lucene). Perhaps it's better suited for this problem. Not sure.

  Read the article

• F# exercise help - Beginner

  - by bobjink

  I hope you can help me with these exercises I have been stuck with. I am not in particular looking for the answers. Tips that help me solve them myself are just as good :) 1. Write a function implode : char list - string so that implode s returns the characters concatenated into a string: let implode (cArray:char list) = List.foldBack (+) 0 cArray;; Error. I am thinking that i need to cast every char to strings before I do the above. I bet however, that there is a much simpler and better solution. 2. Write a function palindrome : string - bool, so that palindrome s returns true if the string s is a palindrome let isIdentical cArray1 cArray2 = (cArray1 = cArray2);; let palinDrome (word:string) = isIdentical(word.ToCharArray(), Array.rev(word.ToCharArray()));; I get the value: val palinDrome : string - (char [] * char [] - bool), which is not what I want. 3. Write a function combinePair : int list - int list so that combinePair xs returns the list with elements from xs combined into pairs. If xs contains an odd number of elements, then the last element is thrown away: I have no idea for this one.

  Read the article

• HTTP POST prarameters order / REST urls

  - by pq

  Let's say that I'm uploading a large file via a POST HTTP request. Let's also say that I have another parameter (other than the file) that names the resource which the file is updating. The resource cannot be not part of the URL the way you can do it with REST (e.g. foo.com/bar/123). Let's say this is due to a combination of technical and political reasons. The server needs to ignore the file if the resource name is invalid or, say, the IP address and/or the logged in user are not authorized to update the resource. Looks like, if this POST came from an HTML form that contains the resource name first and file field second, for most (all?) browsers, this order is preserved in the POST request. But it would be naive to fully rely on that, no? In other words the order of HTTP parameters is insignificant and a client is free to construct the POST in any order. Isn't that true? Which means that, at least in theory, the server may end up storing the whole large file before it can deny the request. It seems to me that this is a clear case where RESTful urls have an advantage, since you don't have to look at the POST content to perform certain authorization/error checking on the request. Do you agree? What are your thoughts, experiences?

  Read the article

• CUDA: When to use shared memory and when to rely on L1 caching?

  - by Roger Dahl

  After Compute Capability 2.0 (Fermi) was released, I've wondered if there are any use cases left for shared memory. That is, when is it better to use shared memory than just let L1 perform its magic in the background? Is shared memory simply there to let algorithms designed for CC < 2.0 run efficiently without modifications? To collaborate via shared memory, threads in a block write to shared memory and synchronize with __syncthreads(). Why not simply write to global memory (through L1), and synchronize with __threadfence_block()? The latter option should be easier to implement since it doesn't have to relate to two different locations of values, and it should be faster because there is no explicit copying from global to shared memory. Since the data gets cached in L1, threads don't have to wait for data to actually make it all the way out to global memory. With shared memory, one is guaranteed that a value that was put there remains there throughout the duration of the block. This is as opposed to values in L1, which get evicted if they are not used often enough. Are there any cases where it's better too cache such rarely used data in shared memory than to let the L1 manage them based on the usage pattern that the algorithm actually has?

  Read the article

• Important question about linq to SQL performance on high loaded web applications

  - by Alex

  I started working with linq to SQL several weeks ago. I got really tired of working with SQL server directly through the SQL queries (sqldatareader, sqlcommand and all this good stuff).  After hearing about linq to SQL and mvc I quickly moved all my projects to these technologies. I expected linq to SQL work slower but it suprisongly turned out to be pretty fast, primarily because I always forgot to close my connections when using datareaders. Now I don't have to worry about it. But there's one problem that really bothers me. There's one page that's requested thousands of times a day. The system gets data in the beginning, works with it and updates it. Primarily the updates are ++ @ -- (increase and decrease values). I used to do it like this UPDATE table SET value=value+1 WHERE ID=@I'd It worked with no problems obviously. But with linq to SQL the data is taken in the beginning, moved to the class, changed and then saved. Stats.registeredusers++; Db.submitchanges(); Let's say there were 100 000 users. Linq will say "let it be 100 001" instead of "let it be increased by 1". But if there value of users has already been increased (that happens in my site all the time) then linq will be like oops, this value is already 100 001. Whatever I'll throw an exception" You can change this behavior so that it won't throw an exception but it still will not set the value to 100 002. Like I said, it happened with me all the time. The stas value was increased twice a second on average. I simply had to rewrite this chunk of code with classic ado net. So my question is how can you solve the problem with linq

  Read the article

• Can parser combinators be made efficient?

  - by Jon Harrop

  Around 6 years ago, I benchmarked my own parser combinators in OCaml and found that they were ~5× slower than the parser generators on offer at the time. I recently revisited this subject and benchmarked Haskell's Parsec vs a simple hand-rolled precedence climbing parser written in F# and was surprised to find the F# to be 25× faster than the Haskell. Here's the Haskell code I used to read a large mathematical expression from file, parse and evaluate it: import Control.Applicative import Text.Parsec hiding ((<|>)) expr = chainl1 term ((+) <$ char '+' <|> (-) <$ char '-') term = chainl1 fact ((*) <$ char '*' <|> div <$ char '/') fact = read <$> many1 digit <|> char '(' *> expr <* char ')' eval :: String -> Int eval = either (error . show) id . parse expr "" . filter (/= ' ') main :: IO () main = do file <- readFile "expr" putStr $ show $ eval file putStr "\n" and here's my self-contained precedence climbing parser in F#: let rec (|Expr|) (P(f, xs)) = Expr(loop (' ', f, xs)) and loop = function | ' ' as oop, f, ('+' | '-' as op)::P(g, xs) | (' ' | '+' | '-' as oop), f, ('*' | '/' as op)::P(g, xs) -> let h, xs = loop (op, g, xs) let op = match op with | '+' -> (+) | '-' -> (-) | '*' -> (*) | '/' -> (/) loop (oop, op f h, xs) | _, f, xs -> f, xs and (|P|) = function | '('::Expr(f, ')'::xs) -> P(f, xs) | c::xs when '0' <= c && c <= '9' -> P(int(string c), xs) My impression is that even state-of-the-art parser combinators waste a lot of time back tracking. Is that correct? If so, is it possible to write parser combinators that generate state machines to obtain competitive performance or is it necessary to use code generation?

  Read the article

• Difference in F# and Clojure when calling redefined functions

  - by Michiel Borkent

  In F#: > let f x = x + 2;; val f : int -> int > let g x = f x;; val g : int -> int > g 10;; val it : int = 12 > let f x = x + 3;; val f : int -> int > g 10;; val it : int = 12 In Clojure: 1:1 user=> (defn f [x] (+ x 2)) #'user/f 1:2 user=> (defn g [x] (f x)) #'user/g 1:3 user=> (g 10) 12 1:4 user=> (defn f [x] (+ x 3)) #'user/f 1:5 user=> (g 10) 13 Note that in Clojure the most recent version of f gets called in the last line. In F# however still the old version of f is called. Why is this and how does this work?

  Read the article

• onTouchListener togglebutton, ignores first press?

  - by Paul

  I have a togglebutton that should run code when I press it down and more code when I let go. However the first time I press and let go nothing happens. Every other time it is fine, why is this? I can see the method only runs the first time when I let go of the button (it does not trigger any onTouch part of the method though), how can I get around this, and have it work for the first press? public void pushtotalk3(final View view) { ((ToggleButton) view).setChecked(true); ((ToggleButton) view).setChecked(false); view.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { //if more than one call, change this code int callId = 0; for (SipCallSession callInfo : callsInfo) { callId = callInfo.getCallId(); Log.e(TAG, "" + callInfo.getCallId()); } final int id = callId; switch (event.getAction()) { case MotionEvent.ACTION_DOWN: { //press ((ToggleButton) view).setBackgroundResource(R.drawable.btn_blue_glossy); ((ToggleButton) view).setChecked(true); OnDtmf(id, 17, 10); OnDtmf(id, 16, 9); return true; } case MotionEvent.ACTION_UP: { //release ((ToggleButton) view).setBackgroundResource(R.drawable.btn_lightblue_glossy); ((ToggleButton) view).setChecked(false); OnDtmf(id, 18, 11); OnDtmf(id, 18, 11); return true; } default: return false; } } }); } EDIT: the xml for the button: <ToggleButton android:id="@+id/PTT_button5" android:layout_width="0dp" android:layout_height="fill_parent" android:text="@string/ptt5" android:onClick="pushtotalk5" android:layout_weight="50" android:textOn="Push To Talk On" android:textOff="Push To Talk Off" android:background="@drawable/btn_lightblue_glossy" android:textColor="@android:color/white" android:textSize="15sp" /> EDIT: hardware problem, can't test solutions atm.

  Read the article

• linq: SQL performance on high loaded web applications

  - by Alex

  I started working with linq to SQL several weeks ago. I got really tired of working with SQL server directly through the SQL queries (sqldatareader, sqlcommand and all this good stuff).  After hearing about linq to SQL and mvc I quickly moved all my projects to these technologies. I expected linq to SQL work slower but it suprisongly turned out to be pretty fast, primarily because I always forgot to close my connections when using datareaders. Now I don't have to worry about it. But there's one problem that really bothers me. There's one page that's requested thousands of times a day. The system gets data in the beginning, works with it and updates it. Primarily the updates are ++ @ -- (increase and decrease values). I used to do it like this UPDATE table SET value=value+1 WHERE ID=@I'd It worked with no problems obviously. But with linq to SQL the data is taken in the beginning, moved to the class, changed and then saved. Stats.registeredusers++; Db.submitchanges(); Let's say there were 100 000 users. Linq will say "let it be 100 001" instead of "let it be increased by 1". But if there value of users has already been increased (that happens in my site all the time) then linq will be like oops, this value is already 100 001. Whatever I'll throw an exception" You can change this behavior so that it won't throw an exception but it still will not set the value to 100 002. Like I said, it happened with me all the time. The stas value was increased twice a second on average. I simply had to rewrite this chunk of code with classic ado net. So my question is how can you solve the problem with linq

  Read the article

• Simple encryption - Sum of Hashes in C

  - by Dogbert

  I am attempting to demonstrate a simple proof of concept with respect to a vulnerability in a piece of code in a game written in C. Let's say that we want to validate a character login. The login is handled by the user choosing n items, (let's just assume n=5 for now) from a graphical menu. The items are all medieval themed: eg: _______________________________ | | | | | Bow | Sword | Staff | |-----------|-----------|-------| | Shield | Potion | Gold | |___________|___________|_______| The user must click on each item, then choose a number for each item. The validation algorithm then does the following: Determines which items were selected Drops each string to lowercase (ie: Bow becomes bow, etc) Calculates a simple string hash for each string (ie: `bow = b=2, o=15, w=23, sum = (2+15+23=40) Multiplies the hash by the value the user selected for the corresponding item; This new value is called the key Sums together the keys for each of the selected items; this is the final validation hash IMPORTANT: The validator will accept this hash, along with non-zero multiples of it (ie: if the final hash equals 1111, then 2222, 3333, 8888, etc are also valid). So, for example, let's say I select: Bow (1) Sword (2) Staff (10) Shield (1) Potion (6) The algorithm drops each of these strings to lowercase, calculates their string hashes, multiplies that hash by the number selected for each string, then sums these keys together. eg: Final_Validation_Hash = 1*HASH(Bow) + 2*HASH(Sword) + 10*HASH(Staff) + 1*HASH(Shield) + 6*HASH(Potion) By application of Euler's Method, I plan to demonstrate that these hashes are not unique, and want to devise a simple application to prove it. in my case, for 5 items, I would essentially be trying to calculate: (B)(y) = (A_1)(x_1) + (A_2)(x_2) + (A_3)(x_3) + (A_4)(x_4) + (A_5)(x_5) Where: B is arbitrary A_j are the selected coefficients/values for each string/category x_j are the hash values for each string/category y is the final validation hash (eg: 1111 above) B,y,A_j,x_j are all discrete-valued, positive, and non-zero (ie: natural numbers) Can someone either assist me in solving this problem or point me to a similar example (ie: code, worked out equations, etc)? I just need to solve the final step (ie: (B)(Y) = ...). Thank you all in advance.

  Read the article

• Unit Testing Private Method in Resource Managing Class (C++)

  - by BillyONeal

  I previously asked this question under another name but deleted it because I didn't explain it very well. Let's say I have a class which manages a file. Let's say that this class treats the file as having a specific file format, and contains methods to perform operations on this file: class Foo { std::wstring fileName_; public: Foo(const std::wstring& fileName) : fileName_(fileName) { //Construct a Foo here. }; int getChecksum() { //Open the file and read some part of it //Long method to figure out what checksum it is. //Return the checksum. } }; Let's say I'd like to be able to unit test the part of this class that calculates the checksum. Unit testing the parts of the class that load in the file and such is impractical, because to test every part of the getChecksum() method I might need to construct 40 or 50 files! Now lets say I'd like to reuse the checksum method elsewhere in the class. I extract the method so that it now looks like this: class Foo { std::wstring fileName_; static int calculateChecksum(const std::vector<unsigned char> &fileBytes) { //Long method to figure out what checksum it is. } public: Foo(const std::wstring& fileName) : fileName_(fileName) { //Construct a Foo here. }; int getChecksum() { //Open the file and read some part of it return calculateChecksum( something ); } void modifyThisFileSomehow() { //Perform modification int newChecksum = calculateChecksum( something ); //Apply the newChecksum to the file } }; Now I'd like to unit test the calculateChecksum() method because it's easy to test and complicated, and I don't care about unit testing getChecksum() because it's simple and very difficult to test. But I can't test calculateChecksum() directly because it is private. Does anyone know of a solution to this problem?

  Read the article

• help me reason about F# threads

  - by Kevin Cantu

  In goofing around with some F# (via MonoDevelop), I have written a routine which lists files in a directory with one thread: let rec loop (path:string) = Array.append ( path |> Directory.GetFiles ) ( path |> Directory.GetDirectories |> Array.map loop |> Array.concat ) And then an asynchronous version of it: let rec loopPar (path:string) = Array.append ( path |> Directory.GetFiles ) ( let paths = path |> Directory.GetDirectories if paths <> [||] then [| for p in paths -> async { return (loopPar p) } |] |> Async.Parallel |> Async.RunSynchronously |> Array.concat else [||] ) On small directories, the asynchronous version works fine. On bigger directories (e.g. many thousands of directories and files), the asynchronous version seems to hang. What am I missing? I know that creating thousands of threads is never going to be the most efficient solution -- I only have 8 CPUs -- but I am baffled that for larger directories the asynchronous function just doesn't respond (even after a half hour). It doesn't visibly fail, though, which baffles me. Is there a thread pool which is exhausted? How do these threads actually work?

  Read the article

• Using shared_ptr to implement RCU (read-copy-update)?

  - by yongsun

  I'm very interested in the user-space RCU (read-copy-update), and trying to simulate one via tr1::shared_ptr, here is the code, while I'm really a newbie in concurrent programming, would some experts help me to review? The basic idea is, reader calls get_reading_copy() to gain the pointer of current protected data (let's say it's generation one, or G1). writer calls get_updating_copy() to gain a copy of the G1 (let's say it's G2), and only one writer is allowed to enter the critical section. After the updating is done, writer calls update() to do a swap, and make the m_data_ptr pointing to data G2. The ongoing readers and the writer now hold the shared_ptr of G1, and either a reader or a writer will eventually deallocate the G1 data. Any new readers would get the pointer to G2, and a new writer would get the copy of G2 (let's say G3). It's possible the G1 is not released yet, so multiple generations of data my co-exists. template <typename T> class rcu_protected { public: typedef T type; typedef std::tr1::shared_ptr<type> rcu_pointer; rcu_protected() : m_data_ptr (new type()) {} rcu_pointer get_reading_copy () { spin_until_eq (m_is_swapping, 0); return m_data_ptr; } rcu_pointer get_updating_copy () { spin_until_eq (m_is_swapping, 0); while (!CAS (m_is_writing, 0, 1)) {/* do sleep for back-off when exceeding maximum retry times */} rcu_pointer new_data_ptr(new type(*m_data_ptr)); // as spin_until_eq does not have memory barrier protection, // we need to place a read barrier to protect the loading of // new_data_ptr not to be re-ordered before its construction _ReadBarrier(); return new_data_ptr; } void update (rcu_pointer new_data_ptr) { while (!CAS (m_is_swapping, 0, 1)) {} m_data_ptr.swap (new_data_ptr); // as spin_until_eq does not have memory barrier protection, // we need to place a write barrier to protect the assignments of // m_is_writing/m_is_swapping be re-ordered bofore the swapping _WriteBarrier(); m_is_writing = 0; m_is_swapping = 0; } private: volatile long m_is_writing; volatile long m_is_swapping; rcu_pointer m_data_ptr; };

  Read the article

• Updating target workbook - extracting data from source workbook

  - by Allan

  My question is as follows: I have given a workbook to multiple people. They have this workbook in a folder of their choice. The workbook name is the same for all people, but folder locations vary. Let's assume the common file name is MyData-1.xls. Now I have updated the workbook and want to give it to these people. However when they receive the new one (let's call it MyData-2.xls) I want specific parts of their data pulled from their file (MyData-1) and automatically put into the new one provided (MyData-2). The columns and cells to be copied/imported are identical for both workbooks. Let's assume I want to import cell data (values only) from MyData-1.xls, Sheet 1, cells B8 through C25 ... to ... the same location in the MyData-2.xls workbook. How can I specify in code (possibly attached to a macro driven import data now button) that I want this data brought into this new workbook. I have tried it at my own location by opening the two workbooks and using the copy/paste-special with links process. It works really well, but It seems to create a hard link between the two physical workbooks. I changed the name of the source workbook and it still worked. This makes me believe that there is a "hard link" between the tow and that this will not allow me to give the target (MyData-2.xls) workbook to others and have it find their source workbook.

  Read the article

• Haskell Cons Operator (:)

  - by Carson Myers

  I am really new to Haskell (Actually I saw "Real World Haskell" from O'Reilly and thought "hmm, I think I'll learn functional programming" yesterday) and I am wondering: I can use the construct operator to add an item to the beginning of a list: 1 : [2,3] [1,2,3] I tried making an example data type I found in the book and then playing with it: --in a file data BillingInfo = CreditCard Int String String | CashOnDelivery | Invoice Int deriving (Show) --in ghci $ let order_list = [Invoice 2345] $ order_list [Invoice 2345] $ let order_list = CashOnDelivery : order_list $ order_list [CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, ...- etc... it just repeats forever, is this because it uses lazy evaluation? -- EDIT -- okay, so it is being pounded into my head that let order_list = CashOnDelivery:order_list doesn't add CashOnDelivery to the original order_list and then set the result to order_list, but instead is recursive and creates an infinite list, forever adding CashOnDelivery to the beginning of itself. Of course now I remember that Haskell is a functional language and I can't change the value of the original order_list, so what should I do for a simple "tack this on to the end (or beginning, whatever) of this list?" Make a function which takes a list and BillingInfo as arguments, and then return a list? -- EDIT 2 -- well, based on all the answers I'm getting and the lack of being able to pass an object by reference and mutate variables (such as I'm used to)... I think that I have just asked this question prematurely and that I really need to delve further into the functional paradigm before I can expect to really understand the answers to my questions... I guess what i was looking for was how to write a function or something, taking a list and an item, and returning a list under the same name so the function could be called more than once, without changing the name every time (as if it was actually a program which would add actual orders to an order list, and the user wouldn't have to think of a new name for the list each time, but rather append an item to the same list).

  Read the article

• Classes with the same name - is it restricted only within the same translation unit?

  - by LeopardSkinPillBoxHat

  Let's just I had the following code: foo.h class Foo { // ... }; foo.cpp #include "foo.h" // Functions for class Foo defined here... Let's say that Foo are built into a static library foo.lib. Now let's say I have the following: foo2.h class Foo { // ... }; foo2.cpp #include "foo2.h" // Functions for class Foo defined here... This is built into a separate static library foo2.lib. Now, if I re-link foo.lib and foo2.lib into an executable program foo.exe, should it be complaining that class Foo has been defined twice? In my experiences, neither the compiler or the linker are complaining. I wouldn't be expecting the compiler to complain, because they have been defined in separate translation units. But why doesn't the linker complain? How does the linker differentiate between the 2 versions of the Foo class? Does it work by decorating the symbols?

  Read the article

• Fast sketching tools for drawing C/C++ structs, pointers, etc...

  - by tomasorti

  Hi. I would like to know what do you use to sketch relations between different entities in C/C++. This can be a very broad issue, so I'll try to clarify a bit more my question and give an example. I'm looking for something that is simple enough as a user, and let me sketch easily containers, pointers, etc... in an informal way. The aim is to document some structs relations to pass them to junior developers. A look at the drawings is supposed to accelerate the understanding of the code. My solutions at this moment are to use: 1) Paper & pencil. 2) Microsoft PowerPoint/Word Autoshapes. 3) Freeware Dia. Other ones could be: 4) Microsoft Visio, but my company does not own licenses. 5) UML tools. I don't want to go this way. This is what I mean a more formal solution. I know tools like Rational Rose are great, and I tried boUML and violet and they are fine in some parts, but I prefer the flexibility of options 2) or 3). Finally, let me write down a more concrete example: Let's say I what to sketch a map that contains another map as the mapped value, and that one contains a struct as the mapped value, that holds a vector of pointers of a type and a pointer to other type. Also, there exist other structs that hold pointers to the objects pointed by the previous map, so there are objects pointed from different places. This is just one example I have, but you can easily come with one from you experience. What would you use to sketch this example or another similar you have dealt with? Best regards, Tomas.

  Read the article

• iphone - grouping UIImageViews x blocking elements

  - by Mike

  I have to rotate several UIImageViews around a specific center. To accomplish this I am using the famous trick of putting these views as subviews of a larger one and rotating that one. The problem is that these subviews have to detect touches, because each one has buttons on it. The hierarchy is like this LARGE_VIEW | |_____ imageView1 | |_________ button1 | |_________ button2 | |_________ button3 | |_____ imageView2 |_________ button4 |_________ button5 |_________ button6 etc So, to make buttons respond to tap, I had to make this; [LARGE_VIEW setUserInteractionEnabled:YES]; [imageView1 setUserInteractionEnabled:YES]; [imageView2 setUserInteractionEnabled:YES]; ImageView1 and 2 are two vertical rows of buttons on each side of the screen. The problem is that there's another view below LARGE_VIEW and this view is not receiving the taps, because LARGE_VIEW is intercepting them first. I don't need LARGE_VIEW to detect any taps except on the two areas where imageView 1 and 2 are. LARGE_VIEW must let pass taps on the area defined by this rect (52, 0, 768-2*52, 1024). ImageView1 and 2 have this size: 52 pixels wide and 1024 pixels high (iPad). ImageView1's rect is: (0, 0, 52, 1024) and ImageView2's rect is: (768-52, 0, 52, 1024) LARGE_VIEW must let pass taps on the area defined by this rect (52, 0, 768-2*52, 1024). How to solve that? I need LARGE_VIEW detect taps on each rect defined on my previous paragraph and pass these taps to its subviews and just let pass taps outside these rects to the app, so other views BELOW, can detect taps too. thanks.

  Read the article

• select all values from a dimension for which there are facts in all other dimensions

  - by ideasculptor

  I've tried to simplify for the purposes of asking this question. Hopefully, this will be comprehensible. Basically, I have a fact table with a time dimension, another dimension, and a hierarchical dimension. For the purposes of the question, let's assume the hierarchical dimension is zip code and state. The other dimension is just descriptive. Let's call it 'customer' Let's assume there are 50 customers. I need to find the set of states for which there is at least one zip code in which EVERY customer has at least one fact row for each day in the time dimension. If a zip code has only 49 customers, I don't care about it. If even one of the 50 customers doesn't have a value for even 1 day in a zip code, I don't care about it. Finally, I also need to know which zip codes qualified the state for selection. Note, there is no requirement that every zip code have a full data set - only that at least one zip code does. I don't mind making multiple queries and doing some processing on the client side. This is a dataset that only needs to be generated once per day and can be cached. I don't even see a particularly clean way to do it with multiple queries short of simply brute-force iteration, and there are a heck of a lot of 'zip codes' in the data set (not actually zip codes, but the there are approximately 100,000 entries in the lower level of the hierarchy and several hundred in the top level, so zipcode-state is a reasonable analogy)

  Read the article

• F# numeric associations

  - by b1g3ar5

  I have a numeric association for a custom type as follows: let DiffNumerics = { new INumeric<Diff> with member op.Zero = C 0.0 member op.One = C 1.0 member op.Add(a,b) = a + b member op.Subtract(a,b) = a - b member op.Multiply(a,b) = a * b member ops.Negate(a) = Diff.negate a member ops.Abs(a) = Diff.abs a member ops.Equals(a, b) = ((=) a b) member ops.Compare(a, b) = Diff.compare a b member ops.Sign(a) = int (Diff.sign a).Val member ops.ToString(x,fmt,fmtprovider) = failwith "not implemented" member ops.Parse(s,numstyle,fmtprovider) = failwith "not implemented" } GlobalAssociations.RegisterNumericAssociation(DiffNumerics) It works fine in f# interactive, but crashes when I run, because .ElementOps is not filled correctly for a matrix of these types. Any ideas why this might be? EDIT: In fsi, the code let A = dmatrix [[Diff.C 1.;Diff.C 2.;Diff.C 3.];[Diff.C 4.;Diff.C 5.;Diff.C 6.]] let B = matrix [[1.;2.;3.];[4.;5.;6.]] gives: > A.ElementOps;; val it : INumeric<Diff> = FSI_0003.NewAD+DiffNumerics@258 > B.ElementOps;; val it : INumeric<float> = Microsoft.FSharp.Math.Instances+FloatNumerics@115 > in the debugger A.ElementOps shows: '(A).ElementOps' threw an exception of type 'System.NotSupportedException' and, for the B matrix: Microsoft.FSharp.Math.Instances+FloatNumerics@115 So somehow the DiffNumerics isn't making it to the compiled program.

  Read the article

• How do I implement "cash out" on my site using PayPal?

  - by Alex

  I have a credit system set up on my site where user A can purchase a document from user B, let's say for 1 credit and user B's account gets credited, let's say for $1. User B can then "cash out" and recieve the money they earned from my (the site's) PayPal account into their PayPal account (let's assume that their email address is valid for now). When user A purchases a credit, they are taken to PayPal where they can login and complete the purchase, for this purpose I have an IPN listener set up on my site that stores credit information to my site's database. However, I can't find a mechanism to send the "cash out" information (i.e. user's email and amount to be paid) to PayPal. To elaborate: I understand that PayPal sends the IPN when someone purchases from me, but how do I post from my site to PayPal when the user clicks the "cash out" button? I have seen mention of Mass Pay, but can't seem to locate any code samples to go from. Am I missing something, or is there perhaps a different (and better) way to do this? Thanks!

  Read the article

• C++ design related question

  - by Kotti

  Hi! Here is the question's plot: suppose I have some abstract classes for objects, let's call it Object. It's definition would include 2D position and dimensions. Let it also have some virtual void Render(Backend& backend) const = 0 method used for rendering. Now I specialize my inheritance tree and add Rectangle and Ellipse class. Guess they won't have their own properties, but they will have their own virtual void Render method. Let's say I implemented these methods, so that Render for Rectangle actually draws some rectangle, and the same for ellipse. Now, I add some object called Plane, which is defined as class Plane : public Rectangle and has a private member of std::vector<Object*> plane_objects; Right after that I add a method to add some object to my plane. And here comes the question. If I design this method as void AddObject(Object& object) I would face trouble like I won't be able to call virtual functions, because I would have to do something like plane_objects.push_back(new Object(object)); and this should be push_back(new Rectangle(object)) for rectangles and new Circle(...) for circles. If I implement this method as void AddObject(Object* object), it looks good, but then somewhere else this means making call like plane.AddObject(new Rectangle(params)); and this is generally a mess because then it's not clear which part of my program should free the allocated memory. ["when destroying the plane? why? are we sure that calls to AddObject were only done as AddObject(new something).] I guess the problems caused by using the second approach could be solved using smart pointers, but I am sure there have to be something better. Any ideas?

  Read the article

< Previous Page | 37 38 39 40 41 42 43 44 45 46 47 48  | Next Page >